WO2014115234A1 - Steering control device - Google Patents

Steering control device Download PDF

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Publication number
WO2014115234A1
WO2014115234A1 PCT/JP2013/007694 JP2013007694W WO2014115234A1 WO 2014115234 A1 WO2014115234 A1 WO 2014115234A1 JP 2013007694 W JP2013007694 W JP 2013007694W WO 2014115234 A1 WO2014115234 A1 WO 2014115234A1
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WO
WIPO (PCT)
Prior art keywords
steering
axial force
reaction force
calculation unit
force
Prior art date
Application number
PCT/JP2013/007694
Other languages
French (fr)
Japanese (ja)
Inventor
佑文 蔡
一弘 五十嵐
裕也 武田
弘樹 谷口
Original Assignee
日産自動車株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 日産自動車株式会社 filed Critical 日産自動車株式会社
Priority to JP2014558305A priority Critical patent/JP5994868B2/en
Publication of WO2014115234A1 publication Critical patent/WO2014115234A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B62D6/008—Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D15/00—Steering not otherwise provided for
    • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
    • B62D15/025—Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation

Definitions

  • the present invention relates to a steer-by-wire steering control device in which a steering wheel and a steered wheel are mechanically separated.
  • Patent Document 1 Conventionally, as a technique of a steering control device, for example, there is a conventional technique described in Patent Document 1.
  • the reaction force motor is driven based on the control amount of the steering reaction force based on the steering angle and the control amount of the steering reaction force based on the steering rack axial force.
  • the influence of the external force acting on the steering wheel is reflected in the steering reaction force.
  • a lane keeping assist device that supports lane keeping by steering control is a correction amount to the control amount of the steering reaction force in the steering control device in order to control steering in a direction that cancels the angular deviation between the traveling direction of the vehicle and the traveling lane. May be added. For this reason, the reaction force motor is driven with a control amount different from that intended by the steering control device.
  • the lane keeping support function has a problem that the steering control may be hindered in spite of providing a new function to the main function steering control. Therefore, an object of the present invention is to provide a steering control device that can prevent the lane keeping assist function from interfering with the steering control.
  • the steering reaction force is calculated based on the feedforward axial force, and when the lane keeping assist unit is in an inoperative state. Calculates the steering reaction force based on the feedforward axial force and the feedback axial force.
  • the lane keeping assist function can be prevented from interfering with the steering control.
  • FIG. 1 is a diagram for explaining a steering control device according to a first embodiment of the present invention, and is a conceptual diagram showing a configuration of a host vehicle A.
  • FIG. FIG. 2 is a diagram illustrating the steering control device according to the first embodiment of the present invention, and is a block diagram illustrating a configuration of a control calculation unit 11. It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a block diagram showing the structure of the target reaction force electric current calculation part 11B. It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a block diagram showing the structure of feedforward axial force calculation part 11Ba.
  • FIG. 1 is a system schematic configuration diagram of a host vehicle to which the lane keeping assist device of the present embodiment is applied.
  • the vehicle of this embodiment employs a steer-by-wire system. That is, the turning angle of the steering wheel can be controlled independently of the steering state of the steering wheel. Further, the steering reaction force of the steering wheel can be controlled independently of the steered state of the steering wheel. Further, the steering wheel and the steering wheel are mechanically separated.
  • a steering input shaft 30 is connected to the steering wheel 12 operated by the driver.
  • the steering input shaft 30 is provided with a steering wheel angle sensor 1 that detects the steering angle of the steering wheel 12.
  • the steering wheel angle sensor 1 outputs the detected steering angle signal to a steering controller 11 (hereinafter sometimes referred to as “control calculation unit 11”).
  • a first intermediate shaft 31 is connected to the steering input shaft 30 via the steering torque sensor 2.
  • the steering torque sensor 2 detects the steering torque input to the steering input shaft 30 and outputs the torque signal to the steering controller 11.
  • the own vehicle A includes a reaction force control unit 3.
  • the reaction force control unit 3 includes a steering reaction force actuator 3A, a steering reaction force motor angle sensor 3B, a reaction force current detection unit 3C, and a reaction force motor drive unit 3D.
  • a steering reaction force actuator 3 ⁇ / b> A is connected to the first intermediate shaft 31.
  • the steering reaction force actuator 3 ⁇ / b> A applies a steering reaction force to the first intermediate shaft 31 based on a command from the steering controller 11.
  • a steering reaction force motor angle sensor 3B is provided in the steering reaction force motor of the steering reaction force actuator 3A.
  • the steering reaction force motor angle sensor 3 ⁇ / b> B detects the rotational angle position of the steering reaction force motor and outputs the detection signal to the steering controller 11.
  • the reaction force motor 4 is configured by the steering reaction force actuator 3A and the steering reaction force motor angle sensor 3B.
  • the reaction force motor 4 is connected to the steering shaft via a reduction gear.
  • the reaction force motor 4 is driven by the reaction force motor drive unit 3D, and applies rotational torque to the steering wheel 12 via the steering shaft. Thereby, the reaction force motor 4 generates a steering reaction force.
  • a driving method of the reaction force motor 4 for example, a method of controlling a current for driving the reaction force motor 4 (hereinafter also referred to as reaction force current) can be employed.
  • the reaction force current detector 3C detects a reaction force current.
  • the reaction force current detection unit 3C outputs a detection signal to the reaction force motor drive unit 3D and the steering controller 11.
  • the reaction force motor drive unit 3 ⁇ / b> D is configured so that the reaction force current detected by the reaction force current detection unit 3 ⁇ / b> C matches the target reaction force current. Controls the reaction force current.
  • the reaction force motor drive unit 3 ⁇ / b> D drives the reaction force motor 4.
  • the target reaction force current is a target value of a current for driving the reaction force motor 4.
  • a second intermediate shaft 32 is connected to the first intermediate shaft 31 via the mechanical backup device 10.
  • the mechanical backup device 10 is in a state in which torque transmission between the first intermediate shaft 31 and the second intermediate shaft 32 is cut off in a normal state. Further, the mechanical backup device 10 connects the first intermediate shaft 31 and the second intermediate shaft 32 based on a command from the steering controller 11 to enable torque transmission.
  • the host vehicle A includes a steering control unit 5.
  • the turning control unit 5 includes a turning actuator 5A, a turning actuator angle sensor 5B, a turning current detection unit 5C, and a turning motor drive unit 5D.
  • the second intermediate shaft 32 is connected to the steering output shaft 33 via the steering torque sensor 7. Further, the steering actuator 5 ⁇ / b> A is connected to the second intermediate shaft 32.
  • the steered actuator 5 ⁇ / b> A rotates and displaces the second intermediate shaft 32 based on a command from the steering controller 11.
  • a steering actuator angle sensor 5B is provided in the steering motor of the steering actuator 5A.
  • the turning actuator angle sensor 5 ⁇ / b> B detects the rotational angle position of the motor of the turning actuator 5 ⁇ / b> A and outputs the detection signal to the steering controller 11.
  • the steered motor 6 includes the steered actuator 5A and the steered actuator angle sensor 5B.
  • the steered motor 6 is connected to the pinion shaft 55 via a speed reducer.
  • the steered motor 6 is driven by the steered motor driving unit 5D and moves a steering rack (hereinafter also referred to as “rack shaft”) 34 to the left and right via the pinion shaft 55. Thereby, the steered motor 6 steers the front wheel (hereinafter, sometimes referred to as a steered wheel) 13.
  • a method for driving the steered motor 6 for example, a method of controlling a current for driving the steered motor 6 (hereinafter also referred to as a steered current) can be employed.
  • the steered current detection unit 5C detects a steered current (a state quantity of the host vehicle A that varies with the tire lateral force Fd acting on the steered wheels 13).
  • the steered current detection unit 5C outputs a detection signal to the steered motor drive unit 5D and the steering controller 11.
  • the steered motor drive unit 5D based on the target steered current calculated by the steering controller 11, turns the steered motor 6 so that the steered current detected by the steered current detector 5C matches the target steered current. Controls the steering current. Thereby, the steered motor driving unit 5D drives the steered motor 6.
  • the target turning current refers to a target value of current for driving the turning motor 6.
  • the steering output shaft 33 is connected to the rack shaft 34 via a rack and pinion mechanism. That is, the pinion shaft 55 connected to the steering output shaft 33 is engaged with the rack of the rack shaft 34.
  • the rack shaft 34 is disposed with its axis directed in the vehicle width direction. Then, by rotating the steering output shaft 33, the rack shaft 34 is displaced in the axial direction toward the vehicle width direction.
  • the turning angle sensor 8 detects the turning angle ⁇ of the front wheels 13. As a method of detecting the turning angle ⁇ , for example, a method of calculating based on the amount of movement of the steering rack can be employed.
  • the turning angle sensor 8 outputs a detection signal to the steering controller 11.
  • the left and right end portions of the rack shaft 34 are connected to a knuckle (not shown) via left and right tie rods 35 and a knuckle arm 36, respectively.
  • the knuckle arm 36 protrudes from the knuckle and rotatably supports the front wheel 13 which is a steering wheel.
  • the tie rod axial force sensor 9 is provided on the tie rod 35.
  • the tie rod axial force sensor 9 detects the axial force of the tie rod 35 and outputs a detection signal to the steering controller 11.
  • the host vehicle A also includes a host vehicle state detection unit 14.
  • the own vehicle state detection unit 14 includes a vehicle speed sensor 14A, a lateral G sensor 14B, and a yaw rate sensor 14C.
  • the vehicle speed sensor 14A detects the vehicle speed V of the host vehicle A.
  • the lateral G sensor 14B detects the lateral acceleration Gy of the host vehicle A (the amount of state of the host vehicle A that varies with the tire lateral force Fd acting on the steered wheel 13).
  • the yaw rate sensor 14C detects the yaw rate ⁇ of the host vehicle A (the state amount of the host vehicle A that varies with the tire lateral force Fd acting on the steering wheel 13).
  • the own vehicle state detection unit 14 outputs detection signals detected by the vehicle speed sensor 14A, the lateral G sensor 14B, and the yaw rate sensor 14C to the steering controller 11 as own vehicle state parameters.
  • the own vehicle state detection part 14 may be provided with the road surface friction coefficient estimation part which detects the friction coefficient estimated value of a driving
  • the steering controller 11 controls the steering actuator 5A so as to obtain a steering command value based on a command from the lane keeping support controller 15, and also performs a steering reaction so as to obtain a command value for applying a steering reaction force.
  • the force actuator 3A is controlled.
  • the host vehicle A includes a brake unit on each wheel of the front wheel 13 and the rear wheel 40.
  • Each brake unit includes a brake disk 22 and a wheel cylinder 23 that frictionally clamps the brake disk 22 to supply a braking force (braking force) by supplying hydraulic pressure.
  • a pressure control unit 24 is connected to each wheel cylinder 23 of these brake units, and the brake unit individually applies braking to each wheel by the hydraulic pressure supplied from the pressure control unit 24.
  • the lane keeping assist device 50 provided in the host vehicle A includes an outside recognition unit 16 and a lane keeping assist controller 15.
  • the external recognition unit 16 is configured by a monocular camera with an image processing function, for example.
  • the monocular camera with an image processing function detects the position of the vehicle A.
  • the monocular camera with an image processing function images the road surface ahead of the host vehicle A. The state of the road surface is determined from the captured camera image, and a signal related to the position of the host vehicle in the travel lane on which the host vehicle travels is output to the lane keeping support controller 15.
  • the signal relating to the position of the host vehicle in the travel lane is information regarding the yaw angle ⁇ , which is the angular deviation of the travel direction of the host vehicle with respect to the travel lane, the lateral displacement X from the center of the travel lane, and the curvature ⁇ of the travel lane.
  • the host vehicle A also includes a direction indicating switch 17.
  • a signal from the direction indicating switch 17 is output to the lane keeping support controller 15 as determination information as to whether or not the driver changes the driving lane. Further, the lane keeping support controller 15 receives signals from the steering controller 11 such as the current steering state and tire steering state.
  • the lane keeping support controller 15 calculates a control amount for keeping the host vehicle in the traveling lane based on the input signal, and for example, the final target corrected steering reaction force ⁇ Y *, the corrected steering reaction force central value ⁇ Tsc, and the final target correction.
  • the turning angle ⁇ Y * is output to at least the steering controller 11.
  • FIG. 2 is a block diagram illustrating the configuration of the control calculation unit 11.
  • the control calculation unit 11 includes a target turning angle calculation unit 11A, a target reaction force current calculation unit 11B, and a target turning current calculation unit 11C.
  • the target turning angle calculation unit 11A is calculated by the steering angle ⁇ detected by the steering wheel angle sensor 1, the vehicle speed V detected by the vehicle speed sensor 14A, and the corrected turning angle calculation unit 15C provided in the lane keeping support controller 15.
  • the target turning angle calculation unit 11A includes a turning command angle calculation unit 11Aa and an adder 11Ab.
  • the steering command angle calculation unit 11Aa calculates a steering command angle based on the steering angle ⁇ detected by the steering wheel angle sensor 1 and the vehicle speed V detected by the vehicle speed sensor 14A.
  • the adder 11Ab adds the final target corrected turning angle ⁇ Y * to the turning command angle.
  • the target turning angle calculation unit 11A calculates the target turning angle ⁇ *.
  • the target turning angle calculation unit 11A outputs the calculation result to the target reaction force current calculation unit 11B.
  • the target reaction force current calculation unit 11B includes the target turning angle ⁇ * calculated by the target turning angle calculation unit 11A, the vehicle speed V detected by the vehicle speed sensor 14A, and the turning current detected by the turning current detection unit 5C.
  • the target reaction force current is calculated based on the final target correction steering reaction force ⁇ Y * calculated by the correction steering reaction force calculation unit 15A and the correction steering reaction force center value ⁇ Tsc calculated by the correction steering reaction force center calculation unit 15B. .
  • a method of calculating the final target corrected steering reaction force ⁇ Y * and the corrected steering reaction force central value ⁇ Tsc will be described later.
  • the target reaction force current calculation unit 11B outputs the calculation result to the reaction force control unit 3 (reaction force motor drive unit 3D).
  • FIG. 3 is a block diagram illustrating a configuration of the target reaction force current calculation unit 11B.
  • the target reaction force current calculation unit 11B includes a feedforward axial force calculation unit 11Ba, a feedback axial force calculation unit 11Bb, an axial force switching output unit 11Bf, a final axial force calculation unit 11Bc, an axial force-steering reaction counter A force conversion unit 11Bd and a target reaction force current calculation unit 11Be are provided.
  • FIG. 4 is a block diagram illustrating the configuration of the feedforward axial force calculation unit 11Ba. As shown in FIG.
  • the feedforward axial force calculation unit 11Ba is based on the steering angle ⁇ detected by the steering wheel angle sensor 1 and the vehicle speed V detected by the vehicle speed sensor 14A according to the equation (5) described later.
  • the force T FF is calculated.
  • feedforward axial force calculation part 11Ba outputs a calculation result to final axial force calculation part 11Bc (refer FIG. 2).
  • FIG. 5 is a diagram for explaining the coefficients of the calculation formula for the pinion axial force Th.
  • the relational expression between the turning pinion angle ⁇ and the pinion axial force Th is based on the following equation (1) based on the equation of motion of a vehicle including a steering mechanism in which the steering wheel 12 and the steered wheel 13 are mechanically connected.
  • Expression As the steered pinion angle ⁇ , for example, there is a rotation angle of the pinion shaft 55.
  • the turning pinion angle ⁇ is a multiplication value of the steering angle ⁇ and the variable gear ratio between the steering angle ⁇ and the turning angle ⁇ .
  • the pinion axial force Th for example, there is a steering reaction force applied to the steering wheel 12.
  • the first term on the right side of the following equation (1) is a damping term representing a component based on the steered pinion angular velocity d ⁇ / dt among the components constituting the pinion axial force Th.
  • the second term on the right side is an inertia term representing a component based on the steered pinion angular acceleration d 2 ⁇ / dt 2 among the components constituting the pinion axial force Th.
  • the third term on the right side is a proportional term representing a component based on the tire lateral force Fd (steering pinion angle ⁇ ) among the components constituting the pinion axial force Th.
  • Th Ks (Jrs 2 + Cr ⁇ s) / (Jr ⁇ s 2 + (Cr + Cs) s + Ks) ⁇ ⁇ + Cs (Jrs 3 + Cr ⁇ s 2 ) / (Jr ⁇ s 2 + (Cr + Cs) s + Ks) ⁇ ⁇ + (Ks + Cs ⁇ s) ) / (Jr ⁇ s 2 + (Cr + Cs) s + Ks) ⁇ Fd (1)
  • Ks is pinion rigidity
  • Cs is pinion viscosity
  • Jr rack inertia
  • Cr rack viscosity.
  • the second term on the right side that is, the inertia term, contains a lot of noise components, and is preferably excluded because it induces vibration in the calculation result of the pinion axial force Th.
  • f (V) for example, there is a function that changes according to the vehicle speed V. Therefore, the above equation (1) can be expressed as the following equation (2).
  • Th Ks (Jrs 2 + Cr ⁇ s) / (Jr ⁇ s 2 + (Cr + Cs) s + Ks) ⁇ ⁇ + (Ks + Cs ⁇ s) / (Jr ⁇ s 2 + (Cr + Cs) s + Ks) ⁇ f (V) ⁇ ⁇ (2)
  • FIG. 6 is a graph showing the control map M1.
  • a method of setting the variable f (V) for example, a method of reading the variable f (V) corresponding to the absolute value of the vehicle speed V from the control map M1 can be adopted.
  • An example of the control map M1 is a map in which a variable f (V) corresponding to the absolute value of the vehicle speed V is registered. Specifically, as shown in FIG. 6, when the absolute value of the vehicle speed V is 0, the control map M1 sets the variable f (V) to a first set value (for example, 0.0).
  • variable f (V) is set to the second set value (> first set value, regardless of the magnitude of the vehicle speed V. For example, 1.0).
  • control map M1 is a absolute value and a first predetermined vehicle speed V 1 lower than the range from 0 or more of the vehicle speed V is increased linearly variable f (V) in accordance with the absolute value of the steering angular velocity d [theta] / dt
  • the control map M1 is a absolute value and a first predetermined vehicle speed V 1 lower than the range from 0 or more of the vehicle speed V, according to a linear function representing the relationship between the absolute value and the variable f of the vehicle speed V (V) Set variable f (V).
  • the linear function sets the variable f (V) to the first set value (0.0) when the absolute value of the vehicle speed V is 0, and sets the variable f (V) when the absolute value of the vehicle speed V is the first set vehicle speed V1.
  • V) be the second set value (1.0).
  • feedforward axial force calculating unit 11Ba the absolute value of the vehicle speed V is in the case of the first less than the set vehicle speed V 1 decreases the absolute value of the more proportional component having a small absolute value of the vehicle speed V (reduced ). Further, the feedforward axial force calculating unit 11Ba, when the absolute value of the vehicle speed V is first set vehicle speed V 1 or more, regardless of the size of the vehicle speed V, is not performed to reduce the absolute value of the proportional component.
  • the pinion axial force Th that is, the steering reaction force generated in the steering wheel 12 can be expressed by the following equation (4) based on the above equation (3).
  • Th P (s + 2 ⁇ ⁇ ⁇ ⁇ n) / (s 2 + 2 ⁇ ⁇ ⁇ ⁇ n ⁇ s + ⁇ n 2 ) d ⁇ / dt + I ⁇ (s + 2 ⁇ ⁇ ⁇ ⁇ n) / (s 2 + 2 ⁇ ⁇ ⁇ ⁇ n ⁇ s + ⁇ n 2 ) ⁇ f ( V) ⁇ ⁇ (4)
  • equation (4) that is, based on a formula of the pinion shaft force Th, as a method of calculating the feedforward axial force T FF of the present embodiment employs the following equation (5).
  • the damping component is P (s + 2 ⁇ ⁇ ⁇ ⁇ n) / (s 2 + 2 ⁇ ⁇ ⁇ ⁇ n ⁇ s + ⁇ n 2 ) d ⁇ / dt,
  • FIG. 7 is a graph showing the control map M2.
  • a method of setting the gain P 1 is, for example, can be employed a method of reading a gain P 1 corresponding to the absolute value of the steering angular velocity d? / Dt from the control map M2.
  • the control map M2 for example, there is a map that has registered the gain P 1 corresponding to the absolute value of the steering angular velocity d? / Dt.
  • the control map M2 is set to the gain P 1 third set value when the steering angular velocity d? / Dt is zero (e.g., 1.0).
  • the gain P 1 is set to the fourth set value ( ⁇ The third set value is set to 0.5, for example.
  • the control map M2 in absolute value and the first set steering angular velocity d? A range of less than 1 / dt greater than 0 steering angular velocity d? / Dt, linear gain P 1 in accordance with the absolute value of the steering angular velocity d? / Dt Decrease.
  • the control map M2 in absolute value range and less than the first set steering angular speed d?
  • the feedforward axial force calculation unit 11Ba increases the damping component as the absolute value of the steering angular velocity d ⁇ / dt increases. Decrease (correct) the absolute value of. Further, when the absolute value of the steering angular velocity d ⁇ / dt is greater than or equal to the first set steering angular velocity d ⁇ 1 / dt, the feedforward axial force calculation unit 11Ba has a gain P regardless of the magnitude of the steering angular velocity d ⁇ / dt. The absolute value of the damping component based on 1 is not corrected.
  • FIG. 8 is a graph showing the relationship between the steering angle ⁇ and the steering reaction force.
  • This graph shows each steering control device (a mechanical steering control device in which the steering wheel 12 and the steering wheel 13 are mechanically coupled, and a steering-by-wire method that does not consider saturation of the damping component).
  • the damping component included in the steering reaction force is saturated. Therefore, in the mechanical steering control device, as shown in FIG. 8, when the damping component is saturated, the Lissajous figure composed of the steering angle ⁇ and the steering reaction force regardless of the magnitude of the steering angular velocity d ⁇ / dt.
  • the shape of is constant.
  • the control calculation unit 11 of the present embodiment decreases the absolute value of the damping component as the absolute value of the steering angular velocity d ⁇ / dt increases. Therefore, the control calculation unit 11 of the present embodiment can suppress an increase in the absolute value of the damping component when the steering angular velocity d ⁇ / dt is large. Therefore, the control calculation part 11 of this embodiment can suppress that a damping component becomes excessive. Thereby, the control calculating part 11 of this embodiment can provide a more suitable steering feeling.
  • FIG. 9 is a graph showing the control map M3. Further, as a method of setting the gain P 2, for example, it can be employed a method of reading a gain P 2 corresponding to the absolute value of the vehicle speed V from the control map M3.
  • the gain P 2 is set to the sixth set value (> 5th set value regardless of the magnitude of the vehicle speed V. For example, 1. Set to 0).
  • the control map M3 is the absolute value and the second predetermined vehicle speed V 2 less than the range from 0 or more of the vehicle speed V is linearly increasing gain P 2 in accordance with the absolute value of the vehicle speed V.
  • the control map M3 is the absolute value and the second predetermined vehicle speed V 2 less than the range from 0 or more of the vehicle speed V, the gain P according to a linear function representing the relationship between the absolute value and the gain P 2 of the vehicle speed V 2 is set.
  • the control calculation unit 11 of the present embodiment decreases the absolute value of the damping component as the absolute value of the vehicle speed V decreases.
  • the control calculation part 11 of this embodiment can reduce a steering reaction force by making the absolute value of a damping component small, so that the absolute value of the vehicle speed V is small.
  • the control calculating part 11 of this embodiment can provide a more suitable steering feeling.
  • FIG. 10 is a graph showing the control map M4.
  • a method for setting the correction damping component for example, a method of reading the correction damping component corresponding to the absolute value of the steering angular velocity d ⁇ / dt from the control map M4 can be employed.
  • the control map M2 for example, there is a map in which a correction damping component corresponding to the absolute value of the steering angular velocity d ⁇ / dt is registered.
  • the control map M4 is set for each vehicle speed V.
  • Each control map M4 sets the correction damping component to the seventh set value (for example, 0.0) when the steering angular velocity d ⁇ / dt is zero.
  • control map M4 indicates that the correction damping component is used regardless of the magnitude of the steering angular velocity d ⁇ / dt in the range where the absolute value of the steering angular velocity d ⁇ / dt is equal to or greater than the second set steering angular velocity d ⁇ 2 / dt (> 0).
  • the steering angular velocity d ⁇ / dt is 0.0 or more and the absolute value of the steering angular velocity d ⁇ / dt is the third set steering angular velocity d ⁇ 3 / dt (0 ⁇ d ⁇ 3 / dt ⁇ d ⁇ 2 / dt).
  • the correction damping component is linearly increased according to the absolute value of the steering angular velocity d ⁇ / dt.
  • the absolute value of the steering angular velocity d ⁇ / dt and the correction damping are set in a range where the absolute value of the steering angular velocity d ⁇ / dt is not less than 0 and less than the third set steering angular velocity d ⁇ 3 / dt.
  • a correction damping component is set according to a linear function representing the relationship with the component.
  • the correction damping component is linearly increased according to the value.
  • the control map M4 indicates that the absolute value of the vehicle speed V is within a range where the absolute value of the steering angular velocity d ⁇ / dt is greater than or equal to the third set steering angular velocity d ⁇ 3 / dt and less than the second set steering angular velocity d ⁇ 2 / dt.
  • the correction damping component is set according to a linear function representing the relationship between the correction damping component and the correction damping component.
  • the correction damping component is the ninth set value
  • the absolute value of the steering angular velocity d ⁇ / dt is the second set steering.
  • the correction damping component is set to the eighth set value.
  • the feedforward axial force calculating unit 11Ba when the absolute value of the steering angular velocity d? / Dt is the second set steering angular velocity d? 2 / dt or more, regardless of the magnitude of the steering angular velocity d? / Dt, correction
  • the absolute value of the damping component is set to a predetermined constant value.
  • the eighth and ninth set values are set to higher values as the vehicle speed V increases.
  • control arithmetic unit 11 of the present embodiment adds the correction damping component absolute value larger the absolute value of the steering angular velocity d? / Dt increases feedforward axial force T FF. Therefore, when the absolute value of the steering angular velocity d ⁇ / dt increases at the start of turning of the steering wheel 12, the control calculation unit 11 of the present embodiment can increase the rising of the steering reaction force. Thereby, the control calculating part 11 of this embodiment can provide a more suitable steering feeling.
  • the control calculation unit 11 of the present embodiment uses a predetermined constant value as a correction damping component. Therefore, when the driver turns the steering wheel 12 and the absolute value of the steering angular velocity d ⁇ / dt becomes equal to or higher than the second set steering angular velocity d ⁇ 2 / dt, fluctuations in the correction damping component can be suppressed. . Therefore, the control calculation unit 11 of the present embodiment does not sense a change in the steering reaction force due to the variation in the correction damping component, and can prevent the driver from feeling uncomfortable with the steering feeling.
  • FIG. 11 is a block diagram illustrating a configuration of the feedback axial force calculation unit 11Bb.
  • the feedback axial force calculation unit 11Bb includes a current axial force calculation unit 11Bba, a blend axial force calculation unit 11Bbb, a steering angular velocity detection unit 11Bbc, a steering determination unit 11Bbd, and a feedback axial force calculation execution unit 11Bbe.
  • the current axial force calculator 11Bba calculates a steering rack axial force (hereinafter also referred to as a current axial force) according to the following equation (6) based on the turning current detected by the turning current detector 5C.
  • the steering current varies when the steering wheel 12 is steered, the target turning angle ⁇ * varies, and a difference occurs between the target turning angle ⁇ * and the actual turning angle ⁇ .
  • the steered current is also generated when the steered wheel 13 is steered, the tire lateral force Fd is applied to the steered wheel 13, and a difference occurs between the target steered angle ⁇ * and the actual steered angle ⁇ . fluctuate.
  • the steering current is caused by a road surface disturbance acting on the steered wheel 13 due to road surface unevenness or the like, and a tire lateral force Fd acting on the steered wheel 13 so that the target steered angle ⁇ * and the actual steered angle ⁇ are It also fluctuates due to differences.
  • the feedback axial force calculation unit 11Bb can calculate the steering rack axial force (current axial force) reflecting the influence of the tire lateral force Fd acting on the steered wheels 13 based on the steering current.
  • the current axial force is generated when there is a difference between the target turning angle ⁇ * and the actual turning angle ⁇ . Therefore, the phase of the current axial force advances as compared with the actual steering rack axial force and lateral G axial force, as shown in FIG.
  • the blend axial force calculating unit 11Bbb calculates a steering rack axial force (hereinafter also referred to as a lateral G-axis force) according to the following equation (7).
  • a steering rack axial force hereinafter also referred to as a lateral G-axis force
  • the front wheel load and the lateral acceleration Gy are multiplied, and the multiplication result is calculated as an axial force (axial force) applied to the steered wheel 13.
  • the calculated axial force applied to the steered wheel 13 is multiplied by a constant (hereinafter also referred to as a link ratio) according to the link angle or suspension, and the multiplication result is represented by the horizontal G axis.
  • a constant hereinafter also referred to as a link ratio
  • Axial force applied to steered wheel 13 front wheel load x lateral acceleration Gy
  • the blend axial force calculation unit 11Bbb can calculate the steering rack axial force (lateral G axial force) reflecting the influence of the tire lateral force Fd acting on the steered wheels 13 based on the lateral acceleration Gy.
  • the lateral G sensor 14B is disposed on the spring (vehicle body)
  • detection of the lateral acceleration Gy is delayed. Therefore, the lateral G-axis force is delayed in phase as compared with the actual steering rack axial force, as shown in FIG.
  • the lateral acceleration Gy detected by the lateral G sensor 14B is used when calculating the lateral G-axis force
  • the yaw rate ⁇ detected by the yaw rate sensor 14C may be multiplied by the vehicle speed V detected by the vehicle speed sensor 14A, and the multiplication result ⁇ ⁇ V may be used instead of the lateral acceleration Gy.
  • the blend axial force calculation unit 11Bbb is based on the vehicle speed V detected by the vehicle speed sensor 14A and the yaw rate ⁇ detected by the yaw rate sensor 14C according to the following equation (8), and the steering rack axial force (hereinafter also referred to as yaw rate axial force). Is calculated.
  • the front wheel load, the vehicle speed V, and the yaw rate ⁇ are multiplied, and the multiplication result is calculated as the axial force applied to the steered wheel 13.
  • the calculated axial force applied to the steered wheel 13 is multiplied by the link ratio, and the multiplication result is calculated as the yaw rate axial force.
  • Yaw rate axial force axial force applied to the steering wheel 13 ⁇ link ratio (8)
  • Axial force applied to steered wheel 13 front wheel load ⁇ vehicle speed V ⁇ yaw rate ⁇
  • the yaw rate ⁇ is generated when the steered wheel 13 is steered, the tire lateral force Fd acts on the steered wheel 13 and the host vehicle A turns. Therefore, the blend axial force calculation unit 11Bbb can calculate the steering rack axial force (yaw rate axial force) reflecting the influence of the tire lateral force Fd acting on the steered wheel 13 based on the yaw rate ⁇ .
  • the yaw rate sensor 14C is disposed on the spring (vehicle body), detection of the yaw rate ⁇ is delayed. For this reason, the phase of the yaw rate axial force is delayed compared to the actual steering rack axial force, as shown in FIG.
  • the blend axial force calculation unit 11Bbb reads the current axial force from the current axial force calculation unit 11Bba. Subsequently, the blend axial force calculation unit 11Bbb calculates the steering rack axial force (hereinafter referred to as “blend axial force”) according to the following equation (9) based on the read current axial force and the calculated lateral G axial force and yaw rate axial force. TBR is calculated. In the following equation (9), the lateral G-axis force is multiplied by the distribution ratio K1, the current axial force is multiplied by the distribution ratio K2, the yaw rate axial force is multiplied by the distribution ratio K3, and the sum of these multiplication results is the blend axis.
  • the blend axial force T BR is calculated based on the value obtained by multiplying the lateral G axial force by the distribution ratio K1, the value obtained by multiplying the current axial force by the distribution ratio K2, and the value obtained by multiplying the yaw rate axial force by the distribution ratio K3. .
  • the blend axial force calculation unit 11Bbb outputs the calculation result to the steering determination unit 11Bbd and the feedback axial force calculation execution unit 11Bbe.
  • the blend axial force T BR has a positive value for the axial force that directs the steered wheel 13 in the right direction, and a negative value for the axial force that directs the steered wheel 13 in the left direction.
  • T BR lateral G axial force ⁇ K1 + current axial force ⁇ K2 + yaw rate axial force ⁇ K3 (9)
  • the distribution ratios K1, K2, and K3 are distribution ratios of the lateral G-axis force, current axial force, and yaw rate axial force.
  • the magnitude relationship between the distribution ratios K1, K2, and K3 is K1>K2> K3. That is, the distribution ratio is set to a large value in the order of the lateral G axial force, the current axial force, and the yaw rate axial force.
  • blending axial force calculating unit 11Bbb as a blend axial force T BR calculates a steering rack axial force that reflects the influence of the tire lateral force Fd acting on the steering wheel 13.
  • the blend axial force calculation unit 11Bbb of the present embodiment calculates the blend axial force T BR based on the value obtained by multiplying the current axial force by the distribution ratio K2 and the value obtained by multiplying the lateral G axial force by the distribution ratio K1. calculate.
  • the phase of the lateral G-axis force is delayed compared to the actual steering rack axial force. Further, the phase of the current axial force advances compared to the actual steering rack axial force.
  • the blend axial force calculation unit 11Bbb of the present embodiment can compensate for the phase lag due to the lateral G-axis force as shown in FIG.
  • the blend axial force TBR can be calculated. Therefore, the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
  • the blend axial force calculation unit 11Bbb of the present embodiment calculates the blend axial force T BR based on a value obtained by multiplying the current axial force by the distribution ratio K2 and a value obtained by multiplying the lateral G axial force by the distribution ratio K1. .
  • the target steered angle ⁇ * and the actual steered angle ⁇ There will be a difference.
  • blends axial force calculating unit 11Bbb of this embodiment by adding the current axial force to the lateral G axial force, it can reflect the influence of the road surface disturbance acting on the steering wheel 13 to the blend axial force T BR, more An appropriate blend axial force TBR can be calculated. Therefore, the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR . Furthermore, the blend axial force calculation unit 11Bbb of the present embodiment increases the lateral G axial force distribution ratio K1 to be greater than the current axial force distribution ratio K2. Therefore, the blend axial force calculation unit 11Bbb of the present embodiment can reduce the distribution ratio of the current axial force.
  • the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
  • the blend axial force calculation unit 11Bbb of the present embodiment has a value obtained by multiplying the current axial force by the distribution ratio K2, a value obtained by multiplying the lateral G axial force by the distribution ratio K1, and a value obtained by multiplying the yaw rate axial force by the distribution ratio K3.
  • the feedback axial force T FB is calculated.
  • the detection result of the lateral G sensor 14B and the detection result of the steering current detection unit 5C are both Maximum value (saturated value).
  • the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
  • the steering angular velocity detector 11Bbc calculates the steering angular velocity d ⁇ / dt of the steering wheel 12 based on the steering angle ⁇ detected by the steering wheel angle sensor 1. And steering angular velocity detection part 11Bbc outputs a calculation result to blend axial force calculation part 11Bbb and steering determination part 11Bbd.
  • the steering angular velocity d ⁇ / dt has a positive value when the steering wheel 12 rotates clockwise, and a negative value when the steering wheel 12 rotates counterclockwise.
  • Steering determining unit 11Bbd based on the steering angular velocity d? / Dt which blends axial force blends axial force calculating unit 11Bbb calculated T BR and steering angular velocity detection unit 11Bbc detects, turning-increasing operation and off the driver's steering wheel 12 It is determined which of the return operations is being performed.
  • the rounding-up operation is, for example, a steering operation in a direction in which the steering wheel 12 (steering angle ⁇ ) is away from the neutral position.
  • the switch back operation for example, there is a steering operation in a direction in which the steering wheel 12 (steering angle ⁇ ) approaches the neutral position.
  • the steering judging portion 11Bbd when blended axial force T BR is positive is a is and the steering angular velocity d? / Dt positive, or blends axial force T BR is a negative value and the steering angular velocity d? / If dt is a negative value, it is determined that the steering wheel 12 is being increased, and the variable K4 is set to 1.0.
  • the variable K4 is a flag that indicates whether the steering wheel 12 is being turned on or turned off.
  • the variable K4 is set to 1.0 when the steering wheel 12 is being increased and 0.0 when the switchback operation is being performed.
  • the steering judging portion 11Bbd is positive blends axial force T BR and the steering angular velocity when d?
  • / Dt is negative value, or a blend axial force T BR is a negative value and the steering angular velocity d? / Dt is positive If the value is a value, it is determined that the steering wheel 12 is not being additionally operated, and the variable K4 is set to zero. Then, the steering determination unit 11Bbd outputs the set variable K4 to the feedback axial force calculation execution unit 11Bbe.
  • the feedback axial force calculation execution unit 11Bbe receives the current axial force, blend axial force T BR , steering angular velocity d ⁇ / dt, and current axial force calculation unit 11Bba, blend axial force calculation unit 11Bbb, steering angular velocity detection unit 11Bbc, and steering determination unit 11Bbd. Read variable K4. Subsequently, the feedback axial force calculation execution unit 11Bbe performs the steering rack axial force (hereinafter referred to as feedback shaft) according to the following equation (10) based on the read current axial force, blend axial force T BR , steering angular velocity d ⁇ / dt, and variable K4. Force T FB ) is calculated. Then, the feedback axial force calculation execution unit 11Bbe outputs the calculation result to the axial force switching output unit 11Bf.
  • Feedback axial force T FB current axial force ⁇ GB + blend axial force T BR ⁇ (1 ⁇ GB) (10)
  • GB is a numerical value representing a ratio (hereinafter referred to as a distribution ratio) for distributing the current axial force and the blend axial force T BR (see FIG. 3).
  • a distribution ratio a ratio for distributing the current axial force and the blend axial force T BR
  • GB may be used not only as a numerical value representing the distribution ratio but also as a sign of the distribution ratio.
  • the feedback axial force calculating execution unit 11Bbe based on the distribution ratio GB, GB and current axial force blended axial force T BR: by combined at a ratio of (1-GB), the feedback axial force T FB calculate.
  • a setting method of the distribution ratio GB for example, a method of setting the distribution ratio GB by the distribution ratio setting unit 11Bbf based on the determination result output by the steering determination unit 11Bbd can be adopted.
  • the distribution ratio setting unit 11Bbf reads the steering angular velocity d ⁇ / dt and the variable K4 from the steering determination unit 11Bbd. Subsequently, the distribution ratio setting unit 11Bbf calculates the distribution ratio GB according to the following equation (11) based on the read steering angular velocity d ⁇ / dt and the variable K4.
  • GB K4 ⁇ K5 (11)
  • K5 is a numerical value representing the distribution ratio GB of the current axial force and the distribution ratio (1-GB) of the blend axial force TBR when K4 is 1.0, that is, when the steering wheel 12 is increased. is there.
  • the feedback axial force calculating execution unit 11Bbe during turning-increasing operation of the steering wheel 12, the current axial force based on variables K5 blended axial force T BR and the K5: by combined at a ratio of (1-K5)
  • the feedback axial force T FB is calculated. Note that when K4 is 0.0, i.e., at the time of switchback operation the steering wheel 12, regardless of the variable K5, the blend axial force T BR feedback axial force T FB.
  • a setting method of the variable K5 for example, a method of reading the variable K5 corresponding to the steering angular velocity d ⁇ / dt from the control map M5 can be adopted.
  • An example of the control map M5 is a map in which a variable K5 corresponding to the steering angular velocity d ⁇ / dt is registered.
  • FIG. 14 is a graph showing the control map M5.
  • the control map M5 in absolute value range and the fourth less than the set steering angular velocity d ⁇ 4 / dt (> 0) at 0 over the steering angular velocity d? / Dt, the magnitude of the steering angular velocity d? / Dt Regardless, the variable K5 is set to the tenth set value (for example, 1.0).
  • control map M5 has a variable K5 in the range where the absolute value of the steering angular velocity d ⁇ / dt is not less than the fifth set steering angular velocity d ⁇ 5 / dt (> d ⁇ 4 / dt) regardless of the magnitude of the steering angular velocity d ⁇ / dt. Is set to an eleventh set value ( ⁇ tenth set value, for example, 0.0). Further, the control map M5, in and fifth sets the steering angular velocity d? Of less than 5 / dt range in absolute value fourth set steering angular velocity d? 4 / dt or the steering angular velocity d? / Dt, the absolute value of the steering angular velocity d?
  • variable K5 is linearly decreased.
  • the control map M5 indicates that the steering angular velocity d ⁇ / dt is within a range where the absolute value of the steering angular velocity d ⁇ / dt is not less than the fourth set steering angular velocity d ⁇ 4 / dt and less than the fifth set steering angular velocity d ⁇ 5 / dt.
  • the variable K5 is set according to a linear function that represents the relationship between the absolute value of and the variable K5.
  • the linear function sets the variable K5 to the tenth set value (1.0), and the absolute value of the steering angular velocity d ⁇ / dt is the first
  • the variable K5 is set to the eleventh set value (0.0) when the 5-set steering angular velocity d ⁇ 5 / dt.
  • the distribution ratio setting unit 11Bbf has the variable K4 of 1.0 (during the addition operation) and the absolute value of the steering angular velocity d ⁇ / dt is less than the fourth set steering angular velocity d ⁇ 4 / dt (during low-speed steering).
  • the distribution ratio GB is set to 1.0.
  • the feedback axial force calculating execution unit 11Bbe is a feedback axial force T FB current axial force.
  • the distribution ratio setting unit 11Bbf has a variable K4 of 1.0 (during the addition operation), and the absolute value of the steering angular velocity d ⁇ / dt is equal to or greater than the fifth setting steering angular velocity d ⁇ 5 / dt (during high-speed steering).
  • the distribution ratio GB is set to 0.0.
  • the feedback axial force calculating execution unit 11Bbe is a blend axial force T BR feedback axial force T FB.
  • the distribution ratio setting unit 11Bbf has a variable K4 of 1.0 (during a rounding operation), the absolute value of the steering angular velocity d ⁇ / dt is equal to or greater than the fourth setting steering angular velocity d ⁇ 4 / dt, and the fifth setting. If the steering angular velocity is less than d ⁇ 5 / dt (during medium speed steering), the variable K5 is set as the distribution ratio GB.
  • the feedback axial force calculating execution unit 11Bbe includes a feedback axial force T FB what the sum of the value obtained by multiplying the (1-K5) to the value blended axial force T BR multiplied by variable K5 current axial force To do.
  • the distribution ratio setting unit 11Bbf sets 0.0 as the distribution ratio GB regardless of the steering angular velocity d ⁇ / dt. Then, the feedback axial force calculating execution unit 11Bbe is a blend axial force T BR feedback axial force T FB.
  • the feedback axial force calculation execution unit 11Bbe of the present embodiment has an absolute value of the steering angular velocity d ⁇ / dt that is less than the fourth set steering angular velocity d ⁇ 4 / dt when the steering wheel 12 is increased.
  • the current axial force is set as the feedback axial force TFB .
  • the tire lateral force Fd accompanying the steering of the steered wheel 13 is increased.
  • the friction generate a steering reaction force that returns the steering wheel 12 to the neutral position.
  • the control calculation part 11 of this embodiment can give the steering reaction force which returns the steering wheel 12 to a neutral position similarly to a mechanical steering control apparatus by setting the current axial force to the feedback axial force TFB. .
  • the control calculating part 11 of this embodiment can provide a more appropriate steering reaction force at the time of the steering wheel 12 turning operation.
  • the blend axial force TBR does not include an element of friction accompanying steering of the steered wheel 13.
  • the feedback axial force calculation execution unit 11Bbe when the steering wheel 12 is switched back, performs the current axial force and the lateral G axial force regardless of the absolute value of the steering angular velocity d ⁇ / dt. Is a blend axial force T BR that is distributed at a preset distribution ratio as a feedback axial force T FB .
  • T BR a blend axial force
  • T FB a feedback axial force
  • the feedback axial force calculating execution unit 11Bbe of the present embodiment by setting the blending axial force T BR feedback axial force T FB, reduced steering current, even a current axial force is reduced, steering It can suppress that the steering reaction force which returns the wheel 12 to a neutral position reduces. Therefore, the feedback axial force calculation execution unit 11Bbe according to the present embodiment is similar to the mechanical steering control device in that the driver reduces the holding force of the steering wheel 12 and slides the steering wheel 12 with the palm of the steering wheel. The wheel 12 can be returned to the neutral position. Thereby, the control calculation part 11 of this embodiment can provide a more appropriate steering reaction force when the steering wheel 12 is switched back.
  • the feedback axial force calculation execution unit 11Bbe of the present embodiment determines that the steering wheel 12 is being increased, and the absolute value of the steering angular velocity d ⁇ / dt is the fourth set steering angular velocity d ⁇ 4 / dt. in a case where it is determined to be equal to or greater than, sets the feedback axial force T FB by distributing the current axial force blended axial force T BR, the absolute value is higher distribution of current axial force small steering angular velocity d? / dt Increase the ratio. Therefore, the feedback axial force calculation execution unit 11Bbe of the present embodiment performs, for example, the steering wheel ⁇ straddling the neutral position during the steering wheel 12 switching operation and the steering wheel 12 is continuously increased in the same direction.
  • the control calculating part 11 of this embodiment can provide a more appropriate steering reaction force.
  • the final axial force calculation unit 11Bc includes the steering angle ⁇ , the vehicle speed V, the steering wheel angle sensor 1, the vehicle speed sensor 14A, the lateral G sensor 14B, the feedforward axial force calculation unit 11Ba, and the feedback axial force calculation unit 11Bb.
  • lateral acceleration Gy reads the feedforward axial force T FF and the feedback axial force T FB.
  • the final axial force calculator 11Bc calculates the steering angular velocity d ⁇ / dt of the steering wheel 12 based on the read steering angle ⁇ .
  • the final axial force calculation unit 11Bc reads the read steering angle ⁇ , vehicle speed V, lateral acceleration Gy, feedforward axial force T FF , axial force Toc output by the axial force switching output unit 11Bf, and calculated steering angular velocity d ⁇ . Based on / dt and the corrected steering reaction force central value ⁇ Tsc, a steering rack axial force (hereinafter referred to as final axial force) is calculated according to the following equation (12). Then, the final axial force calculation unit 11Bc outputs the calculation result to the axial force-steering reaction force conversion unit 11Bd.
  • Final axial force feed forward axial force T FF ⁇ GF + Toc ⁇ (1 ⁇ GF) + ⁇ Tsc (12)
  • GF is a numerical value representing a ratio (hereinafter referred to as a distribution ratio) for distributing the feedforward axial force TFF and the feedback axial force TFB .
  • GF may be used not only as a numerical value representing the distribution ratio but also as a sign of the distribution ratio.
  • ⁇ Tsc in the equation (12) represents the numerical value of the corrected steering reaction force central value ⁇ Tsc.
  • Axial force switching output section 11Bf in a non-actuated state the lane keeping assist controller 15 does not operate and outputs a feedback axial force T FB, feedforward axial force in an operating state in which the lane keeping assist controller 15 is operating F FF Is output. Therefore, the final axial force calculating unit 11Bc, at the time of non-operation of the lane keeping assist controller 15, the feedforward axial force T FF and the feedback axial force T FB GF: a value obtained by summing at a ratio of (1-GF) The final axial force is calculated by adding the corrected steering reaction force central value ⁇ Tsc.
  • the final axial force calculating unit 11Bc during operation of the lane keeping assist controller 15, the feedforward axial force T FF and the feedforward axial force T FF GF: corrected to a value obtained by summing at a ratio of (1-GF)
  • the final axial force is calculated by adding the steering reaction force central value ⁇ Tsc.
  • the final axial force calculating unit 11Bc during operation of the lane keeping assist controller 15, and outputs a value obtained by adding the correction steering reaction force central value ⁇ Tsc feedforward axial force T FF as the final axial force.
  • the final axial force calculating unit 11Bc of the present embodiment calculates the final axial force based on the feedback axial force T FB and feedforward axial force T FF.
  • the feedback axial force T FB changes according to a change in the road surface state or a change in the vehicle state in order to reflect the influence of the tire lateral force Fd acting on the steering wheel 13.
  • the feedforward axial force T FF since not reflect the influence of tire lateral force Fd, smoothly changes regardless of the change or the like of the road surface condition.
  • the final axial force calculating unit 11Bc in addition to the feedback axial force T FB, it calculates the final axial force on the basis of the feedforward axial force T FF, it can be calculated more appropriate final axial force.
  • the vehicle speed V and steering angle ⁇ allocation the ratio GF 3 by multiplying the allocation ratio GF 4 based on the steering angular velocity d? / dt, can be adopted a method for the distribution ratio GF multiplication results.
  • the axial force difference for example, a difference between the feedforward axial force TFF and the feedback axial force TFB can be adopted. Specifically, the axial force difference, a subtraction result obtained by subtracting the feedback axial force T FB from the feedforward axial force T FF.
  • FIG. 15 is a graph showing the control map M6.
  • Method for setting distribution ratio GF 1 for example, can be employed a method of reading the distribution ratio GF 1 which corresponds to the absolute value of the axial force difference from the control map M6.
  • the control map M6 for example, there is a map that has registered the distribution ratio GF 1 which corresponds to the absolute value of the axial force difference.
  • the control map M6 has a large axial force difference in a range where the absolute value of the axial force difference is 0 or more and less than the first set axial force difference Z 1 (> 0).
  • the distribution ratio GF 1 is set to the 12 setting value (e.g., 1.0) regardless of.
  • the first set axial force difference Z 1 for example, can be employed an axial force difference estimation accuracy of the feedforward axial force T FF starts lowering.
  • the control map M6 is the absolute value of the axial force difference is in the second set axial force difference Z 2 (> Z 1) or more ranges, the distribution ratio GF 1 regardless of the magnitude of the axial force difference 13 set value ( ⁇ Twelfth set value. For example, 0.0).
  • the second set axial force difference Z 2 for example, can be employed an axial force difference estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB.
  • control map M6 is in and a second set axial force difference Z 2 than the range in absolute value first set axial force difference Z 1 or more axial force difference, the distribution ratio GF according to the absolute value of the axial force difference 1 is reduced linearly.
  • control map M6 is in and a second set axial force difference Z 2 than the range in absolute value first set axial force difference Z 1 or more axial force difference, distribution and the absolute value of the axial force difference ratio setting the distribution ratio GF 1 according to the primary function representing the relationship between the GF 1.
  • the primary function 12 set value distribution ratio GF 1 when the absolute value of the axial force difference is first set axial force difference Z 1 (1.0) and then, the absolute value of the axial force difference is the second setting axis 13 set value distribution ratio GF 1 when the force difference Z 2 and (0.0).
  • the final axial force calculating unit 11Bc of the present embodiment when the absolute value of the axial force difference is first set axial force difference Z 1 or more, the absolute value of the first setting the axial force of the axial force difference compared to the case it is less than the difference Z 1, to reduce the distribution ratio GF 1 (allocation ratio GF of the feedforward axial force T FF). Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, the road surface ⁇ is reduced during non-operation of the lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, the axial force difference When increased, the distribution ratio (1-GF) of the feedback axial force TFB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
  • FIG. 16 is a graph showing the control map M7.
  • a method of setting the distribution ratio GF 2 for example, it can be employed a method of reading the distribution ratio GF 2 corresponding to the absolute value of the lateral acceleration Gy from the control map M7.
  • the control map M7 for example, there is a map that has registered the distribution ratio GF 2 corresponding to the absolute value of the lateral acceleration Gy.
  • the control map M7 has a lateral acceleration Gy in a range where the absolute value of the lateral acceleration Gy is 0 or more and less than the first set lateral acceleration Gy 1 (> 0).
  • the size of the distribution ratio GF 2 14 set value e.g., 1.0
  • the control map M7 is lateral acceleration in the range absolute value of the second set lateral acceleration Gy 2 (> Gy 1) more Gy, the lateral acceleration distribution ratio GF 2 regardless of the size of the Gy 15 Set to a set value ( ⁇ 14th set value, eg, 0.0).
  • the second set lateral acceleration Gy 2 for example, can be adopted lateral acceleration Gy estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB.
  • control map M7 is distributed according to the absolute value of the lateral acceleration Gy in a range where the absolute value of the lateral acceleration Gy is not less than the first set lateral acceleration Gy 1 and less than the second set lateral acceleration Gy 2. linearly decreasing the ratio GF 2. Specifically, the control map M7 indicates that the absolute value of the lateral acceleration Gy is within a range where the absolute value of the lateral acceleration Gy is not less than the first set lateral acceleration Gy 1 and less than the second set lateral acceleration Gy 2.
  • the distribution ratio GF 2 is set according to a linear function representing the relationship with the distribution ratio GF 2 .
  • the distribution ratio GF3 is set to the 14th set value (1.0), and the absolute value of the lateral acceleration Gy is the second set.
  • the distribution ratio GF3 is set to the fifteenth set value (0.0) when the lateral acceleration Gy 2 is set.
  • the final axial force calculating unit 11Bc of the present embodiment when the absolute value of the lateral acceleration Gy is first set lateral acceleration Gy 1 or more, the absolute value of the first set of lateral acceleration Gy compared with the case of the lateral acceleration Gy less than 1, to reduce the distribution ratio GF 2 (distribution ratio GF of the feedforward axial force T FF). Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, during non-operation of the lane keeping assist controller 15, the lateral acceleration Gy increases, when the estimation accuracy of the feedforward axial force T FF is decreased, feedback The distribution ratio (1-GF) of the axial force T FB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
  • FIG. 17 is a graph showing the control maps M8a and M8b.
  • the control GF 3b map M8a As a method of setting the distribution ratio GF 3, for example, the distribution ratio GF 3a corresponding to the absolute value of the absolute value and the steering angle ⁇ of the vehicle speed V, the control GF 3b map M8a, read from M8b, read allocation ratio A method of multiplying GF 3a and GF 3b and setting the multiplication result as a distribution ratio GF 3 can be adopted.
  • the control map M8a for example, there is a map that has registered the distribution ratio GF 3 corresponding to the absolute value of the vehicle speed V. Specifically, as shown in FIG.
  • the control map M8a is the absolute value range and less than the third set speed V 3 0 or more vehicle speed V is allocated regardless of the size of the vehicle speed V the ratio GF 3a 16th set value (e.g., 0.5) is set to.
  • the third set speed V 3 for example, (tire lateral force nonlinearity of Fd with respect to the tire slip angle) appears nonlinearity of tire characteristic due to the vehicle speed V is low, the degradation estimation accuracy of the feedforward axial force T FF
  • the starting vehicle speed V can be adopted.
  • the distribution ratio GF 3a is set to the 17th set value (> 16th) regardless of the magnitude of the vehicle speed V.
  • Set value for example, 1.0
  • the fourth set vehicle speed V 4 for example, can be employed vehicle speed V estimation accuracy of the feedforward axial force T FF is improved than the estimation accuracy of the feedback axial force T FB.
  • the control map M8a the absolute value of the vehicle speed V is in a range and the fourth less than the set vehicle speed V 4 at the third set speed V 3 or more, linearly increasing the distribution ratio GF 3a in accordance with the absolute value of the vehicle speed V
  • the control map M8a to the extent and in the fourth less than the set vehicle speed V 4 in absolute value the third set speed V 3 or more of the vehicle speed V is a linear function representing the relationship between the distribution ratio GF 3a and the vehicle speed V
  • the distribution ratio GF 3a is set according to The linear function is assigned when the absolute value of the vehicle speed V is the third set vehicle speed V 3 and the allocation ratio GF 3a is the 16th set value (0.5), and when the vehicle speed V is the fourth set vehicle speed V 4.
  • the ratio GF 3a is set to the 17th set value (1.0).
  • the final axial force calculating unit 11Bc of the present embodiment when the absolute value of the vehicle speed V is the fourth less than the set vehicle speed V 4, the absolute value of the vehicle speed V is in the fourth set speed V 4 or more Compared to the case, the distribution ratio GF 3a (the distribution ratio GF of the feedforward axial force T FF ) is reduced. Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, when the vehicle speed V is reduced at the time of non-operation of the lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, the feedback axial force The distribution ratio of T FB (1-GF) can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
  • control map M8b for example, there is a map that has registered the distribution ratio GF 3b corresponding to the absolute value of the steering angle [delta]. Specifically, as shown in FIG. 17B, the control map M8b indicates that the steering angle ⁇ is within a range where the absolute value of the steering angle ⁇ is 0 or more and less than the first set steering angle ⁇ 1 (> 0). , regardless of the size of the distribution ratio GF 3b 18th set value (e.g., 1.0) is set to.
  • the first set steering angle ⁇ 1 for example, a steering angle ⁇ at which the estimation accuracy of the feedforward axial force TFF starts to decrease can be employed.
  • the distribution ratio GF 3b is set to the 19th set value (regardless of the magnitude of the steering angle ⁇ ) in the range where the absolute value of the steering angle ⁇ is equal to or larger than the second set steering angle ⁇ 2 (> ⁇ 1 ). ⁇ 18th set value, for example, 0.6).
  • the second set steering angle [delta] 2 for example, can be adopted steering angle [delta] of the estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB.
  • the distribution ratio GF 3b is set according to the absolute value of the steering angle ⁇ . Decrease linearly.
  • the control map M8b in absolute value and the second set steering angle [delta] 2 of less than the range in the first set steering angle [delta] 1 or more of the steering angle [delta], the distribution ratio GF 3b and the absolute value of the steering angle [delta]
  • An allocation ratio GF 3b is set according to a linear function representing the relationship between In the linear function, when the absolute value of the steering angle ⁇ is the first setting steering angle ⁇ 1 , the distribution ratio GF 3b is set to the 18th setting value (1.0), and the absolute value of the steering angle ⁇ is the second setting steering angle. 19 set value distribution ratio GF3 when a [delta] 2 and (0.6).
  • the final axial force calculating unit 11Bc of the present embodiment when the absolute value of the steering angle [delta] is first set steering angle [delta] 1 or more, the absolute value of the first set steering angle of the steering angle [delta] [delta] compared to the case is less than 1, to reduce the distribution ratio GF 3b (distribution ratio GF of the feedforward axial force T FF). Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, when the increased steering angle ⁇ is in the inoperative lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, the feedback shaft The distribution ratio (1-GF) of the force T FB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
  • FIG. 18 is a graph showing the control map M9.
  • a method of setting the distribution ratio GF 4 for example, it can be employed a method of reading the distribution ratio GF 4 corresponding to the absolute value of the steering angular velocity d? / Dt from the control map M9.
  • the control map M9 for example, there is a map that has registered the distribution ratio GF 4 corresponding to the absolute value of the steering angular velocity d? / Dt.
  • the control map M9 indicates that the steering angular velocity is in the range where the absolute value of the steering angular velocity d ⁇ / dt is 0 or more and less than the fourth set steering angular velocity d ⁇ 4 / dt (> 0).
  • the distribution ratio GF 4 regardless of the size of d? / dt twentieth set value (e.g., 1.0) is set to.
  • the fourth set steering angular velocity d? 4 / dt for example, can be adopted steering angular velocity d? / Dt of estimation accuracy of the feedforward axial force T FF starts lowering.
  • the control map M9 shows that the distribution ratio is independent of the magnitude of the steering angular velocity d ⁇ / dt in the range where the absolute value of the steering angular velocity d ⁇ / dt is not less than the fifth set steering angular velocity d ⁇ 5 / dt (> d ⁇ 4 / dt).
  • the GF 4 21 set value ( ⁇ 20th set value.
  • the fifth set steering angular velocity d? 5 / dt for example, can be adopted steering angular velocity d? / Dt of estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB.
  • the control map M9 indicates that the absolute value of the steering angular velocity d ⁇ / dt is within a range where the absolute value of the steering angular velocity d ⁇ / dt is not less than the fourth set steering angular velocity d ⁇ 4 / dt and less than the fifth set steering angular velocity d ⁇ 5 / dt. linearly decreasing the distribution ratio GF 4 in accordance with the.
  • control map M9 indicates that the steering angular velocity d ⁇ / dt is within a range where the absolute value of the steering angular velocity d ⁇ / dt is not less than the fourth set steering angular velocity d ⁇ 4 / dt and less than the fifth set steering angular velocity d ⁇ 5 / dt.
  • the distribution ratio GF 4 is set in accordance with a linear function that represents the relationship between the absolute value of and the distribution ratio GF 4 .
  • the linear function sets the distribution ratio GF 4 to the twentieth set value (1.0), and the absolute value of the steering angular velocity d ⁇ / dt.
  • the distribution ratio GF 4 is set to the twenty-first set value (0.0).
  • the final axial force calculation unit 11Bc of the present embodiment has the absolute value of the steering angular velocity d ⁇ / dt when the absolute value of the steering angular velocity d ⁇ / dt is equal to or greater than the fourth set steering angular velocity d ⁇ 4 / dt.
  • the distribution ratio GF 4 (the distribution ratio GF of the feed-forward axial force T FF ) is made smaller than when the fourth set steering angular velocity d ⁇ 4 / dt is less. Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, when increasing the steering angular velocity d?
  • the estimation accuracy of the feedforward axial force T FF is decreased,
  • the distribution ratio (1-GF) of the feedback axial force TFB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
  • the final axial force calculating unit 11Bc the absolute value of the first set axial force difference Z less than 1 axial force difference, the absolute value of the first set lateral acceleration Gy less than 1 lateral acceleration Gy, an absolute vehicle speed V value fourth set vehicle speed V 4 above, the steering angle ⁇ of the absolute value of the first set steering angle ⁇ smaller than 1, and when the absolute value of the steering angular velocity d? / dt is the fourth set the steering angular velocity d? less than 4 / dt regardless inoperative and operating state of the lane keeping assist controller 15, the axial force obtained by adding the correction steering reaction force central value ⁇ Tsc feedforward axial force T FF and final axial force.
  • the final axial force calculating unit 11Bc the absolute value of the axial force difference is the second set axial force difference Z 2 or more, the absolute value of the lateral acceleration Gy and the second set lateral acceleration Gy 2 or more, and the steering angular velocity d? / If the absolute value of dt is in a non-operating state of the fifth set steering angular velocity d? 5 / dt or the lane keeping assist controller 15 at least be either the corrected steering reaction force central value ⁇ Tsc the feedback axial force T FB The added axial force is taken as the final axial force.
  • the final axial force calculating unit 11Bc the absolute value and the second set axial force less than the difference Z 2 at first set axial force difference Z 1 or more axial force difference, the absolute value of the first set next to the lateral acceleration Gy direction acceleration Gy 1 or more and a second set lateral acceleration Gy less than 2, the absolute value of the vehicle speed V is less than the fourth predetermined vehicle speed V 4, the absolute value of the steering angle [delta] is first set steering angle [delta] 1 or more, and the steering angular velocity If the absolute value of d? / dt is in a non-operating state of the fourth set steering angular velocity d?
  • the final axial force calculation unit 11Bc determines that the host vehicle A has a high road surface ⁇ (dry road surface), a high vehicle speed V, a small steering angle ⁇ , and a small steering angular velocity d ⁇ / dt (hereinafter, specified). If there also called a situation), regardless inoperative and operating state of the lane keeping assist controller 15, and a final axial force the axial force obtained by adding the correction steering reaction force central value ⁇ Tsc feedforward axial force T FF To do.
  • the feedforward axial force T FF since not reflect the influence of tire lateral force Fd, smoothly changes regardless of the change or the like of the road surface condition.
  • the final axial force calculation unit 11Bc can realize a stable steering feeling when the host vehicle A is in a specific situation. Furthermore, the final axial force calculating unit 11Bc may be the axial force even during operation of the additional function of lane keeping support function based on good feedforward axial force T FF of road feel to the final axial force. Therefore, the final axial force calculation unit 11Bc can realize a stable steering feeling when the additional function called the lane keeping support function is activated.
  • the final axial force calculation unit 11Bc provides a feedback axial force when the host vehicle A is in a situation other than the specific situation (hereinafter also referred to as a normal situation) and the lane keeping support controller 15 is not in operation.
  • the final axial force is T FB or the sum of the feedforward axial force T FF and the feedback axial force T FB .
  • the feedback axial force T FB changes according to a change in the road surface state or a change in the vehicle state in order to reflect the influence of the tire lateral force Fd acting on the steering wheel 13.
  • the final axial force calculation unit 11Bc performs the same steering as the mechanical steering control device in which the steering wheel 12 and the steering wheel 13 are mechanically coupled when the host vehicle A is in a normal state. A feeling can be given and a natural steering feeling can be realized.
  • the axial force-steering reaction force conversion unit 11Bd calculates the final axial force calculated by the final axial force calculation unit 11Bc and the final target corrected steering reaction calculated by the corrected steering reaction force calculation unit 15A (see FIG. 2).
  • a target steering reaction force is calculated based on the force ⁇ Y *.
  • the target steering reaction force is a target value of the steering reaction force.
  • the prior target steering reaction force corresponding to the vehicle speed V and the final axial force is read from the control map M10, and the final target correction steering reaction force ⁇ Y * is added to the read prior target steering reaction force.
  • a method of adding can be adopted.
  • the control map M10 is a map in which the preliminary target steering reaction force corresponding to the final axial force is registered for each vehicle speed V.
  • the axial force-steering reaction force conversion unit 11Bd adds the previous target steering reaction force reading unit 11Bda that reads the previous target steering reaction force from the control map M10, and the previous target steering reaction force and the final target corrected steering reaction force ⁇ Y *. And an adder 11Bdb.
  • FIG. 19 is a graph showing the control map M10. As shown in FIG. 19, the control map M10 is set for each vehicle speed V. Further, the control map M10 sets the prior target steering reaction force to a larger value as the final axial force is larger.
  • the target reaction force current calculation unit 11Be calculates a target reaction force current according to the following equation (13) based on the target steering reaction force calculated by the axial force-steering reaction force conversion unit 11Bd. Then, the target reaction force current calculation unit 11Be outputs the calculation result to the reaction force motor drive unit 3D.
  • Target reaction force current Target steering reaction force ⁇ Gain (13)
  • the target reaction force current calculation unit 11Be calculates the target reaction force current based on the target steering reaction force calculated by the axial force-steering reaction force conversion unit 11Bd.
  • the axial force-steering reaction force converter 11Bd may correct the target steering reaction force by adding the end contact reaction force instead of the final target correction steering reaction force ⁇ Y *.
  • the end contact reaction force for example, there is a steering reaction force applied when the turning angle ⁇ reaches a maximum value.
  • step S100 various data from each sensor and the steering controller 11 are read.
  • the lane keeping support controller 15 reads each wheel speed Vw from the wheel speed sensors 18 to 21, for example.
  • the lane keeping assist controller 15 reads the steering angle ⁇ , the steering angular velocity d ⁇ / dt (hereinafter, d ⁇ / dt may be expressed as “ ⁇ ′”) and the steering torque ⁇ output from the steering controller 11.
  • the lane keeping support controller 15 reads the signal output from the direction instruction switch 17. From the external recognition unit 16, the yaw angle ⁇ of the vehicle with respect to the traveling lane of the host vehicle, the lateral displacement X from the center of the traveling lane, and the curvature ⁇ of the traveling lane are read.
  • the left and right lane edge reference thresholds XLt and XRt are set based on the following equations (14) and (15).
  • the right lane edge reference threshold value XRt specifies the position of the lane edge reference LXR set for the right departure.
  • the left lane edge reference threshold XLt specifies the position of the lane edge reference LXL set for the left departure.
  • XRt (Wlane / 2) ⁇ (Wcar / 2) ⁇ Xoffset (14)
  • XLt ⁇ ((Wlane / 2) ⁇ (Wcar / 2) ⁇ Xoffset) (15)
  • the left and right lane width direction offset threshold values XLt2 and XRt2 are set based on the following equations (16) and (17).
  • XRt2 (Wlane / 2) ⁇ (Wcar / 2) ⁇ Xoffset2 (16)
  • XLt2 ⁇ ((Wlane / 2) ⁇ (Wcar / 2) ⁇ Xoffset2) (17)
  • the lateral displacement X from the travel lane center Ls is positive when the host vehicle A is on the right side of the center with respect to the travel lane L, and is negative when the vehicle is located on the left side. For this reason, the right lane edge reference threshold value XRt and the lane width direction offset threshold value XRt2 side are positive.
  • Wlane is the travel lane width
  • Wcar is the vehicle width of the host vehicle A.
  • Xoffset and Xoffset2 are margins for the position of the traveling lane edge Le (white line or shoulder).
  • the margin allowances Xoffset and Xoffset2 may be changed according to the travel lane width Wlane, the vehicle speed, and the like. For example, the margins Xoffset and Xoffset2 are made smaller as the travel lane width Wlane is narrower. Also, different margins Xoffset and Xoffset2 may be used for the left and right lane edge reference LXL, LXR.
  • the margin allowances Xoffset and Xoffset2 may be zero or negative values. Further, the left and right lane edge reference LXL, LXR may be fixed values. Further, the margin allowances Xoffset and Xoffset2 may be the same value. In this case, the left and right lane edge reference threshold values XLt and XRt are the same as the left and right lane width direction offset threshold values XLt2 and XRt2.
  • ⁇ R ⁇ (when ⁇ ⁇ 0)
  • ⁇ L ⁇ (when ⁇ ⁇ 0)
  • ⁇ L 0 (only negative values are taken).
  • step S140 a first target correction turning angle ⁇ Y1 * is calculated. The process of step S140 is executed by the corrected turning angle calculation unit 15C (see FIG. 2).
  • the first target correction turning angle ⁇ Y1 * is a control amount for canceling the yaw angle ⁇ of the vehicle with respect to the travel lane. That is, it is a control amount for angle deviation for making the traveling lane and the traveling direction of the vehicle parallel.
  • the first target turning angle ⁇ Y1_R * for the right departure and the first target turning angle ⁇ Y1_L * for the left departure are calculated by the following equations, respectively.
  • ⁇ Y1_R * ⁇ (Kc_Y ⁇ Ky_R ⁇ Kv_Y ⁇ ⁇ R)
  • ⁇ Y1_L * ⁇ (Kc_Y ⁇ Ky_L ⁇ Kv_Y ⁇ ⁇ L)
  • Kc_Y is a feedback gain determined by vehicle specifications.
  • Kv_Y is a correction gain according to the vehicle speed.
  • Ky_R and Ky_L are feedback gains that are individually set according to the lateral displacement of the host vehicle with respect to the traveling lane, as shown in FIGS. 24 (a) and 24 (b). Then, the feedback gain Ky_R for the right departure is set so as to increase as it approaches the right lane edge reference LXR. Further, the feedback gain Ky_L for the left departure is set to increase as it approaches the left lane edge reference LXL. In addition, the first target turning angles ⁇ Y1_R * and ⁇ Y1_L * are positive for rightward turning and negative for leftward turning.
  • lane width direction offset threshold values XLt2 and XRt2 may be used as the boundary between the minimum values of the feedback gains Ky_R and Ky_L.
  • the first target corrected turning angle ⁇ Y1 * is calculated as the sum of the first target turning angle ⁇ Y1_R * for the right departure and the first target turning angle ⁇ Y1_L * for the left departure based on the following equation.
  • step S150 the steering reaction force actuator 3A is controlled so that the steering wheel position corresponding to the first target correction turning angle ⁇ Y1 * becomes the neutral position of the steering reaction force.
  • the corrected steering reaction force center calculation unit 15B (see FIG. 2), for example, corrects the steering reaction force center value ⁇ Tsc according to the deviation between the handle position corresponding to the first target turning angle ⁇ Y1 * position and the actual handle position. Is calculated.
  • the corrected steering reaction force center calculation unit 15B (see FIG. 2) outputs a command to the steering controller 11 so as to apply a steering reaction force corresponding to the corrected steering reaction force center value ⁇ Tsc.
  • a target reaction force current calculation unit 11B (see FIG. 3) provided in the steering controller 11 adds the corrected steering reaction force center value ⁇ Tsc to the final axial force calculated by the final axial force calculation unit 11Bc.
  • a target reaction force current based on the steering reaction force is output.
  • the steering controller 11 controls the steering reaction force actuator 3 so as to output a steering reaction force corresponding to the corrected steering reaction force central value ⁇ Tsc.
  • step S160 a steering angle reference value ⁇ R * for a right departure and a steering angle reference value ⁇ L * for a left departure are calculated.
  • the steering angle reference values ⁇ R * and ⁇ L * are reference values used to calculate the amount of increase toward the lane edge by steering of the driver's steering wheel.
  • the steering reaction force becomes the neutral position (the steering torque becomes zero) at the steering wheel position (steering angle) where the traveling lane and the traveling direction of the host vehicle are parallel. For this reason, regardless of whether the traveling lane is a straight road or a curved road, the direction in which the traveling lane and the traveling direction of the host vehicle are parallel to the direction in which the driver approaches the left or right traveling lane end. Whether the vehicle is steered can be detected by the sign of the steering torque ⁇ .
  • the steering angle reference value ⁇ L * for the left departure is updated with the actual steering angle value ⁇ as shown in the following equation.
  • ⁇ L * ⁇ 2
  • ⁇ th is a steering torque threshold for determining driver steering, and is set as an absolute value (positive value).
  • the steering torque ⁇ is a positive value when the steering torque is applied to the right, a negative value when the steering torque is applied to the left, and the steering angle ⁇ is a positive value when steering in the right direction. Value, and leftward steering is a negative value.
  • the actual steering angle value ⁇ when a steering torque equal to or greater than the steering torque threshold ⁇ th is detected becomes the steering angle reference value ⁇ R * for the right departure or the steering angle reference value ⁇ L * for the left departure.
  • step S170 the amount of steering increase to the lane edge side by the steering of the driver is calculated based on the following formula.
  • the amount of steering increase ⁇ R toward the right lane edge reference side is calculated by the following equation.
  • ⁇ R ⁇ - ⁇ R * (when ⁇ > ⁇ R *)
  • ⁇ R 0 (when ⁇ ⁇ ⁇ R *)
  • the steering increase amount ⁇ L toward the left lane edge reference side is calculated by the following equation.
  • the steering amount of the steering wheel toward the left and right lane edge reference sides can be extracted as the amount of steering increase.
  • step S180 a second target correction turning angle ⁇ Y2 * is calculated.
  • the second target turning angle ⁇ Y2 * is a control amount for suppressing in advance the movement of the vehicle toward the departure side.
  • the process of step S180 is executed by the corrected turning angle calculation unit 15C (see FIG. 2).
  • the second target turning angle ⁇ Y2 * is calculated by calculating the second target turning angle ⁇ Y2_R * for the right departure and the second target turning angle ⁇ Y2_L * for the left departure, and taking the sum thereof.
  • the turning angle ⁇ Y2 * is calculated.
  • the second target turning angle ⁇ Y2_R * for the right departure and the second target turning angle ⁇ Y2_L * for the left departure are calculated by the following equations, respectively.
  • Kc_g is a gear ratio coefficient between the steering angle (steering wheel angle) and the tire angle (steering wheel turning angle) determined by the specifications of the vehicle.
  • Kg_R and Kg_L are steering suppression gains with respect to the amount of steering increase toward the traveling lane edge side by the driver's steering.
  • Kg_R and Kg_L are individually set according to the lateral displacement with respect to the traveling lane as shown in FIGS. 25 (a) and 25 (b).
  • the steering suppression gain Kg_R for the right departure is set so as to increase as it approaches the right traveling end reference.
  • the steering suppression gain Kg_L for the left departure is set so as to increase as it approaches the left traveling end reference.
  • the maximum value of these steering suppression gains is 1.0. By setting the maximum value to 1.0, the second target turning angle has an upper limit value for canceling the amount of increase in steering by the driver.
  • lane edge reference threshold values XLt and XRt may be used as the minimum threshold value instead of XLt2 and XRt2.
  • K ⁇ is a value as shown in FIG. That is, the curve correction gain K ⁇ L_R for the right departure and the curve for the left departure are divided into three types according to the direction of the curvature ⁇ (curve direction of the traveling lane L) and using individual maps as follows.
  • a correction gain K ⁇ L_L is set.
  • K ⁇ L_R Read from a curve IN side correction gain map as shown in FIG.
  • K ⁇ L_L Read from the curve OUT side correction gain map as shown in FIG.
  • K ⁇ L_R is read from a curve OUT side correction gain map as shown in FIG.
  • K ⁇ L_L Read from a curve IN side correction gain map as shown in FIG.
  • the curvature ⁇ 0 (straight road)
  • K ⁇ L_R 1.0 (no correction)
  • K ⁇ L_L 1.0 (no correction)
  • the left curve is positive and the right curve is negative.
  • the curve IN-side correction gain map is a map in which the correction gain decreases as the absolute value of the curvature ⁇ increases as the absolute value of the curvature ⁇ increases to a predetermined value or more. And the gain of control with respect to the travel lane edge Le located inside the curved road among the left and right travel lane edges Le is corrected so as to decrease in accordance with the increase in the absolute value of the curvature ⁇ .
  • the curve OUT side correction gain map is a map in which the correction gain increases as the absolute value of the curvature ⁇ increases as the absolute value of the curvature ⁇ increases to a predetermined value or more. .
  • the gain of control with respect to the travel lane edge Le located outside the curve road among the left and right travel lane edges Le is corrected so as to increase in accordance with the increase in the absolute value of the curvature ⁇ .
  • K ⁇ 1 may be set unconditionally.
  • the second target corrected turning angle ⁇ Y2 * is calculated as the sum of the second target turning angle ⁇ Y2_R * for the right departure and the second target turning angle ⁇ Y2_L * for the left departure as shown in the following equation.
  • ⁇ Y2 * ⁇ Y2_R * + ⁇ Y2_L *
  • step S190 a final target corrected turning angle ⁇ Y * for lane keeping support is calculated.
  • the process of step S190 is executed by the corrected turning angle calculation unit 15C (see FIG. 2).
  • step S200 the final target correction turning angle ⁇ Y * is output to the steering controller 11.
  • the corrected turning angle calculation unit 15C outputs the final target corrected turning angle ⁇ Y * to the steering controller 11.
  • the corrected turning angle calculation unit 15C The final target correction turning angle ⁇ Y * for maintenance support is not output to the steering controller 11.
  • the steering controller 11 turns the steering so that the turning angle becomes a target turning angle ⁇ * obtained by adding the final target corrected turning angle ⁇ Y * to the turning command angle calculated by the turning command angle calculation unit 11Aa.
  • Actuator 5A is driven.
  • the turning angle of the front wheel 13 that is the steered wheel becomes the target turning angle ⁇ *.
  • step S210 the first target correction steering reaction force ⁇ Y1 * is calculated as a steering reaction force for lane keeping support.
  • the process of step S210 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3).
  • the first target correction steering reaction force ⁇ Y1 * is a steering reaction force with respect to the steady steering input of the driver.
  • the first target steering reaction force ⁇ Y1 * is calculated according to the steering torque ⁇ applied by the driver to the lane edge side.
  • a first target steering reaction force ⁇ Y1_R * for a right departure and a first target steering reaction force ⁇ Y1_L * for a left departure are calculated for each case as follows.
  • Kt_R and Kt_L are first target steering reaction force calculation gains with respect to the steering torque toward the traveling lane edge by the driver's steering.
  • Kt_R and Kt_L are gains individually set according to the lateral displacement with respect to the traveling lane as shown in FIGS. 27 (a) and 27 (b).
  • the first target steering reaction force calculation gain Kt_R for the right departure is set so as to increase as the right lane edge reference is approached.
  • the first target steering reaction force calculation gain Kt_L for the left departure is set to increase as the left lane edge reference is approached.
  • the first target steering reaction force calculation gains Kt_R and Kt_L have a maximum value of 1.0.
  • the first target steering reaction force has an upper limit for canceling the steering torque due to driver steering. That is, the steering reaction force can be increased only when the driver steers to the departure side. If a steering reaction force greater than the steering torque by the driver is generated, the steering wheel is repelled by the generated reaction force, that is, returned.
  • the gain 1.0 is a position where the force is balanced by the steering torque input by the driver. The above balance means that the handle stops. Thus, it is possible to appropriately perform lane keeping support without feeling of restraint or discomfort.
  • the first target corrected steering reaction force ⁇ Y1 * is calculated as the sum of the first target steering reaction force ⁇ Y1_R * for the right departure and the first target steering reaction force ⁇ Y1_L * for the left departure as shown in the following equation.
  • ⁇ Y1 * ⁇ Y1_R * + ⁇ Y1_L *
  • ⁇ Y1 *, ⁇ Y1_R *, and ⁇ Y1_L * are positive values when the steering reaction force is generated to the left and negative values when the steering reaction force is generated to the right.
  • step S220 a second target correction steering reaction force ⁇ Y2 * is calculated.
  • the process of step S220 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG.
  • the second target correction steering reaction force ⁇ Y2 * is a steering reaction force for supporting lane keeping, and is a steering reaction force with respect to a driver's transient steering input.
  • the second target correction steering reaction force ⁇ Y2 * is calculated according to the steering angular velocity ⁇ ′ that the driver steers to the lane edge side.
  • Ks_R and Ks_L are second target steering reaction force calculation gains with respect to the steering angular velocity toward the lane edge side by the driver's steering.
  • the second target steering reaction force calculation gains Ks_R and Ks_L are individually set according to the lateral displacement with respect to the traveling lane as shown in FIGS. 28 (a) and 28 (b). Then, the second target steering reaction force calculation gain Ks_R for the right departure is set to increase as the right lane edge reference is approached.
  • the second target steering reaction force calculation gain Ks_L for the left departure is set to increase as the left lane edge reference is approached.
  • ⁇ Y2 *, ⁇ Y2_R *, and ⁇ Y2_L * are positive values when the steering reaction force is generated to the left and negative values when the steering reaction force is generated to the right.
  • the steering angular velocity ⁇ ′ is a positive value for steering in the right direction and a negative value for steering in the left direction.
  • step S230 a final target correction steering reaction force ⁇ Y * for lane keeping support is calculated.
  • the process of step S230 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3).
  • the final target corrected steering reaction force is calculated as the sum of the first target correction steering reaction force ⁇ Y1 * calculated in step S210 and the second target correction steering reaction force ⁇ Y2 * calculated in step S220 based on the following equation.
  • the force ⁇ Y * is calculated.
  • ⁇ Y * ⁇ Y1 * + ⁇ Y2 *
  • step S240 the final target correction steering reaction force ⁇ Y * is output to the steering controller 11.
  • the process of step S240 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3).
  • the corrected steering reaction force calculation unit 15A when the direction indicating switch 17 is in the ON state and the indicated direction of the direction indicating switch 17 matches the steering direction of the steering wheel, the corrected steering reaction force calculation unit 15A
  • the target correction steering reaction force ⁇ Y * is not output to the steering controller 11.
  • the steering controller 11 drives the steering reaction force actuator 3A so that the target steering reaction force reflects the final target correction turning angle ⁇ Y * and the corrected steering reaction force central value ⁇ Tsc.
  • FIG. 29 is a graph showing the relationship between the axial force and the steering reaction force.
  • the horizontal axis indicates the absolute value of the axial force
  • the vertical axis indicates the steering reaction force.
  • the absolute value of the axial force increases toward the left side.
  • a curve ⁇ indicates a steering reaction force with respect to an axial force when the steering reaction force is not corrected by the corrected steering reaction force central value ⁇ Tsc (in FIG. 29, this case is represented as “axial force neutral point (original)”). Represents the characteristics.
  • Curve ⁇ represents the axial force and the steering reaction when the steering reaction force is corrected by the corrected steering reaction force central value ⁇ Tsc (in FIG. 29, this case is represented as “axial force neutral point (after offset))”. It represents the relationship with force. As shown in FIG. 29, in the characteristic of the steering reaction force with respect to the axial force, the increase amount of the steering reaction force decreases as the axial force increases. The axial force corresponds to the steering angle of the steering wheel 12. In the case of the axial force neutral point (original), the slope of the tangent of the curve ⁇ when the steering angle value is ⁇ a (a value smaller than ⁇ 1 shown in FIG. 17B) is a steering angle value larger than ⁇ a. ⁇ b (a value larger than ⁇ 2 shown in FIG. 17B) is larger than the slope of the tangent of the curve ⁇ .
  • the characteristic of the steering reaction force with respect to the axial force is a characteristic shifted in the direction in which the absolute value of the axial force is increased by the corrected steering reaction force central value ⁇ Tsc.
  • the characteristic (curve ⁇ ) of the steering reaction force with respect to the axial force in the case of the axial force neutral point (after offset) is the steering reaction force against the axial force in the case of the axial force neutral point (original).
  • the force characteristic (curve ⁇ ) and the shape remain unchanged, and the characteristic is shifted to the left in the figure.
  • the steering reaction force with respect to the steering angle value ⁇ b is smaller in the case of the axial force neutral point (after offset) than in the case of the axial force neutral point (original) by the corrected steering reaction force central value (axial force offset). .
  • the slope of the tangent line of the curve ⁇ at the steering angle value ⁇ b is larger than the slope of the tangent line of the curve ⁇ at the steering angle value ⁇ b.
  • the value of the distribution ratio GF 3 varies depending on the value of the steering angle ⁇ .
  • the contribution ratio of the feedback axial force TFB to the final axial force varies depending on the value (position) of the steering angle ⁇ .
  • the distribution ratio GB is 0.6 at the steering angle value ⁇ b (> ⁇ 2), the contribution ratio of the feedback axial force TFB to the final axial force is relatively large.
  • the feedback axial force T FB that is, the turning current varies depending on the target turning angle ⁇ *.
  • the slope of the tangent of the curve ⁇ at the steering angle value ⁇ b at the axial force neutral point (after offset) is larger than the slope of the tangent of the curve ⁇ at the value ⁇ b at the axial force neutral point (original). Therefore, in the case of the axial force neutral point (after offset), compared to the axial force neutral point (original), the steering reaction force with respect to the fluctuation amount of the steering angle from the value ⁇ b, that is, the fluctuation of the feedback axial force TFB .
  • the amount gets bigger. For this reason, when the value of the steering angle fluctuates from ⁇ b, the amount of fluctuation of the steering current increases.
  • the steering reaction force is more likely to fluctuate in the axial force neutral point (after offset) than in the axial force neutral point (original).
  • the fluctuation of the steering reaction force at the steering angle (for example, the steering angle larger than ⁇ 2) at which the contribution ratio of the feedback axial force TFB to the final axial force becomes relatively large is the non-operating state of the lane keeping assist device 50.
  • the operating state may be larger than the operating state.
  • the control calculation unit 11 provided in the steering control device has an axial force switching output unit 11Bf.
  • the axial force switching output unit 11Bf includes a vehicle speed V detected by the vehicle speed sensor 15A (see FIG. 2), a steering angle ⁇ detected by the steering wheel angle sensor 1 (see FIG. 2), and feedforward.
  • feedforward axial force T FF axial force calculating unit 11Ba is calculated
  • the feedback axial force T FB feedback axial force calculating unit 11Bb is calculated is adapted to enter.
  • the axial force switching output unit 11Bf determines whether the lane keeping assist controller 15 is operating or not based on the input vehicle speed V and the steering angle ⁇ .
  • Axial force switching output section 11Bf once the lane keeping assist controller 15 determines that the operating state, when the feedforward axial force T FF input and output as an axial force Toc for the final axial force calculating, determines that non-actuated state, the input The feedback axial force T FB is output as the axial force Toc.
  • the axial force switching output unit 11Bf determines that the vehicle speed V detected by the vehicle speed sensor 15A is smaller than a predetermined set value (for example, V3 shown in FIG. 17A)
  • the lane keeping assist controller 15 determines that the lane keeping assist controller 15 is in an operating state. If it is determined that the vehicle speed V is equal to or higher than the set value, the lane keeping assist controller 15 determines that the vehicle is not operating.
  • the lane keeping assist controller 15 determines that the steering angle ⁇ detected by the steering wheel angle sensor 1 is greater than or equal to a predetermined set value (for example, ⁇ 2 shown in FIG. 17B), the lane keeping assist controller 15 Is determined to be in an operating state, and if it is determined that the steering angle ⁇ is smaller than the set value, the lane keeping assist controller 15 determines to be in a non-operating state.
  • a predetermined set value for example, ⁇ 2 shown in FIG. 17B
  • Axial force switching output section 11Bf outputs a feedforward axial force T FF when the operating state of the lane keeping assist device 50 does not output the feedback axial force T FB. Therefore, the control calculation unit 11 can calculate the target reaction force current in the operating state of the lane keeping assist device 50, that is, in the operating state of the lane keeping assist controller 15, without being based on the feedback axial force TFB . That is, the control calculation unit 11 can calculate the target reaction force current without being based on the feedback axial force TFB within a range where the contribution ratio of the feedback axial force TFB to the final axial force is relatively large.
  • the control calculation unit 11 can not only eliminate the increase in the steering reaction force fluctuation but also provide the driver with a stable steering feeling when the additional function of the lane keeping assist device 50 is activated.
  • the operating state includes a standby state in which the lane keeping support controller 15 can control the travel support of the host vehicle A, and the lane keeping support controller 15 is controlling the travel support of the host vehicle A. ON state is included.
  • FIG. 30 is a diagram for explaining the operation of the steering control device of the host vehicle A.
  • the control calculation unit 11 calculates the target turning angle ⁇ * based on the steering angle ⁇ and the vehicle speed V (target turning angle calculation unit 11A in FIG. 2).
  • the control calculation unit 11 calculates a target turning current based on a subtraction result obtained by subtracting the actual turning angle ⁇ from the calculated target turning angle ⁇ * (target turning current calculation unit 11C in FIG. 2). .
  • the steering control part 5 steers the steered wheel 13 according to a driver
  • the control calculation unit 11 calculates a feedforward axial force T FF based on the steering angle ⁇ and the vehicle speed V (feedforward axial force calculating unit 11Ba of Figure 3). Subsequently, the control calculation unit 11 calculates a current axial force based on the steering current (current axial force calculation unit 11Bba in FIG. 11). Subsequently, the control calculation unit 11 calculates a lateral G-axis force based on the lateral acceleration Gy (blend axial force calculation unit 11Bbb in FIG. 11). Subsequently, the control calculation unit 11 calculates the yaw rate axial force based on the yaw rate ⁇ and the vehicle speed V (blend axial force calculation unit 11Bbb in FIG.
  • variable K4 becomes 1.0
  • variable K5 becomes 1.0
  • the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB), and the current axial force is set as the feedback axial force T FB (the feedback axis in FIG. 3).
  • Force calculator 11Bb the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB), and the current axial force is set as the feedback axial force T FB (the feedback axis in FIG. 3).
  • the control arithmetic unit 11 the calculated feed and forward axial force T FF and the feedback axial force T FB GF: allocating at (1-GF), final axis and further adding a correction steering reaction force central value ⁇ Tsc
  • the force is calculated (final axial force calculation unit 11Bc in FIG. 3).
  • the final axial force is calculated only with the feedforward axial force T FF and correction steering reaction force central value DerutaTsc.
  • the control calculation unit 11 calculates a target steering reaction force based on the calculated final axial force (axial force-steering reaction force conversion unit 11Bd in FIG. 3). Subsequently, the control calculation unit 11 calculates a target reaction force current based on the calculated target steering reaction force (target reaction force current calculation unit 11Be in FIG. 3). Subsequently, the control calculation unit 11 drives the reaction force motor 4 based on the calculated target reaction force current (reaction force motor drive unit 3D in FIG. 2). As a result, the reaction force control unit 3 applies a steering reaction force to the steering wheel 12.
  • the feedback axial force T FB is calculated based on the current axial force, the blend axial force T BR , and the determination results of the increase operation and the return operation. Therefore, the steering control device of the present embodiment is based on the feedback axial force based on the detection results of the sensors included in a general vehicle such as the steering current of the steering motor 6 and the lateral acceleration Gy of the host vehicle A. T FB can be calculated. Therefore, the steering control device of the present embodiment does not need to include a dedicated sensor for detecting the steering rack axial force by driving the reaction force motor 4 based on the feedback axial force TFB , and the manufacturing cost is reduced. The increase can be suppressed.
  • the steering control device of the present embodiment when the steering wheel 12 is increased, if the absolute value of the steering angular velocity d ⁇ / dt is less than the fourth set steering angular velocity d ⁇ 4 / dt, the current axis The force is a feedback axial force T FB . Therefore, the steering control device of the present embodiment is similar to the mechanical steering control device in which the steering wheel 12 and the steering wheel 13 are mechanically coupled by setting the current axial force to the feedback axial force TFB. In addition, a steering reaction force that returns the steering wheel 12 to the neutral position can be applied. Thereby, the steering control device of the present embodiment can apply a more appropriate steering reaction force when the steering wheel 12 is increased.
  • the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB) to calculate the feedback axial force T FB (feedback axial force calculating unit in FIG. 3). 11Bb). As a result, the feedback axial force T FB switches from the current axial force to the blend axial force T BR .
  • the steering control device when the steering wheel 12 is switched back, the steering control device according to the present embodiment generates the current axial force and the lateral G-axis force regardless of the absolute value of the steering angular velocity d ⁇ / dt.
  • the blend axial force TBR distributed at a preset distribution ratio is defined as a feedback axial force TFB .
  • TFB feedback axial force
  • the steering control device when the steering wheel 12 is switched back, the driver reduces the holding force of the steering wheel 12 and slides the steering wheel 12 with the palm of the hand to make the steering wheel 12 neutral.
  • the steering wheel 13 was returned to the neutral position.
  • the steering control device according to the present embodiment uses the blend axial force T BR as the feedback axial force T FB so that the steering wheel 12 is neutral even if the steering current is reduced and the current axial force is reduced. It can suppress that the steering reaction force which returns to a position reduces. Therefore, as in the case of the mechanical steering control device, the steering control device of the present embodiment reduces the holding force of the steering wheel 12 and causes the steering wheel 12 to slide in the palm of the hand so that the steering wheel 12 is neutral. Can be returned to position. Thereby, the steering control device of the present embodiment can apply a more appropriate steering reaction force when the steering wheel 12 is switched back.
  • the driver continues to operate after the steering angle ⁇ straddles the neutral position during the steering wheel 12 switching operation (for example, during steering in the clockwise direction). It is assumed that the steering wheel 12 is turned up in the clockwise direction. Further, it is assumed that the absolute value of the steering angular velocity d ⁇ / dt is in the range of the fourth set steering angular velocity d ⁇ 4 / dt or more and less than the fifth set steering angular velocity d ⁇ 5 / dt.
  • the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB) to calculate the feedback axial force T FB (feedback axial force calculating unit in FIG. 3). 11Bb). As a result, the feedback axial force T FB gradually shifts from the blend axial force T BR to the current axial force.
  • the steering control device determines that the steering wheel 12 is being increased, and the absolute value of the steering angular velocity d ⁇ / dt is equal to or greater than the fourth set steering angular velocity d ⁇ 4 / dt. If it is determined that there is, the current axial force and the blend axial force T BR are distributed to set the feedback axial force T FB, and the current axial force distribution ratio is increased as the absolute value of the steering angular velocity d ⁇ / dt decreases. Enlarge. Therefore, the steering control device according to the present embodiment increases the steering angle when the steering angle ⁇ straddles the neutral position and the steering wheel 12 is continuously increased in the same direction during the steering wheel 12 switching operation.
  • the steering control device of the present embodiment can apply a more appropriate steering reaction force when switching from the switchback operation to the steering wheel 12 operation.
  • the steering wheel 12 in FIG. 1 constitutes a steering wheel.
  • the steering motor 6 in FIG. 1 constitutes a steering actuator.
  • the steered current detector 5C in FIG. 1 constitutes a steered current detector.
  • the current axial force calculation unit 11Bba in FIG. 11 constitutes a current axial force calculation unit.
  • the blend axial force calculator 11Bbb in FIG. 11 constitutes a lateral G-axis force calculator.
  • the feedback axial force calculation unit 11Bb in FIGS. 3 and 11 constitutes a feedback axial force calculation unit.
  • the feedforward axial force calculation unit 11Ba shown in FIGS. 3 and 14 constitutes a feedforward axial force calculation unit.
  • the target reverse current calculation unit 11B in FIG. 3 constitutes a steering reaction force calculation unit.
  • the axial force switching output unit in FIG. 3 constitutes an axial force switching output unit.
  • target reversing current calculation unit 11B when the lane keeping assist controller 15 is judged to be in operating condition, based on the feedforward axial force T FF without using the feedback axial force T FB, target steering reaction Calculate the force.
  • the steering reaction force at the steering angle at which the contribution ratio of the feedback axial force TFB to the final axial force becomes relatively large is not increased in the lane keeping assist device 50. It is possible to prevent the operating state from becoming larger than the operating state. This can prevent the lane keeping assist function from interfering with the steering control.
  • the steering control device not only eliminates an increase in the steering reaction force fluctuation, but also can provide the driver with a stable steering feeling when the additional function of lane keeping support is activated.
  • the target reverse current calculation unit 11B determines whether or not the lane keeping assist controller 15 is in an operating state based on the vehicle speed V of the host vehicle A and the steering angle ⁇ of the steering wheel 12. According to such a configuration, the operating state of the lane keeping assist unit can be determined by the contribution ratio of the feedback axial force TFB to the final axial force.
  • the operating state of the lane keeping support controller 15 includes a standby state in which the lane keeping support controller 15 can control the running support of the host vehicle A, and the lane keeping support controller 15 provides a driving support for the own vehicle A. It includes an ON state that is under control.
  • the steering reaction force is calculated only by the feedforward axial force T FF without using the feedback axial force T FB , and the lane keeping assist controller 15 Is in the non-operating state, it is calculated by the feedback axial force TFB and the feedforward axial force TFF .
  • operator of a vehicle can judge whether the lane maintenance assistance controller 15 is an operation state.
  • the target inversion current calculation section 11B receives the feedforward axial force T FF output from the feedforward axial force calculating unit 11Ba, and the feedback axis force feedback axial force calculating unit 11Bb outputs T FB is, lane keeping and it outputs a feedback axial force T FB in the non-operating state of the support controller 15, the operating state of the lane keeping assist controller 15 includes an axial force switching output section 11Bf outputs a feedforward axial force T FF.
  • the steering reaction force calculation unit have an axial force switching output unit, it will not only increase the fluctuation of the steering reaction force but also give the driver a stable steering feeling when the additional function of lane keeping support is activated. Can do.
  • the lane keeping support unit turns the steering correction amount for suppressing the turning only when the traveling direction of the host vehicle is directed to the lane edge reference side rather than parallel or parallel to the traveling lane. May be calculated. In this case, if the traveling direction of the host vehicle is away from the lane edge reference even if the host vehicle is in a position approaching the left or right lane edge reference, the left or right lane edge When the steering wheel is steered to the reference side, steering is not suppressed. Accordingly, it is possible to avoid unnecessary turning suppression by performing the turning suppression only when the vehicle is heading in the departure direction.
  • the lane keeping support unit may calculate the steering reaction force correction amount when the traveling direction of the host vehicle is directed to the lane edge reference side rather than parallel or parallel to the traveling lane. .
  • the traveling direction of the host vehicle is moving away from the lane edge reference even when the host vehicle is in a position approaching the left or right lane edge reference, the left or right lane edge When the steering wheel is steered to the part reference side, the steering reaction force is not increased.
  • FIG. 31 is a block diagram of the control calculation unit 11 provided in the steering control device according to the present embodiment.
  • FIG. 32 is a block diagram illustrating a configuration of the target reaction force current calculation unit 11B.
  • the own vehicle in the present embodiment and the control calculation unit and the lane keeping support device provided in the own vehicle have substantially the same configuration as the own vehicle A, the control computation unit 11 and the lane keeping support device 50 in the first embodiment. Have the same function. For this reason, only the differences between these configurations will be described below.
  • the control calculation unit 11 includes a lane keeping assist operation restriction unit 52 including a blocking unit 11D and a distribution ratio calculation unit 11Bcb.
  • the lane keeping assist operation restriction unit 52 restricts the operation of the lane keeping assist controller 15 based on the distribution ratio GF that is a parameter used for determining the final axial force used for calculating the target steering reaction force.
  • the output signal of the lane keeping support controller 15 is blocked from being input to the target reaction force current calculation unit, or the operation of the lane keeping support controller 15 is stopped. Is included.
  • the stop state includes at least the corrected steering reaction force calculation among the non-operation state of the lane keeping support controller 15, the corrected steering reaction force calculation unit 15A, the correction steering reaction force center calculation unit 15B, and the corrected turning angle calculation unit 15C. This includes putting the unit 15A in a stopped state.
  • the distribution ratio GF is a distribution ratio (axial force difference distribution ratio) GF 1 (see FIG. 15) based on the axial force difference between the feedforward axial force and the feedback axial force. It is determined based on a distribution ratio (lateral G distribution ratio) GF 2 (see FIG. 16) based on the lateral acceleration and a steering angular speed distribution ratio (angular speed distribution ratio) GF 3 based on the steering angle.
  • the blocking unit 11 ⁇ / b> D provided in the lane keeping support operation restriction unit 52 receives an output signal of the lane keeping support controller 15.
  • the output signal includes, for example, a final target corrected steering reaction force ⁇ Y *, a corrected steering reaction force central value ⁇ Tsc, and a final target corrected turning angle ⁇ Y *.
  • the blocking unit 11D outputs the input final target correction steering reaction force ⁇ Y * and the correction steering reaction force central value ⁇ Tsc to the target reaction force current calculation unit 11B, and the input final target correction steering angle ⁇ Y *. Is output to the adder 11Ab of the target turning angle calculator 11A.
  • the cut-off unit 11D is configured to receive the operation restriction control signal SC output from the distribution ratio calculation unit 11Bcb (see FIG. 32).
  • the lane keeping support operation restriction unit 52 restricts the operation of the lane keeping support controller 15 based on the operation restriction control signal SC.
  • the blocking unit 11D sets the final target corrected steering reaction force ⁇ Y *, the corrected steering reaction force central value ⁇ Tsc, and the final target corrected turning angle ⁇ Y * based on the signal level of the operation restriction control signal SC. It is determined whether or not to output to the force / current calculation unit 11B and the addition unit 11Ab.
  • the cutoff unit 11D When the signal level of the operation restriction control signal SC is, for example, a low level, the cutoff unit 11D outputs a final target correction steering reaction force ⁇ Y * or the like to the target reaction force current calculation unit 11B or the like, and the signal level is, for example, a high level. In this case, the final target correction steering reaction force ⁇ Y * or the like is not output to the target reaction force current calculation unit 11B or the like.
  • the operation restriction control signal SC is provided for each final target corrected steering reaction force ⁇ Y *, corrected steering reaction force center value ⁇ Tsc, and final target corrected turning angle ⁇ Y *.
  • the lane keeping assist operation restriction unit 52 can individually control whether or not to output the final target corrected steering reaction force ⁇ Y *, the corrected steering reaction force central value ⁇ Tsc, and the final target corrected turning angle ⁇ Y *. Thereby, the lane keeping assist operation restriction unit 52 can independently restrict the operations of the corrected steering reaction force calculation unit 15A, the correction steering reaction force center calculation unit 15B, and the correction turning angle calculation unit 15C.
  • the lane keeping assist device 50 improves the straight traveling performance of the host vehicle A through the turning angle and the steering reaction force control when the state of the host vehicle A is stable and the operation state of the driver is stable.
  • an example of the case where the state of the host vehicle A is stable is a case where the vehicle is not in the limit high G state or the tire slip state.
  • An example of the case where the driver's operation state is stable is a case where the driver is not steering quickly.
  • the driver road surface information such as a road surface condition in which tires are slippery.
  • the lane keeping assist device 50 functions, the host vehicle A goes straight regardless of the road surface condition. For this reason, there is a problem that it is difficult for the driver to notice what the road surface state is.
  • the situation where it is desired to accurately convey the road surface condition to the driver is a region where the distribution ratio of the feedback axial force TFB in the final axial force is high.
  • the set values of the distribution ratio GF 1 , the distribution ratio GF 2 and the distribution ratio GF 3 are relative. It is a very low area. That is, the distribution ratio GF 1 is closer to the thirteenth set value than the fourteenth set value, the distribution ratio GF 2 is closer to the fifteenth set value than the sixteenth set value, and the distribution ratio GF 3 is greater than the twentieth set value. Is also an area set to a value close to the 21st set value.
  • the distribution ratio calculation unit 11Bcb determines whether or not the minimum value among the set values of the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 is smaller than a preset threshold value. It is like that. When it is determined that the minimum value is smaller than the threshold value, the distribution ratio calculation unit 11Bcb blocks the operation restriction control signal SC having a high signal level in order to restrict the operation of the lane keeping support controller 15. To 11D. On the other hand, when the distribution ratio calculation unit 11Bcb determines that the minimum value is larger than the threshold value, it is not necessary to limit the operation of the lane keeping support controller 15, and thus the operation restriction control signal SC having a low signal level. Is output to the blocking unit 11D.
  • the blocking unit 11D sets the final target correction steering reaction force ⁇ Y *, the correction steering reaction force central value ⁇ Tsc, and the final target correction turning angle ⁇ Y * as the target reaction force. Do not output to the current calculation unit 11B and the addition unit 11Ab. Accordingly, the target reaction force current output by the target reaction force current calculation unit 11B and the target turning current output by the target turning current calculation unit 11C do not include the correction amount calculated by the lane keeping assist device 50. For this reason, since the vehicle straight-ahead function of the own vehicle A is limited, the steering control device can accurately convey the road surface information to the driver.
  • the axial force difference is an indicator of a change in road surface ⁇ , that is, a tire slip. Therefore, lane keeping assistance operation limiting portion 52, by using the distribution ratio GF 1 to determine the operating limits of the lane keeping assist controller 15, it is possible to reflect the road surface condition on the determination. Further, the lane keeping assist operation restriction unit 52 may restrict the operation of only the corrected steering reaction force calculation unit 15A, the corrected steering reaction force calculation unit 15A, the corrected steering reaction force center calculation unit 15B, and the corrected turning angle. Any operation of the calculation unit 15C may be limited. Further, the lane keeping support operation restriction unit 52 may be configured to restrict the operation of the lane keeping support controller 15 by stopping the operation of the lane keeping support controller 15 itself.
  • the target steering reaction force calculation unit 11B in the present embodiment does not have an axial force switching output unit, the feedback axial force TFB and the feedforward axial force regardless of whether the lane keeping assist device 50 is in an operating state or not. Based on TFF , the final axial force is calculated.
  • the distribution ratio calculation unit 11Bcb sets the setting values of the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 , a minimum value among these setting values is set in advance. If it is determined that it is smaller than the threshold value, the operation of the lane keeping assist controller 15 is limited via the blocking unit 11D.
  • the steering wheel 12 in FIG. 1 constitutes a steering wheel.
  • the steering motor 6 in FIG. 1 constitutes a steering actuator.
  • the steered current detector 5C in FIG. 1 constitutes a steered current detector.
  • the current axial force calculation unit 11Bba in FIG. 11 constitutes a current axial force calculation unit.
  • the blend axial force calculator 11Bbb in FIG. 11 constitutes a lateral G-axis force calculator.
  • the feedback axial force calculation unit 11Bb in FIGS. 3 and 11 constitutes a feedback axial force calculation unit.
  • the feedforward axial force calculation unit 11Ba shown in FIGS. 3 and 14 constitutes a feedforward axial force calculation unit.
  • the target reverse current calculation unit 11B in FIG. 3 constitutes a steering reaction force calculation unit.
  • the reaction force motor 4 in FIG. 1 constitutes a reaction force actuator. 1 constitutes a lane keeping support unit.
  • the blocking unit 11D and the distribution ratio calculation unit 11Bcb in FIGS. 31 and 32 constitute a line maintenance support operation limiting unit.
  • the blocking part 11D in FIG. 31 constitutes a blocking part.
  • the control calculation unit 11 restricts the operation of the lane keeping support controller 15 based on parameters used for calculating the steering reaction force. According to such a configuration, the steering reaction force calculation unit does not include the correction amount calculated by the lane keeping support unit in the calculation of the steering reaction force. This can prevent the lane keeping assist function from interfering with the steering control.
  • the steering control device can accurately convey the road surface information to the driver.
  • the parameters include distribution ratio is a ratio to distribute the feedback axial force T FB feedforward axial force feedforward axial force calculating unit 11Ba is calculated T FF and the feedback axial force calculating unit 11Bb is calculated Yes. According to such a configuration, road surface information can be accurately transmitted to the driver.
  • the distribution ratio is determined based on the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 . According to such a configuration, road surface information can be accurately transmitted to the driver.
  • the control calculation unit 11 restricts the operation of the lane keeping support controller 15 when the minimum value of the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 is smaller than a preset threshold value, When the minimum value is equal to or greater than the threshold value, the operation of the lane keeping support controller 15 is not limited. According to such a configuration, the operation of the lane keeping assist controller 15 can be limited when the feedback axial force TFB including information such as the road surface condition is easily reflected in the steering reaction force. Thereby, road surface information can be accurately conveyed to the driver. (5) The control calculation unit 11 limits the operation of the corrected steering reaction force calculation unit 15 ⁇ / b> A provided in the lane keeping support controller 15. According to such a configuration, the steering reaction force can be calculated without applying the final target correction steering reaction force that directly contributes to the control amount of the steering reaction force.
  • the control calculation unit 11 restricts the operations of the corrected steering reaction force center calculation unit 15B and the corrected turning angle calculation unit 15C. According to such a configuration, the steering reaction force can be calculated without providing a correction amount that contributes to the control amount of the steering reaction force.
  • the control calculation unit 11 blocks at least one of the final target correction turning angle ⁇ Y *, the final target correction steering reaction force ⁇ Y *, and the correction steering reaction force central value ⁇ Tsc from being input to the control calculation unit 11.
  • the lane keeping support controller 15 has a blocking unit that restricts the operation. According to such a configuration, the steering reaction force can be calculated without giving a correction amount that contributes to the control amount of the steering reaction force while the operation state of the lane keeping assist controller 15 is continued.
  • the limitation of the operation of the lane keeping support controller 15 includes the stop of the operation of the lane keeping support controller 15. According to such a configuration, the steering reaction force can be calculated without providing a correction amount that contributes to the control amount of the steering reaction force.
  • FIG. 33 is a block diagram illustrating a configuration of the target reaction force current calculation unit 11B.
  • FIG. 34 is a diagram illustrating a control map M11 that is referred to when the friction calculation unit 11Bg calculates pre-friction.
  • the own vehicle in the present embodiment and the control calculation unit and the lane keeping support device provided in the own vehicle have substantially the same configuration as the own vehicle A, the control computation unit 11 and the lane keeping support device 50 in the first embodiment. Have the same function. For this reason, only the differences between these configurations will be described below.
  • the target reaction force current calculation unit 11B does not have the axial force switching output unit 11Bf unlike the above embodiment.
  • the target reaction force current calculation unit 11B includes a friction calculation unit 11Bg that calculates the friction generated when the steered wheel 13 (see FIG. 1) is steered based on the correction value for correcting the first steering reaction force.
  • the first steering reaction force is the preliminary target steering reaction force read by the preliminary target steering reaction force reading unit 11Bda.
  • the correction value includes a corrected steering reaction force center value ⁇ Tsc and a final target correction steering reaction force ⁇ Y * used for calculating the final axial force.
  • the correction value for correcting the preliminary target steering reaction force is not only the correction value (final target correction steering reaction force ⁇ Y *) to be added to the preliminary target steering reaction force, but also the final value used for reading the preliminary target steering reaction force. It also includes a correction value (corrected steering reaction force central value ⁇ Tsc) used for calculating the axial force.
  • the lane keeping support controller 15 (see FIG. 2) corrects the prior target steering reaction force read by the prior target steering reaction force reading unit 11Bda with the corrected steering reaction force central value ⁇ Tsc and the final target corrected steering reaction force ⁇ Y *.
  • the vehicle A is supported to travel without departing from the traveling lane.
  • the friction calculation unit 11Bg includes a friction calculation pre-stage unit 11Bga and a friction calculation post-stage unit 11Bgb.
  • the friction calculation pre-stage unit 11Bga calculates a prior friction based on the steering angular velocity d ⁇ / dt calculated from the steering angle ⁇ of the steering wheel 12 and the vehicle speed V of the host vehicle A.
  • FIG. 34 is a graph showing the control map M11.
  • a method for calculating the preliminary friction for example, a method of reading the preliminary friction corresponding to the absolute value of the steering angular velocity d ⁇ / dt from the control map M11 can be employed.
  • the control map M11 for example, there is a map in which pre-friction corresponding to the absolute value of the steering angular velocity d ⁇ / dt is registered. Specifically, as shown in FIG. 34, the control map M11 is set for each vehicle speed V. Each control map M11 sets the prior friction to the 22nd set value (for example, 0.0) when the steering angular velocity d ⁇ / dt is 0.
  • control map M11 shows that the prior friction is the 23rd in the range where the absolute value of the steering angular velocity d ⁇ / dt is not less than the sixth set steering angular velocity d ⁇ 6 / dt (> 0) regardless of the magnitude of the steering angular velocity d ⁇ / dt.
  • the control map M11 indicates that the absolute value of the steering angular velocity d ⁇ / dt is within a range where the steering angular velocity d ⁇ / dt is 0.0 or more and the absolute value of the steering angular velocity d ⁇ / dt is less than the sixth set steering angular velocity d ⁇ 6 / dt.
  • the pre-friction is increased linearly according to Specifically, in each control map M11, the absolute value of the steering angular velocity d ⁇ / dt and the prior friction are obtained when the absolute value of the steering angular velocity d ⁇ / dt is not less than 0 and less than the sixth set steering angular velocity d ⁇ 6 / dt.
  • Pre-friction is set according to a linear function that expresses the relationship. In the linear function, when the absolute value of the steering angular velocity d ⁇ / dt is 0, the prior friction is set to the 22nd set value (0.0), and the absolute value of the steering angular velocity d ⁇ / dt is the sixth set steering angular velocity d ⁇ 6 / dt.
  • the pre-friction calculation pre-stage unit 11Bga increases the pre-friction as the absolute value of the steering angular velocity d ⁇ / dt increases. Increase the absolute value.
  • the pre-friction calculation pre-stage unit 11Bga when the absolute value of the steering angular velocity d ⁇ / dt is equal to or larger than the sixth set steering angular velocity d ⁇ 6 / dt, regardless of the magnitude of the steering angular velocity d ⁇ / dt,
  • the absolute value is a predetermined constant value.
  • the sixth set value is set to a higher value as the vehicle speed V increases.
  • the pre-friction calculation pre-stage unit 11Bga outputs the pre-friction obtained using the control map M11 to the friction calculation post-stage unit 11Bgb.
  • the target steering reaction force is input to the friction calculation post-stage portion 11Bgb.
  • the target steering reaction force is a steering reaction force obtained by correcting the prior target steering reaction force with the final target correction steering reaction force ⁇ Y *. That is, the target steering reaction force corresponds to the second steering reaction force obtained by correcting the first steering reaction force with the correction value.
  • the friction calculation post-stage unit 11Bgb calculates a coefficient based on the input target steering reaction force.
  • the friction calculation post-stage unit 11Bgb calculates the friction by multiplying the input prior friction by a coefficient obtained from the target steering reaction force. As described above, the friction calculation unit 11Bg calculates the friction based on the coefficient obtained from the target steering reaction force.
  • the friction calculation post-stage unit 11Bgb outputs the calculated friction to the addition unit 11Bh provided in the target reaction force current calculation unit 11B.
  • the adder 11Bh adds the friction output by the friction calculator 11Bg and the target steering reaction force, and outputs the result to the target reaction force current calculator 11Be.
  • the target reaction force current calculation unit 11Be calculates a target reaction force current based on the target steering reaction force to which friction is added.
  • the target reaction force current calculation unit 11Be outputs the target reaction force current to the reaction force motor drive unit 3D (see FIG. 2).
  • the friction calculation unit 11Bg in this embodiment multiplies the pre-friction by a coefficient based on the target steering reaction force in consideration of the corrected steering reaction force central value ⁇ Tsc and the final target correction steering reaction force ⁇ Y *, and steers the steered wheels 13.
  • the friction generated along with this is calculated.
  • FIG. 35 is a graph showing the relationship between the steering angular velocity and the friction term.
  • the horizontal axis indicates the absolute value of the steering angular velocity, and the vertical axis indicates the friction term.
  • a curve ⁇ 0 represents a characteristic of the friction term with respect to the steering angular velocity when the corrected steering reaction force central value ⁇ Tsc is taken into consideration (considering the lane keeping assist control).
  • a curve ⁇ 1 represents the characteristic of the friction term with respect to the steering angular velocity when the corrected steering reaction force central value ⁇ Tsc is not taken into consideration. That is, the characteristic represented by the curve ⁇ 0 corresponds to the characteristic of the friction output by the friction calculation unit 11Bg. The characteristic represented by the curve ⁇ 1 corresponds to the characteristic of the prior friction. As shown in FIG. 35, when the corrected steering reaction force central value ⁇ Tsc is taken into consideration, the friction term is reduced as compared with the case where the corrected steering reaction force central value ⁇ Tsc is not taken into consideration.
  • the control calculation unit 11 in the present embodiment can reduce the friction term in accordance with the reduction amount of the steering reaction force. It is possible to obtain a good steering feeling.
  • the target steering reaction force calculation unit 11B in the present embodiment does not have an axial force switching output unit, the feedback axial force TFB and the feedforward axial force regardless of whether the lane keeping assist device 50 is in an operating state or not. Based on TFF , the final axial force is calculated. Further, in the steering control device, the target reversal current calculation unit 11B is based on a coefficient based on the target steering reaction force in consideration of the corrected steering reaction force center value ⁇ Tsc and the final target correction steering reaction force ⁇ Y *. Friction generated with turning is calculated. Subsequently, the target reverse current calculation unit 11B calculates the target reverse current by adding the calculated friction and the target steering reaction force.
  • the steering wheel 12 in FIG. 1 constitutes a steering wheel.
  • the steering motor 6 in FIG. 1 constitutes a steering actuator.
  • the steered current detector 5C in FIG. 1 constitutes a steered current detector.
  • the current axial force calculation unit 11Bba in FIG. 11 constitutes a current axial force calculation unit.
  • the blend axial force calculator 11Bbb in FIG. 11 constitutes a lateral G-axis force calculator.
  • the feedback axial force calculation unit 11Bb in FIGS. 3 and 11 constitutes a feedback axial force calculation unit.
  • the feedforward axial force calculation unit 11Ba shown in FIGS. 3 and 14 constitutes a feedforward axial force calculation unit.
  • the target reverse current calculation unit 11B in FIG. 3 constitutes a steering reaction force calculation unit.
  • the reaction force motor 4 in FIG. 1 constitutes a reaction force actuator. 1 constitutes a lane keeping support unit.
  • the friction calculation unit 11Bg in FIG. 35 constitutes a friction calculation unit.
  • the friction calculation pre-stage unit 11Bga in FIG. 35 constitutes the friction calculation pre-stage unit.
  • the friction calculation post-stage part 11Bgb of FIG. 35 constitutes the friction calculation post-stage part.
  • the pre-target steering reaction force read by the pre-target steering reaction force reading unit 11Bda constitutes the first steering reaction force.
  • the correction steering reaction force central value ⁇ Tsc and the final target correction steering reaction force ⁇ Y * used for calculating the final axial force constitute a correction value.
  • the friction calculation unit 11Bg calculates the friction generated when the steered wheels 13 are steered based on the correction value for correcting the steering reaction force. According to such a configuration, it is possible to prevent the friction term for the steering reaction force from becoming excessive. This can prevent the lane keeping assist function from interfering with the steering control. Further, a good steering feeling can be obtained.
  • the correction value includes a corrected steering reaction force center value ⁇ Tsc and a final target correction steering reaction force ⁇ Y *. According to such a configuration, it is possible to prevent the friction term for the steering reaction force from becoming excessive.
  • the friction calculator 11Bg calculates the friction based on the coefficient obtained from the steering reaction force corrected by the corrected steering reaction force central value ⁇ Tsc and the final target correction steering reaction force ⁇ Y *. According to such a configuration, it is possible to prevent the friction term for the steering reaction force from becoming excessive.
  • the friction calculation unit 11Bg includes a friction calculation pre-stage unit 11Bga that calculates pre-friction based on the steering angular velocity d ⁇ / dt calculated from the steering angle ⁇ of the steering wheel 12 and the vehicle speed V of the host vehicle A; And a friction calculation post-stage unit 11Bgb for calculating the friction based on the coefficient. According to this configuration, the correction amount for correcting the steering reaction force can be reflected in the calculation of the friction generated when the steered wheel 13 is steered. This can prevent the friction term for the steering reaction force from becoming excessive.
  • the target reaction force current calculation unit 11Be is based on the target steering reaction force corrected by the corrected steering reaction force central value ⁇ Tsc and the final target correction steering reaction force ⁇ Y *, and the friction calculated by the friction calculation unit 11Bg.
  • the target reaction force current is calculated. According to this configuration, the target reverse current can be calculated based on an appropriate friction term for the steering reaction force. Thereby, a favorable steering feeling can be obtained.

Abstract

The purpose of the present invention is to provide a steering control device capable of preventing a lane-keeping assist function from interfering with steering control. The steering control device is equipped with: a target reaction force current calculation unit (11B) that calculates a steering reaction force on the basis of a feedforward axial force calculated by a feedforward axial force calculation section (11Ba) and a feedback axial force calculated by a feedback axial force calculation section (11Bb); and a lane-keeping assist unit (15) that assists a vehicle in travel without deviating from a traveling lane. The target reaction force current calculation unit (11B) calculates the steering reaction force on the basis of the feedforward axial force without using the feedback axial force when the lane-keeping assist unit (15) is determined to be operating.

Description

操舵制御装置Steering control device
　本発明は、ステアリングホイールと操向輪とが機械的に分離したステア・バイ・ワイヤ方式の操舵制御装置に関するものである。 The present invention relates to a steer-by-wire steering control device in which a steering wheel and a steered wheel are mechanically separated.
　従来、操舵制御装置の技術としては、例えば、特許文献１に記載の従来技術がある。
　この従来技術では、操舵角に基づく操舵反力の制御量と、ステアリングラック軸力に基づく操舵反力の制御量とに基づいて、反力モータを駆動する。これにより、この従来技術では、操向輪に作用する外力の影響を操舵反力に反映させている。 Conventionally, as a technique of a steering control device, for example, there is a conventional technique described in Patent Document 1.
In this prior art, the reaction force motor is driven based on the control amount of the steering reaction force based on the steering angle and the control amount of the steering reaction force based on the steering rack axial force. Thereby, in this prior art, the influence of the external force acting on the steering wheel is reflected in the steering reaction force.
特開２０００－１０８９１４号公報JP 2000-108914 A
　操舵制御により車線維持を支援する車線維持支援装置は、車両の進行方向と走行車線との角度偏差を打ち消す方向に操舵を制御するために、上記操舵制御装置における操舵反力の制御量に補正量を付加する場合がある。このため、反力モータは、当該操舵制御装置が意図したのとは異なる制御量で駆動される。
　このように、車線維持支援機能は、主機能である操舵制御に新たな機能を付与するものであるにもかかわらず、当該操舵制御を妨げてしまう場合があるという問題を有している。
　そこで、本発明の目的は、車線維持支援機能が操舵制御を妨げるのを防止することができる操舵制御装置を提供することにある。 A lane keeping assist device that supports lane keeping by steering control is a correction amount to the control amount of the steering reaction force in the steering control device in order to control steering in a direction that cancels the angular deviation between the traveling direction of the vehicle and the traveling lane. May be added. For this reason, the reaction force motor is driven with a control amount different from that intended by the steering control device.
As described above, the lane keeping support function has a problem that the steering control may be hindered in spite of providing a new function to the main function steering control.
Therefore, an object of the present invention is to provide a steering control device that can prevent the lane keeping assist function from interfering with the steering control.
　上記課題を解決するため、本発明の一態様では、車線維持支援部が作動状態の場合にはフィードフォワード軸力に基づいて操舵反力を算出し、車線維持支援部が非作動状態の場合には、フィードフォワード軸力とフィードバック軸力とに基づいて操舵反力を算出する。 In order to solve the above problem, according to one aspect of the present invention, when the lane keeping assist unit is in an operating state, the steering reaction force is calculated based on the feedforward axial force, and when the lane keeping assist unit is in an inoperative state. Calculates the steering reaction force based on the feedforward axial force and the feedback axial force.
　本発明によれば、車線維持支援機能が操舵制御を妨げるのを防止できる。 According to the present invention, the lane keeping assist function can be prevented from interfering with the steering control.
本発明の第１の実施形態による操舵制御装置を説明する図であって、自車両Ａの構成を表す概念図である。1 is a diagram for explaining a steering control device according to a first embodiment of the present invention, and is a conceptual diagram showing a configuration of a host vehicle A. FIG. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御演算部１１の構成を表すブロック図である。FIG. 2 is a diagram illustrating the steering control device according to the first embodiment of the present invention, and is a block diagram illustrating a configuration of a control calculation unit 11. 本発明の第１の実施形態による操舵制御装置を説明する図であって、目標反力電流算出部１１Ｂの構成を表すブロック図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a block diagram showing the structure of the target reaction force electric current calculation part 11B. 本発明の第１の実施形態による操舵制御装置を説明する図であって、フィードフォワード軸力算出部１１Ｂａの構成を表すブロック図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a block diagram showing the structure of feedforward axial force calculation part 11Ba. 本発明の第１の実施形態による操舵制御装置を説明する図であって、ピニオン軸力Ｔｈの算出式の係数を説明するための図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure for demonstrating the coefficient of the calculation formula of pinion axial force Th. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ１を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M1. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ２を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M2. 本発明の第１の実施形態による操舵制御装置を説明する図であって、操舵角δと操舵反力との関係を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing the relation between steering angle delta and steering reaction force. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ３を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M3. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ４を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M4. 本発明の第１の実施形態による操舵制御装置を説明する図であって、フィードバック軸力算出部１１Ｂｂの構成を表すブロック図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a block diagram showing the structure of feedback axial force calculation part 11Bb. 本発明の第１の実施形態による操舵制御装置を説明する図であって、横Ｇ軸力、電流軸力、ヨーレート軸力、および実際のステアリングラック軸力を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing lateral G axial force, current axial force, yaw rate axial force, and actual steering rack axial force. 本発明の第１の実施形態による操舵制御装置を説明する図であって、ブレンド軸力ＴＢＲ、および実際のステアリングラック軸力を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing blend axial force TBR and actual steering rack axial force. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ５を表すグラフである。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a graph showing the control map M5. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ６を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M6. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ７を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M7. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ８ａ、Ｍ８ｂを表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control maps M8a and M8b. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ９を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M9. 本発明の第１の実施形態による操舵制御装置を説明する図であって、制御マップＭ１０を表すグラフである。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a graph showing control map M10. 本発明の第１の実施形態による操舵制御装置を説明する図であって、車線維持支援コントローラの処理を説明する図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure explaining the process of a lane keeping assistance controller. 本発明の第１の実施形態による操舵制御装置を説明する図であって、各値の関係を説明する平面図である。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a top view explaining the relation of each value. 本発明の第１の実施形態による操舵制御装置を説明する図であって、各値の関係を説明する平面図である。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a top view explaining the relation of each value. 本発明の第１の実施形態による操舵制御装置を説明する図であって、ヨー角φとヨー角偏差との関係を示す図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure which shows the relationship between yaw angle (phi) and yaw angle deviation. 本発明の第１の実施形態による操舵制御装置を説明する図であって、自車両の横位置に対するゲインＫｙ＿Ｒ、Ｋｙ＿Ｌの関係を示す図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure which shows the relationship of the gain Ky_R and Ky_L with respect to the horizontal position of the own vehicle. 本発明の第１の実施形態による操舵制御装置を説明する図であって、自車両の横位置に対する転舵抑制ゲインの関係を示す図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure which shows the relationship of the steering suppression gain with respect to the horizontal position of the own vehicle. 本発明の第１の実施形態による操舵制御装置を説明する図であって、カーブ曲率に対するカーブ補正ゲインを示す概念図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a conceptual diagram which shows the curve correction gain with respect to a curve curvature. 本発明の第１の実施形態による操舵制御装置を説明する図であって、自車両の横位置に対する第１目標操舵反力算出ゲインの関係を説明する図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure explaining the relationship of the 1st target steering reaction force calculation gain with respect to the lateral position of the own vehicle. 本発明の第１の実施形態による操舵制御装置を説明する図であって、自車両の横位置に対する第２目標操舵反力算出ゲインの関係を説明する図である。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a figure explaining the relationship of the 2nd target steering reaction force calculation gain with respect to the horizontal position of the own vehicle. 本発明の第１の実施形態による操舵制御装置を説明する図であって、軸力と操舵反力との関係を示すグラフである。It is a figure explaining the steering control apparatus by the 1st Embodiment of this invention, Comprising: It is a graph which shows the relationship between an axial force and a steering reaction force. 本発明の第１の実施形態による操舵制御装置を説明する図であって、自車両Ａの操舵制御装置の動作を説明するための図である。It is a figure explaining the steering control device by a 1st embodiment of the present invention, and is a figure for explaining operation of the steering control device of self-vehicles A. 本発明の第２の実施形態による操舵制御装置を説明する図であって、制御演算部１１の構成を表すブロック図である。It is a figure explaining the steering control apparatus by the 2nd Embodiment of this invention, Comprising: It is a block diagram showing the structure of the control calculating part. 本発明の第２の実施形態による操舵制御装置を説明する図であって、目標反力電流算出部１１Ｂの構成を表すブロック図である。It is a figure explaining the steering control apparatus by the 2nd Embodiment of this invention, Comprising: It is a block diagram showing the structure of the target reaction force electric current calculation part 11B. 本発明の第３の実施形態による操舵制御装置を説明する図であって、目標反力電流算出部１１Ｂの構成を表すブロック図である。It is a figure explaining the steering control apparatus by the 3rd Embodiment of this invention, Comprising: It is a block diagram showing the structure of the target reaction force electric current calculation part 11B. 本発明の第３の実施形態による操舵制御装置を説明する図であって、制御マップＭ１１を表すグラフである。It is a figure explaining the steering control apparatus by the 3rd Embodiment of this invention, Comprising: It is a graph showing the control map M11. 本発明の第３の実施形態による操舵制御装置を説明する図であって、操舵角速度とフリクション項との関係を示すグラフである。It is a figure explaining the steering control apparatus by the 3rd Embodiment of this invention, Comprising: It is a graph which shows the relationship between a steering angular velocity and a friction term.
〔第１の実施形態〕
　本発明に係る第１の実施形態について図面を参照して説明する。
　図１は、本実施形態の車線維持支援装置を適用した自車両のシステム概要構成図である。この実施形態の自車両は、ステア・バイ・ワイヤシステムを採用している。すなわち、ステアリングホイールの操舵状態と独立して操舵輪の転舵角を制御可能となっている。また、操舵輪の転舵状態と独立してステアリングホイールの操舵反力を制御可能となっている。また、操向輪とステアリングホイールとは機械的に分離している。 [First Embodiment]
A first embodiment according to the present invention will be described with reference to the drawings.
FIG. 1 is a system schematic configuration diagram of a host vehicle to which the lane keeping assist device of the present embodiment is applied. The vehicle of this embodiment employs a steer-by-wire system. That is, the turning angle of the steering wheel can be controlled independently of the steering state of the steering wheel. Further, the steering reaction force of the steering wheel can be controlled independently of the steered state of the steering wheel. Further, the steering wheel and the steering wheel are mechanically separated.
（構成）
　まず、自車両Ａの構成について図１を参照しながら説明する。
　運転者が操作するステアリングホイール１２にステアリング入力軸３０が連結する。そのステアリング入力軸３０には、ステアリングホイール１２の操舵角を検出するステアリングホイール角度センサ１を設ける。そのステアリングホイール角度センサ１は、検出した操舵角度信号を操舵用コントローラ１１（以下、「制御演算部１１」と称する場合がある）に出力する。
　上記ステアリング入力軸３０に、操舵トルクセンサ２を介して第１中間軸３１が連結する。操舵トルクセンサ２は、ステアリング入力軸３０に入力した操舵トルクを検出し、そのトルク信号を操舵用コントローラ１１に出力する。
　自車両Ａは反力制御部３を備える。反力制御部３は、操舵反力アクチュエータ３Ａと、操舵反力モータ角度センサ３Ｂと、反力電流検出部３Ｃと、反力モータ駆動部３Ｄとを備える。 (Constitution)
First, the configuration of the host vehicle A will be described with reference to FIG.
A steering input shaft 30 is connected to the steering wheel 12 operated by the driver. The steering input shaft 30 is provided with a steering wheel angle sensor 1 that detects the steering angle of the steering wheel 12. The steering wheel angle sensor 1 outputs the detected steering angle signal to a steering controller 11 (hereinafter sometimes referred to as “control calculation unit 11”).
A first intermediate shaft 31 is connected to the steering input shaft 30 via the steering torque sensor 2. The steering torque sensor 2 detects the steering torque input to the steering input shaft 30 and outputs the torque signal to the steering controller 11.
The own vehicle A includes a reaction force control unit 3. The reaction force control unit 3 includes a steering reaction force actuator 3A, a steering reaction force motor angle sensor 3B, a reaction force current detection unit 3C, and a reaction force motor drive unit 3D.
　上記第１中間軸３１に、操舵反力アクチュエータ３Ａが連結する。操舵反力アクチュエータ３Ａは、操舵用コントローラ１１からの指令に基づき操舵反力を第１中間軸３１に付加する。その操舵反力アクチュエータ３Ａの操舵反力モータに操舵反力モータ角度センサ３Ｂを設ける。操舵反力モータ角度センサ３Ｂは、操舵反力モータの回転角度位置を検出し、その検出信号を操舵用コントローラ１１に出力する。
　操舵反力アクチュエータ３Ａと、操舵反力モータ角度センサ３Ｂとで反力モータ４が構成される。反力モータ４は、減速機を介してステアリングシャフトと連結される。そして、反力モータ４は、反力モータ駆動部３Ｄによって駆動され、ステアリングシャフトを介してステアリングホイール１２に回転トルクを付与する。これにより、反力モータ４は、操舵反力を発生する。反力モータ４の駆動方法としては、例えば、反力モータ４を駆動する電流（以下、反力電流とも呼ぶ）を制御する方法を採用できる。 A steering reaction force actuator 3 </ b> A is connected to the first intermediate shaft 31. The steering reaction force actuator 3 </ b> A applies a steering reaction force to the first intermediate shaft 31 based on a command from the steering controller 11. A steering reaction force motor angle sensor 3B is provided in the steering reaction force motor of the steering reaction force actuator 3A. The steering reaction force motor angle sensor 3 </ b> B detects the rotational angle position of the steering reaction force motor and outputs the detection signal to the steering controller 11.
The reaction force motor 4 is configured by the steering reaction force actuator 3A and the steering reaction force motor angle sensor 3B. The reaction force motor 4 is connected to the steering shaft via a reduction gear. The reaction force motor 4 is driven by the reaction force motor drive unit 3D, and applies rotational torque to the steering wheel 12 via the steering shaft. Thereby, the reaction force motor 4 generates a steering reaction force. As a driving method of the reaction force motor 4, for example, a method of controlling a current for driving the reaction force motor 4 (hereinafter also referred to as reaction force current) can be employed.
　反力電流検出部３Ｃは、反力電流を検出する。そして、反力電流検出部３Ｃは、検出信号を反力モータ駆動部３Ｄおよび操舵用コントローラ１１に出力する。
　反力モータ駆動部３Ｄは、操舵用コントローラ１１が算出する目標反力電流に基づいて、反力電流検出部３Ｃが検出する反力電流が当該目標反力電流と一致するように反力モータ４の反力電流を制御する。これにより、反力モータ駆動部３Ｄは、反力モータ４を駆動する。目標反力電流とは、反力モータ４を駆動する電流の目標値をいう。
　上記第１中間軸３１に、メカニカルバックアップ装置１０を介して第２中間軸３２が連結する。メカニカルバックアップ装置１０は、通常状態では、第１中間軸３１と第２中間軸３２との間のトルク伝達を切った状態とする。また、メカニカルバックアップ装置１０は、操舵用コントローラ１１からの指令に基づき、第１中間軸３１と第２中間軸３２とを接続してトルク伝達を可能な状態とする。
　自車両Ａは転舵制御部５を備える。転舵制御部５は、転舵アクチュエータ５Ａと、転舵アクチュエータ角度センサ５Ｂと、転舵電流検出部５Ｃと、転舵モータ駆動部５Ｄとを備える。 The reaction force current detector 3C detects a reaction force current. The reaction force current detection unit 3C outputs a detection signal to the reaction force motor drive unit 3D and the steering controller 11.
Based on the target reaction force current calculated by the steering controller 11, the reaction force motor drive unit 3 </ b> D is configured so that the reaction force current detected by the reaction force current detection unit 3 </ b> C matches the target reaction force current. Controls the reaction force current. Thereby, the reaction force motor drive unit 3 </ b> D drives the reaction force motor 4. The target reaction force current is a target value of a current for driving the reaction force motor 4.
A second intermediate shaft 32 is connected to the first intermediate shaft 31 via the mechanical backup device 10. The mechanical backup device 10 is in a state in which torque transmission between the first intermediate shaft 31 and the second intermediate shaft 32 is cut off in a normal state. Further, the mechanical backup device 10 connects the first intermediate shaft 31 and the second intermediate shaft 32 based on a command from the steering controller 11 to enable torque transmission.
The host vehicle A includes a steering control unit 5. The turning control unit 5 includes a turning actuator 5A, a turning actuator angle sensor 5B, a turning current detection unit 5C, and a turning motor drive unit 5D.
　上記第２中間軸３２は、転舵トルクセンサ７を介してステアリング出力軸３３に連結している。また、上記第２中間軸３２に、転舵アクチュエータ５Ａが連結する。転舵アクチュエータ５Ａは、操舵用コントローラ１１からの指令に基づき第２中間軸３２を回動変位する。その転舵アクチュエータ５Ａの転舵用モータに転舵アクチュエータ角度センサ５Ｂを設ける。転舵アクチュエータ角度センサ５Ｂは、転舵アクチュエータ５Ａのモータの回転角度位置を検出し、その検出信号を操舵用コントローラ１１に出力する。
　転舵アクチュエータ５Ａと、転舵アクチュエータ角度センサ５Ｂとで、転舵モータ６が構成される。転舵モータ６は、減速機を介してピニオンシャフト５５と連結される。そして、転舵モータ６は、転舵モータ駆動部５Ｄによって駆動され、ピニオンシャフト５５を介してステアリングラック（以下、「ラック軸」と称する場合がある）３４を左右に移動させる。これにより、転舵モータ６は、前輪（以下、操向輪と称する場合がある）１３を転舵する。転舵モータ６の駆動方法としては、例えば、転舵モータ６を駆動する電流（以下、転舵電流とも呼ぶ）を制御する方法を採用できる。 The second intermediate shaft 32 is connected to the steering output shaft 33 via the steering torque sensor 7. Further, the steering actuator 5 </ b> A is connected to the second intermediate shaft 32. The steered actuator 5 </ b> A rotates and displaces the second intermediate shaft 32 based on a command from the steering controller 11. A steering actuator angle sensor 5B is provided in the steering motor of the steering actuator 5A. The turning actuator angle sensor 5 </ b> B detects the rotational angle position of the motor of the turning actuator 5 </ b> A and outputs the detection signal to the steering controller 11.
The steered motor 6 includes the steered actuator 5A and the steered actuator angle sensor 5B. The steered motor 6 is connected to the pinion shaft 55 via a speed reducer. The steered motor 6 is driven by the steered motor driving unit 5D and moves a steering rack (hereinafter also referred to as “rack shaft”) 34 to the left and right via the pinion shaft 55. Thereby, the steered motor 6 steers the front wheel (hereinafter, sometimes referred to as a steered wheel) 13. As a method for driving the steered motor 6, for example, a method of controlling a current for driving the steered motor 6 (hereinafter also referred to as a steered current) can be employed.
　転舵電流検出部５Ｃは、転舵電流（操向輪１３に作用するタイヤ横力Ｆｄで変動する自車両Ａの状態量）を検出する。そして、転舵電流検出部５Ｃは、検出信号を転舵モータ駆動部５Ｄおよび操舵用コントローラ１１に出力する。
　転舵モータ駆動部５Ｄは、操舵用コントローラ１１が算出する目標転舵電流に基づいて、転舵電流検出部５Ｃが検出する転舵電流が当該目標転舵電流と一致するように転舵モータ６の転舵電流を制御する。これにより、転舵モータ駆動部５Ｄは、転舵モータ６を駆動する。目標転舵電流とは、転舵モータ６を駆動する電流の目標値をいう。
　上記ステアリング出力軸３３は、ラックアンドピニオン機構を介してラック軸３４に連結する。すなわち、ステアリング出力軸３３に連結するピニオンシャフト５５がラック軸３４のラックに噛み合う。ラック軸３４は、車幅方向に軸を向けて配置してある。そして、ステアリング出力軸３３を回動変位させることで、ラック軸３４は車幅方向に向けて軸方向変位する。
　転舵角センサ８は、前輪１３の転舵角θを検出する。転舵角θの検出方法としては、例えば、ステアリングラックのラック移動量を基に算出する方法を採用できる。転舵角センサ８は、検出信号を操舵用コントローラ１１に出力する。 The steered current detection unit 5C detects a steered current (a state quantity of the host vehicle A that varies with the tire lateral force Fd acting on the steered wheels 13). The steered current detection unit 5C outputs a detection signal to the steered motor drive unit 5D and the steering controller 11.
The steered motor drive unit 5D, based on the target steered current calculated by the steering controller 11, turns the steered motor 6 so that the steered current detected by the steered current detector 5C matches the target steered current. Controls the steering current. Thereby, the steered motor driving unit 5D drives the steered motor 6. The target turning current refers to a target value of current for driving the turning motor 6.
The steering output shaft 33 is connected to the rack shaft 34 via a rack and pinion mechanism. That is, the pinion shaft 55 connected to the steering output shaft 33 is engaged with the rack of the rack shaft 34. The rack shaft 34 is disposed with its axis directed in the vehicle width direction. Then, by rotating the steering output shaft 33, the rack shaft 34 is displaced in the axial direction toward the vehicle width direction.
The turning angle sensor 8 detects the turning angle θ of the front wheels 13. As a method of detecting the turning angle θ, for example, a method of calculating based on the amount of movement of the steering rack can be employed. The turning angle sensor 8 outputs a detection signal to the steering controller 11.
　上記ラック軸３４の左右端部は、それぞれ左右のタイロッド３５およびナックルアーム３６を介してナックル（不図示）に連結する。ナックルアーム３６は当該ナックルから突出しており、操向輪である前輪１３を回転自在に支持する。上記タイロッド３５にタイロッド軸力センサ９を設ける。タイロッド軸力センサ９は、タイロッド３５の軸力を検出し、その検出信号を操舵用コントローラ１１に出力する。
　また、自車両Ａは自車両状態検出部１４を備える。自車両状態検出部１４は、車速センサ１４Ａ、横Ｇセンサ１４Ｂ及びヨーレートセンサ１４Ｃを備える。車速センサ１４Ａは、自車両Ａの車速Ｖを検出する。横Ｇセンサ１４Ｂは、自車両Ａの横方向加速度Ｇｙ（操向輪１３に作用するタイヤ横力Ｆｄで変動する自車両Ａの状態量）を検出する。ヨーレートセンサ１４Ｃは、自車両Ａのヨーレートγ（操向輪１３に作用するタイヤ横力Ｆｄで変動する自車両Ａの状態量）を検出する。 The left and right end portions of the rack shaft 34 are connected to a knuckle (not shown) via left and right tie rods 35 and a knuckle arm 36, respectively. The knuckle arm 36 protrudes from the knuckle and rotatably supports the front wheel 13 which is a steering wheel. The tie rod axial force sensor 9 is provided on the tie rod 35. The tie rod axial force sensor 9 detects the axial force of the tie rod 35 and outputs a detection signal to the steering controller 11.
The host vehicle A also includes a host vehicle state detection unit 14. The own vehicle state detection unit 14 includes a vehicle speed sensor 14A, a lateral G sensor 14B, and a yaw rate sensor 14C. The vehicle speed sensor 14A detects the vehicle speed V of the host vehicle A. The lateral G sensor 14B detects the lateral acceleration Gy of the host vehicle A (the amount of state of the host vehicle A that varies with the tire lateral force Fd acting on the steered wheel 13). The yaw rate sensor 14C detects the yaw rate γ of the host vehicle A (the state amount of the host vehicle A that varies with the tire lateral force Fd acting on the steering wheel 13).
　自車両状態検出部１４は、車速センサ１４Ａ、横Ｇセンサ１４Ｂ及びヨーレートセンサ１４Ｃにおいてそれぞれ検出した検出信号を自車両状態パラメータとして操舵用コントローラ１１に出力する。なお、自車両状態検出部１４は、走行路面の摩擦係数推定値を検出する路面摩擦係数推定部を備えていてもよい。
　操舵用コントローラ１１は、車線維持支援コントローラ１５からの指令に基づき、転舵指令値となるように転舵アクチュエータ５Ａを制御すると共に、操舵反力を付与するための指令値となるように操舵反力アクチュエータ３Ａを制御する。
　また、自車両Ａは、前輪１３及び後輪４０の各車輪にブレーキユニットを備える。各ブレーキユニットは、ブレーキディスク２２と、液圧の供給によりブレーキディスク２２を摩擦挟持してブレーキ力（制動力）を与えるホイルシリンダ２３とを備える。これらブレーキユニットの各ホイルシリンダ２３に、圧力制御ユニット２４が連結し、圧力制御ユニット２４から供給した液圧によって、ブレーキユニットは各車輪に対し個別に制動を付加する。 The own vehicle state detection unit 14 outputs detection signals detected by the vehicle speed sensor 14A, the lateral G sensor 14B, and the yaw rate sensor 14C to the steering controller 11 as own vehicle state parameters. In addition, the own vehicle state detection part 14 may be provided with the road surface friction coefficient estimation part which detects the friction coefficient estimated value of a driving | running | working road surface.
The steering controller 11 controls the steering actuator 5A so as to obtain a steering command value based on a command from the lane keeping support controller 15, and also performs a steering reaction so as to obtain a command value for applying a steering reaction force. The force actuator 3A is controlled.
In addition, the host vehicle A includes a brake unit on each wheel of the front wheel 13 and the rear wheel 40. Each brake unit includes a brake disk 22 and a wheel cylinder 23 that frictionally clamps the brake disk 22 to supply a braking force (braking force) by supplying hydraulic pressure. A pressure control unit 24 is connected to each wheel cylinder 23 of these brake units, and the brake unit individually applies braking to each wheel by the hydraulic pressure supplied from the pressure control unit 24.
　図１に示すように、自車両Ａに備えられた車線維持支援装置５０は外界認識部１６と、車線維持支援コントローラ１５とを有している。外界認識部１６は、例えば画像処理機能付き単眼カメラで構成する。画像処理機能付き単眼カメラは自車両Ａの位置を検出する。画像処理機能付き単眼カメラは、自車両Ａ前方の路面を撮像する。その撮像したカメラ画像から路面の状態を判断し、自車が走行する走行車線内の自車両の位置に関する信号を、車線維持支援コントローラ１５に出力する。走行車線内の自車両の位置に関する信号は、走行車線に対する自車両の進行方向の角度偏差であるヨー角φ、走行車線中央からの横変位Ｘ、及び走行車線の曲率ρに関する情報である。
　また、自車両Ａは方向指示スイッチ１７を備える。方向指示スイッチ１７の信号は、運転者が走行車線を変更するか否かの判断情報として、車線維持支援コントローラ１５に出力する。
　また、車線維持支援コントローラ１５は、操舵用コントローラ１１から、現在のステアの状態やタイヤの操舵状態などの信号を入力する。
　車線維持支援コントローラ１５は、入力した信号に基づき自車両を走行車線に維持させるための制御量を算出して、例えば最終目標補正操舵反力τＹ＊、補正操舵反力中心値ΔＴｓｃ及び最終目標補正転舵角θＹ＊を少なくとも上記操舵用コントローラ１１に出力する。 As shown in FIG. 1, the lane keeping assist device 50 provided in the host vehicle A includes an outside recognition unit 16 and a lane keeping assist controller 15. The external recognition unit 16 is configured by a monocular camera with an image processing function, for example. The monocular camera with an image processing function detects the position of the vehicle A. The monocular camera with an image processing function images the road surface ahead of the host vehicle A. The state of the road surface is determined from the captured camera image, and a signal related to the position of the host vehicle in the travel lane on which the host vehicle travels is output to the lane keeping support controller 15. The signal relating to the position of the host vehicle in the travel lane is information regarding the yaw angle φ, which is the angular deviation of the travel direction of the host vehicle with respect to the travel lane, the lateral displacement X from the center of the travel lane, and the curvature ρ of the travel lane.
The host vehicle A also includes a direction indicating switch 17. A signal from the direction indicating switch 17 is output to the lane keeping support controller 15 as determination information as to whether or not the driver changes the driving lane.
Further, the lane keeping support controller 15 receives signals from the steering controller 11 such as the current steering state and tire steering state.
The lane keeping support controller 15 calculates a control amount for keeping the host vehicle in the traveling lane based on the input signal, and for example, the final target corrected steering reaction force τY *, the corrected steering reaction force central value ΔTsc, and the final target correction. The turning angle θY * is output to at least the steering controller 11.
　次に、自車両Ａに備えられた操舵用コントローラ１１（制御演算部１１）について図２から図３０を用いて説明する。
　図２は、制御演算部１１の構成を表すブロック図である。なお、図２では、理解を容易にするため、車線維持支援装置５０に備えられた外界視認部１６及び車線維持支援コントローラ１５が併せて図示されている。
　図２に示すように、制御演算部１１は、目標転舵角演算部１１Ａ、目標反力電流算出部１１Ｂ、および目標転舵電流演算部１１Ｃを備える。
　目標転舵角演算部１１Ａは、ステアリングホイール角度センサ１が検出した操舵角δと、車速センサ１４Ａが検出した車速Ｖと、車線維持支援コントローラ１５に設けられた補正転舵角演算部１５Ｃが演算した最終目標補正転舵角θＹ＊とに基づいて、転舵角θ（ピニオンシャフト５５の回転角）の目標値である目標転舵角θ＊を算出する。目標転舵角演算部１１Ａは、転舵指令角演算部１１Ａａと、加算器１１Ａｂとを有している。転舵指令角演算部１１Ａａはステアリングホイール角度センサ１が検出した操舵角δ及び車速センサ１４Ａが検出した車速Ｖに基づいて転舵指令角を演算するようになっている。加算器１１Ａｂは当該転舵指令角に最終目標補正転舵角θＹ＊を加算するようになっている。これにより、目標転舵角演算部１１Ａは目標転舵角θ＊を算出するようになっている。転舵指令角の算出方法としては、例えば、操舵角δと、操舵角δおよび転舵角θの可変ギア比との乗算値を採用する方法がある。なお、最終目標補正転舵角θＹ＊の算出方法は後述する。目標転舵角演算部１１Ａは、算出結果を目標反力電流算出部１１Ｂに出力する。 Next, the steering controller 11 (control calculation unit 11) provided in the host vehicle A will be described with reference to FIGS.
FIG. 2 is a block diagram illustrating the configuration of the control calculation unit 11. In FIG. 2, for easy understanding, the external world visual recognition unit 16 and the lane keeping assist controller 15 provided in the lane keeping assist device 50 are illustrated together.
As shown in FIG. 2, the control calculation unit 11 includes a target turning angle calculation unit 11A, a target reaction force current calculation unit 11B, and a target turning current calculation unit 11C.
The target turning angle calculation unit 11A is calculated by the steering angle δ detected by the steering wheel angle sensor 1, the vehicle speed V detected by the vehicle speed sensor 14A, and the corrected turning angle calculation unit 15C provided in the lane keeping support controller 15. Based on the final target corrected turning angle θY *, a target turning angle θ * that is a target value of the turning angle θ (the rotation angle of the pinion shaft 55) is calculated. The target turning angle calculation unit 11A includes a turning command angle calculation unit 11Aa and an adder 11Ab. The steering command angle calculation unit 11Aa calculates a steering command angle based on the steering angle δ detected by the steering wheel angle sensor 1 and the vehicle speed V detected by the vehicle speed sensor 14A. The adder 11Ab adds the final target corrected turning angle θY * to the turning command angle. Thus, the target turning angle calculation unit 11A calculates the target turning angle θ *. As a calculation method of the turning command angle, for example, there is a method of adopting a multiplication value of the steering angle δ and the variable gear ratio of the steering angle δ and the turning angle θ. A method for calculating the final target correction turning angle θY * will be described later. The target turning angle calculation unit 11A outputs the calculation result to the target reaction force current calculation unit 11B.
　目標反力電流算出部１１Ｂは、目標転舵角演算部１１Ａが算出した目標転舵角θ＊と、車速センサ１４Ａが検出した車速Ｖと、転舵電流検出部５Ｃが検出した転舵電流と、補正操舵反力演算部１５Ａが演算した最終目標補正操舵反力τＹ＊と、補正操舵反力中心演算部１５Ｂが演算した補正操舵反力中心値ΔＴｓｃとに基づいて目標反力電流を算出する。最終目標補正操舵反力τＹ＊及び補正操舵反力中心値ΔＴｓｃの算出方法は後述する。目標反力電流算出部１１Ｂは、算出結果を反力制御部３（反力モータ駆動部３Ｄ）に出力する。 The target reaction force current calculation unit 11B includes the target turning angle θ * calculated by the target turning angle calculation unit 11A, the vehicle speed V detected by the vehicle speed sensor 14A, and the turning current detected by the turning current detection unit 5C. The target reaction force current is calculated based on the final target correction steering reaction force τY * calculated by the correction steering reaction force calculation unit 15A and the correction steering reaction force center value ΔTsc calculated by the correction steering reaction force center calculation unit 15B. . A method of calculating the final target corrected steering reaction force τY * and the corrected steering reaction force central value ΔTsc will be described later. The target reaction force current calculation unit 11B outputs the calculation result to the reaction force control unit 3 (reaction force motor drive unit 3D).
　ここで、目標反力電流算出部１１Ｂの構成を説明する。
　図３は、目標反力電流算出部１１Ｂの構成を表すブロック図である。
　図３に示すように、目標反力電流算出部１１Ｂは、フィードフォワード軸力算出部１１Ｂａ、フィードバック軸力算出部１１Ｂｂ、軸力切替出力部１１Ｂｆ、最終軸力算出部１１Ｂｃ、軸力－操舵反力変換部１１Ｂｄ、および目標反力電流演算部１１Ｂｅを備える。
　図４は、フィードフォワード軸力算出部１１Ｂａの構成を表すブロック図である。
　図４に示すように、フィードフォワード軸力算出部１１Ｂａは、ステアリングホイール角度センサ１が検出した操舵角δ、および車速センサ１４Ａが検出した車速Ｖに基づき、後述する（５）式に従ってフィードフォワード軸力ＴＦＦを算出する。そして、フィードフォワード軸力算出部１１Ｂａは、算出結果を最終軸力算出部１１Ｂｃ（図２参照）に出力する。 Here, the configuration of the target reaction force current calculation unit 11B will be described.
FIG. 3 is a block diagram illustrating a configuration of the target reaction force current calculation unit 11B.
As shown in FIG. 3, the target reaction force current calculation unit 11B includes a feedforward axial force calculation unit 11Ba, a feedback axial force calculation unit 11Bb, an axial force switching output unit 11Bf, a final axial force calculation unit 11Bc, an axial force-steering reaction counter A force conversion unit 11Bd and a target reaction force current calculation unit 11Be are provided.
FIG. 4 is a block diagram illustrating the configuration of the feedforward axial force calculation unit 11Ba.
As shown in FIG. 4, the feedforward axial force calculation unit 11Ba is based on the steering angle δ detected by the steering wheel angle sensor 1 and the vehicle speed V detected by the vehicle speed sensor 14A according to the equation (5) described later. The force T FF is calculated. And feedforward axial force calculation part 11Ba outputs a calculation result to final axial force calculation part 11Bc (refer FIG. 2).
　図５は、ピニオン軸力Ｔｈの算出式の係数を説明するための図である。
　ここで、転舵ピニオン角Θとピニオン軸力Ｔｈとの関係式は、ステアリングホイール１２と操向輪１３とが機械的に接続している操舵機構を備える車両の運動方程式を基に下記（１）式で表される。転舵ピニオン角Θとしては、例えば、ピニオンシャフト５５の回転角がある。具体的には、転舵ピニオン角Θは、操舵角δと、操舵角δおよび転舵角θとの間の可変ギア比との乗算値とする。また、ピニオン軸力Ｔｈとしては、例えば、ステアリングホイール１２に付与される操舵反力がある。下記（１）式の右辺第１項は、ピニオン軸力Ｔｈを構成する成分のうち、転舵ピニオン角速度ｄΘ／ｄｔに基づく成分を表すダンピング項である。また、右辺第２項は、ピニオン軸力Ｔｈを構成する成分のうち、転舵ピニオン角加速度ｄ２Θ／ｄｔ２に基づく成分を表す慣性項である。さらに、右辺第３項は、ピニオン軸力Ｔｈを構成する成分のうち、タイヤ横力Ｆｄ（転舵ピニオン角Θ）に基づく成分を表す比例項である。
　Ｔｈ＝Ｋｓ（Ｊｒｓ２＋Ｃｒ・ｓ）／（Ｊｒ・ｓ２＋（Ｃｒ＋Ｃｓ）ｓ＋Ｋｓ）・Θ＋Ｃｓ（Ｊｒｓ３＋Ｃｒ・ｓ２）／（Ｊｒ・ｓ２＋（Ｃｒ＋Ｃｓ）ｓ＋Ｋｓ）・Θ＋（Ｋｓ＋Ｃｓ・ｓ）／（Ｊｒ・ｓ２＋（Ｃｒ＋Ｃｓ）ｓ＋Ｋｓ）・Ｆｄ　・・・（１）
　ただし、図５に示すように、Ｋｓはピニオン剛性、Ｃｓはピニオン粘性、Ｊｒはラック慣性、Ｃｒはラック粘性である。 FIG. 5 is a diagram for explaining the coefficients of the calculation formula for the pinion axial force Th.
Here, the relational expression between the turning pinion angle Θ and the pinion axial force Th is based on the following equation (1) based on the equation of motion of a vehicle including a steering mechanism in which the steering wheel 12 and the steered wheel 13 are mechanically connected. ) Expression. As the steered pinion angle Θ, for example, there is a rotation angle of the pinion shaft 55. Specifically, the turning pinion angle Θ is a multiplication value of the steering angle δ and the variable gear ratio between the steering angle δ and the turning angle θ. Further, as the pinion axial force Th, for example, there is a steering reaction force applied to the steering wheel 12. The first term on the right side of the following equation (1) is a damping term representing a component based on the steered pinion angular velocity dΘ / dt among the components constituting the pinion axial force Th. The second term on the right side is an inertia term representing a component based on the steered pinion angular acceleration d 2 Θ / dt 2 among the components constituting the pinion axial force Th. Further, the third term on the right side is a proportional term representing a component based on the tire lateral force Fd (steering pinion angle Θ) among the components constituting the pinion axial force Th.
Th = Ks (Jrs 2 + Cr · s) / (Jr · s 2 + (Cr + Cs) s + Ks) · Θ + Cs (Jrs 3 + Cr · s 2 ) / (Jr · s 2 + (Cr + Cs) s + Ks) · Θ + (Ks + Cs · s) ) / (Jr · s 2 + (Cr + Cs) s + Ks) · Fd (1)
However, as shown in FIG. 5, Ks is pinion rigidity, Cs is pinion viscosity, Jr is rack inertia, and Cr is rack viscosity.
　また、上記（１）式では、右辺第２項、つまり、慣性項は、ノイズ成分を多く含み、ピニオン軸力Ｔｈの算出結果に振動を誘発するため除くのが好ましい。さらに、タイヤ横力Ｆｄは、転舵ピニオン角Θおよび車速Ｖに依存するものとして、Ｆｄ＝ｆ（Ｖ）・Θと表すことができる。ｆ（Ｖ）としては、例えば、車速Ｖに応じて変化する関数がある。それゆえ、上記（１）式は、下記（２）式のように表すことができる。
　Ｔｈ＝Ｋｓ（Ｊｒｓ２＋Ｃｒ・ｓ）／（Ｊｒ・ｓ２＋（Ｃｒ＋Ｃｓ）ｓ＋Ｋｓ）・Θ＋（Ｋｓ＋Ｃｓ・ｓ）／（Ｊｒ・ｓ２＋（Ｃｒ＋Ｃｓ）ｓ＋Ｋｓ）・ｆ（Ｖ）・Θ　・・・（２） In the above equation (1), the second term on the right side, that is, the inertia term, contains a lot of noise components, and is preferably excluded because it induces vibration in the calculation result of the pinion axial force Th. Further, the tire lateral force Fd can be expressed as Fd = f (V) · Θ depending on the turning pinion angle Θ and the vehicle speed V. As f (V), for example, there is a function that changes according to the vehicle speed V. Therefore, the above equation (1) can be expressed as the following equation (2).
Th = Ks (Jrs 2 + Cr · s) / (Jr · s 2 + (Cr + Cs) s + Ks) · Θ + (Ks + Cs · s) / (Jr · s 2 + (Cr + Cs) s + Ks) · f (V) · Θ (2)
　図６は、制御マップＭ１を表すグラフである。
　ここで、変数ｆ（Ｖ）の設定方法としては、例えば、車速Ｖの絶対値に対応した変数ｆ（Ｖ）を制御マップＭ１から読み出す方法を採用できる。制御マップＭ１としては、例えば、車速Ｖの絶対値に対応した変数ｆ（Ｖ）を登録したマップがある。具体的には、図６に示すように、制御マップＭ１は、車速Ｖの絶対値が０である場合に変数ｆ（Ｖ）を第１設定値（例えば、０．０）に設定する。また、車速Ｖの絶対値が第１設定車速Ｖ１（＞０）以上の範囲では、車速Ｖの大きさにかかわらず変数ｆ（Ｖ）を第２設定値（＞第１設定値。例えば、１．０）に設定する。さらに、制御マップＭ１は、車速Ｖの絶対値が０以上で且つ第１設定車速Ｖ１未満の範囲では、転舵角速度ｄθ／ｄｔの絶対値に応じて変数ｆ（Ｖ）を直線的に増加させる。具体的には、制御マップＭ１は、車速Ｖの絶対値が０以上で且つ第１設定車速Ｖ１未満の範囲では、車速Ｖの絶対値と変数ｆ（Ｖ）との関係を表す一次関数に従って変数ｆ（Ｖ）を設定する。一次関数は、車速Ｖの絶対値が０である場合に変数ｆ（Ｖ）を第１設定値（０．０）とし、車速Ｖの絶対値が第１設定車速Ｖ１である場合に変数ｆ（Ｖ）を第２設定値（１．０）とする。これにより、フィードフォワード軸力算出部１１Ｂａは、車速Ｖの絶対値が第１設定車速Ｖ１未満である場合には、車速Ｖの絶対値が小さいほど比例成分の絶対値を小さくする（低減する）。また、フィードフォワード軸力算出部１１Ｂａは、車速Ｖの絶対値が第１設定車速Ｖ１以上である場合には、車速Ｖの大きさにかかわらず、比例成分の絶対値の低減を行わない。 FIG. 6 is a graph showing the control map M1.
Here, as a method of setting the variable f (V), for example, a method of reading the variable f (V) corresponding to the absolute value of the vehicle speed V from the control map M1 can be adopted. An example of the control map M1 is a map in which a variable f (V) corresponding to the absolute value of the vehicle speed V is registered. Specifically, as shown in FIG. 6, when the absolute value of the vehicle speed V is 0, the control map M1 sets the variable f (V) to a first set value (for example, 0.0). Further, in the range where the absolute value of the vehicle speed V is equal to or higher than the first set vehicle speed V 1 (> 0), the variable f (V) is set to the second set value (> first set value, regardless of the magnitude of the vehicle speed V. For example, 1.0). Further, the control map M1 is a absolute value and a first predetermined vehicle speed V 1 lower than the range from 0 or more of the vehicle speed V is increased linearly variable f (V) in accordance with the absolute value of the steering angular velocity d [theta] / dt Let Specifically, the control map M1 is a absolute value and a first predetermined vehicle speed V 1 lower than the range from 0 or more of the vehicle speed V, according to a linear function representing the relationship between the absolute value and the variable f of the vehicle speed V (V) Set variable f (V). The linear function sets the variable f (V) to the first set value (0.0) when the absolute value of the vehicle speed V is 0, and sets the variable f (V) when the absolute value of the vehicle speed V is the first set vehicle speed V1. Let V) be the second set value (1.0). Thus, feedforward axial force calculating unit 11Ba the absolute value of the vehicle speed V is in the case of the first less than the set vehicle speed V 1 decreases the absolute value of the more proportional component having a small absolute value of the vehicle speed V (reduced ). Further, the feedforward axial force calculating unit 11Ba, when the absolute value of the vehicle speed V is first set vehicle speed V 1 or more, regardless of the size of the vehicle speed V, is not performed to reduce the absolute value of the proportional component.
　また、上記（２）式は、等価的に、下記（３）式のように表すことができる。
　Ｔｈ＝Ｐ（ｓ＋２・ζ・ωｎ）ｓ／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）δ＋Ｉ・（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）・ｆ（Ｖ）・δ
　　　＝Ｐ（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）ｄδ／ｄｔ＋Ｉ・（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）・ｆ（Ｖ）・δ　・・・（３）
　ただし、Ｐ、Ｉは制御定数、ζは減衰係数、ωｎは固有振動数である。ζ、ωｎの設定方法としては、例えば、設計値とする方法や、実験結果から同定する方法を採用できる。
　そのため、ピニオン軸力Ｔｈ、つまり、ステアリングホイール１２に発生する操舵反力は、上記（３）式を基に下記（４）式で表すことができる。
　Ｔｈ＝Ｐ（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）ｄδ／ｄｔ＋Ｉ・（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）・ｆ（Ｖ）・δ　・・・（４） The above equation (2) can be equivalently expressed as the following equation (3).
Th = P (s + 2 · ζ · ωn) s / (s 2 + 2 · ζ · ωn · s + ωn 2 ) δ + I · (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) · f (V ) ・ Δ
= P (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) dδ / dt + I · (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) · f (V ) · Δ (3)
However, P and I are control constants, ζ is a damping coefficient, and ωn is a natural frequency. As a method for setting ζ and ωn, for example, a method of setting a design value or a method of identifying from experimental results can be adopted.
Therefore, the pinion axial force Th, that is, the steering reaction force generated in the steering wheel 12 can be expressed by the following equation (4) based on the above equation (3).
Th = P (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) dδ / dt + I · (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) · f ( V) · δ (4)
　そして、上記（４）式、つまり、ピニオン軸力Ｔｈの数式を基に、本実施形態のフィードフォワード軸力ＴＦＦの算出方法としては、下記（５）式を採用する。
　ＴＦＦ＝Ｐ・Ｐ１・Ｐ２（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）ｄδ／ｄｔ＋Ｉ・（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）・ｆ（Ｖ）・δ＋補正用ダンピング成分
　　　＝ダンピング成分・Ｐ１・Ｐ２＋比例成分＋補正用ダンピング成分　・・・（５）
　ただし、ダンピング成分はＰ（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）ｄδ／ｄｔ、比例成分はＩ・（ｓ＋２・ζ・ωｎ）／（ｓ２＋２・ζ・ωｎ・ｓ＋ωｎ２）・ｆ（Ｖ）・δである。また、補正用ダンピング成分は、操舵角速度ｄδ／ｄｔに基づくダンピング成分であり、操舵角速度ｄδ／ｄｔと反対方向に操舵反力を発生させるものである。 Then, equation (4), that is, based on a formula of the pinion shaft force Th, as a method of calculating the feedforward axial force T FF of the present embodiment employs the following equation (5).
T FF = P · P 1 · P 2 (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) dδ / dt + I · (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · S + ωn 2 ) · f (V) · δ + correction damping component = damping component · P 1 · P 2 + proportional component + correction damping component (5)
However, the damping component is P (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) dδ / dt, and the proportional component is I · (s + 2 · ζ · ωn) / (s 2 + 2 · ζ · ωn · s + ωn 2 ) · f (V) · δ. The correction damping component is a damping component based on the steering angular velocity dδ / dt, and generates a steering reaction force in a direction opposite to the steering angular velocity dδ / dt.
　図７は、制御マップＭ２を表すグラフである。
　ここで、ゲインＰ１の設定方法としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応したゲインＰ１を制御マップＭ２から読み出す方法を採用できる。制御マップＭ２としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応したゲインＰ１を登録したマップがある。具体的には、図７に示すように、制御マップＭ２は、操舵角速度ｄδ／ｄｔが０である場合にゲインＰ１を第３設定値（例えば、１．０）に設定する。また、操舵角速度ｄδ／ｄｔの絶対値が第１設定操舵角速度ｄδ１／ｄｔ（＞０）以上の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらずゲインＰ１を第４設定値（＜第３設定値。例えば、０．５）に設定する。さらに、制御マップＭ２は、操舵角速度ｄδ／ｄｔの絶対値が０以上で且つ第１設定操舵角速度ｄδ１／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値に応じてゲインＰ１を直線的に低下させる。具体的には、制御マップＭ２は、操舵角速度ｄδ／ｄｔの絶対値が０以上で且つ第１設定操舵角速度ｄδ１／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値とゲインＰ１との関係を表す一次関数に従ってゲインＰ１を設定する。一次関数は、操舵角速度ｄδ／ｄｔが０である場合にゲインＰ１を第３設定値（１．０）とし、操舵角速度ｄδ／ｄｔの絶対値が第１設定操舵角速度ｄδ１／ｄｔである場合にゲインＰ１を第４設定値（０．５）とする。これにより、フィードフォワード軸力算出部１１Ｂａは、操舵角速度ｄδ／ｄｔの絶対値が第１設定操舵角速度ｄδ１／ｄｔ未満である場合には、操舵角速度ｄδ／ｄｔの絶対値が大きいほどダンピング成分の絶対値を小さくする（補正する）。また、フィードフォワード軸力算出部１１Ｂａは、操舵角速度ｄδ／ｄｔの絶対値が第１設定操舵角速度ｄδ１／ｄｔ以上である場合には、操舵角速度ｄδ／ｄｔの大きさにかかわらず、ゲインＰ１に基づくダンピング成分の絶対値の補正を行わない。 FIG. 7 is a graph showing the control map M2.
Here, as a method of setting the gain P 1 is, for example, can be employed a method of reading a gain P 1 corresponding to the absolute value of the steering angular velocity d? / Dt from the control map M2. The control map M2, for example, there is a map that has registered the gain P 1 corresponding to the absolute value of the steering angular velocity d? / Dt. Specifically, as shown in FIG. 7, the control map M2 is set to the gain P 1 third set value when the steering angular velocity d? / Dt is zero (e.g., 1.0). In the range where the absolute value of the steering angular velocity dδ / dt is equal to or higher than the first set steering angular velocity dδ 1 / dt (> 0), the gain P 1 is set to the fourth set value (< The third set value is set to 0.5, for example. Further, the control map M2, in absolute value and the first set steering angular velocity d? A range of less than 1 / dt greater than 0 steering angular velocity d? / Dt, linear gain P 1 in accordance with the absolute value of the steering angular velocity d? / Dt Decrease. Specifically, the control map M2, in absolute value range and less than the first set steering angular speed d? 1 / dt greater than 0 steering angular velocity d? / Dt, the absolute value of the steering angular velocity d? / Dt and the gain P 1 It sets the gain P 1 according to a linear function representing the relationship. The primary function of the gain P 1 when the steering angular velocity d? / Dt is zero and the third set value (1.0), the absolute value of the steering angular velocity d? / Dt is the first set steering angular speed d? 1 / dt and the gain P 1 fourth set value (0.5) in the case. Thereby, when the absolute value of the steering angular velocity dδ / dt is less than the first set steering angular velocity dδ 1 / dt, the feedforward axial force calculation unit 11Ba increases the damping component as the absolute value of the steering angular velocity dδ / dt increases. Decrease (correct) the absolute value of. Further, when the absolute value of the steering angular velocity dδ / dt is greater than or equal to the first set steering angular velocity dδ 1 / dt, the feedforward axial force calculation unit 11Ba has a gain P regardless of the magnitude of the steering angular velocity dδ / dt. The absolute value of the damping component based on 1 is not corrected.
　図８は、操舵角δと操舵反力との関係を表すグラフである。このグラフは、操舵制御装置毎（ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置、およびダンピング成分の飽和を考慮していないステアリング・バイ・ワイヤ方式の操舵制御装置毎）に示されている。機械式の操舵制御装置では、操舵角速度ｄδ／ｄｔの増大に伴い、操舵反力に含まれるダンピング成分が飽和する。それゆえ、機械式の操舵制御装置では、図８に示すように、ダンピング成分が飽和することで、操舵角速度ｄδ／ｄｔの大きさにかかわらず、操舵角δと操舵反力とからなるリサジュー図形の形状が一定となる。しかしながら、操舵反力に含まれるダンピング成分の飽和を考慮していないステア・バイ・ワイヤ方式の操舵制御装置では、操舵角速度ｄδ／ｄｔの増大に応じて操舵反力が増大し続ける。これに対し、本実施形態の制御演算部１１は、操舵角速度ｄδ／ｄｔの絶対値が大きいほどダンピング成分の絶対値を小さくする。それゆえ、本実施形態の制御演算部１１は、操舵角速度ｄδ／ｄｔが大きい場合に、ダンピング成分の絶対値の増大を抑制できる。そのため、本実施形態の制御演算部１１は、ダンピング成分が過剰となることを抑制できる。これにより、本実施形態の制御演算部１１は、より適切な操舵感を付与できる。 FIG. 8 is a graph showing the relationship between the steering angle δ and the steering reaction force. This graph shows each steering control device (a mechanical steering control device in which the steering wheel 12 and the steering wheel 13 are mechanically coupled, and a steering-by-wire method that does not consider saturation of the damping component). For each steering control device). In the mechanical steering control device, as the steering angular velocity dδ / dt increases, the damping component included in the steering reaction force is saturated. Therefore, in the mechanical steering control device, as shown in FIG. 8, when the damping component is saturated, the Lissajous figure composed of the steering angle δ and the steering reaction force regardless of the magnitude of the steering angular velocity dδ / dt. The shape of is constant. However, in a steer-by-wire steering control device that does not consider saturation of the damping component included in the steering reaction force, the steering reaction force continues to increase as the steering angular velocity dδ / dt increases. In contrast, the control calculation unit 11 of the present embodiment decreases the absolute value of the damping component as the absolute value of the steering angular velocity dδ / dt increases. Therefore, the control calculation unit 11 of the present embodiment can suppress an increase in the absolute value of the damping component when the steering angular velocity dδ / dt is large. Therefore, the control calculation part 11 of this embodiment can suppress that a damping component becomes excessive. Thereby, the control calculating part 11 of this embodiment can provide a more suitable steering feeling.
　図９は、制御マップＭ３を表すグラフである。
　また、ゲインＰ２の設定方法としては、例えば、車速Ｖの絶対値に対応したゲインＰ２を制御マップＭ３から読み出す方法を採用できる。制御マップＭ３としては、例えば、車速Ｖの絶対値に対応したゲインＰ２を登録したマップがある。具体的には、図９に示すように、制御マップＭ３は、車速Ｖの絶対値が０である場合にゲインＰ２を第５設定値（例えば、０．５）に設定する。また、車速Ｖの絶対値が第２設定車速Ｖ２（＞０）以上の範囲では、車速Ｖの大きさにかかわらずゲインＰ２を第６設定値（＞第５設定値。例えば、１．０）に設定する。さらに、制御マップＭ３は、車速Ｖの絶対値が０以上で且つ第２設定車速Ｖ２未満の範囲では、車速Ｖの絶対値に応じてゲインＰ２を直線的に増加させる。具体的には、制御マップＭ３は、車速Ｖの絶対値が０以上で且つ第２設定車速Ｖ２未満の範囲では、車速Ｖの絶対値とゲインＰ２との関係を表す一次関数に従ってゲインＰ２を設定する。一次関数は、車速Ｖの絶対値が０である場合にゲインＰ２を第５設定値（０．５）とし、車速Ｖの絶対値が第２設定車速Ｖ２である場合にゲインＰ２を第６設定値（１．０）とする。これにより、フィードフォワード軸力算出部１１Ｂａは、車速Ｖの絶対値が第２設定車速Ｖ２未満である場合には、車速Ｖの絶対値が小さいほどダンピング成分の絶対値を小さくする（補正する）。また、フィードフォワード軸力算出部１１Ｂａは、車速Ｖの絶対値が第２設定車速Ｖ２以上である場合には、車速Ｖの大きさにかかわらず、ゲインＰ２に基づくダンピング成分の絶対値の補正を行わない。 FIG. 9 is a graph showing the control map M3.
Further, as a method of setting the gain P 2, for example, it can be employed a method of reading a gain P 2 corresponding to the absolute value of the vehicle speed V from the control map M3. The control map M3, for example, there is a map that has registered the gain P 2 corresponding to the absolute value of the vehicle speed V. Specifically, as shown in FIG. 9, the control map M3 is the gain P 2 fifth set value when the absolute value of the vehicle speed V is zero (e.g., 0.5) is set to. Further, in the range where the absolute value of the vehicle speed V is equal to or higher than the second set vehicle speed V 2 (> 0), the gain P 2 is set to the sixth set value (> 5th set value regardless of the magnitude of the vehicle speed V. For example, 1. Set to 0). Further, the control map M3 is the absolute value and the second predetermined vehicle speed V 2 less than the range from 0 or more of the vehicle speed V is linearly increasing gain P 2 in accordance with the absolute value of the vehicle speed V. Specifically, the control map M3 is the absolute value and the second predetermined vehicle speed V 2 less than the range from 0 or more of the vehicle speed V, the gain P according to a linear function representing the relationship between the absolute value and the gain P 2 of the vehicle speed V 2 is set. Linear function, when the absolute value of the vehicle speed V is zero the gain P 2 fifth set value and (0.5), when the absolute value of the vehicle speed V is a second set speed V 2 of the gain P 2 The sixth set value (1.0) is assumed. Thus, feedforward axial force calculating unit 11Ba the absolute value of the vehicle speed V is in the case of the second lower than the set vehicle speed V 2, the smaller the absolute value of the more damping component having a small absolute value of the vehicle speed V (corrected ). Further, the feedforward axial force calculating unit 11Ba, when the absolute value of the vehicle speed V is a second set speed V 2 or greater, regardless of the size of the vehicle speed V, the absolute value of the damping component based on the gain P 2 Do not make corrections.
　本実施形態の制御演算部１１は、車速Ｖの絶対値が小さいほどダンピング成分の絶対値を小さくする。ところで、ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置では、車速Ｖが低減すると、操向輪１３のタイヤ横力Ｆｄが低減し、操舵反力が低減する。これに対し、本実施形態の制御演算部１１は、車速Ｖの絶対値が小さいほどダンピング成分の絶対値を小さくすることで、操舵反力を低減できる。これにより、本実施形態の制御演算部１１は、より適切な操舵感を付与できる。 The control calculation unit 11 of the present embodiment decreases the absolute value of the damping component as the absolute value of the vehicle speed V decreases. By the way, in the mechanical steering control device in which the steering wheel 12 and the steered wheel 13 are mechanically coupled, when the vehicle speed V is reduced, the tire lateral force Fd of the steered wheel 13 is reduced, and the steering reaction force is reduced. Reduce. On the other hand, the control calculation part 11 of this embodiment can reduce a steering reaction force by making the absolute value of a damping component small, so that the absolute value of the vehicle speed V is small. Thereby, the control calculating part 11 of this embodiment can provide a more suitable steering feeling.
　図１０は、制御マップＭ４を表すグラフである。
　さらに、補正用ダンピング成分の設定方法としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応した補正用ダンピング成分を制御マップＭ４から読み出す方法を採用できる。制御マップＭ２としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応した補正用ダンピング成分を登録したマップがある。具体的には、図１０に示すように、制御マップＭ４は、車速Ｖ毎に設定される。各制御マップＭ４は、操舵角速度ｄδ／ｄｔが０である場合に補正用ダンピング成分を第７設定値（例えば、０．０）に設定する。また、制御マップＭ４は、操舵角速度ｄδ／ｄｔの絶対値が第２設定操舵角速度ｄδ２／ｄｔ（＞０）以上の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらず補正用ダンピング成分を第８設定値（一定値）に設定する。さらに、制御マップＭ４は、操舵角速度ｄδ／ｄｔが０．０以上で且つ操舵角速度ｄδ／ｄｔの絶対値が第３設定操舵角速度ｄδ３／ｄｔ（０＜ｄδ３／ｄｔ＜ｄδ２／ｄｔ）未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値に応じて補正用ダンピング成分を直線的に増加させる。具体的には、各制御マップＭ４は、操舵角速度ｄδ／ｄｔの絶対値が０以上で且つ第３設定操舵角速度ｄδ３／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値と補正用ダンピング成分との関係を表す一次関数に従って補正用ダンピング成分を設定する。一次関数は、操舵角速度ｄδ／ｄｔの絶対値が０である場合に補正用ダンピング成分を第７設定値（０．０）とし、操舵角速度ｄδ／ｄｔの絶対値が第３設定操舵角速度ｄδ３／ｄｔである場合に補正用ダンピング成分を第９設定値（０＜第９設定値＜第８設定値）に設定する。また、各制御マップＭ４は、操舵角速度ｄδ／ｄｔの絶対値が第３設定操舵角速度ｄδ３／ｄｔ以上で且つ第２設定操舵角速度ｄδ２／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値に応じて補正用ダンピング成分を直線的に増加させる。具体的には、制御マップＭ４は、操舵角速度ｄδ／ｄｔの絶対値が第３設定操舵角速度ｄδ３／ｄｔ以上で且つ第２設定操舵角速度ｄδ２／ｄｔ未満の範囲では、車速Ｖの絶対値と補正用ダンピング成分との関係を表す一次関数に従って補正用ダンピング成分を設定する。一次関数は、操舵角速度ｄδ／ｄｔの絶対値が第３設定操舵角速度ｄδ３／ｄｔである場合に補正用ダンピング成分を第９設定値とし、操舵角速度ｄδ／ｄｔの絶対値が第２設定操舵角速度ｄδ２／ｄｔである場合に補正用ダンピング成分を第８設定値とする。これにより、フィードフォワード軸力算出部１１Ｂａは、操舵角速度ｄδ／ｄｔの絶対値が第２設定操舵角速度ｄδ２／ｄｔ未満である場合には、操舵角速度ｄδ／ｄｔの絶対値が大きいほど補正用ダンピング成分の絶対値を大きくする。また、フィードフォワード軸力算出部１１Ｂａは、操舵角速度ｄδ／ｄｔの絶対値が第２設定操舵角速度ｄδ２／ｄｔ以上である場合には、操舵角速度ｄδ／ｄｔの大きさにかかわらず、補正用ダンピング成分の絶対値を予め定めた一定値とする。第８及び第９設定値は、車速Ｖが増加するほど高い値に設定される。 FIG. 10 is a graph showing the control map M4.
Further, as a method for setting the correction damping component, for example, a method of reading the correction damping component corresponding to the absolute value of the steering angular velocity dδ / dt from the control map M4 can be employed. As the control map M2, for example, there is a map in which a correction damping component corresponding to the absolute value of the steering angular velocity dδ / dt is registered. Specifically, as shown in FIG. 10, the control map M4 is set for each vehicle speed V. Each control map M4 sets the correction damping component to the seventh set value (for example, 0.0) when the steering angular velocity dδ / dt is zero. Further, the control map M4 indicates that the correction damping component is used regardless of the magnitude of the steering angular velocity dδ / dt in the range where the absolute value of the steering angular velocity dδ / dt is equal to or greater than the second set steering angular velocity dδ 2 / dt (> 0). Set to the eighth set value (constant value). Further, in the control map M4, the steering angular velocity dδ / dt is 0.0 or more and the absolute value of the steering angular velocity dδ / dt is the third set steering angular velocity dδ 3 / dt (0 <dδ 3 / dt <dδ 2 / dt). In the range below, the correction damping component is linearly increased according to the absolute value of the steering angular velocity dδ / dt. Specifically, in each control map M4, the absolute value of the steering angular velocity dδ / dt and the correction damping are set in a range where the absolute value of the steering angular velocity dδ / dt is not less than 0 and less than the third set steering angular velocity dδ 3 / dt. A correction damping component is set according to a linear function representing the relationship with the component. In the linear function, when the absolute value of the steering angular velocity dδ / dt is 0, the correction damping component is set to the seventh set value (0.0), and the absolute value of the steering angular velocity dδ / dt is the third set steering angular velocity dδ 3. In the case of / dt, the correction damping component is set to the ninth set value (0 <9th set value <8th set value). Further, each control map M4, in the absolute value and the second set steering angular velocity d? 2 / dt of less than the range in the third set steering angular velocity d? 3 / dt or the steering angular velocity d? / Dt, the absolute steering angular velocity d? / Dt The correction damping component is linearly increased according to the value. Specifically, the control map M4 indicates that the absolute value of the vehicle speed V is within a range where the absolute value of the steering angular velocity dδ / dt is greater than or equal to the third set steering angular velocity dδ 3 / dt and less than the second set steering angular velocity dδ 2 / dt. The correction damping component is set according to a linear function representing the relationship between the correction damping component and the correction damping component. In the linear function, when the absolute value of the steering angular velocity dδ / dt is the third set steering angular velocity dδ 3 / dt, the correction damping component is the ninth set value, and the absolute value of the steering angular velocity dδ / dt is the second set steering. When the angular velocity is dδ 2 / dt, the correction damping component is set to the eighth set value. Thereby, when the absolute value of the steering angular velocity dδ / dt is less than the second set steering angular velocity dδ 2 / dt, the feedforward axial force calculation unit 11Ba corrects the larger the absolute value of the steering angular velocity dδ / dt. Increase the absolute value of the damping component. Further, the feedforward axial force calculating unit 11Ba, when the absolute value of the steering angular velocity d? / Dt is the second set steering angular velocity d? 2 / dt or more, regardless of the magnitude of the steering angular velocity d? / Dt, correction The absolute value of the damping component is set to a predetermined constant value. The eighth and ninth set values are set to higher values as the vehicle speed V increases.
　このように、本実施形態の制御演算部１１は、操舵角速度ｄδ／ｄｔの絶対値が大きいほど絶対値が大きくなる補正用ダンピング成分をフィードフォワード軸力ＴＦＦに加算する。それゆえ、本実施形態の制御演算部１１は、ステアリングホイール１２の切り始めに、操舵角速度ｄδ／ｄｔの絶対値が増大した場合に、操舵反力の立ち上がりを増大できる。これにより、本実施形態の制御演算部１１は、より適切な操舵感を付与できる。
　また、本実施形態の制御演算部１１は、操舵角速度ｄδ／ｄｔの絶対値が第２設定操舵角速度ｄδ２／ｄｔ以上である場合には、予め定めた一定値を補正用ダンピング成分とする。それゆえ、運転者がステアリングホイール１２を切ったことで、操舵角速度ｄδ／ｄｔの絶対値が第２設定操舵角速度ｄδ２／ｄｔ以上となった場合には、補正用ダンピング成分の変動を抑制できる。そのため、本実施形態の制御演算部１１は、補正用ダンピング成分の変動による操舵反力の変化が感知されず、運転者に操舵感の違和感を与えることを防止できる。 Thus, control arithmetic unit 11 of the present embodiment adds the correction damping component absolute value larger the absolute value of the steering angular velocity d? / Dt increases feedforward axial force T FF. Therefore, when the absolute value of the steering angular velocity dδ / dt increases at the start of turning of the steering wheel 12, the control calculation unit 11 of the present embodiment can increase the rising of the steering reaction force. Thereby, the control calculating part 11 of this embodiment can provide a more suitable steering feeling.
In addition, when the absolute value of the steering angular velocity dδ / dt is equal to or greater than the second set steering angular velocity dδ 2 / dt, the control calculation unit 11 of the present embodiment uses a predetermined constant value as a correction damping component. Therefore, when the driver turns the steering wheel 12 and the absolute value of the steering angular velocity dδ / dt becomes equal to or higher than the second set steering angular velocity dδ 2 / dt, fluctuations in the correction damping component can be suppressed. . Therefore, the control calculation unit 11 of the present embodiment does not sense a change in the steering reaction force due to the variation in the correction damping component, and can prevent the driver from feeling uncomfortable with the steering feeling.
　図１１は、フィードバック軸力算出部１１Ｂｂの構成を表すブロック図である。
　図１１に示すように、フィードバック軸力算出部１１Ｂｂは、電流軸力算出部１１Ｂｂａ、ブレンド軸力算出部１１Ｂｂｂ、操舵角速度検出部１１Ｂｂｃ、操舵判定部１１Ｂｂｄ、およびフィードバック軸力算出実行部１１Ｂｂｅを備える。
　電流軸力算出部１１Ｂｂａは、転舵電流検出部５Ｃが検出した転舵電流に基づき、下記（６）式に従ってステアリングラック軸力（以下、電流軸力とも呼ぶ）を算出する。下記（６）式では、まず、転舵電流と、転舵電流を基に転舵モータ６の出力トルクを算出するためのトルク定数［Ｎｍ／Ａ］と、転舵モータ６のモータトルクを伝達するためのモータギア比とを乗算する。続いて、下記（６）式では、乗算結果を転舵モータ６のピニオンギアのピニオン半径［ｍ］で除算し、除算結果に、転舵モータ６の出力トルクが伝達される際の効率を乗算し、乗算結果を電流軸力として算出する。そして、電流軸力算出部１１Ｂｂａは、算出結果をブレンド軸力算出部１１Ｂｂｂおよびフィードバック軸力算出実行部１１Ｂｂｅに出力する。
　電流軸力＝（転舵電流×モータギア比×トルク定数［Ｎｍ／Ａ］／ピニオン半径［ｍ］）×効率　・・・（６） FIG. 11 is a block diagram illustrating a configuration of the feedback axial force calculation unit 11Bb.
As shown in FIG. 11, the feedback axial force calculation unit 11Bb includes a current axial force calculation unit 11Bba, a blend axial force calculation unit 11Bbb, a steering angular velocity detection unit 11Bbc, a steering determination unit 11Bbd, and a feedback axial force calculation execution unit 11Bbe. .
The current axial force calculator 11Bba calculates a steering rack axial force (hereinafter also referred to as a current axial force) according to the following equation (6) based on the turning current detected by the turning current detector 5C. In the following formula (6), first, the steering current, the torque constant [Nm / A] for calculating the output torque of the steering motor 6 based on the steering current, and the motor torque of the steering motor 6 are transmitted. Multiply by the motor gear ratio. Subsequently, in the following equation (6), the multiplication result is divided by the pinion radius [m] of the pinion gear of the steered motor 6, and the division result is multiplied by the efficiency when the output torque of the steered motor 6 is transmitted. Then, the multiplication result is calculated as the current axial force. And current axial force calculation part 11Bba outputs a calculation result to blend axial force calculation part 11Bbb and feedback axial force calculation execution part 11Bbe.
Current axial force = (steering current × motor gear ratio × torque constant [Nm / A] / pinion radius [m]) × efficiency (6)
　ここで、転舵電流は、ステアリングホイール１２が操舵され、目標転舵角θ＊が変動し、目標転舵角θ＊と実際の転舵角θとに差が生じることによって変動する。また、転舵電流は、操向輪１３が転舵され、操向輪１３にタイヤ横力Ｆｄが作用し、目標転舵角θ＊と実際の転舵角θとに差が生じることによっても変動する。さらに、転舵電流は、路面凹凸等によって操向輪１３に路面外乱が作用し、操向輪１３にタイヤ横力Ｆｄが作用し、目標転舵角θ＊と実際の転舵角θとに差が生じることによっても変動する。それゆえ、フィードバック軸力算出部１１Ｂｂは、転舵電流に基づくことで、操向輪１３に作用するタイヤ横力Ｆｄの影響を反映したステアリングラック軸力（電流軸力）を算出できる。ここで、電流軸力は、目標転舵角θ＊と実際の転舵角θとに差が生じた時点で発生する。そのため、電流軸力は、図１２に示すように、実際のステアリングラック軸力や横Ｇ軸力に比べ、位相が進む。 Here, the steering current varies when the steering wheel 12 is steered, the target turning angle θ * varies, and a difference occurs between the target turning angle θ * and the actual turning angle θ. Further, the steered current is also generated when the steered wheel 13 is steered, the tire lateral force Fd is applied to the steered wheel 13, and a difference occurs between the target steered angle θ * and the actual steered angle θ. fluctuate. Further, the steering current is caused by a road surface disturbance acting on the steered wheel 13 due to road surface unevenness or the like, and a tire lateral force Fd acting on the steered wheel 13 so that the target steered angle θ * and the actual steered angle θ are It also fluctuates due to differences. Therefore, the feedback axial force calculation unit 11Bb can calculate the steering rack axial force (current axial force) reflecting the influence of the tire lateral force Fd acting on the steered wheels 13 based on the steering current. Here, the current axial force is generated when there is a difference between the target turning angle θ * and the actual turning angle θ. Therefore, the phase of the current axial force advances as compared with the actual steering rack axial force and lateral G axial force, as shown in FIG.
　ブレンド軸力算出部１１Ｂｂｂは、横Ｇセンサ１４Ｂが検出した横方向加速度Ｇｙに基づき、下記（７）式に従ってステアリングラック軸力（以下、横Ｇ軸力とも呼ぶ）を算出する。下記（７）式では、まず、前輪荷重と横方向加速度Ｇｙとを乗算し、乗算結果を操向輪１３にかかる軸力（軸方向の力）として算出する。続いて、下記（７）式では、算出した操向輪１３にかかる軸力と、リンクの角度やサスペンションに応じた定数（以下、リンク比とも呼ぶ）とを乗算し、乗算結果を横Ｇ軸力として算出する。
　横Ｇ軸力＝操向輪１３にかかる軸力×リンク比　・・・（７）
　操向輪１３にかかる軸力＝前輪荷重×横方向加速度Ｇｙ Based on the lateral acceleration Gy detected by the lateral G sensor 14B, the blend axial force calculating unit 11Bbb calculates a steering rack axial force (hereinafter also referred to as a lateral G-axis force) according to the following equation (7). In the following equation (7), first, the front wheel load and the lateral acceleration Gy are multiplied, and the multiplication result is calculated as an axial force (axial force) applied to the steered wheel 13. Subsequently, in the following equation (7), the calculated axial force applied to the steered wheel 13 is multiplied by a constant (hereinafter also referred to as a link ratio) according to the link angle or suspension, and the multiplication result is represented by the horizontal G axis. Calculated as force.
Lateral G axial force = Axial force applied to steered wheel 13 × link ratio (7)
Axial force applied to steered wheel 13 = front wheel load x lateral acceleration Gy
　ここで、横方向加速度Ｇｙは、操向輪１３が転舵され、操向輪１３にタイヤ横力Ｆｄが作用し、自車両Ａが旋回することによって発生する。それゆえ、ブレンド軸力算出部１１Ｂｂｂは、横方向加速度Ｇｙに基づくことで、操向輪１３に作用するタイヤ横力Ｆｄの影響を反映したステアリングラック軸力（横Ｇ軸力）を算出できる。ここで、横Ｇセンサ１４Ｂは、バネ上（車体）に配置したため、横方向加速度Ｇｙの検出が遅れる。そのため、横Ｇ軸力は、図１２に示すように、実際のステアリングラック軸力に比べ、位相が遅れる。
　なお、本実施形態では、横Ｇ軸力を算出する際に、横Ｇセンサ１４Ｂで検出した横方向加速度Ｇｙを用いる例を示したが、他の構成を採用してもよい。例えば、ヨーレートセンサ１４Ｃが検出したヨーレートγに車速センサ１４Ａが検出した車速Ｖを乗算し、乗算結果γ×Ｖを横方向加速度Ｇｙに代えて用いる構成としてもよい。 Here, the lateral acceleration Gy is generated when the steered wheel 13 is steered, the tire lateral force Fd acts on the steered wheel 13, and the host vehicle A turns. Therefore, the blend axial force calculation unit 11Bbb can calculate the steering rack axial force (lateral G axial force) reflecting the influence of the tire lateral force Fd acting on the steered wheels 13 based on the lateral acceleration Gy. Here, since the lateral G sensor 14B is disposed on the spring (vehicle body), detection of the lateral acceleration Gy is delayed. Therefore, the lateral G-axis force is delayed in phase as compared with the actual steering rack axial force, as shown in FIG.
In the present embodiment, an example in which the lateral acceleration Gy detected by the lateral G sensor 14B is used when calculating the lateral G-axis force is shown, but other configurations may be employed. For example, the yaw rate γ detected by the yaw rate sensor 14C may be multiplied by the vehicle speed V detected by the vehicle speed sensor 14A, and the multiplication result γ × V may be used instead of the lateral acceleration Gy.
　また、ブレンド軸力算出部１１Ｂｂｂは、車速センサ１４Ａが検出した車速Ｖ、およびヨーレートセンサ１４Ｃが検出したヨーレートγに基づき、下記（８）式に従ってステアリングラック軸力（以下、ヨーレート軸力とも呼ぶ）を算出する。下記（８）式では、まず、前輪荷重と車速Ｖとヨーレートγとを乗算し、乗算結果を操向輪１３にかかる軸力として算出する。続いて、下記（８）式では、算出した操向輪１３にかかる軸力とリンク比とを乗算し、乗算結果をヨーレート軸力として算出する。
　ヨーレート軸力＝操向輪１３にかかる軸力×リンク比　・・・（８）
　操向輪１３にかかる軸力＝前輪荷重×車速Ｖ×ヨーレートγ
　ここで、ヨーレートγは、操向輪１３が転舵され、操向輪１３にタイヤ横力Ｆｄが作用し、自車両Ａが旋回することによって発生する。それゆえ、ブレンド軸力算出部１１Ｂｂｂは、ヨーレートγに基づくことで、操向輪１３に作用するタイヤ横力Ｆｄの影響を反映したステアリングラック軸力（ヨーレート軸力）を算出できる。ここで、ヨーレートセンサ１４Ｃは、バネ上（車体）に配置したため、ヨーレートγの検出が遅れる。そのため、ヨーレート軸力は、図１２に示すように、実際のステアリングラック軸力に比べ、位相が遅れる。 The blend axial force calculation unit 11Bbb is based on the vehicle speed V detected by the vehicle speed sensor 14A and the yaw rate γ detected by the yaw rate sensor 14C according to the following equation (8), and the steering rack axial force (hereinafter also referred to as yaw rate axial force). Is calculated. In the following equation (8), first, the front wheel load, the vehicle speed V, and the yaw rate γ are multiplied, and the multiplication result is calculated as the axial force applied to the steered wheel 13. Subsequently, in the following equation (8), the calculated axial force applied to the steered wheel 13 is multiplied by the link ratio, and the multiplication result is calculated as the yaw rate axial force.
Yaw rate axial force = axial force applied to the steering wheel 13 × link ratio (8)
Axial force applied to steered wheel 13 = front wheel load × vehicle speed V × yaw rate γ
Here, the yaw rate γ is generated when the steered wheel 13 is steered, the tire lateral force Fd acts on the steered wheel 13 and the host vehicle A turns. Therefore, the blend axial force calculation unit 11Bbb can calculate the steering rack axial force (yaw rate axial force) reflecting the influence of the tire lateral force Fd acting on the steered wheel 13 based on the yaw rate γ. Here, since the yaw rate sensor 14C is disposed on the spring (vehicle body), detection of the yaw rate γ is delayed. For this reason, the phase of the yaw rate axial force is delayed compared to the actual steering rack axial force, as shown in FIG.
　さらに、ブレンド軸力算出部１１Ｂｂｂは、電流軸力算出部１１Ｂｂａから電流軸力を読み込む。続いて、ブレンド軸力算出部１１Ｂｂｂは、読み込んだ電流軸力、および算出した横Ｇ軸力、ヨーレート軸力に基づき、下記（９）式に従ってステアリングラック軸力（以下、「ブレンド軸力」とも呼ぶ）ＴＢＲを算出する。下記（９）式では、横Ｇ軸力に配分比率Ｋ１を乗算し、電流軸力に配分比率Ｋ２を乗算し、ヨーレート軸力に配分比率Ｋ３を乗算し、これらの乗算結果の和をブレンド軸力ＴＢＲとして算出する。すなわち、横Ｇ軸力に配分比率Ｋ１を乗算した値、電流軸力に配分比率Ｋ２を乗算した値およびヨーレート軸力に配分比率Ｋ３を乗算した値に基づいて、ブレンド軸力ＴＢＲを算出する。そして、ブレンド軸力算出部１１Ｂｂｂは、算出結果を操舵判定部１１Ｂｂｄおよびフィードバック軸力算出実行部１１Ｂｂｅに出力する。ここで、ブレンド軸力ＴＢＲは、操向輪１３を右方向に向ける軸力を正値とし、操向輪１３を左方向に向ける軸力を負値とする。
　ＴＢＲ＝横Ｇ軸力×Ｋ１＋電流軸力×Ｋ２＋ヨーレート軸力×Ｋ３　・・・（９） Further, the blend axial force calculation unit 11Bbb reads the current axial force from the current axial force calculation unit 11Bba. Subsequently, the blend axial force calculation unit 11Bbb calculates the steering rack axial force (hereinafter referred to as “blend axial force”) according to the following equation (9) based on the read current axial force and the calculated lateral G axial force and yaw rate axial force. TBR is calculated. In the following equation (9), the lateral G-axis force is multiplied by the distribution ratio K1, the current axial force is multiplied by the distribution ratio K2, the yaw rate axial force is multiplied by the distribution ratio K3, and the sum of these multiplication results is the blend axis. Calculated as force TBR . That is, the blend axial force T BR is calculated based on the value obtained by multiplying the lateral G axial force by the distribution ratio K1, the value obtained by multiplying the current axial force by the distribution ratio K2, and the value obtained by multiplying the yaw rate axial force by the distribution ratio K3. . Then, the blend axial force calculation unit 11Bbb outputs the calculation result to the steering determination unit 11Bbd and the feedback axial force calculation execution unit 11Bbe. Here, the blend axial force T BR has a positive value for the axial force that directs the steered wheel 13 in the right direction, and a negative value for the axial force that directs the steered wheel 13 in the left direction.
T BR = lateral G axial force × K1 + current axial force × K2 + yaw rate axial force × K3 (9)
　ここで、配分比率Ｋ１、Ｋ２、Ｋ３は横Ｇ軸力、電流軸力、ヨーレート軸力の配分比率である。配分比率Ｋ１、Ｋ２、Ｋ３の大小関係は、Ｋ１＞Ｋ２＞Ｋ３とする。すなわち、横Ｇ軸力、電流軸力、ヨーレート軸力の順に配分比率を大きい値とする。例えば、配分比率Ｋ１、Ｋ２、Ｋ３のそれぞれは、Ｋ１＝０．６、Ｋ２＝０．３、Ｋ３＝０．１に設定する。これにより、ブレンド軸力算出部１１Ｂｂｂは、ブレンド軸力ＴＢＲとして、操向輪１３に作用するタイヤ横力Ｆｄの影響を反映したステアリングラック軸力を算出する。
　このように、本実施形態のブレンド軸力算出部１１Ｂｂｂは、電流軸力に配分比率Ｋ２を乗算した値と横Ｇ軸力に配分比率Ｋ１を乗算した値とに基づいてブレンド軸力ＴＢＲを算出する。ここで、図１２に示すように、横Ｇ軸力は、実際のステアリングラック軸力に比べ、位相が遅れる。また、電流軸力は、実際のステアリングラック軸力に比べ、位相が進む。それゆえ、本実施形態のブレンド軸力算出部１１Ｂｂｂは、横Ｇ軸力に電流軸力を加えることで、図１３に示すように、横Ｇ軸力による位相の遅れを補償でき、より適切なブレンド軸力ＴＢＲを算出できる。そのため、本実施形態の制御演算部１１は、ブレンド軸力ＴＢＲに基づいて反力モータ４を駆動することで、より適切な操舵反力を付与できる。 Here, the distribution ratios K1, K2, and K3 are distribution ratios of the lateral G-axis force, current axial force, and yaw rate axial force. The magnitude relationship between the distribution ratios K1, K2, and K3 is K1>K2> K3. That is, the distribution ratio is set to a large value in the order of the lateral G axial force, the current axial force, and the yaw rate axial force. For example, the distribution ratios K1, K2, and K3 are set to K1 = 0.6, K2 = 0.3, and K3 = 0.1, respectively. Thus, blending axial force calculating unit 11Bbb as a blend axial force T BR, calculates a steering rack axial force that reflects the influence of the tire lateral force Fd acting on the steering wheel 13.
As described above, the blend axial force calculation unit 11Bbb of the present embodiment calculates the blend axial force T BR based on the value obtained by multiplying the current axial force by the distribution ratio K2 and the value obtained by multiplying the lateral G axial force by the distribution ratio K1. calculate. Here, as shown in FIG. 12, the phase of the lateral G-axis force is delayed compared to the actual steering rack axial force. Further, the phase of the current axial force advances compared to the actual steering rack axial force. Therefore, the blend axial force calculation unit 11Bbb of the present embodiment can compensate for the phase lag due to the lateral G-axis force as shown in FIG. The blend axial force TBR can be calculated. Therefore, the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
　また、本実施形態のブレンド軸力算出部１１Ｂｂｂは、電流軸力に配分比率Ｋ２を乗算した値と横Ｇ軸力に配分比率Ｋ１を乗算した値とに基づいてブレンド軸力ＴＢＲを算出する。ここで、車両Ａは、路面凹凸等によって操向輪１３に路面外乱が作用し、操向輪１３にタイヤ横力Ｆｄが作用した場合、目標転舵角θ＊と実際の転舵角θとに差が生じる。それゆえ、本実施形態のブレンド軸力算出部１１Ｂｂｂは、横Ｇ軸力に電流軸力を加えることで、操向輪１３に作用する路面外乱の影響をブレンド軸力ＴＢＲに反映でき、より適切なブレンド軸力ＴＢＲを算出できる。そのため、本実施形態の制御演算部１１は、ブレンド軸力ＴＢＲに基づいて反力モータ４を駆動することで、より適切な操舵反力を付与できる。
　さらに、本実施形態のブレンド軸力算出部１１Ｂｂｂは、電流軸力の配分比率Ｋ２よりも横Ｇ軸力の配分比率Ｋ１を大きくする。それゆえ、本実施形態のブレンド軸力算出部１１Ｂｂｂは、電流軸力の配分比率を低減でき、例えば、電流軸力の推定精度が転舵モータ６の慣性やフリクションの影響によって低下したとしても、ブレンド軸力ＴＢＲの推定精度の低下を抑制できる。そのため、本実施形態の制御演算部１１は、ブレンド軸力ＴＢＲに基づいて反力モータ４を駆動することで、より適切な操舵反力を付与できる。 Further, the blend axial force calculation unit 11Bbb of the present embodiment calculates the blend axial force T BR based on a value obtained by multiplying the current axial force by the distribution ratio K2 and a value obtained by multiplying the lateral G axial force by the distribution ratio K1. . Here, in the vehicle A, when a road surface disturbance acts on the steered wheel 13 due to road surface unevenness and the like, and a tire lateral force Fd acts on the steered wheel 13, the target steered angle θ * and the actual steered angle θ There will be a difference. Thus, blends axial force calculating unit 11Bbb of this embodiment, by adding the current axial force to the lateral G axial force, it can reflect the influence of the road surface disturbance acting on the steering wheel 13 to the blend axial force T BR, more An appropriate blend axial force TBR can be calculated. Therefore, the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
Furthermore, the blend axial force calculation unit 11Bbb of the present embodiment increases the lateral G axial force distribution ratio K1 to be greater than the current axial force distribution ratio K2. Therefore, the blend axial force calculation unit 11Bbb of the present embodiment can reduce the distribution ratio of the current axial force. For example, even if the estimation accuracy of the current axial force decreases due to the inertia of the steered motor 6 or the influence of friction, A decrease in the estimation accuracy of the blend axial force TBR can be suppressed. Therefore, the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
　また、本実施形態のブレンド軸力算出部１１Ｂｂｂは、電流軸力に配分比率Ｋ２を乗算した値と横Ｇ軸力に配分比率Ｋ１を乗算した値とヨーレート軸力に配分比率Ｋ３を乗算した値とに基づいてフィードバック軸力ＴＦＢを算出する。ここで、例えば、自車両Ａがスピン状態になった場合に、転舵電流および横方向加速度Ｇｙが増大するため、横Ｇセンサ１４Ｂの検出結果および転舵電流検出部５Ｃの検出結果はいずれも最大値（飽和値）となる。これに対し、ヨーレートγも増大するが、ヨーレートγの増大量は転舵電流および横方向加速度Ｇｙの増加量に比べて比較的小さいので、ヨーレートセンサ１４Ｃの検出結果は最大値（飽和値）に到達しない。そのため、車両Ａのスピン状態の度合いに応じてヨーレートセンサ１４Ｃの検出結果は変動する。それゆえ、車両Ａのスピン状態の度合いに応じてブレンド軸力ＴＢＲを変動できる。その結果、本実施形態の制御演算部１１は、ブレンド軸力ＴＢＲに基づいて反力モータ４を駆動することで、より適切な操舵反力を付与できる。
　操舵角速度検出部１１Ｂｂｃは、ステアリングホイール角度センサ１が検出した操舵角δに基づいて、ステアリングホイール１２の操舵角速度ｄδ／ｄｔを算出する。そして、操舵角速度検出部１１Ｂｂｃは、算出結果をブレンド軸力算出部１１Ｂｂｂおよび操舵判定部１１Ｂｂｄに出力する。ここで、操舵角速度ｄδ／ｄｔは、ステアリングホイール１２が時計回りに回転する場合の角速度を正値とし、反時計回りに回転する場合の角速度を負値とする。 Also, the blend axial force calculation unit 11Bbb of the present embodiment has a value obtained by multiplying the current axial force by the distribution ratio K2, a value obtained by multiplying the lateral G axial force by the distribution ratio K1, and a value obtained by multiplying the yaw rate axial force by the distribution ratio K3. Based on the above, the feedback axial force T FB is calculated. Here, for example, when the host vehicle A is in a spin state, the steering current and the lateral acceleration Gy are increased. Therefore, the detection result of the lateral G sensor 14B and the detection result of the steering current detection unit 5C are both Maximum value (saturated value). On the other hand, although the yaw rate γ also increases, the increase amount of the yaw rate γ is relatively small compared to the increase amounts of the steering current and the lateral acceleration Gy, so that the detection result of the yaw rate sensor 14C reaches the maximum value (saturated value). Not reach. Therefore, the detection result of the yaw rate sensor 14C varies according to the degree of the spin state of the vehicle A. Therefore, the blend axial force T BR can be changed according to the degree of the spin state of the vehicle A. As a result, the control calculation unit 11 of the present embodiment can apply a more appropriate steering reaction force by driving the reaction force motor 4 based on the blend axial force TBR .
The steering angular velocity detector 11Bbc calculates the steering angular velocity dδ / dt of the steering wheel 12 based on the steering angle δ detected by the steering wheel angle sensor 1. And steering angular velocity detection part 11Bbc outputs a calculation result to blend axial force calculation part 11Bbb and steering determination part 11Bbd. Here, the steering angular velocity dδ / dt has a positive value when the steering wheel 12 rotates clockwise, and a negative value when the steering wheel 12 rotates counterclockwise.
　操舵判定部１１Ｂｂｄは、ブレンド軸力算出部１１Ｂｂｂが算出したブレンド軸力ＴＢＲおよび操舵角速度検出部１１Ｂｂｃが検出した操舵角速度ｄδ／ｄｔに基づいて、運転者がステアリングホイール１２の切り増し操作および切り戻し操作のいずれを行っているかを判定する。切り増し操作としては、例えば、ステアリングホイール１２（操舵角δ）が中立位置から離れる方向への操舵操作である。また、切り戻し操作としては、例えば、ステアリングホイール１２（操舵角δ）が中立位置に近づく方向への操舵操作がある。具体的には、操舵判定部１１Ｂｂｄは、ブレンド軸力ＴＢＲが正値であり且つ操舵角速度ｄδ／ｄｔが正値である場合、またはブレンド軸力ＴＢＲが負値であり且つ操舵角速度ｄδ／ｄｔが負値である場合には、ステアリングホイール１２の切り増し操作を行っていると判定し、変数Ｋ４を１．０とする。変数Ｋ４は、ステアリングホイール１２の切り増し操作および切り戻し操作のいずれを行なっているかを表すフラグである。変数Ｋ４は、ステアリングホイール１２の切り増し操作を行なっている場合に１．０とし、切り戻し操作を行なっている場合に０．０とする。さらに、操舵判定部１１Ｂｂｄは、ブレンド軸力ＴＢＲが正値であり且つ操舵角速度ｄδ／ｄｔが負値である場合、またはブレンド軸力ＴＢＲが負値であり且つ操舵角速度ｄδ／ｄｔが正値である場合には、ステアリングホイール１２の切り増し操作を行っていないと判定し、変数Ｋ４を０とする。そして、操舵判定部１１Ｂｂｄは、設定した変数Ｋ４をフィードバック軸力算出実行部１１Ｂｂｅに出力する。 Steering determining unit 11Bbd, based on the steering angular velocity d? / Dt which blends axial force blends axial force calculating unit 11Bbb calculated T BR and steering angular velocity detection unit 11Bbc detects, turning-increasing operation and off the driver's steering wheel 12 It is determined which of the return operations is being performed. The rounding-up operation is, for example, a steering operation in a direction in which the steering wheel 12 (steering angle δ) is away from the neutral position. Further, as the switch back operation, for example, there is a steering operation in a direction in which the steering wheel 12 (steering angle δ) approaches the neutral position. Specifically, the steering judging portion 11Bbd, when blended axial force T BR is positive is a is and the steering angular velocity d? / Dt positive, or blends axial force T BR is a negative value and the steering angular velocity d? / If dt is a negative value, it is determined that the steering wheel 12 is being increased, and the variable K4 is set to 1.0. The variable K4 is a flag that indicates whether the steering wheel 12 is being turned on or turned off. The variable K4 is set to 1.0 when the steering wheel 12 is being increased and 0.0 when the switchback operation is being performed. Further, the steering judging portion 11Bbd is positive blends axial force T BR and the steering angular velocity when d? / Dt is negative value, or a blend axial force T BR is a negative value and the steering angular velocity d? / Dt is positive If the value is a value, it is determined that the steering wheel 12 is not being additionally operated, and the variable K4 is set to zero. Then, the steering determination unit 11Bbd outputs the set variable K4 to the feedback axial force calculation execution unit 11Bbe.
　フィードバック軸力算出実行部１１Ｂｂｅは、電流軸力算出部１１Ｂｂａ、ブレンド軸力算出部１１Ｂｂｂ、操舵角速度検出部１１Ｂｂｃおよび操舵判定部１１Ｂｂｄから電流軸力、ブレンド軸力ＴＢＲ、操舵角速度ｄδ／ｄｔおよび変数Ｋ４を読み込む。続いて、フィードバック軸力算出実行部１１Ｂｂｅは、読み込んだ電流軸力、ブレンド軸力ＴＢＲ、操舵角速度ｄδ／ｄｔおよび変数Ｋ４に基づき、下記（１０）式に従ってステアリングラック軸力（以下、フィードバック軸力ＴＦＢ）を算出する。そして、フィードバック軸力算出実行部１１Ｂｂｅは、算出結果を軸力切替出力部１１Ｂｆに出力する。
　フィードバック軸力ＴＦＢ＝電流軸力×ＧＢ＋ブレンド軸力ＴＢＲ×（１－ＧＢ）　・・・（１０） The feedback axial force calculation execution unit 11Bbe receives the current axial force, blend axial force T BR , steering angular velocity dδ / dt, and current axial force calculation unit 11Bba, blend axial force calculation unit 11Bbb, steering angular velocity detection unit 11Bbc, and steering determination unit 11Bbd. Read variable K4. Subsequently, the feedback axial force calculation execution unit 11Bbe performs the steering rack axial force (hereinafter referred to as feedback shaft) according to the following equation (10) based on the read current axial force, blend axial force T BR , steering angular velocity dδ / dt, and variable K4. Force T FB ) is calculated. Then, the feedback axial force calculation execution unit 11Bbe outputs the calculation result to the axial force switching output unit 11Bf.
Feedback axial force T FB = current axial force × GB + blend axial force T BR × (1−GB) (10)
　ただし、ＧＢは、電流軸力とブレンド軸力ＴＢＲ（図３参照）とを配分する比率（以下、配分比率と呼ぶ）を表す数値である。なお、以下、ＧＢは、配分比率を表す数値としてだけでなく、配分比率の符号として用いられる場合がある。これにより、フィードバック軸力算出実行部１１Ｂｂｅは、配分比率ＧＢに基づいて、電流軸力とブレンド軸力ＴＢＲとをＧＢ：（１－ＧＢ）の割合で合算させて、フィードバック軸力ＴＦＢを算出する。
　ここで、配分比率ＧＢの設定方法としては、例えば、操舵判定部１１Ｂｂｄが出力した判定結果を基に配分比率設定部１１Ｂｂｆで配分比率ＧＢを設定する方法を採用できる。配分比率設定部１１Ｂｂｆは、操舵判定部１１Ｂｂｄから操舵角速度ｄδ／ｄｔおよび変数Ｋ４を読み込む。続いて、配分比率設定部１１Ｂｂｆは、読み込んだ操舵角速度ｄδ／ｄｔおよび変数Ｋ４に基づき、下記（１１）式に従って配分比率ＧＢを算出する。
　ＧＢ＝Ｋ４×Ｋ５　・・・（１１） However, GB is a numerical value representing a ratio (hereinafter referred to as a distribution ratio) for distributing the current axial force and the blend axial force T BR (see FIG. 3). Hereinafter, GB may be used not only as a numerical value representing the distribution ratio but also as a sign of the distribution ratio. Thus, the feedback axial force calculating execution unit 11Bbe, based on the distribution ratio GB, GB and current axial force blended axial force T BR: by combined at a ratio of (1-GB), the feedback axial force T FB calculate.
Here, as a setting method of the distribution ratio GB, for example, a method of setting the distribution ratio GB by the distribution ratio setting unit 11Bbf based on the determination result output by the steering determination unit 11Bbd can be adopted. The distribution ratio setting unit 11Bbf reads the steering angular velocity dδ / dt and the variable K4 from the steering determination unit 11Bbd. Subsequently, the distribution ratio setting unit 11Bbf calculates the distribution ratio GB according to the following equation (11) based on the read steering angular velocity dδ / dt and the variable K4.
GB = K4 × K5 (11)
　ただし、Ｋ５は、Ｋ４が１．０のとき、つまり、ステアリングホイール１２の切り増し操作時における、電流軸力の配分比率ＧＢとブレンド軸力ＴＢＲの配分比率（１－ＧＢ）を表す数値である。これにより、フィードバック軸力算出実行部１１Ｂｂｅは、ステアリングホイール１２の切り増し操作時には、変数Ｋ５に基づいて電流軸力とブレンド軸力ＴＢＲとをＫ５：（１－Ｋ５）の割合で合算させて、フィードバック軸力ＴＦＢを算出する。なお、Ｋ４が０．０のとき、つまり、ステアリングホイール１２の切り戻し操作時には、変数Ｋ５にかかわらず、ブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとする。
　ここで、変数Ｋ５の設定方法としては、例えば、操舵角速度ｄδ／ｄｔに対応した変数Ｋ５を制御マップＭ５から読み出す方法を採用できる。制御マップＭ５としては、例えば、操舵角速度ｄδ／ｄｔに対応した変数Ｋ５を登録したマップがある。 However, K5 is a numerical value representing the distribution ratio GB of the current axial force and the distribution ratio (1-GB) of the blend axial force TBR when K4 is 1.0, that is, when the steering wheel 12 is increased. is there. Thus, the feedback axial force calculating execution unit 11Bbe, during turning-increasing operation of the steering wheel 12, the current axial force based on variables K5 blended axial force T BR and the K5: by combined at a ratio of (1-K5) The feedback axial force T FB is calculated. Note that when K4 is 0.0, i.e., at the time of switchback operation the steering wheel 12, regardless of the variable K5, the blend axial force T BR feedback axial force T FB.
Here, as a setting method of the variable K5, for example, a method of reading the variable K5 corresponding to the steering angular velocity dδ / dt from the control map M5 can be adopted. An example of the control map M5 is a map in which a variable K5 corresponding to the steering angular velocity dδ / dt is registered.
　図１４は、制御マップＭ５を表すグラフである。
　図１４に示すように、制御マップＭ５は、操舵角速度ｄδ／ｄｔの絶対値が０以上で且つ第４設定操舵角速度ｄδ４／ｄｔ（＞０）未満の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらず変数Ｋ５を第１０設定値（例えば、１．０）に設定する。また、制御マップＭ５は、操舵角速度ｄδ／ｄｔの絶対値が第５設定操舵角速度ｄδ５／ｄｔ（＞ｄδ４／ｄｔ）以上の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらず変数Ｋ５を第１１設定値（＜第１０設定値。例えば、０．０）に設定する。さらに、制御マップＭ５は、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上で且つ第５設定操舵角速度ｄδ５／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値に応じて変数Ｋ５を直線的に低下させる。具体的には、制御マップＭ５は、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上で且つ第５設定操舵角速度ｄδ５／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値と変数Ｋ５との関係を表す一次関数に従って変数Ｋ５を設定する。一次関数は、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔである場合に変数Ｋ５を第１０設定値（１．０）とし、操舵角速度ｄδ／ｄｔの絶対値が第５設定操舵角速度ｄδ５／ｄｔである場合に変数Ｋ５を第１１設定値（０．０）とする。これにより、配分比率設定部１１Ｂｂｆは、変数Ｋ４が１．０（切り増し操作時）であり、且つ、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ未満（低速操舵時）である場合には、配分比率ＧＢを１．０とする。そして、フィードバック軸力算出実行部１１Ｂｂｅは、電流軸力をフィードバック軸力ＴＦＢとする。また、配分比率設定部１１Ｂｂｆは、変数Ｋ４が１．０（切り増し操作時）であり、且つ、操舵角速度ｄδ／ｄｔの絶対値が第５設定操舵角速度ｄδ５／ｄｔ以上（高速操舵時）である場合には、配分比率ＧＢを０．０とする。これにより、フィードバック軸力算出実行部１１Ｂｂｅは、ブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとする。また、配分比率設定部１１Ｂｂｆは、変数Ｋ４が１．０（切り増し操作時）であり、且つ、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上で且つ第５設定操舵角速度ｄδ５／ｄｔ未満（中速操舵時）である場合には、変数Ｋ５を配分比率ＧＢとする。これにより、フィードバック軸力算出実行部１１Ｂｂｅは、電流軸力に変数Ｋ５を乗算した値とブレンド軸力ＴＢＲに（１－Ｋ５）を乗算した値とを合算したものをフィードバック軸力ＴＦＢとする。一方、配分比率設定部１１Ｂｂｆは、変数Ｋ４が０．０（切り戻し操作時）である場合には、操舵角速度ｄδ／ｄｔにかかわらず、０．０を配分比率ＧＢとする。そして、フィードバック軸力算出実行部１１Ｂｂｅは、ブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとする。 FIG. 14 is a graph showing the control map M5.
As shown in FIG. 14, the control map M5, in absolute value range and the fourth less than the set steering angular velocity dδ 4 / dt (> 0) at 0 over the steering angular velocity d? / Dt, the magnitude of the steering angular velocity d? / Dt Regardless, the variable K5 is set to the tenth set value (for example, 1.0). Further, the control map M5 has a variable K5 in the range where the absolute value of the steering angular velocity dδ / dt is not less than the fifth set steering angular velocity dδ 5 / dt (> dδ 4 / dt) regardless of the magnitude of the steering angular velocity dδ / dt. Is set to an eleventh set value (<tenth set value, for example, 0.0). Further, the control map M5, in and fifth sets the steering angular velocity d? Of less than 5 / dt range in absolute value fourth set steering angular velocity d? 4 / dt or the steering angular velocity d? / Dt, the absolute value of the steering angular velocity d? / Dt Accordingly, the variable K5 is linearly decreased. Specifically, the control map M5 indicates that the steering angular velocity dδ / dt is within a range where the absolute value of the steering angular velocity dδ / dt is not less than the fourth set steering angular velocity dδ 4 / dt and less than the fifth set steering angular velocity dδ 5 / dt. The variable K5 is set according to a linear function that represents the relationship between the absolute value of and the variable K5. When the absolute value of the steering angular velocity dδ / dt is the fourth set steering angular velocity dδ 4 / dt, the linear function sets the variable K5 to the tenth set value (1.0), and the absolute value of the steering angular velocity dδ / dt is the first The variable K5 is set to the eleventh set value (0.0) when the 5-set steering angular velocity dδ 5 / dt. As a result, the distribution ratio setting unit 11Bbf has the variable K4 of 1.0 (during the addition operation) and the absolute value of the steering angular velocity dδ / dt is less than the fourth set steering angular velocity dδ 4 / dt (during low-speed steering). ), The distribution ratio GB is set to 1.0. Then, the feedback axial force calculating execution unit 11Bbe is a feedback axial force T FB current axial force. In addition, the distribution ratio setting unit 11Bbf has a variable K4 of 1.0 (during the addition operation), and the absolute value of the steering angular velocity dδ / dt is equal to or greater than the fifth setting steering angular velocity dδ 5 / dt (during high-speed steering). In this case, the distribution ratio GB is set to 0.0. Thus, the feedback axial force calculating execution unit 11Bbe is a blend axial force T BR feedback axial force T FB. Further, the distribution ratio setting unit 11Bbf has a variable K4 of 1.0 (during a rounding operation), the absolute value of the steering angular velocity dδ / dt is equal to or greater than the fourth setting steering angular velocity dδ 4 / dt, and the fifth setting. If the steering angular velocity is less than dδ 5 / dt (during medium speed steering), the variable K5 is set as the distribution ratio GB. Thus, the feedback axial force calculating execution unit 11Bbe includes a feedback axial force T FB what the sum of the value obtained by multiplying the (1-K5) to the value blended axial force T BR multiplied by variable K5 current axial force To do. On the other hand, when the variable K4 is 0.0 (during a switchback operation), the distribution ratio setting unit 11Bbf sets 0.0 as the distribution ratio GB regardless of the steering angular velocity dδ / dt. Then, the feedback axial force calculating execution unit 11Bbe is a blend axial force T BR feedback axial force T FB.
　このように、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅは、ステアリングホイール１２の切り増し操作が行われると、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ未満である場合には、電流軸力をフィードバック軸力ＴＦＢとする。ここで、ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置では、ステアリングホイール１２の切り増し操作時には、操向輪１３の転舵に伴うタイヤ横力Ｆｄとフリクションとにより、ステアリングホイール１２を中立位置に戻す操舵反力が発生する。また、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅでは、ステアリングホイール１２の切り増し操作時には、電流軸力は、タイヤ横力Ｆｄとフリクションとの合算値と等しくなる。そのため、本実施形態の制御演算部１１は、電流軸力をフィードバック軸力ＴＦＢとすることで、機械式の操舵制御装置と同様に、ステアリングホイール１２を中立位置に戻す操舵反力を付与できる。これにより、本実施形態の制御演算部１１は、ステアリングホイール１２の切り増し操作時に、より適切な操舵反力を付与できる。
　ちなみに、ブレンド軸力ＴＢＲは、操向輪１３の転舵に伴うフリクションの要素が含まれていない。それゆえ、例えば、ステアリングホイール１２の切り増し操作時に、ブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとする方法では、操舵感に違和感を与える可能性がある。 Thus, the feedback axial force calculation execution unit 11Bbe of the present embodiment has an absolute value of the steering angular velocity dδ / dt that is less than the fourth set steering angular velocity dδ 4 / dt when the steering wheel 12 is increased. In this case, the current axial force is set as the feedback axial force TFB . Here, in the mechanical steering control device in which the steering wheel 12 and the steered wheel 13 are mechanically coupled, when the steering wheel 12 is increased, the tire lateral force Fd accompanying the steering of the steered wheel 13 is increased. And the friction generate a steering reaction force that returns the steering wheel 12 to the neutral position. In the feedback axial force calculation execution unit 11Bbe of the present embodiment, the current axial force becomes equal to the sum of the tire lateral force Fd and the friction when the steering wheel 12 is increased. Therefore, the control calculation part 11 of this embodiment can give the steering reaction force which returns the steering wheel 12 to a neutral position similarly to a mechanical steering control apparatus by setting the current axial force to the feedback axial force TFB. . Thereby, the control calculating part 11 of this embodiment can provide a more appropriate steering reaction force at the time of the steering wheel 12 turning operation.
Incidentally, the blend axial force TBR does not include an element of friction accompanying steering of the steered wheel 13. Thus, for example, at the time of turning-increasing operation of the steering wheel 12, in the method of the blending axial force T BR feedback axial force T FB, which may give uncomfortable feeling to the steering feeling.
　また、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅは、ステアリングホイール１２の切り戻し操作が行われると、操舵角速度ｄδ／ｄｔの絶対値の大きさにかかわらず、電流軸力と横Ｇ軸力とを予め設定された配分比率で配分したブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとする。ここで、ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置では、ステアリングホイール１２の切り戻し操作時には、操向輪１３の転舵に伴うタイヤ横力Ｆｄにより、ステアリングホイール１２を中立位置に戻す操舵反力が発生する。それゆえ、機械式の操舵制御装置では、ステアリングホイール１２の切り戻し操作時には、運転者は、ステアリングホイール１２の保持力を低減し、ステアリングホイール１２を手の平で滑らせることで、ステアリングホイール１２を中立位置に戻し、操向輪１３を中立位置に戻していた。これに対し、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅでは、ブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとすることで、転舵電流が低減し、電流軸力が低減したとしても、ステアリングホイール１２を中立位置に戻す操舵反力が低減することを抑制できる。そのため、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅは、機械式の操舵制御装置と同様に、運転者がステアリングホイール１２の保持力を低減し、ステアリングホイール１２を手の平で滑らせることで、ステアリングホイール１２を中立位置に戻すことができる。これにより、本実施形態の制御演算部１１は、ステアリングホイール１２の切り戻し操作時に、より適切な操舵反力を付与できる。 In addition, when the steering wheel 12 is switched back, the feedback axial force calculation execution unit 11Bbe according to the present embodiment performs the current axial force and the lateral G axial force regardless of the absolute value of the steering angular velocity dδ / dt. Is a blend axial force T BR that is distributed at a preset distribution ratio as a feedback axial force T FB . Here, in the mechanical steering control device in which the steering wheel 12 and the steered wheel 13 are mechanically coupled, when the steering wheel 12 is switched back, the tire lateral force Fd accompanying the steering of the steered wheel 13 is obtained. Thus, a steering reaction force that returns the steering wheel 12 to the neutral position is generated. Therefore, in the mechanical steering control device, when the steering wheel 12 is switched back, the driver reduces the holding force of the steering wheel 12 and slides the steering wheel 12 with the palm of the hand to make the steering wheel 12 neutral. The steering wheel 13 was returned to the neutral position. In contrast, in the feedback axial force calculating execution unit 11Bbe of the present embodiment, by setting the blending axial force T BR feedback axial force T FB, reduced steering current, even a current axial force is reduced, steering It can suppress that the steering reaction force which returns the wheel 12 to a neutral position reduces. Therefore, the feedback axial force calculation execution unit 11Bbe according to the present embodiment is similar to the mechanical steering control device in that the driver reduces the holding force of the steering wheel 12 and slides the steering wheel 12 with the palm of the steering wheel. The wheel 12 can be returned to the neutral position. Thereby, the control calculation part 11 of this embodiment can provide a more appropriate steering reaction force when the steering wheel 12 is switched back.
　さらに、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅは、ステアリングホイール１２の切り増し操作を行っていると判定し、且つ、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上であると判定した場合には、電流軸力とブレンド軸力ＴＢＲとを配分してフィードバック軸力ＴＦＢを設定するとともに、操舵角速度ｄδ／ｄｔの絶対値が小さくなるほど電流軸力の配分比率を大きくする。それゆえ、本実施形態のフィードバック軸力算出実行部１１Ｂｂｅは、例えば、ステアリングホイール１２の切り戻し操作中に、操舵角δが中立位置を跨ぎ、引き続き同方向へステアリングホイール１２の切り増し操作が行われた場合、切り増し操作中に操舵角速度ｄδ／ｄｔの絶対値が徐々に低減するにつれ、ブレンド軸力ＴＢＲから電流軸力へとフィードバック軸力ＴＦＢを徐々に移行できる。これにより、本実施形態の制御演算部１１は、より適切な操舵反力を付与できる。 Furthermore, the feedback axial force calculation execution unit 11Bbe of the present embodiment determines that the steering wheel 12 is being increased, and the absolute value of the steering angular velocity dδ / dt is the fourth set steering angular velocity dδ 4 / dt. in a case where it is determined to be equal to or greater than, sets the feedback axial force T FB by distributing the current axial force blended axial force T BR, the absolute value is higher distribution of current axial force small steering angular velocity d? / dt Increase the ratio. Therefore, the feedback axial force calculation execution unit 11Bbe of the present embodiment performs, for example, the steering wheel δ straddling the neutral position during the steering wheel 12 switching operation and the steering wheel 12 is continuously increased in the same direction. If we, as the absolute value of the steering angular velocity d? / dt during turning-increasing operation is gradually reduced, can gradually transition from a blend axial force T BR to current axial force feedback axial force T FB. Thereby, the control calculating part 11 of this embodiment can provide a more appropriate steering reaction force.
　図３に戻り、最終軸力算出部１１Ｂｃは、ステアリングホイール角度センサ１、車速センサ１４Ａ、横Ｇセンサ１４Ｂ、フィードフォワード軸力算出部１１Ｂａおよびフィードバック軸力算出部１１Ｂｂから操舵角δ、車速Ｖ、横方向加速度Ｇｙ、フィードフォワード軸力ＴＦＦおよびフィードバック軸力ＴＦＢを読み込む。続いて、最終軸力算出部１１Ｂｃは、読み込んだ操舵角δに基づいて、ステアリングホイール１２の操舵角速度ｄδ／ｄｔを算出する。続いて、最終軸力算出部１１Ｂｃは、読み込んだ操舵角δ、車速Ｖ、横方向加速度Ｇｙ、フィードフォワード軸力ＴＦＦ、軸力切替出力部１１Ｂｆが出力する軸力Ｔｏｃ、算出した操舵角速度ｄδ／ｄｔ及び補正操舵反力中心値ΔＴｓｃに基づき、下記（１２）式に従ってステアリングラック軸力（以下、最終軸力）を算出する。そして、最終軸力算出部１１Ｂｃは、算出結果を軸力－操舵反力変換部１１Ｂｄに出力する。
　最終軸力＝フィードフォワード軸力ＴＦＦ×ＧＦ＋Ｔｏｃ×（１－ＧＦ）＋ΔＴｓｃ　・・・（１２） Returning to FIG. 3, the final axial force calculation unit 11Bc includes the steering angle δ, the vehicle speed V, the steering wheel angle sensor 1, the vehicle speed sensor 14A, the lateral G sensor 14B, the feedforward axial force calculation unit 11Ba, and the feedback axial force calculation unit 11Bb. lateral acceleration Gy, reads the feedforward axial force T FF and the feedback axial force T FB. Subsequently, the final axial force calculator 11Bc calculates the steering angular velocity dδ / dt of the steering wheel 12 based on the read steering angle δ. Subsequently, the final axial force calculation unit 11Bc reads the read steering angle δ, vehicle speed V, lateral acceleration Gy, feedforward axial force T FF , axial force Toc output by the axial force switching output unit 11Bf, and calculated steering angular velocity dδ. Based on / dt and the corrected steering reaction force central value ΔTsc, a steering rack axial force (hereinafter referred to as final axial force) is calculated according to the following equation (12). Then, the final axial force calculation unit 11Bc outputs the calculation result to the axial force-steering reaction force conversion unit 11Bd.
Final axial force = feed forward axial force T FF × GF + Toc × (1−GF) + ΔTsc (12)
　ここで、ＧＦは、フィードフォワード軸力ＴＦＦとフィードバック軸力ＴＦＢとを配分する比率（以下、配分比率と呼ぶ）を表す数値である。なお、以下、ＧＦは、配分比率を表す数値としてだけでなく、配分比率の符号として用いられる場合がある。また、（１２）式中のΔＴｓｃは、補正操舵反力中心値ΔＴｓｃの数値を表している。これにより、最終軸力算出部１１Ｂｃは、配分比率ＧＦに基づいて、フィードフォワード軸力ＴＦＦと軸力ＴｏｃとをＧＦ：（１－ＧＦ）の割合で合算させた値に補正操舵反力中心値ΔＴｓｃを加算して、最終軸力を算出する。軸力切替出力部１１Ｂｆは、車線維持支援コントローラ１５が作動していない非作動状態ではフィードバック軸力ＴＦＢを出力し、車線維持支援コントローラ１５が作動している作動状態ではフィードフォワード軸力ＦＦＦを出力するようになっている。このため、最終軸力算出部１１Ｂｃは、車線維持支援コントローラ１５の非作動時には、フィードフォワード軸力ＴＦＦとフィードバック軸力ＴＦＢとをＧＦ：（１－ＧＦ）の割合で合算させた値に補正操舵反力中心値ΔＴｓｃを加算して、最終軸力を算出する。また、最終軸力算出部１１Ｂｃは、車線維持支援コントローラ１５の作動時には、フィードフォワード軸力ＴＦＦとフィードフォワード軸力ＴＦＦとをＧＦ：（１－ＧＦ）の割合で合算させた値に補正操舵反力中心値ΔＴｓｃを加算して、最終軸力を算出する。すなわち、最終軸力算出部１１Ｂｃは、車線維持支援コントローラ１５の作動時には、フィードフォワード軸力ＴＦＦに補正操舵反力中心値ΔＴｓｃを加算した値を最終軸力として出力するようになっている。 Here, GF is a numerical value representing a ratio (hereinafter referred to as a distribution ratio) for distributing the feedforward axial force TFF and the feedback axial force TFB . Hereinafter, GF may be used not only as a numerical value representing the distribution ratio but also as a sign of the distribution ratio. In addition, ΔTsc in the equation (12) represents the numerical value of the corrected steering reaction force central value ΔTsc. Thus, the final axial force calculating unit 11Bc, based on the distribution ratio GF, a feedforward axial force T FF and axial force Toc GF: correction steering reaction force central to a value obtained by summing at a ratio of (1-GF) The final axial force is calculated by adding the value ΔTsc. Axial force switching output section 11Bf, in a non-actuated state the lane keeping assist controller 15 does not operate and outputs a feedback axial force T FB, feedforward axial force in an operating state in which the lane keeping assist controller 15 is operating F FF Is output. Therefore, the final axial force calculating unit 11Bc, at the time of non-operation of the lane keeping assist controller 15, the feedforward axial force T FF and the feedback axial force T FB GF: a value obtained by summing at a ratio of (1-GF) The final axial force is calculated by adding the corrected steering reaction force central value ΔTsc. Also, the final axial force calculating unit 11Bc, during operation of the lane keeping assist controller 15, the feedforward axial force T FF and the feedforward axial force T FF GF: corrected to a value obtained by summing at a ratio of (1-GF) The final axial force is calculated by adding the steering reaction force central value ΔTsc. In other words, the final axial force calculating unit 11Bc, during operation of the lane keeping assist controller 15, and outputs a value obtained by adding the correction steering reaction force central value ΔTsc feedforward axial force T FF as the final axial force.
　このように、本実施形態の最終軸力算出部１１Ｂｃは、フィードバック軸力ＴＦＢおよびフィードフォワード軸力ＴＦＦに基づいて最終軸力を算出する。ここで、フィードバック軸力ＴＦＢは、操向輪１３に作用するタイヤ横力Ｆｄの影響を反映するため、路面状態の変化や車両状態の変化に応じて変化する。これに対し、フィードフォワード軸力ＴＦＦは、タイヤ横力Ｆｄの影響を反映しないため、路面状態の変化等にかかわらず滑らかに変化する。それゆえ、最終軸力算出部１１Ｂｃは、フィードバック軸力ＴＦＢに加え、フィードフォワード軸力ＴＦＦに基づいて最終軸力を算出することで、より適切な最終軸力を算出できる。
　ここで、配分比率ＧＦの設定方法としては、軸力差分に基づく配分比率ＧＦ１と横方向加速度Ｇｙに基づく配分比率ＧＦ２とのうちいずれか小さい値と、車速Ｖおよび操舵角δに基づく配分比率ＧＦ３と、操舵角速度ｄδ／ｄｔに基づく配分比率ＧＦ４とを乗算し、乗算結果を配分比率ＧＦとする方法を採用できる。軸力差分としては、例えば、フィードフォワード軸力ＴＦＦとフィードバック軸力ＴＦＢとの差を採用できる。具体的には、軸力差分は、フィードフォワード軸力ＴＦＦからフィードバック軸力ＴＦＢを減算した減算結果とする。 Thus, the final axial force calculating unit 11Bc of the present embodiment calculates the final axial force based on the feedback axial force T FB and feedforward axial force T FF. Here, the feedback axial force T FB changes according to a change in the road surface state or a change in the vehicle state in order to reflect the influence of the tire lateral force Fd acting on the steering wheel 13. In contrast, the feedforward axial force T FF, since not reflect the influence of tire lateral force Fd, smoothly changes regardless of the change or the like of the road surface condition. Therefore, the final axial force calculating unit 11Bc, in addition to the feedback axial force T FB, it calculates the final axial force on the basis of the feedforward axial force T FF, it can be calculated more appropriate final axial force.
Here, as a method of setting the distribution ratio GF is based on the one smaller value of the distribution ratio GF 2 based on the distribution ratio GF 1 and lateral acceleration Gy based on the axial force difference, the vehicle speed V and steering angle δ allocation the ratio GF 3, by multiplying the allocation ratio GF 4 based on the steering angular velocity d? / dt, can be adopted a method for the distribution ratio GF multiplication results. As the axial force difference, for example, a difference between the feedforward axial force TFF and the feedback axial force TFB can be adopted. Specifically, the axial force difference, a subtraction result obtained by subtracting the feedback axial force T FB from the feedforward axial force T FF.
　図１５は、制御マップＭ６を表すグラフである。
　配分比率ＧＦ１の設定方法としては、例えば、軸力差分の絶対値に対応した配分比率ＧＦ１を制御マップＭ６から読み出す方法を採用できる。制御マップＭ６としては、例えば、軸力差分の絶対値に対応した配分比率ＧＦ１を登録したマップがある。具体的には、図１５に示すように、制御マップＭ６は、軸力差分の絶対値が０以上で且つ第１設定軸力差分Ｚ１（＞０）未満の範囲では、軸力差分の大きさにかかわらず配分比率ＧＦ１を第１２設定値（例えば、１．０）に設定する。第１設定軸力差分Ｚ１としては、例えば、フィードフォワード軸力ＴＦＦの推定精度が低下を開始する軸力差分を採用できる。また、制御マップＭ６は、軸力差分の絶対値が第２設定軸力差分Ｚ２（＞Ｚ１）以上の範囲では、軸力差分の大きさにかかわらず配分比率ＧＦ１を第１３設定値（＜第１２設定値。例えば、０．０）に設定する。第２設定軸力差分Ｚ２としては、例えば、フィードフォワード軸力ＴＦＦの推定精度がフィードバック軸力ＴＦＢの推定精度よりも低下する軸力差分を採用できる。さらに、制御マップＭ６は、軸力差分の絶対値が第１設定軸力差分Ｚ１以上で且つ第２設定軸力差分Ｚ２未満の範囲では、軸力差分の絶対値に応じて配分比率ＧＦ１を直線的に低下させる。具体的には、制御マップＭ６は、軸力差分の絶対値が第１設定軸力差分Ｚ１以上で且つ第２設定軸力差分Ｚ２未満の範囲では、軸力差分の絶対値と配分比率ＧＦ１との関係を表す一次関数に従って配分比率ＧＦ１を設定する。一次関数は、軸力差分の絶対値が第１設定軸力差分Ｚ１である場合に配分比率ＧＦ１を第１２設定値（１．０）とし、軸力差分の絶対値が第２設定軸力差分Ｚ２である場合に配分比率ＧＦ１を第１３設定値（０．０）とする。 FIG. 15 is a graph showing the control map M6.
Method for setting distribution ratio GF 1, for example, can be employed a method of reading the distribution ratio GF 1 which corresponds to the absolute value of the axial force difference from the control map M6. The control map M6, for example, there is a map that has registered the distribution ratio GF 1 which corresponds to the absolute value of the axial force difference. Specifically, as shown in FIG. 15, the control map M6 has a large axial force difference in a range where the absolute value of the axial force difference is 0 or more and less than the first set axial force difference Z 1 (> 0). the distribution ratio GF 1 is set to the 12 setting value (e.g., 1.0) regardless of. The first set axial force difference Z 1, for example, can be employed an axial force difference estimation accuracy of the feedforward axial force T FF starts lowering. Further, the control map M6 is the absolute value of the axial force difference is in the second set axial force difference Z 2 (> Z 1) or more ranges, the distribution ratio GF 1 regardless of the magnitude of the axial force difference 13 set value (<Twelfth set value. For example, 0.0). As the second set axial force difference Z 2, for example, can be employed an axial force difference estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB. Further, the control map M6 is in and a second set axial force difference Z 2 than the range in absolute value first set axial force difference Z 1 or more axial force difference, the distribution ratio GF according to the absolute value of the axial force difference 1 is reduced linearly. Specifically, the control map M6 is in and a second set axial force difference Z 2 than the range in absolute value first set axial force difference Z 1 or more axial force difference, distribution and the absolute value of the axial force difference ratio setting the distribution ratio GF 1 according to the primary function representing the relationship between the GF 1. The primary function 12 set value distribution ratio GF 1 when the absolute value of the axial force difference is first set axial force difference Z 1 (1.0) and then, the absolute value of the axial force difference is the second setting axis 13 set value distribution ratio GF 1 when the force difference Z 2 and (0.0).
　このように、本実施形態の最終軸力算出部１１Ｂｃは、軸力差分の絶対値が第１設定軸力差分Ｚ１以上である場合には、軸力差分の絶対値が第１設定軸力差分Ｚ１未満である場合に比べ、配分比率ＧＦ１（フィードフォワード軸力ＴＦＦの配分比率ＧＦ）を小さくする。それゆえ、本実施形態の最終軸力算出部１１Ｂｃは、例えば、車線維持支援コントローラ１５の非作動時に路面μが低減し、フィードフォワード軸力ＴＦＦの推定精度が低下して、軸力差分が増大した場合に、フィードバック軸力ＴＦＢの配分比率（１－ＧＦ）を増大できる。そのため、本実施形態の最終軸力算出部１１Ｂｃは、より適切な操舵反力を付与することができる。 Thus, the final axial force calculating unit 11Bc of the present embodiment, when the absolute value of the axial force difference is first set axial force difference Z 1 or more, the absolute value of the first setting the axial force of the axial force difference compared to the case it is less than the difference Z 1, to reduce the distribution ratio GF 1 (allocation ratio GF of the feedforward axial force T FF). Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, the road surface μ is reduced during non-operation of the lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, the axial force difference When increased, the distribution ratio (1-GF) of the feedback axial force TFB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
　図１６は、制御マップＭ７を表すグラフである。
　ここで、配分比率ＧＦ２の設定方法としては、例えば、横方向加速度Ｇｙの絶対値に対応した配分比率ＧＦ２を制御マップＭ７から読み出す方法を採用できる。制御マップＭ７としては、例えば、横方向加速度Ｇｙの絶対値に対応した配分比率ＧＦ２を登録したマップがある。具体的には、図１６に示すように、制御マップＭ７は、横方向加速度Ｇｙの絶対値が０以上で且つ第１設定横方向加速度Ｇｙ１（＞０）未満の範囲では、横方向加速度Ｇｙの大きさにかかわらず配分比率ＧＦ２を第１４設定値（例えば、１．０）に設定する。第１設定横方向加速度Ｇｙ１としては、例えば、フィードフォワード軸力ＴＦＦの推定精度が低下を開始する横方向加速度Ｇｙを採用できる。また、制御マップＭ７は、横方向加速度Ｇｙの絶対値が第２設定横方向加速度Ｇｙ２（＞Ｇｙ１）以上の範囲では、横方向加速度Ｇｙの大きさにかかわらず配分比率ＧＦ２を第１５設定値（＜第１４設定値。例えば、０．０）に設定する。第２設定横方向加速度Ｇｙ２としては、例えば、フィードフォワード軸力ＴＦＦの推定精度がフィードバック軸力ＴＦＢの推定精度よりも低下する横方向加速度Ｇｙを採用できる。さらに、制御マップＭ７は、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１以上で且つ第２設定横方向加速度Ｇｙ２未満の範囲では、横方向加速度Ｇｙの絶対値に応じて配分比率ＧＦ２を直線的に低下させる。具体的には、制御マップＭ７は、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１以上で且つ第２設定横方向加速度Ｇｙ２未満の範囲では、横方向加速度Ｇｙの絶対値と配分比率ＧＦ２との関係を表す一次関数に従って配分比率ＧＦ２を設定する。一次関数は、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１である場合に配分比率ＧＦ３を第１４設定値（１．０）とし、横方向加速度Ｇｙの絶対値が第２設定横方向加速度Ｇｙ２である場合に配分比率ＧＦ３を第１５設定値（０．０）とする。 FIG. 16 is a graph showing the control map M7.
Here, as a method of setting the distribution ratio GF 2, for example, it can be employed a method of reading the distribution ratio GF 2 corresponding to the absolute value of the lateral acceleration Gy from the control map M7. The control map M7, for example, there is a map that has registered the distribution ratio GF 2 corresponding to the absolute value of the lateral acceleration Gy. Specifically, as shown in FIG. 16, the control map M7 has a lateral acceleration Gy in a range where the absolute value of the lateral acceleration Gy is 0 or more and less than the first set lateral acceleration Gy 1 (> 0). , regardless of the size of the distribution ratio GF 2 14 set value (e.g., 1.0) is set to. As the first set lateral acceleration Gy 1, for example, it can be adopted lateral acceleration Gy estimation accuracy of the feedforward axial force T FF starts lowering. Further, the control map M7 is lateral acceleration in the range absolute value of the second set lateral acceleration Gy 2 (> Gy 1) more Gy, the lateral acceleration distribution ratio GF 2 regardless of the size of the Gy 15 Set to a set value (<14th set value, eg, 0.0). As the second set lateral acceleration Gy 2, for example, can be adopted lateral acceleration Gy estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB. Further, the control map M7 is distributed according to the absolute value of the lateral acceleration Gy in a range where the absolute value of the lateral acceleration Gy is not less than the first set lateral acceleration Gy 1 and less than the second set lateral acceleration Gy 2. linearly decreasing the ratio GF 2. Specifically, the control map M7 indicates that the absolute value of the lateral acceleration Gy is within a range where the absolute value of the lateral acceleration Gy is not less than the first set lateral acceleration Gy 1 and less than the second set lateral acceleration Gy 2. The distribution ratio GF 2 is set according to a linear function representing the relationship with the distribution ratio GF 2 . In the linear function, when the absolute value of the lateral acceleration Gy is the first set lateral acceleration Gy 1 , the distribution ratio GF3 is set to the 14th set value (1.0), and the absolute value of the lateral acceleration Gy is the second set. The distribution ratio GF3 is set to the fifteenth set value (0.0) when the lateral acceleration Gy 2 is set.
　このように、本実施形態の最終軸力算出部１１Ｂｃは、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１以上である場合には、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１未満である場合に比べ、配分比率ＧＦ２（フィードフォワード軸力ＴＦＦの配分比率ＧＦ）を小さくする。それゆえ、本実施形態の最終軸力算出部１１Ｂｃは、例えば車線維持支援コントローラ１５の非作動時に、横方向加速度Ｇｙが増大し、フィードフォワード軸力ＴＦＦの推定精度が低下した場合に、フィードバック軸力ＴＦＢの配分比率（１－ＧＦ）を増大できる。そのため、本実施形態の最終軸力算出部１１Ｂｃは、より適切な操舵反力を付与することができる。 Thus, the final axial force calculating unit 11Bc of the present embodiment, when the absolute value of the lateral acceleration Gy is first set lateral acceleration Gy 1 or more, the absolute value of the first set of lateral acceleration Gy compared with the case of the lateral acceleration Gy less than 1, to reduce the distribution ratio GF 2 (distribution ratio GF of the feedforward axial force T FF). Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, during non-operation of the lane keeping assist controller 15, the lateral acceleration Gy increases, when the estimation accuracy of the feedforward axial force T FF is decreased, feedback The distribution ratio (1-GF) of the axial force T FB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
　図１７は、制御マップＭ８ａ、Ｍ８ｂを表すグラフである。
　ここで、配分比率ＧＦ３の設定方法としては、例えば、車速Ｖの絶対値および操舵角δの絶対値に対応した配分比率ＧＦ３ａ、ＧＦ３ｂを制御マップＭ８ａ、Ｍ８ｂから読み出し、読み出した配分比率ＧＦ３ａ、ＧＦ３ｂを乗算し、乗算結果を配分比率ＧＦ３とする方法を採用できる。制御マップＭ８ａとしては、例えば、車速Ｖの絶対値に対応した配分比率ＧＦ３を登録したマップがある。具体的には、図１７（ａ）に示すように、制御マップＭ８ａは、車速Ｖの絶対値が０以上で且つ第３設定車速Ｖ３未満の範囲では、車速Ｖの大きさにかかわらず配分比率ＧＦ３ａを第１６設定値（例えば、０．５）に設定する。第３設定車速Ｖ３としては、例えば、車速Ｖが低いことによるタイヤ特性の非線形性（タイヤすべり角に対するタイヤ横力Ｆｄの非線形性）が現れ、フィードフォワード軸力ＴＦＦの推定精度が低下を開始する車速Ｖを採用できる。また、制御マップＭ８ａは、車速Ｖの絶対値が第４設定車速Ｖ４（＞Ｖ３）以上の範囲では、車速Ｖの大きさにかかわらず配分比率ＧＦ３ａを第１７設定値（＞第１６設定値。例えば、１．０）に設定する。第４設定車速Ｖ４としては、例えば、フィードフォワード軸力ＴＦＦの推定精度がフィードバック軸力ＴＦＢの推定精度よりも向上する車速Ｖを採用できる。さらに、制御マップＭ８ａは、車速Ｖの絶対値が第３設定車速Ｖ３以上で且つ第４設定車速Ｖ４未満の範囲では、車速Ｖの絶対値に応じて配分比率ＧＦ３ａを直線的に増加させる。具体的には、制御マップＭ８ａは、車速Ｖの絶対値が第３設定車速Ｖ３以上で且つ第４設定車速Ｖ４未満の範囲では、車速Ｖと配分比率ＧＦ３ａとの関係を表す一次関数に従って配分比率ＧＦ３ａを設定する。一次関数は、車速Ｖの絶対値が第３設定車速Ｖ３である場合に配分比率ＧＦ３ａを第１６設定値（０．５）とし、車速Ｖが第４設定車速Ｖ４である場合に配分比率ＧＦ３ａを第１７設定値（１．０）とする。 FIG. 17 is a graph showing the control maps M8a and M8b.
Here, as a method of setting the distribution ratio GF 3, for example, the distribution ratio GF 3a corresponding to the absolute value of the absolute value and the steering angle δ of the vehicle speed V, the control GF 3b map M8a, read from M8b, read allocation ratio A method of multiplying GF 3a and GF 3b and setting the multiplication result as a distribution ratio GF 3 can be adopted. The control map M8a, for example, there is a map that has registered the distribution ratio GF 3 corresponding to the absolute value of the vehicle speed V. Specifically, as shown in FIG. 17 (a), the control map M8a is the absolute value range and less than the third set speed V 3 0 or more vehicle speed V is allocated regardless of the size of the vehicle speed V the ratio GF 3a 16th set value (e.g., 0.5) is set to. The third set speed V 3, for example, (tire lateral force nonlinearity of Fd with respect to the tire slip angle) appears nonlinearity of tire characteristic due to the vehicle speed V is low, the degradation estimation accuracy of the feedforward axial force T FF The starting vehicle speed V can be adopted. Further, in the control map M8a, in the range where the absolute value of the vehicle speed V is equal to or higher than the fourth set vehicle speed V 4 (> V 3 ), the distribution ratio GF 3a is set to the 17th set value (> 16th) regardless of the magnitude of the vehicle speed V. Set value, for example, 1.0). The fourth set vehicle speed V 4, for example, can be employed vehicle speed V estimation accuracy of the feedforward axial force T FF is improved than the estimation accuracy of the feedback axial force T FB. Further, the control map M8a, the absolute value of the vehicle speed V is in a range and the fourth less than the set vehicle speed V 4 at the third set speed V 3 or more, linearly increasing the distribution ratio GF 3a in accordance with the absolute value of the vehicle speed V Let Specifically, the control map M8a, to the extent and in the fourth less than the set vehicle speed V 4 in absolute value the third set speed V 3 or more of the vehicle speed V is a linear function representing the relationship between the distribution ratio GF 3a and the vehicle speed V The distribution ratio GF 3a is set according to The linear function is assigned when the absolute value of the vehicle speed V is the third set vehicle speed V 3 and the allocation ratio GF 3a is the 16th set value (0.5), and when the vehicle speed V is the fourth set vehicle speed V 4. The ratio GF 3a is set to the 17th set value (1.0).
　このように、本実施形態の最終軸力算出部１１Ｂｃは、車速Ｖの絶対値が第４設定車速Ｖ４未満である場合には、車速Ｖの絶対値が第４設定車速Ｖ４以上である場合に比べ、配分比率ＧＦ３ａ（フィードフォワード軸力ＴＦＦの配分比率ＧＦ）を小さくする。それゆえ、本実施形態の最終軸力算出部１１Ｂｃは、例えば、車線維持支援コントローラ１５の非作動時に車速Ｖが低減し、フィードフォワード軸力ＴＦＦの推定精度が低下した場合に、フィードバック軸力ＴＦＢの配分比率（１－ＧＦ）を増大できる。そのため、本実施形態の最終軸力算出部１１Ｂｃは、より適切な操舵反力を付与することができる。 Thus, the final axial force calculating unit 11Bc of the present embodiment, when the absolute value of the vehicle speed V is the fourth less than the set vehicle speed V 4, the absolute value of the vehicle speed V is in the fourth set speed V 4 or more Compared to the case, the distribution ratio GF 3a (the distribution ratio GF of the feedforward axial force T FF ) is reduced. Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, when the vehicle speed V is reduced at the time of non-operation of the lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, the feedback axial force The distribution ratio of T FB (1-GF) can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
　また、制御マップＭ８ｂとしては、例えば、操舵角δの絶対値に対応した配分比率ＧＦ３ｂを登録したマップがある。具体的には、図１７（ｂ）に示すように、制御マップＭ８ｂは、操舵角δの絶対値が０以上で且つ第１設定操舵角δ１（＞０）未満の範囲では、操舵角δの大きさにかかわらず配分比率ＧＦ３ｂを第１８設定値（例えば、１．０）に設定する。第１設定操舵角δ１としては、例えば、フィードフォワード軸力ＴＦＦの推定精度が低下を開始する操舵角δを採用できる。また、制御マップＭ８ｂは、操舵角δの絶対値が第２設定操舵角δ２（＞δ１）以上の範囲では、操舵角δの大きさにかかわらず配分比率ＧＦ３ｂを第１９設定値（＜第１８設定値。例えば、０．６）に設定する。第２設定操舵角δ２としては、例えば、フィードフォワード軸力ＴＦＦの推定精度がフィードバック軸力ＴＦＢの推定精度よりも低下する操舵角δを採用できる。さらに、制御マップＭ８ｂは、操舵角δの絶対値が第１設定操舵角δ１以上で且つ第２設定操舵角δ２未満の範囲では、操舵角δの絶対値に応じて配分比率ＧＦ３ｂを直線的に低下させる。具体的には、制御マップＭ８ｂは、操舵角δの絶対値が第１設定操舵角δ１以上で且つ第２設定操舵角δ２未満の範囲では、操舵角δの絶対値と配分比率ＧＦ３ｂとの関係を表す一次関数に従って配分比率ＧＦ３ｂを設定する。一次関数は、操舵角δの絶対値が第１設定操舵角δ１である場合に配分比率ＧＦ３ｂを第１８設定値（１．０）とし、操舵角δの絶対値が第２設定操舵角δ２である場合に配分比率ＧＦ３を第１９設定値（０．６）とする。 As the control map M8b, for example, there is a map that has registered the distribution ratio GF 3b corresponding to the absolute value of the steering angle [delta]. Specifically, as shown in FIG. 17B, the control map M8b indicates that the steering angle δ is within a range where the absolute value of the steering angle δ is 0 or more and less than the first set steering angle δ 1 (> 0). , regardless of the size of the distribution ratio GF 3b 18th set value (e.g., 1.0) is set to. As the first set steering angle δ 1 , for example, a steering angle δ at which the estimation accuracy of the feedforward axial force TFF starts to decrease can be employed. Further, in the control map M8b, the distribution ratio GF 3b is set to the 19th set value (regardless of the magnitude of the steering angle δ) in the range where the absolute value of the steering angle δ is equal to or larger than the second set steering angle δ 2 (> δ 1 ). <18th set value, for example, 0.6). As the second set steering angle [delta] 2, for example, can be adopted steering angle [delta] of the estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB. Further, in the control map M8b, in the range where the absolute value of the steering angle δ is not less than the first set steering angle δ 1 and less than the second set steering angle δ 2 , the distribution ratio GF 3b is set according to the absolute value of the steering angle δ. Decrease linearly. Specifically, the control map M8b, in absolute value and the second set steering angle [delta] 2 of less than the range in the first set steering angle [delta] 1 or more of the steering angle [delta], the distribution ratio GF 3b and the absolute value of the steering angle [delta] An allocation ratio GF 3b is set according to a linear function representing the relationship between In the linear function, when the absolute value of the steering angle δ is the first setting steering angle δ 1 , the distribution ratio GF 3b is set to the 18th setting value (1.0), and the absolute value of the steering angle δ is the second setting steering angle. 19 set value distribution ratio GF3 when a [delta] 2 and (0.6).
　このように、本実施形態の最終軸力算出部１１Ｂｃは、操舵角δの絶対値が第１設定操舵角δ１以上である場合には、操舵角δの絶対値が第１設定操舵角δ１未満である場合に比べ、配分比率ＧＦ３ｂ（フィードフォワード軸力ＴＦＦの配分比率ＧＦ）を小さくする。それゆえ、本実施形態の最終軸力算出部１１Ｂｃは、例えば、車線維持支援コントローラ１５の非作動時に操舵角δが増大し、フィードフォワード軸力ＴＦＦの推定精度が低下した場合に、フィードバック軸力ＴＦＢの配分比率（１－ＧＦ）を増大できる。そのため、本実施形態の最終軸力算出部１１Ｂｃは、より適切な操舵反力を付与することができる。 Thus, the final axial force calculating unit 11Bc of the present embodiment, when the absolute value of the steering angle [delta] is first set steering angle [delta] 1 or more, the absolute value of the first set steering angle of the steering angle [delta] [delta] compared to the case is less than 1, to reduce the distribution ratio GF 3b (distribution ratio GF of the feedforward axial force T FF). Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, when the increased steering angle δ is in the inoperative lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, the feedback shaft The distribution ratio (1-GF) of the force T FB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
　図１８は、制御マップＭ９を表すグラフである。
　ここで、配分比率ＧＦ４の設定方法としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応した配分比率ＧＦ４を制御マップＭ９から読み出す方法を採用できる。制御マップＭ９としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応した配分比率ＧＦ４を登録したマップがある。具体的には、図１８に示すように、制御マップＭ９は、操舵角速度ｄδ／ｄｔの絶対値が０以上で且つ第４設定操舵角速度ｄδ４／ｄｔ（＞０）未満の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらず配分比率ＧＦ４を第２０設定値（例えば、１．０）に設定する。第４設定操舵角速度ｄδ４／ｄｔとしては、例えば、フィードフォワード軸力ＴＦＦの推定精度が低下を開始する操舵角速度ｄδ／ｄｔを採用できる。また、制御マップＭ９は、操舵角速度ｄδ／ｄｔの絶対値が第５設定操舵角速度ｄδ５／ｄｔ（＞ｄδ４／ｄｔ）以上の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらず配分比率ＧＦ４を第２１設定値（＜第２０設定値。例えば、０．０）に設定する。第５設定操舵角速度ｄδ５／ｄｔとしては、例えば、フィードフォワード軸力ＴＦＦの推定精度がフィードバック軸力ＴＦＢの推定精度よりも低下する操舵角速度ｄδ／ｄｔを採用できる。さらに、制御マップＭ９は、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上で且つ第５設定操舵角速度ｄδ５／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値に応じて配分比率ＧＦ４を直線的に低下させる。具体的には、制御マップＭ９は、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上で且つ第５設定操舵角速度ｄδ５／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値と配分比率ＧＦ４との関係を表す一次関数に従って配分比率ＧＦ４を設定する。一次関数は、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔである場合に配分比率ＧＦ４を第２０設定値（１．０）とし、操舵角速度ｄδ／ｄｔの絶対値が第５設定操舵角速度ｄδ５／ｄｔである場合に配分比率ＧＦ４を第２１設定値（０．０）とする。 FIG. 18 is a graph showing the control map M9.
Here, as a method of setting the distribution ratio GF 4, for example, it can be employed a method of reading the distribution ratio GF 4 corresponding to the absolute value of the steering angular velocity d? / Dt from the control map M9. The control map M9, for example, there is a map that has registered the distribution ratio GF 4 corresponding to the absolute value of the steering angular velocity d? / Dt. Specifically, as shown in FIG. 18, the control map M9 indicates that the steering angular velocity is in the range where the absolute value of the steering angular velocity dδ / dt is 0 or more and less than the fourth set steering angular velocity dδ 4 / dt (> 0). the distribution ratio GF 4 regardless of the size of d? / dt twentieth set value (e.g., 1.0) is set to. The fourth set steering angular velocity d? 4 / dt, for example, can be adopted steering angular velocity d? / Dt of estimation accuracy of the feedforward axial force T FF starts lowering. In addition, the control map M9 shows that the distribution ratio is independent of the magnitude of the steering angular velocity dδ / dt in the range where the absolute value of the steering angular velocity dδ / dt is not less than the fifth set steering angular velocity dδ 5 / dt (> dδ 4 / dt). the GF 4 21 set value (<20th set value. for example, 0.0) is set to. The fifth set steering angular velocity d? 5 / dt, for example, can be adopted steering angular velocity d? / Dt of estimation accuracy of the feedforward axial force T FF is lower than the estimation accuracy of the feedback axial force T FB. Further, the control map M9 indicates that the absolute value of the steering angular velocity dδ / dt is within a range where the absolute value of the steering angular velocity dδ / dt is not less than the fourth set steering angular velocity dδ 4 / dt and less than the fifth set steering angular velocity dδ 5 / dt. linearly decreasing the distribution ratio GF 4 in accordance with the. Specifically, the control map M9 indicates that the steering angular velocity dδ / dt is within a range where the absolute value of the steering angular velocity dδ / dt is not less than the fourth set steering angular velocity dδ 4 / dt and less than the fifth set steering angular velocity dδ 5 / dt. The distribution ratio GF 4 is set in accordance with a linear function that represents the relationship between the absolute value of and the distribution ratio GF 4 . When the absolute value of the steering angular velocity dδ / dt is the fourth set steering angular velocity dδ 4 / dt, the linear function sets the distribution ratio GF 4 to the twentieth set value (1.0), and the absolute value of the steering angular velocity dδ / dt. Is the fifth set steering angular velocity dδ 5 / dt, the distribution ratio GF 4 is set to the twenty-first set value (0.0).
　このように、本実施形態の最終軸力算出部１１Ｂｃは、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上である場合には、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ未満である場合に比べ、配分比率ＧＦ４（フィードフォワード軸力ＴＦＦの配分比率ＧＦ）を小さくする。それゆえ、本実施形態の最終軸力算出部１１Ｂｃは、例えば、車線維持支援コントローラ１５の非作動時に操舵角速度ｄδ／ｄｔが増大し、フィードフォワード軸力ＴＦＦの推定精度が低下した場合に、フィードバック軸力ＴＦＢの配分比率（１－ＧＦ）を増大できる。そのため、本実施形態の最終軸力算出部１１Ｂｃは、より適切な操舵反力を付与することができる。 Thus, the final axial force calculation unit 11Bc of the present embodiment has the absolute value of the steering angular velocity dδ / dt when the absolute value of the steering angular velocity dδ / dt is equal to or greater than the fourth set steering angular velocity dδ 4 / dt. The distribution ratio GF 4 (the distribution ratio GF of the feed-forward axial force T FF ) is made smaller than when the fourth set steering angular velocity dδ 4 / dt is less. Therefore, the final axial force calculating unit 11Bc of the present embodiment, for example, when increasing the steering angular velocity d? / Dt at the time of non-operation of the lane keeping assist controller 15, the estimation accuracy of the feedforward axial force T FF is decreased, The distribution ratio (1-GF) of the feedback axial force TFB can be increased. Therefore, the final axial force calculation unit 11Bc of the present embodiment can apply a more appropriate steering reaction force.
　これにより、最終軸力算出部１１Ｂｃは、軸力差分の絶対値が第１設定軸力差分Ｚ１未満、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１未満、車速Ｖの絶対値が第４設定車速Ｖ４以上、操舵角δの絶対値が第１設定操舵角δ１未満、および操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ未満である場合には、車線維持支援コントローラ１５の非作動状態及び作動状態に関わらず、フィードフォワード軸力ＴＦＦに補正操舵反力中心値ΔＴｓｃを加算した軸力を最終軸力とする。また、最終軸力算出部１１Ｂｃは、軸力差分の絶対値が第２設定軸力差分Ｚ２以上、横方向加速度Ｇｙの絶対値が第２設定横方向加速度Ｇｙ２以上、および操舵角速度ｄδ／ｄｔの絶対値が第５設定操舵角速度ｄδ５／ｄｔ以上の少なくともいずれかであって車線維持支援コントローラ１５の非作動状態の場合には、フィードバック軸力ＴＦＢに補正操舵反力中心値ΔＴｓｃを加算した軸力を最終軸力とする。さらに、最終軸力算出部１１Ｂｃは、軸力差分の絶対値が第１設定軸力差分Ｚ１以上で且つ第２設定軸力差分Ｚ２未満、横方向加速度Ｇｙの絶対値が第１設定横方向加速度Ｇｙ１以上で且つ第２設定横方向加速度Ｇｙ２未満、車速Ｖの絶対値が第４設定車速Ｖ４未満、操舵角δの絶対値が第１設定操舵角δ１以上、および操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上であって車線維持支援コントローラ１５の非作動状態の場合には、フィードフォワード軸力ＴＦＦに配分比率ＧＦを乗算した値とフィードバック軸力ＴＦＢに配分比率（１－ＧＦ）を乗算した値に補正操舵反力中心値ΔＴｓｃを加算した軸力を最終軸力とする。 Thus, the final axial force calculating unit 11Bc the absolute value of the first set axial force difference Z less than 1 axial force difference, the absolute value of the first set lateral acceleration Gy less than 1 lateral acceleration Gy, an absolute vehicle speed V value fourth set vehicle speed V 4 above, the steering angle δ of the absolute value of the first set steering angle δ smaller than 1, and when the absolute value of the steering angular velocity d? / dt is the fourth set the steering angular velocity d? less than 4 / dt regardless inoperative and operating state of the lane keeping assist controller 15, the axial force obtained by adding the correction steering reaction force central value ΔTsc feedforward axial force T FF and final axial force. Also, the final axial force calculating unit 11Bc the absolute value of the axial force difference is the second set axial force difference Z 2 or more, the absolute value of the lateral acceleration Gy and the second set lateral acceleration Gy 2 or more, and the steering angular velocity d? / If the absolute value of dt is in a non-operating state of the fifth set steering angular velocity d? 5 / dt or the lane keeping assist controller 15 at least be either the corrected steering reaction force central value ΔTsc the feedback axial force T FB The added axial force is taken as the final axial force. Furthermore, the final axial force calculating unit 11Bc the absolute value and the second set axial force less than the difference Z 2 at first set axial force difference Z 1 or more axial force difference, the absolute value of the first set next to the lateral acceleration Gy direction acceleration Gy 1 or more and a second set lateral acceleration Gy less than 2, the absolute value of the vehicle speed V is less than the fourth predetermined vehicle speed V 4, the absolute value of the steering angle [delta] is first set steering angle [delta] 1 or more, and the steering angular velocity If the absolute value of d? / dt is in a non-operating state of the fourth set steering angular velocity d? 4 / dt Exceeded by the lane keeping assist controller 15, the value and the feedback obtained by multiplying the allocation ratio GF feedforward axial force T FF axial force T FB to distribution ratio (1-GF) axial force obtained by adding the correction steering reaction force central value ΔTsc to a value obtained by multiplying the a and final axial force.
　それゆえ、最終軸力算出部１１Ｂｃは、自車両Ａが、道路の路面μが高く（ドライ路面）、車速Ｖが高く、操舵角δが小さく、操舵角速度ｄδ／ｄｔが小さい状況（以下、特定状況とも呼ぶ）にある場合には、車線維持支援コントローラ１５の非作動状態及び作動状態に関わらず、フィードフォワード軸力ＴＦＦに補正操舵反力中心値ΔＴｓｃを加算した軸力を最終軸力とする。ここで、フィードフォワード軸力ＴＦＦは、タイヤ横力Ｆｄの影響を反映しないため、路面状態の変化等にかかわらず滑らかに変化する。それゆえ、最終軸力算出部１１Ｂｃは、自車両Ａが特定状況にある場合には、安定した操舵感を実現することができる。さらに、最終軸力算出部１１Ｂｃは、車線維持支援機能という付加機能の作動時にも操舵感のよいフィードフォワード軸力ＴＦＦに基づく軸力を最終軸力とすることができる。それゆえ、最終軸力算出部１１Ｂｃは、車線維持支援機能という付加機能の作動時に、安定した操舵感を実現することができる。 Therefore, the final axial force calculation unit 11Bc determines that the host vehicle A has a high road surface μ (dry road surface), a high vehicle speed V, a small steering angle δ, and a small steering angular velocity dδ / dt (hereinafter, specified). If there also called a situation), regardless inoperative and operating state of the lane keeping assist controller 15, and a final axial force the axial force obtained by adding the correction steering reaction force central value ΔTsc feedforward axial force T FF To do. Here, the feedforward axial force T FF, since not reflect the influence of tire lateral force Fd, smoothly changes regardless of the change or the like of the road surface condition. Therefore, the final axial force calculation unit 11Bc can realize a stable steering feeling when the host vehicle A is in a specific situation. Furthermore, the final axial force calculating unit 11Bc may be the axial force even during operation of the additional function of lane keeping support function based on good feedforward axial force T FF of road feel to the final axial force. Therefore, the final axial force calculation unit 11Bc can realize a stable steering feeling when the additional function called the lane keeping support function is activated.
　これに対し、最終軸力算出部１１Ｂｃは、自車両Ａが、特定状況以外の状況（以下、通常状況とも呼ぶ）にあって車線維持支援コントローラ１５の非作動状態の場合には、フィードバック軸力ＴＦＢ、またはフィードフォワード軸力ＴＦＦとフィードバック軸力ＴＦＢとを合算したものを最終軸力とする。ここで、フィードバック軸力ＴＦＢは、操向輪１３に作用するタイヤ横力Ｆｄの影響を反映するため、路面状態の変化や車両状態の変化に応じて変化する。それゆえ、最終軸力算出部１１Ｂｃは、自車両Ａが通常状況にある場合には、ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置と同様の操舵感を付与でき、自然な操舵感を実現することができる。 On the other hand, the final axial force calculation unit 11Bc provides a feedback axial force when the host vehicle A is in a situation other than the specific situation (hereinafter also referred to as a normal situation) and the lane keeping support controller 15 is not in operation. The final axial force is T FB or the sum of the feedforward axial force T FF and the feedback axial force T FB . Here, the feedback axial force T FB changes according to a change in the road surface state or a change in the vehicle state in order to reflect the influence of the tire lateral force Fd acting on the steering wheel 13. Therefore, the final axial force calculation unit 11Bc performs the same steering as the mechanical steering control device in which the steering wheel 12 and the steering wheel 13 are mechanically coupled when the host vehicle A is in a normal state. A feeling can be given and a natural steering feeling can be realized.
　図３に戻り、軸力－操舵反力変換部１１Ｂｄは、最終軸力算出部１１Ｂｃが算出した最終軸力と、補正操舵反力演算部１５Ａ（図２参照）が演算した最終目標補正操舵反力τＹ＊とに基づいて目標操舵反力を算出する。目標操舵反力とは、操舵反力の目標値をいう。目標操舵反力の算出方法としては、例えば、車速Ｖおよび最終軸力に対応した事前目標操舵反力を制御マップＭ１０から読み出し、読み出した事前目標操舵反力に最終目標補正操舵反力τＹ＊を加算する方法を採用できる。制御マップＭ１０とは、車速Ｖ毎に、最終軸力に対応した事前目標操舵反力を登録したマップをいう。軸力－操舵反力変換部１１Ｂｄは、制御マップＭ１０から事前目標操舵反力を読み出す事前目標操舵反力読み出し部１１Ｂｄａと、事前目標操舵反力と最終目標補正操舵反力τＹ＊とを加算する加算部１１Ｂｄｂとを有している。 Returning to FIG. 3, the axial force-steering reaction force conversion unit 11Bd calculates the final axial force calculated by the final axial force calculation unit 11Bc and the final target corrected steering reaction calculated by the corrected steering reaction force calculation unit 15A (see FIG. 2). A target steering reaction force is calculated based on the force τY *. The target steering reaction force is a target value of the steering reaction force. As a method for calculating the target steering reaction force, for example, the prior target steering reaction force corresponding to the vehicle speed V and the final axial force is read from the control map M10, and the final target correction steering reaction force τY * is added to the read prior target steering reaction force. A method of adding can be adopted. The control map M10 is a map in which the preliminary target steering reaction force corresponding to the final axial force is registered for each vehicle speed V. The axial force-steering reaction force conversion unit 11Bd adds the previous target steering reaction force reading unit 11Bda that reads the previous target steering reaction force from the control map M10, and the previous target steering reaction force and the final target corrected steering reaction force τY *. And an adder 11Bdb.
　図１９は、制御マップＭ１０を表すグラフである。
　図１９に示すように、制御マップＭ１０は、車速Ｖ毎に設定される。また、制御マップＭ１０は、最終軸力が大きいほど事前目標操舵反力を大きい値とする。
　図３に戻り、目標反力電流演算部１１Ｂｅは、軸力－操舵反力変換部１１Ｂｄが算出した目標操舵反力に基づき、下記（１３）式に従って目標反力電流を算出する。そして、目標反力電流演算部１１Ｂｅは、算出結果を反力モータ駆動部３Ｄに出力する。
　目標反力電流＝目標操舵反力×ゲイン　・・・（１３）
　なお、本実施形態では、目標反力電流演算部１１Ｂｅが、軸力－操舵反力変換部１１Ｂｄが算出した目標操舵反力を基に目標反力電流を算出する例を示したが、他の構成を採用することもできる。例えば、軸力－操舵反力変換部１１Ｂｄは、最終目標補正操舵反力τＹ＊に代えて端当て反力を加算して目標操舵反力を補正するようになっていてもよい。端当て反力としては、例えば、転舵角θが最大値となった場合に付与する操舵反力がある。 FIG. 19 is a graph showing the control map M10.
As shown in FIG. 19, the control map M10 is set for each vehicle speed V. Further, the control map M10 sets the prior target steering reaction force to a larger value as the final axial force is larger.
Returning to FIG. 3, the target reaction force current calculation unit 11Be calculates a target reaction force current according to the following equation (13) based on the target steering reaction force calculated by the axial force-steering reaction force conversion unit 11Bd. Then, the target reaction force current calculation unit 11Be outputs the calculation result to the reaction force motor drive unit 3D.
Target reaction force current = Target steering reaction force × Gain (13)
In this embodiment, the target reaction force current calculation unit 11Be calculates the target reaction force current based on the target steering reaction force calculated by the axial force-steering reaction force conversion unit 11Bd. A configuration can also be adopted. For example, the axial force-steering reaction force converter 11Bd may correct the target steering reaction force by adding the end contact reaction force instead of the final target correction steering reaction force τY *. As the end contact reaction force, for example, there is a steering reaction force applied when the turning angle θ reaches a maximum value.
　次に、車線維持支援コントローラ１５の処理について、図２０を参照しつつ説明する。
　車線維持支援コントローラ１５は、所定サンプリング周期毎に繰り返して当該処理を実行する。
　まず、ステップＳ１００にて、各センサ及び操舵用コントローラ１１からの各種データを読み込む。車線維持支援コントローラ１５は、例えば車輪速センサ１８～２１から各車輪速Ｖｗを読み込む。また、車線維持支援コントローラ１５は、操舵用コントローラ１１が出力した操舵角δ、操舵角速度ｄδ／ｄｔ（以下、ｄδ／ｄｔを「δ′」と表記する場合がある）及び操舵トルクτを読み込む。さらに、車線維持支援コントローラ１５は、方向指示スイッチ１７が出力した信号を読み込む。外界認識部１６からは、自車両の走行車線に対する車両のヨー角φ、走行車線中央からの横変位Ｘ、及び走行車線の曲率ρをそれぞれ読み込む。 Next, processing of the lane keeping support controller 15 will be described with reference to FIG.
The lane keeping support controller 15 executes the processing repeatedly every predetermined sampling period.
First, in step S100, various data from each sensor and the steering controller 11 are read. The lane keeping support controller 15 reads each wheel speed Vw from the wheel speed sensors 18 to 21, for example. Further, the lane keeping assist controller 15 reads the steering angle δ, the steering angular velocity dδ / dt (hereinafter, dδ / dt may be expressed as “δ ′”) and the steering torque τ output from the steering controller 11. Further, the lane keeping support controller 15 reads the signal output from the direction instruction switch 17. From the external recognition unit 16, the yaw angle φ of the vehicle with respect to the traveling lane of the host vehicle, the lateral displacement X from the center of the traveling lane, and the curvature ρ of the traveling lane are read.
　続いてステップＳ１１０にて、下記（１４）式および（１５）式に基づき、左右の車線端部基準閾値ＸＬｔ、ＸＲｔの設定を行う。
　ここで、図２１に示すように、右側の車線端部基準閾値ＸＲｔは、右逸脱に対して設定する車線端部基準ＬＸＲの位置を特定するものである。左側の車線端部基準閾値ＸＬｔは、左逸脱に対して設定する車線端部基準ＬＸＬの位置を特定するものである。
　ＸＲｔ＝（Ｗｌａｎｅ／２）－（Ｗｃａｒ／２）－Ｘｏｆｆｓｅｔ　・・・（１４）
　ＸＬｔ＝－（（Ｗｌａｎｅ／２　）－（Ｗｃａｒ／２）－Ｘｏｆｆｓｅｔ）　・・・（１５）
　また、下記（１６）式および（１７）式に基づき、左右の車線幅方向オフセット閾値ＸＬｔ２、ＸＲｔ２の設定を行う。
　ＸＲｔ２＝（Ｗｌａｎｅ／２）－（Ｗｃａｒ／２）－Ｘｏｆｆｓｅｔ２　・・・（１６）
　ＸＬｔ２＝－（（Ｗｌａｎｅ／２）－（Ｗｃａｒ／２）－Ｘｏｆｆｓｅｔ２）　・・・（１７）
　ここで、走行車線中央Ｌｓからの横変位Ｘは、走行車線Ｌに対して自車両Ａが中心よりも右側にいる場合を正とし、左側に位置する場合を負とする。このため、右側の車線端部基準閾値ＸＲｔ及び車線幅方向オフセット閾値ＸＲｔ２側を正としている。 Subsequently, in step S110, the left and right lane edge reference thresholds XLt and XRt are set based on the following equations (14) and (15).
Here, as shown in FIG. 21, the right lane edge reference threshold value XRt specifies the position of the lane edge reference LXR set for the right departure. The left lane edge reference threshold XLt specifies the position of the lane edge reference LXL set for the left departure.
XRt = (Wlane / 2) − (Wcar / 2) −Xoffset (14)
XLt = − ((Wlane / 2) − (Wcar / 2) −Xoffset) (15)
Further, the left and right lane width direction offset threshold values XLt2 and XRt2 are set based on the following equations (16) and (17).
XRt2 = (Wlane / 2) − (Wcar / 2) −Xoffset2 (16)
XLt2 = − ((Wlane / 2) − (Wcar / 2) −Xoffset2) (17)
Here, the lateral displacement X from the travel lane center Ls is positive when the host vehicle A is on the right side of the center with respect to the travel lane L, and is negative when the vehicle is located on the left side. For this reason, the right lane edge reference threshold value XRt and the lane width direction offset threshold value XRt2 side are positive.
　また、図２１に示すように、Ｗｌａｎｅは走行車線幅であり、Ｗｃａｒは自車両Ａの車幅である。
　また、Ｘｏｆｆｓｅｔ及びＸｏｆｆｓｅｔ２は走行車線端部Ｌｅ（白線や路肩）の位置に対する余裕代である。この余裕代Ｘｏｆｆｓｅｔ及びＸｏｆｆｓｅｔ２は、走行車線幅Ｗｌａｎｅや車速などに応じて変更しても良い。例えば、走行車線幅Ｗｌａｎｅが狭い程、余裕代Ｘｏｆｆｓｅｔ及びＸｏｆｆｓｅｔ２を小さくする。また、左右の車線端部基準ＬＸＬ、ＬＸＲ毎に異なる余裕代Ｘｏｆｆｓｅｔ及びＸｏｆｆｓｅｔ２を使用しても良い。 Further, as shown in FIG. 21, Wlane is the travel lane width, and Wcar is the vehicle width of the host vehicle A.
Xoffset and Xoffset2 are margins for the position of the traveling lane edge Le (white line or shoulder). The margin allowances Xoffset and Xoffset2 may be changed according to the travel lane width Wlane, the vehicle speed, and the like. For example, the margins Xoffset and Xoffset2 are made smaller as the travel lane width Wlane is narrower. Also, different margins Xoffset and Xoffset2 may be used for the left and right lane edge reference LXL, LXR.
　また、余裕代Ｘｏｆｆｓｅｔ及びＸｏｆｆｓｅｔ２は、ゼロ又は負値としても良い。また、この左右の車線端部基準ＬＸＬ、ＬＸＲは固定値であっても良い。また、余裕代Ｘｏｆｆｓｅｔ及びＸｏｆｆｓｅｔ２は、同じ値であっても良い。この場合には、左右の車線端部基準閾値ＸＬｔ、ＸＲｔとが左右の車線幅方向オフセット閾値ＸＬｔ２、ＸＲｔ２とが同じものとなる。
　次に、ステップＳ１２０にて、下記式に基づき、右逸脱に対するヨー角偏差ΔφＲを算出する。
　ΔφＲ＝φ（φ＞０の場合）
　ΔφＲ＝０（φ≦０の場合）
　ここで、走行車線に対する車両のヨー角φは、図２２に示すように、右側へヨー角がついている場合を正とし、左側へヨー角がついている場合を負とする。また、ΔφＲは、右逸脱に対してのみ設定するヨー角偏差であるため、図２３（ａ）に示すように、ΔφＲ≦０の場合、ΔφＲ＝０とする（正の値のみをとるようにする）。 Further, the margin allowances Xoffset and Xoffset2 may be zero or negative values. Further, the left and right lane edge reference LXL, LXR may be fixed values. Further, the margin allowances Xoffset and Xoffset2 may be the same value. In this case, the left and right lane edge reference threshold values XLt and XRt are the same as the left and right lane width direction offset threshold values XLt2 and XRt2.
Next, in step S120, the yaw angle deviation ΔφR with respect to the right departure is calculated based on the following equation.
ΔφR = φ (when φ> 0)
ΔφR = 0 (when φ ≦ 0)
Here, as shown in FIG. 22, the yaw angle φ of the vehicle with respect to the travel lane is positive when the yaw angle is on the right side and negative when the yaw angle is on the left side. Further, since ΔφR is a yaw angle deviation set only for the right deviation, as shown in FIG. 23A, when ΔφR ≦ 0, ΔφR = 0 (only a positive value is taken). To do).
　図２０に戻って、次にステップＳ１３０にて、下記式に基づき、左逸脱に対するヨー角偏差ΔφＬを算出する。
　ΔφＬ＝φ（φ＜０の場合）
　ΔφＬ＝０（φ≧０の場合）
　ここで、ΔφＬは、左逸脱に対してのみ設定したヨー角偏差であるため、図２３（ｂ）に示すように、ΔφＬ≧０の場合、ΔφＬ＝０とする（負の値のみをとるようにする）。
　図２０に戻って、次に、ステップＳ１４０にて、第１目標補正転舵角θＹ１＊を算出する。ステップＳ１４０の処理は補正転舵角演算部１５Ｃ（図２参照）が実行する。第１目標補正転舵角θＹ１＊は、走行車線に対する車両のヨー角φを打ち消すための制御量である。すなわち、走行車線と車両の進行方向が平行となるようにするための角度偏差用の制御量である。 Returning to FIG. 20, in step S130, the yaw angle deviation ΔφL for the left deviation is calculated based on the following equation.
ΔφL = φ (when φ <0)
ΔφL = 0 (when φ ≧ 0)
Here, since ΔφL is a yaw angle deviation set only for the left deviation, as shown in FIG. 23B, when ΔφL ≧ 0, ΔφL = 0 (only negative values are taken). ).
Returning to FIG. 20, next, in step S140, a first target correction turning angle θY1 * is calculated. The process of step S140 is executed by the corrected turning angle calculation unit 15C (see FIG. 2). The first target correction turning angle θY1 * is a control amount for canceling the yaw angle φ of the vehicle with respect to the travel lane. That is, it is a control amount for angle deviation for making the traveling lane and the traveling direction of the vehicle parallel.
　第１目標補正転舵角θＹ１＊の算出について説明する。
　まず、下記式によって、右逸脱に対する第１目標転舵角θＹ１＿Ｒ＊、及び左逸脱に対する第１目標転舵角θＹ１＿Ｌ＊をそれぞれ算出する。
　θＹ１＿Ｒ＊＝－（Ｋｃ＿Ｙ×Ｋｙ＿Ｒ×Ｋｖ＿Ｙ×ΔφＲ）
　θＹ１＿Ｌ＊＝－（Ｋｃ＿Ｙ×Ｋｙ＿Ｌ×Ｋｖ＿Ｙ×ΔφＬ）
　ここで、Ｋｃ＿Ｙは車両諸元により定まるフィードバックゲインである。また、Ｋｖ＿Ｙは車速に応じた補正ゲインである。
　また、Ｋｙ＿Ｒ、Ｋｙ＿Ｌは、図２４（ａ）及び図２４（ｂ）に示すような、走行車線に対する自車両の横変位に応じてそれぞれ個別に設定するフィードバックゲインである。そして、右逸脱に対するフィードバックゲインＫｙ＿Ｒは、右側の車線端部基準ＬＸＲに近づくにつれて大きくなるように設定する。また、左逸脱に対するフィードバックゲインＫｙ＿Ｌは、左側の車線端部基準ＬＸＬに近づくにつれて大きくなるように設定する。また、第１目標転舵角θＹ１＿Ｒ＊、及びθＹ１＿Ｌ＊は、右方向への転舵を正とし、左方向への転舵を負とする。
　ここで、フィードバックゲインＫｙ＿Ｒ、Ｋｙ＿Ｌの最小値の境界として、ＸＬｔ，ＸＲｔの代わりに、車線幅方向オフセット閾値ＸＬｔ２，ＸＲｔ２を使用しても良い。 The calculation of the first target correction turning angle θY1 * will be described.
First, the first target turning angle θY1_R * for the right departure and the first target turning angle θY1_L * for the left departure are calculated by the following equations, respectively.
θY1_R * = − (Kc_Y × Ky_R × Kv_Y × ΔφR)
θY1_L * = − (Kc_Y × Ky_L × Kv_Y × ΔφL)
Here, Kc_Y is a feedback gain determined by vehicle specifications. Kv_Y is a correction gain according to the vehicle speed.
Ky_R and Ky_L are feedback gains that are individually set according to the lateral displacement of the host vehicle with respect to the traveling lane, as shown in FIGS. 24 (a) and 24 (b). Then, the feedback gain Ky_R for the right departure is set so as to increase as it approaches the right lane edge reference LXR. Further, the feedback gain Ky_L for the left departure is set to increase as it approaches the left lane edge reference LXL. In addition, the first target turning angles θY1_R * and θY1_L * are positive for rightward turning and negative for leftward turning.
Here, instead of XLt and XRt, lane width direction offset threshold values XLt2 and XRt2 may be used as the boundary between the minimum values of the feedback gains Ky_R and Ky_L.
　次に、下記式に基づき、右逸脱に対する第１目標転舵角θＹ１＿Ｒ＊と、左逸脱に対する第１目標転舵角θＹ１＿Ｌ＊との和として、第１目標補正転舵角θＹ１＊を算出する。
　θＹ１＊＝θＹ１＿Ｒ＊＋θＹ１＿Ｌ＊
　ここで、右側へヨー角がついている場合には、ステップＳ１３０によりΔφＬ＝０となる（図２３（ｂ）参照）。したがって、左逸脱に対する第１目標転舵角θＹ１＿Ｌ＊は０となり、第１目標補正転舵角θＹ１＊として、右逸脱に対する第１目標転舵角θＹ１＿Ｒ＊のみが採用される。同様に、左側へヨー角がついている場合には、ステップＳ１２０によりΔφＲ＝０となる（図２３（ａ）参照）。したがって、右逸脱に対する第１目標転舵角θＹ＿Ｒ＊は０となり、第１目標補正転舵角θＹ１＊として、左逸脱に対する第１目標転舵角θＹ＿Ｌ＊のみが採用される。 Next, the first target corrected turning angle θY1 * is calculated as the sum of the first target turning angle θY1_R * for the right departure and the first target turning angle θY1_L * for the left departure based on the following equation.
θY1 * = θY1_R * + θY1_L *
If the yaw angle is on the right side, ΔφL = 0 is set in step S130 (see FIG. 23B). Accordingly, the first target turning angle θY1_L * for the left departure is 0, and only the first target turning angle θY1_R * for the right departure is employed as the first target correction turning angle θY1 *. Similarly, if the yaw angle is on the left side, ΔφR = 0 is set in step S120 (see FIG. 23A). Therefore, the first target turning angle θY_R * for the right departure is 0, and only the first target turning angle θY_L * for the left departure is adopted as the first target correction turning angle θY1 *.
　これにより、逸脱側へヨー角が発生している場合には積極的に逸脱を防止するよう制御する。一方、逸脱回避側へヨー角が発生している場合には、違和感なく、穏やかに、走行車線に対して車両の向きを合わせることができる。
　図２０に戻って、次に、ステップＳ１５０では、上記第１目標補正転舵角θＹ１＊に応じたハンドル位置が、操舵反力の中立位置となるように、操舵反力アクチュエータ３Ａを制御する。
　補正操舵反力中心演算部１５Ｂ（図２参照）は、例えば、上記第１目標転舵角θＹ１＊位置に対応するハンドル位置と実際のハンドル位置との偏差に応じた補正操舵反力中心値ΔＴｓｃを演算する。そして、補正操舵反力中心演算部１５Ｂ（図２参照）は、その補正操舵反力中心値ΔＴｓｃ相当の操舵反力を付与するように操舵用コントローラ１１に指令を出力する。操舵用コントローラ１１に設けられた目標反力電流算出部１１Ｂ（図３参照）は、最終軸力算出部１１Ｂｃが算出した最終軸力に補正操舵反力中心値ΔＴｓｃを加算して得られた目標操舵反力に基づく目標反力電流を出力する。これにより、操舵用コントローラ１１は、補正操舵反力中心値ΔＴｓｃ相当の操舵反力を出力するように、上記操舵反力アクチュエータ３を制御する。 As a result, when the yaw angle is generated on the departure side, control is performed to positively prevent the departure. On the other hand, when the yaw angle is generated toward the departure avoidance side, the direction of the vehicle can be adjusted gently with respect to the traveling lane without a sense of incongruity.
Returning to FIG. 20, next, in step S150, the steering reaction force actuator 3A is controlled so that the steering wheel position corresponding to the first target correction turning angle θY1 * becomes the neutral position of the steering reaction force.
The corrected steering reaction force center calculation unit 15B (see FIG. 2), for example, corrects the steering reaction force center value ΔTsc according to the deviation between the handle position corresponding to the first target turning angle θY1 * position and the actual handle position. Is calculated. Then, the corrected steering reaction force center calculation unit 15B (see FIG. 2) outputs a command to the steering controller 11 so as to apply a steering reaction force corresponding to the corrected steering reaction force center value ΔTsc. A target reaction force current calculation unit 11B (see FIG. 3) provided in the steering controller 11 adds the corrected steering reaction force center value ΔTsc to the final axial force calculated by the final axial force calculation unit 11Bc. A target reaction force current based on the steering reaction force is output. As a result, the steering controller 11 controls the steering reaction force actuator 3 so as to output a steering reaction force corresponding to the corrected steering reaction force central value ΔTsc.
　次に、ステップＳ１６０では、右逸脱に対する操舵角基準値δＲ＊、及び左逸脱に対する操舵角基準値δＬ＊をそれぞれ算出する。この操舵角基準値δＲ＊、δＬ＊は、運転者のハンドル操舵による車線端部側への切り増し量を算出するために使用する基準値である。
　ここで、上記ステップＳ１５０の処理により、走行車線と自車両の進行方向とが平行となるハンドル位置（操舵角）で操舵反力が中立位置となる（操舵トルクが０となる）。このため、走行車線が直線路であってもカーブ路であっても、走行車線と自車両の進行方向が平行となる向きから、運転者が左右どちらの走行車線端部に対して近づく方向に操舵したかを、操舵トルクτの符号により検出できるようになる。 Next, in step S160, a steering angle reference value δR * for a right departure and a steering angle reference value δL * for a left departure are calculated. The steering angle reference values δR * and δL * are reference values used to calculate the amount of increase toward the lane edge by steering of the driver's steering wheel.
Here, by the process of step S150, the steering reaction force becomes the neutral position (the steering torque becomes zero) at the steering wheel position (steering angle) where the traveling lane and the traveling direction of the host vehicle are parallel. For this reason, regardless of whether the traveling lane is a straight road or a curved road, the direction in which the traveling lane and the traveling direction of the host vehicle are parallel to the direction in which the driver approaches the left or right traveling lane end. Whether the vehicle is steered can be detected by the sign of the steering torque τ.
　下記のように場合分けして、右逸脱に対する操舵角基準値δＲ＊を算出する。
　すなわち、
１）操舵トルクτ≦τｔｈの場合（右へ操舵トルクをかけていない場合）、下記式のように、右逸脱に対する操舵角基準値δＲ＊を実操舵角値δで更新する。
　δＲ＊＝δ
２）操舵トルクτ＞τｔｈの場合、右逸脱に対する操舵角基準値δＲ＊を更新しない（保持する）。
　同様に、下記のように場合分けして、左逸脱に対する操舵角基準値δＬ＊を算出する。
　すなわち、
１）操舵トルクτ≧－τｔｈの場合（左へ操舵トルクをかけていない場合）、下記式のように、左逸脱に対する操舵角基準値δＬ＊を実操舵角値δで更新する。
　δＬ＊　＝　δ
２）操舵トルクτ＜－τｔｈの場合、左逸脱に対する操舵角基準値δＬ＊を更新しない（保持する）。
　ここで、上記τｔｈは運転者操舵を判断するための操舵トルク閾値であり、絶対値（正の値）で設定する。また、操舵トルクτは、右へ操舵トルクをかけている場合を正の値とし、左へ操舵トルクをかけている場合を負の値とし、操舵角δは、右方向への操舵を正の値とし、左方向への操舵を負の値とする。
　上記算出によって、操舵トルク閾値τｔｈ以上の操舵トルクを検出したときの実操舵角値δが、右逸脱に対する操舵角基準値δＲ＊、又は左逸脱に対する操舵角基準値δＬ＊となる。 The steering angle reference value δR * for the right departure is calculated for each case as follows.
That is,
1) When the steering torque τ ≦ τth (when the steering torque is not applied to the right), the steering angle reference value δR * for the right departure is updated with the actual steering angle value δ as in the following equation.
δR * = δ
2) When the steering torque τ> τth, the steering angle reference value δR * for the right departure is not updated (held).
Similarly, the steering angle reference value δL * for the left departure is calculated for each case as follows.
That is,
1) When the steering torque τ ≧ −τth (when the steering torque is not applied to the left), the steering angle reference value δL * for the left departure is updated with the actual steering angle value δ as shown in the following equation.
δL * = δ
2) When the steering torque τ <−τth, the steering angle reference value δL * for the left deviation is not updated (held).
Here, τth is a steering torque threshold for determining driver steering, and is set as an absolute value (positive value). The steering torque τ is a positive value when the steering torque is applied to the right, a negative value when the steering torque is applied to the left, and the steering angle δ is a positive value when steering in the right direction. Value, and leftward steering is a negative value.
Based on the above calculation, the actual steering angle value δ when a steering torque equal to or greater than the steering torque threshold τth is detected becomes the steering angle reference value δR * for the right departure or the steering angle reference value δL * for the left departure.
　次に、ステップＳ１７０では、下記式に基づき、運転者のハンドル操舵による車線端部側への操舵切り増し量を算出する。
　右側の車線端部基準側への操舵切り増し量ΔδＲを、下記式によって算出する。
　ΔδＲ＝δ－δＲ＊（δ＞δＲ＊の場合）
　ΔδＲ＝０（δ≦δＲ＊の場合）
　同様に、左側の車線端部基準側への操舵切り増し量ΔδＬを、下記式によって算出する。
　ΔδＬ＝δ－δＬ＊（δ＜δＬ＊の場合）
　ΔδＬ＝０（δ≧δＬ＊の場合）
　これによって、左右それぞれの車線端部基準側へのハンドル操舵分を、操舵切り増し量として抽出することができる。 Next, in step S170, the amount of steering increase to the lane edge side by the steering of the driver is calculated based on the following formula.
The amount of steering increase ΔδR toward the right lane edge reference side is calculated by the following equation.
ΔδR = δ-δR * (when δ> δR *)
ΔδR = 0 (when δ ≦ δR *)
Similarly, the steering increase amount ΔδL toward the left lane edge reference side is calculated by the following equation.
ΔδL = δ−δL * (when δ <δL *)
ΔδL = 0 (when δ ≧ δL *)
As a result, the steering amount of the steering wheel toward the left and right lane edge reference sides can be extracted as the amount of steering increase.
　次に、ステップＳ１８０では、第２目標補正転舵角θＹ２＊を算出する。第２目標転舵角θＹ２＊は、車両の逸脱側への動きを予め抑えるための制御量である。ステップＳ１８０の処理は補正転舵角演算部１５Ｃ（図２参照）が実行する。
　第２目標転舵角θＹ２＊の算出は、右逸脱に対する第２目標転舵角θＹ２＿Ｒ＊、左逸脱に対する第２目標転舵角θＹ２＿Ｌ＊をそれぞれ算出し、その和を取ることで当該第２目標転舵角θＹ２＊を算出する。
　まず、下記式によって、右逸脱に対する第２目標転舵角θＹ２＿Ｒ＊、及び左逸脱に対する第２目標転舵角θＹ２＿Ｌ＊をそれぞれ算出する。
　すなわち、右逸脱に対する第２目標転舵角θＹ２＿Ｒ＊を、下記式によって算出する。１）操舵トルクτ≧τｔｈの場合（右へ操舵トルクをかけている場合）
　θＹ２＿Ｒ＊＝－（Ｋｃ＿ｇ×Ｋｇ＿Ｒ×ＫρＬ＿Ｒ×ΔδＲ）
２）操舵トルクτ＜τｔｈの場合
　θＹ２＿Ｒ＊＝０
　また、左逸脱に対する第２目標転舵角θＹ２＿Ｌ＊を、下記式によって算出する。
１）操舵トルクτ≦－τｔｈの場合（左へ操舵トルクをかけている場合）
　θＹ２＿Ｌ＊＝－（Ｋｃ＿ｇ×Ｋｇ＿Ｌ×ＫρＬ＿Ｌ×ΔδＬ）
２）　操舵トルクτ＞－τｔｈの場合
　θＹ２＿Ｌ＊＝０
　ここで、Ｋｃ＿ｇは、車両の諸元によって決まる、操舵角（ハンドル角）とタイヤ角（操舵輪の転舵角）とのギア比係数である。 Next, in step S180, a second target correction turning angle θY2 * is calculated. The second target turning angle θY2 * is a control amount for suppressing in advance the movement of the vehicle toward the departure side. The process of step S180 is executed by the corrected turning angle calculation unit 15C (see FIG. 2).
The second target turning angle θY2 * is calculated by calculating the second target turning angle θY2_R * for the right departure and the second target turning angle θY2_L * for the left departure, and taking the sum thereof. The turning angle θY2 * is calculated.
First, the second target turning angle θY2_R * for the right departure and the second target turning angle θY2_L * for the left departure are calculated by the following equations, respectively.
That is, the second target turning angle θY2_R * for the right departure is calculated by the following formula. 1) When steering torque τ ≧ τth (when steering torque is applied to the right)
θY2_R * = − (Kc_g × Kg_R × KρL_R × ΔδR)
2) When steering torque τ <τth θY2_R * = 0
Further, the second target turning angle θY2_L * for the left departure is calculated by the following formula.
1) When steering torque τ ≦ −τth (when steering torque is applied to the left)
θY2_L * = − (Kc_g × Kg_L × KρL_L × ΔδL)
2) When steering torque τ> −τth θY2_L * = 0
Here, Kc_g is a gear ratio coefficient between the steering angle (steering wheel angle) and the tire angle (steering wheel turning angle) determined by the specifications of the vehicle.
　また、Ｋｇ＿Ｒ、Ｋｇ＿Ｌは、運転者操舵による走行車線端部側への操舵切り増し量に対する転舵抑制ゲインである。そして、Ｋｇ＿Ｒ、Ｋｇ＿Ｌは、図２５（ａ）及び図２５（ｂ）に示すような、走行車線に対する横変位に応じてそれぞれ個別に設定しておく。
ここで、右逸脱に対する転舵抑制ゲインＫｇ＿Ｒは、右側走行端部基準に近づくにつれて大きくなるように設定する。左逸脱に対する転舵抑制ゲインＫｇ＿Ｌは、左側走行端部基準に近づくにつれて大きくなるように設定する。但し、これら転舵抑制ゲインは、最大値を１．０とする。最大値を１．０とすることで、第２目標転舵角は運転者による操舵切り増し量を打ち消す分が上限値となる。つまり、逸脱側への運転者操舵時にのみ、操舵角（ハンドル角）に対するタイヤ角の転舵応答を下げることができ、拘束感や違和感のなく、適切に車線維持支援を行うことができる。なお、最小値となる閾値として、ＸＬｔ２，ＸＲｔ２の代わりに車線端部基準閾値ＸＬｔ、ＸＲｔを使用しても良い。 Kg_R and Kg_L are steering suppression gains with respect to the amount of steering increase toward the traveling lane edge side by the driver's steering. Kg_R and Kg_L are individually set according to the lateral displacement with respect to the traveling lane as shown in FIGS. 25 (a) and 25 (b).
Here, the steering suppression gain Kg_R for the right departure is set so as to increase as it approaches the right traveling end reference. The steering suppression gain Kg_L for the left departure is set so as to increase as it approaches the left traveling end reference. However, the maximum value of these steering suppression gains is 1.0. By setting the maximum value to 1.0, the second target turning angle has an upper limit value for canceling the amount of increase in steering by the driver. In other words, only when the driver steers to the departure side, the turning response of the tire angle with respect to the steering angle (steering wheel angle) can be lowered, and lane keeping support can be performed appropriately without feeling of restraint or discomfort. Note that the lane edge reference threshold values XLt and XRt may be used as the minimum threshold value instead of XLt2 and XRt2.
　また、Ｋρは、図２６のような値である。
　すなわち　すなわち、曲率ρの向き（走行車線Ｌのカーブ方向）に応じて３種類に分けて、下記のように、個別のマップを使用して、右逸脱に対するカーブ補正ゲインＫρＬ＿Ｒ、及び左逸脱に対するカーブ補正ゲインＫρＬ＿Ｌを設定する。
曲率ρ＜０（右カーブ）と判定した場合：
　ＫρＬ＿Ｒ：図２６（ａ）に示すような、カーブＩＮ側補正ゲインマップから読み込む。
　ＫρＬ＿Ｌ：図２６（ｂ）に示すような、カーブＯＵＴ側補正ゲインマップから読み込む。
　曲率ρ＞０（左カーブ）と判定した場合
ＫρＬ＿Ｒ：図２６（ｂ）に示すような、カーブＯＵＴ側補正ゲインマップから読み込む。
ＫρＬ＿Ｌ：図２６（ａ）に示すような、カーブＩＮ側補正ゲインマップから読み込む。
　曲率ρ＝０（直線路）と判定した場合
ＫρＬ＿Ｒ＝１．０（補正なし）
ＫρＬ＿Ｌ＝１．０（補正なし）
　ここで、走行車線Ｌの曲率ρは、旋回半径の逆数であり、直線路でρ＝０となり、カーブがきつくなる（旋回半径が小さくなる）につれて、曲率ρの絶対値が大きな値となる。また、左カーブを正とし、右カーブを負とする。 Kρ is a value as shown in FIG.
That is, the curve correction gain KρL_R for the right departure and the curve for the left departure are divided into three types according to the direction of the curvature ρ (curve direction of the traveling lane L) and using individual maps as follows. A correction gain KρL_L is set.
When it is determined that the curvature ρ <0 (right curve):
KρL_R: Read from a curve IN side correction gain map as shown in FIG.
KρL_L: Read from the curve OUT side correction gain map as shown in FIG.
When it is determined that the curvature ρ> 0 (left curve), KρL_R is read from a curve OUT side correction gain map as shown in FIG.
KρL_L: Read from a curve IN side correction gain map as shown in FIG.
When it is determined that the curvature ρ = 0 (straight road) KρL_R = 1.0 (no correction)
KρL_L = 1.0 (no correction)
Here, the curvature ρ of the traveling lane L is the reciprocal of the turning radius, ρ = 0 on a straight road, and the absolute value of the curvature ρ increases as the curve becomes tighter (the turning radius becomes smaller). The left curve is positive and the right curve is negative.
　上記カーブＩＮ側補正ゲインマップは、図２６（ａ）のように、曲率ρの絶対値が所定以上となると、曲率ρの絶対値が大きくなるにつれて、補正のゲインが小さくなるマップである。そして、左右の走行車線端部Ｌｅのうち、カーブ路の内側に位置する走行車線端部Ｌｅに対する制御のゲインを、曲率ρの絶対値の増大に応じて低減するように補正するものである。
　また、上記カーブＯＵＴ側補正ゲインマップは、図２６（ｂ）のように、曲率ρの絶対値が所定以上となると、曲率ρの絶対値が大きくなるにつれて、補正のゲインが大きくなるマップである。そして、左右の走行車線端部Ｌｅのうち、カーブ路の外側に位置する走行車線端部Ｌｅに対する制御のゲインを、曲率ρの絶対値の増大に応じて増加するように補正するものである。
　但し、無条件で、Ｋρ＝１としても良い。
　そして、下記式のように、右逸脱に対する第２目標転舵角θＹ２＿Ｒ＊と左逸脱に対する第２目標転舵角θＹ２＿Ｌ＊との和として、第２目標補正転舵角θＹ２＊を算出する。
　θＹ２＊＝θＹ２＿Ｒ＊＋θＹ２＿Ｌ＊ As shown in FIG. 26A, the curve IN-side correction gain map is a map in which the correction gain decreases as the absolute value of the curvature ρ increases as the absolute value of the curvature ρ increases to a predetermined value or more. And the gain of control with respect to the travel lane edge Le located inside the curved road among the left and right travel lane edges Le is corrected so as to decrease in accordance with the increase in the absolute value of the curvature ρ.
Further, as shown in FIG. 26B, the curve OUT side correction gain map is a map in which the correction gain increases as the absolute value of the curvature ρ increases as the absolute value of the curvature ρ increases to a predetermined value or more. . And the gain of control with respect to the travel lane edge Le located outside the curve road among the left and right travel lane edges Le is corrected so as to increase in accordance with the increase in the absolute value of the curvature ρ.
However, Kρ = 1 may be set unconditionally.
Then, the second target corrected turning angle θY2 * is calculated as the sum of the second target turning angle θY2_R * for the right departure and the second target turning angle θY2_L * for the left departure as shown in the following equation.
θY2 * = θY2_R * + θY2_L *
　図２０に戻って、次に、ステップＳ１９０では、車線維持支援のための最終目標補正転舵角θＹ＊を算出する。ステップＳ１９０の処理は補正転舵角演算部１５Ｃ（図２参照）が実行する。本実施形態では、下記式のように、ステップＳ１４０において算出した第１目標転舵角θＹ１＊と、ステップＳ１８０において算出した第１目標転舵角θＹ２＊の和として、最終目標補正転舵角θＹ＊を算出する。
　θＹ＊＝θＹ１＊＋θＹ２＊
　次に、ステップＳ２００では、最終目標補正転舵角θＹ＊を操舵用コントローラ１１に出力する。例えば補正転舵角演算部１５Ｃは、最終目標補正転舵角θＹ＊を操舵用コントローラ１１に出力する。
　但し、方向指示スイッチ１７がオン状態となっている場合であって、方向指示スイッチ１７の指示方向と、ハンドル操舵方向とが一致している場合には、補正転舵角演算部１５Ｃは、車線維持支援のための最終目標補正転舵角θＹ＊を操舵用コントローラ１１に出力しない。
　操舵用コントローラ１１は、転舵角が、転舵指令角演算部１１Ａａが演算した転舵指令角に最終目標補正転舵角θＹ＊を加算した目標転舵角θ＊になるように、転舵アクチュエータ５Ａを駆動する。これによって、操舵輪である前輪１３の転舵角が目標転舵角θ＊となる。 Returning to FIG. 20, next, in step S190, a final target corrected turning angle θY * for lane keeping support is calculated. The process of step S190 is executed by the corrected turning angle calculation unit 15C (see FIG. 2). In the present embodiment, the final target corrected turning angle θY is calculated as the sum of the first target turning angle θY1 * calculated in step S140 and the first target turning angle θY2 * calculated in step S180, as in the following equation. * Is calculated.
θY * = θY1 * + θY2 *
Next, in step S200, the final target correction turning angle θY * is output to the steering controller 11. For example, the corrected turning angle calculation unit 15C outputs the final target corrected turning angle θY * to the steering controller 11.
However, when the direction indicating switch 17 is in the ON state and the indicated direction of the direction indicating switch 17 matches the steering direction of the steering wheel, the corrected turning angle calculation unit 15C The final target correction turning angle θY * for maintenance support is not output to the steering controller 11.
The steering controller 11 turns the steering so that the turning angle becomes a target turning angle θ * obtained by adding the final target corrected turning angle θY * to the turning command angle calculated by the turning command angle calculation unit 11Aa. Actuator 5A is driven. As a result, the turning angle of the front wheel 13 that is the steered wheel becomes the target turning angle θ *.
　また、ステップＳ２１０では、第１目標補正操舵反力τＹ１＊を、車線維持支援のための操舵反力として算出する。ステップＳ２１０の処理は、例えば補正操舵反力演算部１５Ａ（図３参照）が実行する。この第１目標補正操舵反力τＹ１＊は、運転者の定常的な操舵入力に対する操舵反力である。そして、この第１目標操舵反力τＹ１＊は、運転者が車線端部側に付加した操舵トルクτに応じて算出するものである。
　まず、下記のように場合分けして、右逸脱に対する第１目標操舵反力τＹ１＿Ｒ＊、及び左逸脱に対する第１目標操舵反力τＹ１＿Ｌ＊をそれぞれ算出する。
　まず、下記式によって、右逸脱に対する第１目標操舵反力τＹ１＿Ｒ＊を算出する。
１）操舵トルクτ≧τｔｈの場合（右へ操舵トルクをかけている場合）
　τＹ１＿Ｒ＊＝Ｋｔ＿Ｒ×（τ－τｔｈ）
２）操舵トルクτ＜τｔｈの場合
　τＹ１＿Ｒ＊＝０
　また、下記式によって、左逸脱に対する第１目標操舵反力τＹ１＿Ｌ＊を算出する。
１）操舵トルクτ≦－τｔｈの場合（左へ操舵トルクをかけている場合）
　τＹ１＿Ｌ＊＝Ｋｔ＿Ｌ×（τ＋τｔｈ）
２）操舵トルクτ＞－τｔｈの場合
　τＹ１＿Ｌ＊＝０ In step S210, the first target correction steering reaction force τY1 * is calculated as a steering reaction force for lane keeping support. The process of step S210 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3). The first target correction steering reaction force τY1 * is a steering reaction force with respect to the steady steering input of the driver. The first target steering reaction force τY1 * is calculated according to the steering torque τ applied by the driver to the lane edge side.
First, a first target steering reaction force τY1_R * for a right departure and a first target steering reaction force τY1_L * for a left departure are calculated for each case as follows.
First, the first target steering reaction force τY1_R * for the right departure is calculated by the following equation.
1) When steering torque τ ≧ τth (when steering torque is applied to the right)
τY1_R * = Kt_R × (τ−τth)
2) When steering torque τ <τth τY1_R * = 0
Further, the first target steering reaction force τY1_L * for the left departure is calculated by the following equation.
1) When steering torque τ ≦ −τth (when steering torque is applied to the left)
τY1_L * = Kt_L × (τ + τth)
2) When steering torque τ> −τth τY1_L * = 0
　ここで、Ｋｔ＿Ｒ、Ｋｔ＿Ｌは、運転者操舵による走行車線端部側への操舵トルクに対する第１目標操舵反力算出ゲインである。このＫｔ＿Ｒ、Ｋｔ＿Ｌは、図２７（ａ）及び図２７（ｂ）に示すような、走行車線に対する横変位に応じてそれぞれ個別に設定するゲインである。右逸脱に対する第１目標操舵反力算出ゲインＫｔ＿Ｒは、右側の走行車線端部基準に近づくにつれて大きくなるように設定する。左逸脱に対する第１目標操舵反力算出ゲインＫｔ＿Ｌは、左側の走行車線端部基準に近づくにつれて大きくなるように設定する。但し、これら第１目標操舵反力算出ゲインＫｔ＿Ｒ、Ｋｔ＿Ｌは、最大値を１．０とする。これによって、第１目標操舵反力は、運転者操舵による操舵トルクを打ち消す分が上限値となる。つまり、逸脱側への運転者操舵時にのみ、操舵反力を重くすることができる。なお、運転者による操舵トルク以上の操舵反力を発生させると、発生反力によりハンドルがはじき返されて、つまり、戻されてしまう。しかし、上記のように上限を設定することにより、あくまで操舵反力が「重い」という範囲内での制御が可能となる。ここで、ゲイン１．０は、運転者が入力した操舵トルクで力が釣り合う位置である。上記釣り合うとは、ハンドルが止まることを意味する。これによって、拘束感や違和感のなく、適切に車線維持支援を行うことができる。 Here, Kt_R and Kt_L are first target steering reaction force calculation gains with respect to the steering torque toward the traveling lane edge by the driver's steering. Kt_R and Kt_L are gains individually set according to the lateral displacement with respect to the traveling lane as shown in FIGS. 27 (a) and 27 (b). The first target steering reaction force calculation gain Kt_R for the right departure is set so as to increase as the right lane edge reference is approached. The first target steering reaction force calculation gain Kt_L for the left departure is set to increase as the left lane edge reference is approached. However, the first target steering reaction force calculation gains Kt_R and Kt_L have a maximum value of 1.0. As a result, the first target steering reaction force has an upper limit for canceling the steering torque due to driver steering. That is, the steering reaction force can be increased only when the driver steers to the departure side. If a steering reaction force greater than the steering torque by the driver is generated, the steering wheel is repelled by the generated reaction force, that is, returned. However, by setting the upper limit as described above, control within the range where the steering reaction force is “heavy” is possible. Here, the gain 1.0 is a position where the force is balanced by the steering torque input by the driver. The above balance means that the handle stops. Thus, it is possible to appropriately perform lane keeping support without feeling of restraint or discomfort.
　次に、下記式のように、右逸脱に対する第１目標操舵反力τＹ１＿Ｒ＊と左逸脱に対する第１目標操舵反力τＹ１＿Ｌ＊との和として、第１目標補正操舵反力τＹ１＊を算出する。
　τＹ１＊＝τＹ１＿Ｒ＊＋τＹ１＿Ｌ＊
　ここで、τＹ１＊、τＹ１＿Ｒ＊、τＹ１＿Ｌ＊は、左へ操舵反力を発生させる場合を正の値とし、右へ操舵反力を発生させる場合を負の値とする。
　図２０に戻って、次に、ステップＳ２２０では、第２目標補正操舵反力τＹ２＊を算出する。ステップＳ２２０の処理は、例えば補正操舵反力演算部１５Ａ（図３参照）が実行する。第２目標補正操舵反力τＹ２＊は、車線維持支援のための操舵反力であり、運転者の過渡的な操舵入力に対する操舵反力である。この第２目標補正操舵反力τＹ２＊は、運転者が車線端部側へ操舵した操舵角速度δ′に応じて算出する。 Next, the first target corrected steering reaction force τY1 * is calculated as the sum of the first target steering reaction force τY1_R * for the right departure and the first target steering reaction force τY1_L * for the left departure as shown in the following equation.
τY1 * = τY1_R * + τY1_L *
Here, τY1 *, τY1_R *, and τY1_L * are positive values when the steering reaction force is generated to the left and negative values when the steering reaction force is generated to the right.
Returning to FIG. 20, next, in step S220, a second target correction steering reaction force τY2 * is calculated. The process of step S220 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3). The second target correction steering reaction force τY2 * is a steering reaction force for supporting lane keeping, and is a steering reaction force with respect to a driver's transient steering input. The second target correction steering reaction force τY2 * is calculated according to the steering angular velocity δ ′ that the driver steers to the lane edge side.
　その算出について説明する。
　まず、下記のように場合分けして、右逸脱に対する第２目標操舵反力τＹ２＿Ｒ＊、左逸脱に対する第２目標操舵反力τＹ２＿Ｌ＊をそれぞれ算出する。
　すなわち、下記式によって、右逸脱に対する第２目標操舵反力τＹ２＿Ｒ＊を算出する。
１）操舵角速度δ′≧δ′ｔｈ　の場合（右へ操舵している場合）
　τＹ２＿Ｒ＊＝Ｋｓ＿Ｒ×（δ′－δ′ｔｈ）
２）操舵角速度δ′＜δ′ｔｈ　の場合
　τＹ２＿Ｒ＊＝０
　また、左逸脱に対する第２目標操舵反力τＹ２＿Ｌ＊を算出する。
１）操舵角速度δ′≦　－δ′ｔｈ　の場合（左へ操舵している場合）
　τＹ２＿Ｌ＊＝Ｋｓ＿Ｌ×（δ′＋δ′ｔｈ）
２）操舵角速度δ′＞－δ′ｔｈの場合
　τＹ２＿Ｌ＊＝０ The calculation will be described.
First, a second target steering reaction force τY2_R * for a right departure and a second target steering reaction force τY2_L * for a left departure are calculated for each case as follows.
That is, the second target steering reaction force τY2_R * for the right departure is calculated by the following equation.
1) When the steering angular velocity δ ′ ≧ δ′th (when steering to the right)
τY2_R * = Ks_R × (δ′−δ′th)
2) When steering angular velocity δ ′ <δ′th τY2_R * = 0
Further, the second target steering reaction force τY2_L * for the left departure is calculated.
1) When the steering angular velocity δ ′ ≦ −δ′th (when steering to the left)
τY2_L * = Ks_L × (δ ′ + δ′th)
2) When steering angular velocity δ ′> − δ′th τY2_L * = 0
　ここで、Ｋｓ＿Ｒ、Ｋｓ＿Ｌは、運転者操舵による車線端部側への操舵角速度に対する第２目標操舵反力算出ゲインである。この第２目標操舵反力算出ゲインＫｓ＿Ｒ、Ｋｓ＿Ｌは、図２８（ａ）及び図２８（ｂ）に示すような、走行車線に対する横変位に応じてそれぞれ個別に設定する。そして、右逸脱に対する第２目標操舵反力算出ゲインＫｓ＿Ｒは、右側の車線端部基準に近づくにつれて大きくなるように設定する。左逸脱に対する第２目標操舵反力算出ゲインＫｓ＿Ｌは、左側の車線端部基準に近づくにつれて大きくなるように設定する。これにより、逸脱側への運転者の操舵時にのみ、操舵反力を重くすることができ、拘束感や違和感のなく、適切に車線維持支援を行うことができる。 Here, Ks_R and Ks_L are second target steering reaction force calculation gains with respect to the steering angular velocity toward the lane edge side by the driver's steering. The second target steering reaction force calculation gains Ks_R and Ks_L are individually set according to the lateral displacement with respect to the traveling lane as shown in FIGS. 28 (a) and 28 (b). Then, the second target steering reaction force calculation gain Ks_R for the right departure is set to increase as the right lane edge reference is approached. The second target steering reaction force calculation gain Ks_L for the left departure is set to increase as the left lane edge reference is approached. As a result, the steering reaction force can be increased only when the driver steers to the departure side, and lane keeping support can be performed appropriately without feeling restrained or uncomfortable.
　次に、下記式のように、右逸脱に対する第２目標操舵反力τＹ２＿Ｒ＊と、左逸脱に対する第２目標操舵反力τＹ２＿Ｌ＊との和として、第２目標補正操舵反力τＹ２＊を算出する。
　τＹ２＊　＝τＹ２＿Ｒ＊　＋τＹ２＿Ｌ＊
　ここで、τＹ２＊、τＹ２＿Ｒ＊、τＹ２＿Ｌ＊は、左へ操舵反力を発生させる場合を正の値とし、右へ操舵反力を発生させる場合を負の値とする。また、操舵角速度δ′は、右方向への操舵を正の値とし、左方向への操舵を負の値とする。
　図２０に戻って、次に、ステップＳ２３０では、車線維持支援のための最終目標補正操舵反力τＹ＊を算出する。ステップＳ２３０の処理は、例えば補正操舵反力演算部１５Ａ（図３参照）が実行する。本実施形態では、下記式に基づき、ステップＳ２１０において算出した第１目標補正操舵反力τＹ１＊と、ステップＳ２２０において算出した第２目標補正操舵反力τＹ２＊との和として、最終目標補正操舵反力τＹ＊を算出する。
　τＹ＊＝τＹ１＊＋τＹ２＊ Next, the second target corrected steering reaction force τY2 * is calculated as the sum of the second target steering reaction force τY2_R * for the right departure and the second target steering reaction force τY2_L * for the left departure as shown in the following equation. .
τY2 * = τY2_R * + τY2_L *
Here, τY2 *, τY2_R *, and τY2_L * are positive values when the steering reaction force is generated to the left and negative values when the steering reaction force is generated to the right. Further, the steering angular velocity δ ′ is a positive value for steering in the right direction and a negative value for steering in the left direction.
Returning to FIG. 20, next, in step S230, a final target correction steering reaction force τY * for lane keeping support is calculated. The process of step S230 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3). In this embodiment, the final target corrected steering reaction force is calculated as the sum of the first target correction steering reaction force τY1 * calculated in step S210 and the second target correction steering reaction force τY2 * calculated in step S220 based on the following equation. The force τY * is calculated.
τY * = τY1 * + τY2 *
　次に、ステップＳ２４０では、最終目標補正操舵反力τＹ＊を操舵用コントローラ１１に出力する。ステップＳ２４０の処理は、例えば補正操舵反力演算部１５Ａ（図３参照）が実行する。
　但し、方向指示スイッチ１７がオン状態となっている場合であって、方向指示スイッチ１７の指示方向と、ハンドル操舵方向とが一致している場合には、補正操舵反力演算部１５Ａは、最終目標補正操舵反力τＹ＊を操舵用コントローラ１１に出力しない。
　操舵用コントローラ１１は、最終目標補正転舵角θＹ＊と補正操舵反力中心値ΔＴｓｃとが反映された目標操舵反力となるように操舵反力アクチュエータ３Ａを駆動する。 Next, in step S240, the final target correction steering reaction force τY * is output to the steering controller 11. The process of step S240 is executed by, for example, the corrected steering reaction force calculation unit 15A (see FIG. 3).
However, when the direction indicating switch 17 is in the ON state and the indicated direction of the direction indicating switch 17 matches the steering direction of the steering wheel, the corrected steering reaction force calculation unit 15A The target correction steering reaction force τY * is not output to the steering controller 11.
The steering controller 11 drives the steering reaction force actuator 3A so that the target steering reaction force reflects the final target correction turning angle θY * and the corrected steering reaction force central value ΔTsc.
　ここで、車線維持支援コントローラ１５の車線維持支援機能が制御演算部１１の機能を妨げる問題のうち、本実施形態に関連する特有の問題点について図１７（ｂ）を参照しつつ、図２９を用いて説明する。
　図２９は、軸力と操舵反力との関係を示すグラフである。横軸は軸力の絶対値を示し、縦軸は操舵反力を示している。図２９において、軸力の絶対値は、左側に向かうほど大きくなる。曲線αは、操舵反力が補正操舵反力中心値ΔＴｓｃによって補正されていない場合（図２９では、この場合を「軸力中立点（元）」と表している）の軸力に対する操舵反力の特性を表している。曲線βは、操舵反力が補正操舵反力中心値ΔＴｓｃによって補正されている場合（図２９では、この場合を「軸力中立点（オフセット後）」と表している）の軸力と操舵反力との関係を表している。
　図２９に示すように、軸力に対する操舵反力の特性は、軸力が大きくになるにしたがって操舵反力の増加量は小さくなる。軸力はステアリングホイール１２の操舵角に対応する。軸力中立点（元）の場合、操舵角の値がδａ（図１７（ｂ）の図中に示すδ１よりも小さい値）における曲線αの接線の傾きは、δａよりも大きい操舵角の値のδｂ（図１７（ｂ）の図中に示すδ２よりも大きい値）における曲線αの接線の傾きよりも大きくなる。 Here, among the problems that the lane keeping support function of the lane keeping support controller 15 obstructs the function of the control calculation unit 11, FIG. 29 will be described with reference to FIG. It explains using.
FIG. 29 is a graph showing the relationship between the axial force and the steering reaction force. The horizontal axis indicates the absolute value of the axial force, and the vertical axis indicates the steering reaction force. In FIG. 29, the absolute value of the axial force increases toward the left side. A curve α indicates a steering reaction force with respect to an axial force when the steering reaction force is not corrected by the corrected steering reaction force central value ΔTsc (in FIG. 29, this case is represented as “axial force neutral point (original)”). Represents the characteristics. Curve β represents the axial force and the steering reaction when the steering reaction force is corrected by the corrected steering reaction force central value ΔTsc (in FIG. 29, this case is represented as “axial force neutral point (after offset))”. It represents the relationship with force.
As shown in FIG. 29, in the characteristic of the steering reaction force with respect to the axial force, the increase amount of the steering reaction force decreases as the axial force increases. The axial force corresponds to the steering angle of the steering wheel 12. In the case of the axial force neutral point (original), the slope of the tangent of the curve α when the steering angle value is δa (a value smaller than δ1 shown in FIG. 17B) is a steering angle value larger than δa. Δb (a value larger than δ2 shown in FIG. 17B) is larger than the slope of the tangent of the curve α.
　軸力中立点（オフセット後）の場合、軸力に対する操舵反力の特性は、補正操舵反力中心値ΔＴｓｃの分だけ軸力の絶対値が大きい方向にシフトした特性となる。このため、図２９に示すように、軸力中立点（オフセット後）の場合の軸力に対する操舵反力の特性（曲線β）は、軸力中立点（元）の場合の軸力に対する操舵反力の特性（曲線α）と形状は変わらずに、図中左方向にシフトした特性となる。操舵角の値δｂに対する操舵反力は、補正操舵反力中心値（軸力オフセット）分だけ軸力中立点（元）の場合よりも軸力中立点（オフセット後）の場合の方が小さくなる。これにより、操舵角の値δｂにおける曲線βの接線の傾きは、操舵角の値δｂにおける曲線αの接線の傾きよりも大きくなる。
　図１７（ｂ）に示すように、操舵角度δの値によって配分比率ＧＦ３の値が変化する。このため、操舵角度δの値（位置）によって最終軸力に対するフィードバック軸力ＴＦＢの寄与率が変化する。例えば、操舵角度の値δｂ（＞δ２）では、配分比率ＧＢが０．６となるため、最終軸力に対するフィードバック軸力ＴＦＢの寄与率は相対的に大きくなる。 In the case of the axial force neutral point (after offset), the characteristic of the steering reaction force with respect to the axial force is a characteristic shifted in the direction in which the absolute value of the axial force is increased by the corrected steering reaction force central value ΔTsc. For this reason, as shown in FIG. 29, the characteristic (curve β) of the steering reaction force with respect to the axial force in the case of the axial force neutral point (after offset) is the steering reaction force against the axial force in the case of the axial force neutral point (original). The force characteristic (curve α) and the shape remain unchanged, and the characteristic is shifted to the left in the figure. The steering reaction force with respect to the steering angle value δb is smaller in the case of the axial force neutral point (after offset) than in the case of the axial force neutral point (original) by the corrected steering reaction force central value (axial force offset). . As a result, the slope of the tangent line of the curve β at the steering angle value δb is larger than the slope of the tangent line of the curve α at the steering angle value δb.
As shown in FIG. 17B, the value of the distribution ratio GF 3 varies depending on the value of the steering angle δ. For this reason, the contribution ratio of the feedback axial force TFB to the final axial force varies depending on the value (position) of the steering angle δ. For example, since the distribution ratio GB is 0.6 at the steering angle value δb (> δ2), the contribution ratio of the feedback axial force TFB to the final axial force is relatively large.
　フィードバック軸力ＴＦＢ、すなわち転舵電流は、目標転舵角θ＊によって変動する。
　軸力中立点（オフセット後）の場合の操舵角度の値δｂにおける曲線βの接線の傾きは、軸力中立点（元）の場合の値δｂにおける曲線αの接線の傾きと比較して大きい。このため、軸力中立点（オフセット後）の場合は軸力中立点（元）の場合と比較して、操舵角が値δｂからの変動量に対する操舵反力、すなわちフィードバック軸力ＴＦＢの変動量は大きくなる。このため、操舵角の値がδｂから変動すると転舵電流の変動分が大きくなる。これにより、軸力中立点（オフセット後）の場合は軸力中立点（元）の場合と比較して、操舵反力が変動しやすくなる。
　このように、最終軸力に対するフィードバック軸力ＴＦＢの寄与率が相対的に大きくなる操舵角（例えば、δ２より大きい操舵角）における操舵反力の変動は、車線維持支援装置５０の非作動状態よりも作動状態の方が大きくなる場合がある。これにより、運転者は違和感を覚えてしまうという問題がある。 The feedback axial force T FB , that is, the turning current varies depending on the target turning angle θ *.
The slope of the tangent of the curve β at the steering angle value δb at the axial force neutral point (after offset) is larger than the slope of the tangent of the curve α at the value δb at the axial force neutral point (original). Therefore, in the case of the axial force neutral point (after offset), compared to the axial force neutral point (original), the steering reaction force with respect to the fluctuation amount of the steering angle from the value δb, that is, the fluctuation of the feedback axial force TFB . The amount gets bigger. For this reason, when the value of the steering angle fluctuates from δb, the amount of fluctuation of the steering current increases. As a result, the steering reaction force is more likely to fluctuate in the axial force neutral point (after offset) than in the axial force neutral point (original).
Thus, the fluctuation of the steering reaction force at the steering angle (for example, the steering angle larger than δ2) at which the contribution ratio of the feedback axial force TFB to the final axial force becomes relatively large is the non-operating state of the lane keeping assist device 50. The operating state may be larger than the operating state. As a result, there is a problem that the driver feels uncomfortable.
　本実施形態による操舵制御装置に備えられた制御演算部１１は、軸力切替出力部１１Ｂｆを有している。図３に示すように、軸力切替出力部１１Ｂｆは、車速センサ１５Ａ（図２参照）が検出した車速Ｖと、ステアリングホイール角度センサ１（図２参照）が検出した操舵角δと、フィードフォワード軸力算出部１１Ｂａが算出したフィードフォワード軸力ＴＦＦと、フィードバック軸力算出部１１Ｂｂが算出したフィードバック軸力ＴＦＢとが入力するようになっている。軸力切替出力部１１Ｂｆは、入力した車速Ｖ及び操舵角δに基づいて車線維持支援コントローラ１５の作動状態と非作動状態とを判定する。軸力切替出力部１１Ｂｆは、車線維持支援コントローラ１５が作動状態と判定したら、入力したフィードフォワード軸力ＴＦＦを最終軸力算出用の軸力Ｔｏｃとして出力し、非作動状態と判定したら、入力したフィードバック軸力ＴＦＢを軸力Ｔｏｃとして出力するようになっている。軸力切替出力部１１Ｂｆは、車速センサ１５Ａが検出した車速Ｖが予め定めた設定値（例えば、図１７（ａ）に示すＶ３）より小さいと判断したら車線維持支援コントローラ１５が作動状態と判定し、当該車速Ｖが当該設定値以上であると判定したら車線維持支援コントローラ１５が非作動状態と判定する。あるいは、軸力切替出力部１１Ｂｆは、ステアリングホイール角度センサ１が検出した操舵角δが予め定めた設定値（例えば、図１７（ｂ）に示すδ２）以上であると判断したら車線維持支援コントローラ１５が作動状態と判定し、当該操舵角δが当該設定値より小さいと判定したら車線維持支援コントローラ１５が非作動状態と判定する。 The control calculation unit 11 provided in the steering control device according to the present embodiment has an axial force switching output unit 11Bf. As shown in FIG. 3, the axial force switching output unit 11Bf includes a vehicle speed V detected by the vehicle speed sensor 15A (see FIG. 2), a steering angle δ detected by the steering wheel angle sensor 1 (see FIG. 2), and feedforward. feedforward axial force T FF axial force calculating unit 11Ba is calculated, and the feedback axial force T FB feedback axial force calculating unit 11Bb is calculated is adapted to enter. The axial force switching output unit 11Bf determines whether the lane keeping assist controller 15 is operating or not based on the input vehicle speed V and the steering angle δ. Axial force switching output section 11Bf, once the lane keeping assist controller 15 determines that the operating state, when the feedforward axial force T FF input and output as an axial force Toc for the final axial force calculating, determines that non-actuated state, the input The feedback axial force T FB is output as the axial force Toc. When the axial force switching output unit 11Bf determines that the vehicle speed V detected by the vehicle speed sensor 15A is smaller than a predetermined set value (for example, V3 shown in FIG. 17A), the lane keeping assist controller 15 determines that the lane keeping assist controller 15 is in an operating state. If it is determined that the vehicle speed V is equal to or higher than the set value, the lane keeping assist controller 15 determines that the vehicle is not operating. Alternatively, if the axial force switching output unit 11Bf determines that the steering angle δ detected by the steering wheel angle sensor 1 is greater than or equal to a predetermined set value (for example, δ2 shown in FIG. 17B), the lane keeping assist controller 15 Is determined to be in an operating state, and if it is determined that the steering angle δ is smaller than the set value, the lane keeping assist controller 15 determines to be in a non-operating state.
　軸力切替出力部１１Ｂｆは、車線維持支援装置５０の作動状態時にフィードフォワード軸力ＴＦＦを出力し、フィードバック軸力ＴＦＢを出力しない。このため、制御演算部１１は、車線維持支援装置５０の作動状態、すなわち車線維持支援コントローラ１５の作動状態においてフィードバック軸力ＴＦＢに基づかずに目標反力電流を算出できる。すなわち、制御演算部１１は、最終軸力に対するフィードバック軸力ＴＦＢの寄与率が相対的に大きくなる範囲においてフィードバック軸力ＴＦＢに基づかずに目標反力電流を算出できる。これにより、制御演算部１１は、操舵反力変動が大きくなることを解消するだけでなく、車線維持支援装置５０という付加機能の作動時に、安定した操舵感を運転者に与えることができる。
　本実施形態では、作動状態には、車線維持支援コントローラ１５が自車両Ａの走行支援を制御可能な状態である待機状態と、車線維持支援コントローラ１５が自車両Ａの走行支援の制御中であるオン状態とが含まれる。 Axial force switching output section 11Bf outputs a feedforward axial force T FF when the operating state of the lane keeping assist device 50 does not output the feedback axial force T FB. Therefore, the control calculation unit 11 can calculate the target reaction force current in the operating state of the lane keeping assist device 50, that is, in the operating state of the lane keeping assist controller 15, without being based on the feedback axial force TFB . That is, the control calculation unit 11 can calculate the target reaction force current without being based on the feedback axial force TFB within a range where the contribution ratio of the feedback axial force TFB to the final axial force is relatively large. As a result, the control calculation unit 11 can not only eliminate the increase in the steering reaction force fluctuation but also provide the driver with a stable steering feeling when the additional function of the lane keeping assist device 50 is activated.
In the present embodiment, the operating state includes a standby state in which the lane keeping support controller 15 can control the travel support of the host vehicle A, and the lane keeping support controller 15 is controlling the travel support of the host vehicle A. ON state is included.
（動作その他）
　次に、自車両Ａの操舵制御装置の動作について説明する。
　図３０は、自車両Ａの操舵制御装置の動作を説明するための図である。
　図３０の時刻ｔ１に示すように、自車両Ａの走行中、運転者がステアリングホイール１２を操作し、ステアリングホイール１２の切り増し操作を行ったとする。すると、制御演算部１１が、操舵角δおよび車速Ｖに基づき目標転舵角θ＊を算出する（図２の目標転舵角演算部１１Ａ）。続いて、制御演算部１１が、算出した目標転舵角θ＊から実際の転舵角θを減じた減算結果に基づき目標転舵電流を算出する（図２の目標転舵電流演算部１１Ｃ）。これにより、転舵制御部５が、運転者の操舵操作に応じて操向輪１３を転舵する。 (Operation other)
Next, the operation of the steering control device for the host vehicle A will be described.
FIG. 30 is a diagram for explaining the operation of the steering control device of the host vehicle A.
As shown at time t <b> 1 in FIG. 30, it is assumed that the driver operates the steering wheel 12 and rotates the steering wheel 12 while the host vehicle A is traveling. Then, the control calculation unit 11 calculates the target turning angle θ * based on the steering angle δ and the vehicle speed V (target turning angle calculation unit 11A in FIG. 2). Subsequently, the control calculation unit 11 calculates a target turning current based on a subtraction result obtained by subtracting the actual turning angle θ from the calculated target turning angle θ * (target turning current calculation unit 11C in FIG. 2). . Thereby, the steering control part 5 steers the steered wheel 13 according to a driver | operator's steering operation.
　同時に、制御演算部１１が、操舵角δおよび車速Ｖに基づきフィードフォワード軸力ＴＦＦを算出する（図３のフィードフォワード軸力算出部１１Ｂａ）。続いて、制御演算部１１が、転舵電流に基づき電流軸力を算出する（図１１の電流軸力算出部１１Ｂｂａ）。続いて、制御演算部１１が、横方向加速度Ｇｙに基づき横Ｇ軸力を算出する（図１１のブレンド軸力算出部１１Ｂｂｂ）。続いて、制御演算部１１が、ヨーレートγおよび車速Ｖに基づきヨーレート軸力を算出する（図１１のブレンド軸力算出部１１Ｂｂｂ）。続いて、制御演算部１１が、算出した電流軸力に配分比率Ｋ２を乗算した値と横Ｇ軸力に配分比率Ｋ１を乗算した値とヨーレート軸力に配分比率Ｋ３を乗算した値とに基づき、ブレンド軸力ＴＢＲを算出する（図１１のブレンド軸力算出部１１Ｂｂｂ）。横Ｇ軸力、電流軸力、ヨーレート軸力の配分比率Ｋ１、Ｋ２、Ｋ３は、０．６：０．３：０．１とする。ここで、操舵角速度ｄδ／ｄｔの絶対値が、第４設定操舵角速度ｄδ４／ｄｔ未満であったとする。すると、変数Ｋ４が１．０となり、変数Ｋ５が１．０となり、配分比率ＧＢ（＝Ｋ４×Ｋ５）が１．０となる（図１１のフィードバック軸力算出実行部１１Ｂｂｅ）。そして、制御演算部１１が、算出した電流軸力とブレンド軸力ＴＢＲとをＧＢ：（１－ＧＢ）で配分して、電流軸力をフィードバック軸力ＴＦＢとする（図３のフィードバック軸力算出部１１Ｂｂ）。続いて、制御演算部１１が、算出したフィードフォワード軸力ＴＦＦとフィードバック軸力ＴＦＢとをＧＦ：（１－ＧＦ）で配分し、さらに補正操舵反力中心値ΔＴｓｃを付加して最終軸力を算出する（図３の最終軸力算出部１１Ｂｃ）。最終軸力を算出する際に、車線維持支援装置５０が作動中である場合には、最終軸力は、フィードフォワード軸力ＴＦＦ及び補正操舵反力中心値ΔＴｓｃのみで算出される。 At the same time, the control calculation unit 11 calculates a feedforward axial force T FF based on the steering angle δ and the vehicle speed V (feedforward axial force calculating unit 11Ba of Figure 3). Subsequently, the control calculation unit 11 calculates a current axial force based on the steering current (current axial force calculation unit 11Bba in FIG. 11). Subsequently, the control calculation unit 11 calculates a lateral G-axis force based on the lateral acceleration Gy (blend axial force calculation unit 11Bbb in FIG. 11). Subsequently, the control calculation unit 11 calculates the yaw rate axial force based on the yaw rate γ and the vehicle speed V (blend axial force calculation unit 11Bbb in FIG. 11). Subsequently, based on the value obtained by multiplying the calculated current axial force by the distribution ratio K2, the value obtained by multiplying the lateral G-axis force by the distribution ratio K1, and the value obtained by multiplying the yaw rate axial force by the distribution ratio K3. calculates the blending axial force T BR (blend axial force calculating unit 11Bbb in Figure 11). The distribution ratios K1, K2, and K3 of the lateral G axial force, current axial force, and yaw rate axial force are set to 0.6: 0.3: 0.1. Here, it is assumed that the absolute value of the steering angular velocity dδ / dt is less than the fourth set steering angular velocity dδ 4 / dt. Then, the variable K4 becomes 1.0, the variable K5 becomes 1.0, and the distribution ratio GB (= K4 × K5) becomes 1.0 (feedback axial force calculation execution unit 11Bbe in FIG. 11). Then, the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB), and the current axial force is set as the feedback axial force T FB (the feedback axis in FIG. 3). Force calculator 11Bb). Subsequently, the control arithmetic unit 11, the calculated feed and forward axial force T FF and the feedback axial force T FB GF: allocating at (1-GF), final axis and further adding a correction steering reaction force central value ΔTsc The force is calculated (final axial force calculation unit 11Bc in FIG. 3). When calculating the final axial force, the lane keeping assist device 50 when it is in operation, the final axial force is calculated only with the feedforward axial force T FF and correction steering reaction force central value DerutaTsc.
　続いて、制御演算部１１が、算出した最終軸力に基づき目標操舵反力を算出する（図３の軸力－操舵反力変換部１１Ｂｄ）。続いて、制御演算部１１が、算出した目標操舵反力に基づき目標反力電流を算出する（図３の目標反力電流演算部１１Ｂｅ）。続いて、制御演算部１１が、算出した目標反力電流に基づき反力モータ４を駆動する（図２の反力モータ駆動部３Ｄ）。これにより、反力制御部３が、ステアリングホイール１２に操舵反力を付与する。
　このように、本実施形態の操舵制御装置では、電流軸力、ブレンド軸力ＴＢＲ、並びに切り増し操作および切り戻し操作の判定結果に基づいてフィードバック軸力ＴＦＢを算出する。それゆえ、本実施形態の操舵制御装置は、転舵モータ６の転舵電流および自車両Ａの横方向加速度Ｇｙ等、一般的な車両が備えているセンサの検出結果に基づいて、フィードバック軸力ＴＦＢを算出できる。そのため、本実施形態の操舵制御装置は、フィードバック軸力ＴＦＢに基づいて反力モータ４を駆動することで、ステアリングラック軸力を検出するための専用のセンサを備える必要がなく、製造コストの増大を抑制できる。 Subsequently, the control calculation unit 11 calculates a target steering reaction force based on the calculated final axial force (axial force-steering reaction force conversion unit 11Bd in FIG. 3). Subsequently, the control calculation unit 11 calculates a target reaction force current based on the calculated target steering reaction force (target reaction force current calculation unit 11Be in FIG. 3). Subsequently, the control calculation unit 11 drives the reaction force motor 4 based on the calculated target reaction force current (reaction force motor drive unit 3D in FIG. 2). As a result, the reaction force control unit 3 applies a steering reaction force to the steering wheel 12.
As described above, in the steering control device according to the present embodiment, the feedback axial force T FB is calculated based on the current axial force, the blend axial force T BR , and the determination results of the increase operation and the return operation. Therefore, the steering control device of the present embodiment is based on the feedback axial force based on the detection results of the sensors included in a general vehicle such as the steering current of the steering motor 6 and the lateral acceleration Gy of the host vehicle A. T FB can be calculated. Therefore, the steering control device of the present embodiment does not need to include a dedicated sensor for detecting the steering rack axial force by driving the reaction force motor 4 based on the feedback axial force TFB , and the manufacturing cost is reduced. The increase can be suppressed.
　また、本実施形態の操舵制御装置は、ステアリングホイール１２の切り増し操作が行われると、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ未満である場合には、電流軸力をフィードバック軸力ＴＦＢとする。そのため、本実施形態の操舵制御装置は、電流軸力をフィードバック軸力ＴＦＢとすることで、ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置と同様に、ステアリングホイール１２を中立位置に戻す操舵反力を付与できる。これにより、本実施形態の操舵制御装置は、ステアリングホイール１２の切り増し操作時に、より適切な操舵反力を付与できる。
　ここで、図３０の時刻ｔ２に示すように、運転者が、ステアリングホイール１２の切り増し操作を終え、切り戻し操作を行ったとする。すると、変数Ｋ４が０．０となり、変数Ｋ５にかかわらず、配分比率ＧＢ（＝Ｋ４×Ｋ５）が０．０となる（図１１のフィードバック軸力算出実行部１１Ｂｂｅ）。そして、制御演算部１１が、算出した電流軸力とブレンド軸力ＴＢＲとをＧＢ：（１－ＧＢ）で配分して、フィードバック軸力ＴＦＢを算出する（図３のフィードバック軸力算出部１１Ｂｂ）。これにより、フィードバック軸力ＴＦＢが、電流軸力からブレンド軸力ＴＢＲへと切り換わる。 Further, in the steering control device of the present embodiment, when the steering wheel 12 is increased, if the absolute value of the steering angular velocity dδ / dt is less than the fourth set steering angular velocity dδ 4 / dt, the current axis The force is a feedback axial force T FB . Therefore, the steering control device of the present embodiment is similar to the mechanical steering control device in which the steering wheel 12 and the steering wheel 13 are mechanically coupled by setting the current axial force to the feedback axial force TFB. In addition, a steering reaction force that returns the steering wheel 12 to the neutral position can be applied. Thereby, the steering control device of the present embodiment can apply a more appropriate steering reaction force when the steering wheel 12 is increased.
Here, as shown at time t <b> 2 in FIG. 30, it is assumed that the driver finishes the turning operation of the steering wheel 12 and performs the returning operation. Then, the variable K4 becomes 0.0, and the distribution ratio GB (= K4 × K5) becomes 0.0 regardless of the variable K5 (feedback axial force calculation execution unit 11Bbe in FIG. 11). Then, the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB) to calculate the feedback axial force T FB (feedback axial force calculating unit in FIG. 3). 11Bb). As a result, the feedback axial force T FB switches from the current axial force to the blend axial force T BR .
　このように、本実施形態の操舵制御装置は、ステアリングホイール１２の切り戻し操作が行われると、操舵角速度ｄδ／ｄｔの絶対値の大きさにかかわらず、電流軸力と横Ｇ軸力とを予め設定された配分比率で配分したブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとする。ここで、ステアリングホイール１２と操向輪１３とが機械的に結合している機械式の操舵制御装置では、ステアリングホイール１２の切り戻し操作時には、操向輪１３の転舵に伴うタイヤ横力Ｆｄにより、ステアリングホイール１２を中立位置に戻す操舵反力が発生する。それゆえ、機械式の操舵制御装置では、ステアリングホイール１２の切り戻し操作時には、運転者は、ステアリングホイール１２の保持力を低減し、ステアリングホイール１２を手の平で滑らせることで、ステアリングホイール１２を中立位置に戻し、操向輪１３を中立位置に戻していた。これに対し、本実施形態の操舵制御装置は、ブレンド軸力ＴＢＲをフィードバック軸力ＴＦＢとすることで、転舵電流が低減し、電流軸力が低減したとしても、ステアリングホイール１２を中立位置に戻す操舵反力が低減することを抑制できる。そのため、本実施形態の操舵制御装置は、機械式の操舵制御装置と同様に、運転者がステアリングホイール１２の保持力を低減し、ステアリングホイール１２を手の平で滑らせることで、ステアリングホイール１２を中立位置に戻すことができる。これにより、本実施形態の操舵制御装置は、ステアリングホイール１２の切り戻し操作時に、より適切な操舵反力を付与できる。 As described above, when the steering wheel 12 is switched back, the steering control device according to the present embodiment generates the current axial force and the lateral G-axis force regardless of the absolute value of the steering angular velocity dδ / dt. The blend axial force TBR distributed at a preset distribution ratio is defined as a feedback axial force TFB . Here, in the mechanical steering control device in which the steering wheel 12 and the steered wheel 13 are mechanically coupled, when the steering wheel 12 is switched back, the tire lateral force Fd accompanying the steering of the steered wheel 13 is obtained. Thus, a steering reaction force that returns the steering wheel 12 to the neutral position is generated. Therefore, in the mechanical steering control device, when the steering wheel 12 is switched back, the driver reduces the holding force of the steering wheel 12 and slides the steering wheel 12 with the palm of the hand to make the steering wheel 12 neutral. The steering wheel 13 was returned to the neutral position. In contrast, the steering control device according to the present embodiment uses the blend axial force T BR as the feedback axial force T FB so that the steering wheel 12 is neutral even if the steering current is reduced and the current axial force is reduced. It can suppress that the steering reaction force which returns to a position reduces. Therefore, as in the case of the mechanical steering control device, the steering control device of the present embodiment reduces the holding force of the steering wheel 12 and causes the steering wheel 12 to slide in the palm of the hand so that the steering wheel 12 is neutral. Can be returned to position. Thereby, the steering control device of the present embodiment can apply a more appropriate steering reaction force when the steering wheel 12 is switched back.
　ここで、図３０の時刻ｔ３に示すように、運転者が、ステアリングホイール１２の切り戻し操作中（例えば、時計回り方向への操舵中）に、操舵角δが中立位置を跨いだ後、引き続き時計回り方向へステアリングホイール１２の切り増し操作を行ったとする。また、操舵角速度ｄδ／ｄｔの絶対値が、第４設定操舵角速度ｄδ４／ｄｔ以上で且つ第５設定操舵角速度ｄδ５／ｄｔ未満の範囲にあったとする。すると、操舵角速度ｄδ／ｄｔの絶対値が小さくなるにつれ、変数Ｋ４が１．０となり、変数Ｋ５が増大し、電流軸力の配分比率ＧＢ（＝Ｋ４×Ｋ５）が増大する（図１１のフィードバック軸力算出実行部１１Ｂｂｅ）。そして、制御演算部１１が、算出した電流軸力とブレンド軸力ＴＢＲとをＧＢ：（１－ＧＢ）で配分して、フィードバック軸力ＴＦＢを算出する（図３のフィードバック軸力算出部１１Ｂｂ）。これにより、フィードバック軸力ＴＦＢが、ブレンド軸力ＴＢＲから電流軸力へと徐々に移行する。 Here, as shown at time t3 in FIG. 30, the driver continues to operate after the steering angle δ straddles the neutral position during the steering wheel 12 switching operation (for example, during steering in the clockwise direction). It is assumed that the steering wheel 12 is turned up in the clockwise direction. Further, it is assumed that the absolute value of the steering angular velocity dδ / dt is in the range of the fourth set steering angular velocity dδ 4 / dt or more and less than the fifth set steering angular velocity dδ 5 / dt. Then, as the absolute value of the steering angular velocity dδ / dt decreases, the variable K4 becomes 1.0, the variable K5 increases, and the current axial force distribution ratio GB (= K4 × K5) increases (feedback in FIG. 11). Axial force calculation execution unit 11Bbe). Then, the control calculation unit 11 distributes the calculated current axial force and the blend axial force T BR by GB: (1-GB) to calculate the feedback axial force T FB (feedback axial force calculating unit in FIG. 3). 11Bb). As a result, the feedback axial force T FB gradually shifts from the blend axial force T BR to the current axial force.
　このように、本実施形態の操舵制御装置は、ステアリングホイール１２の切り増し操作を行っていると判定し、且つ、操舵角速度ｄδ／ｄｔの絶対値が第４設定操舵角速度ｄδ４／ｄｔ以上であると判定した場合には、電流軸力とブレンド軸力ＴＢＲとを配分してフィードバック軸力ＴＦＢを設定するとともに、操舵角速度ｄδ／ｄｔの絶対値が小さくなるほど電流軸力の配分比率を大きくする。それゆえ、本実施形態の操舵制御装置は、ステアリングホイール１２の切り戻し操作中に、操舵角δが中立位置を跨ぎ、引き続き同方向へステアリングホイール１２の切り増し操作が行われた場合、切り増し操作中に操舵角速度ｄδ／ｄｔの絶対値が徐々に低減するにつれ、ブレンド軸力ＴＢＲから電流軸力へとフィードバック軸力ＴＦＢを徐々に移行できる。これにより、本実施形態の操舵制御装置は、ステアリングホイール１２の切り戻し操作から切り増し操作への切り換え時に、より適切な操舵反力を付与できる。 As described above, the steering control device according to the present embodiment determines that the steering wheel 12 is being increased, and the absolute value of the steering angular velocity dδ / dt is equal to or greater than the fourth set steering angular velocity dδ 4 / dt. If it is determined that there is, the current axial force and the blend axial force T BR are distributed to set the feedback axial force T FB, and the current axial force distribution ratio is increased as the absolute value of the steering angular velocity dδ / dt decreases. Enlarge. Therefore, the steering control device according to the present embodiment increases the steering angle when the steering angle δ straddles the neutral position and the steering wheel 12 is continuously increased in the same direction during the steering wheel 12 switching operation. as the absolute value of the during operation the steering angular velocity d? / dt is gradually reduced, can gradually transition from a blend axial force T BR to current axial force feedback axial force T FB. As a result, the steering control device of the present embodiment can apply a more appropriate steering reaction force when switching from the switchback operation to the steering wheel 12 operation.
　本実施形態では、図１のステアリングホイール１２がステアリングホイールを構成する。図１の転舵モータ６が転舵アクチュエータを構成する。図１の転舵電流検出部５Ｃが転舵電流検出部を構成する。図１１の電流軸力算出部１１Ｂｂａが電流軸力算出部を構成する。図１１のブレンド軸力算出部１１Ｂｂｂが横Ｇ軸力算出部を構成する。図３及び図１１のフィードバック軸力算出部１１Ｂｂがフィードバック軸力算出部を構成する。図３及び図１４のフィードフォワード軸力算出部１１Ｂａがフィードフォワード軸力算出部を構成する。図３の目標反転電流演算部１１Ｂが操舵反力算出部を構成する。図１の反力モータ４が反力アクチュエータを構成する。図１の車線維持支援コントローラ１５が車線維持支援部を構成する。図３の軸力切替出力部が軸力切替出力部を構成する。 In this embodiment, the steering wheel 12 in FIG. 1 constitutes a steering wheel. The steering motor 6 in FIG. 1 constitutes a steering actuator. The steered current detector 5C in FIG. 1 constitutes a steered current detector. The current axial force calculation unit 11Bba in FIG. 11 constitutes a current axial force calculation unit. The blend axial force calculator 11Bbb in FIG. 11 constitutes a lateral G-axis force calculator. The feedback axial force calculation unit 11Bb in FIGS. 3 and 11 constitutes a feedback axial force calculation unit. The feedforward axial force calculation unit 11Ba shown in FIGS. 3 and 14 constitutes a feedforward axial force calculation unit. The target reverse current calculation unit 11B in FIG. 3 constitutes a steering reaction force calculation unit. The reaction force motor 4 in FIG. 1 constitutes a reaction force actuator. 1 constitutes a lane keeping support unit. The axial force switching output unit in FIG. 3 constitutes an axial force switching output unit.
（本実施形態の効果）
　本実施形態は、次のような効果を奏する。
（１）目標反転電流演算部１１Ｂは、車線維持支援コントローラ１５が作動状態にあると判定した場合には、フィードバック軸力ＴＦＢを用いずにフィードフォワード軸力ＴＦＦに基づいて、目標操舵反力を算出する。
　このような構成によれば、最終軸力に対するフィードバック軸力ＴＦＢの寄与率が相対的に大きくなる操舵角（例えば、δ２より大きい操舵角）における操舵反力が、車線維持支援装置５０の非作動状態よりも作動状態の方が大きくなるのを防止できる。これにより、車線維持支援機能が操舵制御を妨げるのを防止できる。また、操舵制御装置は、操舵反力変動が大きくなることを解消するだけでなく、車線維持支援という付加機能の作動時に安定した操舵感を運転者に与えることができる。 (Effect of this embodiment)
This embodiment has the following effects.
(1) target reversing current calculation unit 11B, when the lane keeping assist controller 15 is judged to be in operating condition, based on the feedforward axial force T FF without using the feedback axial force T FB, target steering reaction Calculate the force.
According to such a configuration, the steering reaction force at the steering angle at which the contribution ratio of the feedback axial force TFB to the final axial force becomes relatively large (for example, the steering angle larger than δ2) is not increased in the lane keeping assist device 50. It is possible to prevent the operating state from becoming larger than the operating state. This can prevent the lane keeping assist function from interfering with the steering control. In addition, the steering control device not only eliminates an increase in the steering reaction force fluctuation, but also can provide the driver with a stable steering feeling when the additional function of lane keeping support is activated.
（２）目標反転電流演算部１１Ｂは、自車両Ａの車速Ｖと、ステアリングホイール１２の操舵角δとに基づいて、車線維持支援コントローラ１５が作動状態か否かを判定する。
　このような構成によれば、車線維持支援部の作動状態を最終軸力に対するフィードバック軸力ＴＦＢの寄与率で判定できる。
（３）車線維持支援コントローラ１５の作動状態には、車線維持支援コントローラ１５が自車両Ａの走行支援を制御可能な状態である待機状態と、車線維持支援コントローラ１５が自車両Ａの走行支援の制御中であるオン状態とが含まれる。
　このような構成によれば、車線維持支援コントローラ１５が作動状態の場合には、操舵反力はフィードバック軸力ＴＦＢを用いずにフィードフォワード軸力ＴＦＦのみで算出され、車線維持支援コントローラ１５が非作動状態の場合には、フィードバック軸力ＴＦＢ及びフィードフォワード軸力ＴＦＦで算出される。これにより、車両の運転者は車線維持支援コントローラ１５が作動状態か否かを判断できる。 (2) The target reverse current calculation unit 11B determines whether or not the lane keeping assist controller 15 is in an operating state based on the vehicle speed V of the host vehicle A and the steering angle δ of the steering wheel 12.
According to such a configuration, the operating state of the lane keeping assist unit can be determined by the contribution ratio of the feedback axial force TFB to the final axial force.
(3) The operating state of the lane keeping support controller 15 includes a standby state in which the lane keeping support controller 15 can control the running support of the host vehicle A, and the lane keeping support controller 15 provides a driving support for the own vehicle A. It includes an ON state that is under control.
According to such a configuration, when the lane keeping assist controller 15 is in the operating state, the steering reaction force is calculated only by the feedforward axial force T FF without using the feedback axial force T FB , and the lane keeping assist controller 15 Is in the non-operating state, it is calculated by the feedback axial force TFB and the feedforward axial force TFF . Thereby, the driver | operator of a vehicle can judge whether the lane maintenance assistance controller 15 is an operation state.
（４）目標反転電流演算部１１Ｂは、フィードフォワード軸力算出部１１Ｂａが出力するフィードフォワード軸力ＴＦＦと、フィードバック軸力算出部１１Ｂｂが出力するフィードバック軸力ＴＦＢとが入力し、車線維持支援コントローラ１５の非作動状態ではフィードバック軸力ＴＦＢを出力し、車線維持支援コントローラ１５の作動状態ではフィードフォワード軸力ＴＦＦを出力する軸力切替出力部１１Ｂｆを備える。
　操舵反力算出部に軸力切替出力部を備えるだけで、操舵反力変動が大きくなることを解消するだけでなく、車線維持支援という付加機能の作動時に安定した操舵感を運転者に与えることができる。 (4) the target inversion current calculation section 11B receives the feedforward axial force T FF output from the feedforward axial force calculating unit 11Ba, and the feedback axis force feedback axial force calculating unit 11Bb outputs T FB is, lane keeping and it outputs a feedback axial force T FB in the non-operating state of the support controller 15, the operating state of the lane keeping assist controller 15 includes an axial force switching output section 11Bf outputs a feedforward axial force T FF.
Not only does the steering reaction force calculation unit have an axial force switching output unit, it will not only increase the fluctuation of the steering reaction force but also give the driver a stable steering feeling when the additional function of lane keeping support is activated. Can do.
（変形例）
（１）車線維持支援部は、自車両の進行方向が、走行車線と平行若しくは平行よりも上記車線端部基準側に向いている場合にだけ、上記転舵の抑制のための転舵補正量を算出するようにしても良い。
　この場合には、自車両が左右一方の車線端部基準に近づいた位置にいても、自車両の進行方向が車線端部基準から離れる方向に向かっている場合には、当該左右一方の車線端部基準側にハンドル操舵した場合には、転舵抑制を行わない。
　これによって、逸脱方向に車両が向かっている場合にだけ転舵の抑制を実施することで、不必要に転舵抑制を行うことを回避できる。 (Modification)
(1) The lane keeping support unit turns the steering correction amount for suppressing the turning only when the traveling direction of the host vehicle is directed to the lane edge reference side rather than parallel or parallel to the traveling lane. May be calculated.
In this case, if the traveling direction of the host vehicle is away from the lane edge reference even if the host vehicle is in a position approaching the left or right lane edge reference, the left or right lane edge When the steering wheel is steered to the reference side, steering is not suppressed.
Accordingly, it is possible to avoid unnecessary turning suppression by performing the turning suppression only when the vehicle is heading in the departure direction.
（２）車線維持支援部は、自車両の進行方向が走行車線と平行若しくは平行よりも上記車線端部基準側に向いている場合に、上記操舵反力補正量を算出するようにしても良い。
　この場合には、自車両が左右一方の車線端部基準に近づいた位置にいても、自車両の進行方向が車線端部基準から離れる方向に向かっている場合には、当該左右一方の車線端部基準側にハンドル操舵した場合には、上記操舵反力を重くすることを行わない。
　これによって、逸脱方向に自車両が向かっている場合にだけ操舵反力を重くする制御を実施することで、不必要に操舵反力を重くすることを回避できる。 (2) The lane keeping support unit may calculate the steering reaction force correction amount when the traveling direction of the host vehicle is directed to the lane edge reference side rather than parallel or parallel to the traveling lane. .
In this case, if the traveling direction of the host vehicle is moving away from the lane edge reference even when the host vehicle is in a position approaching the left or right lane edge reference, the left or right lane edge When the steering wheel is steered to the part reference side, the steering reaction force is not increased.
Thus, it is possible to avoid unnecessarily increasing the steering reaction force by performing the control to increase the steering reaction force only when the host vehicle is moving in the departure direction.
〔第２の実施形態〕
（構成）
　次に、本発明の第２の実施形態について図１から図２９を参照しつつ、図３１及び図３２を用いて説明する。図３１は、本実施形態による操舵制御装置に備えられた制御演算部１１のブロック図である。図３２は、目標反力電流算出部１１Ｂの構成を表すブロック図である。
　本実施形態における自車両並びに当該自車両に備えられた制御演算部及び車線維持支援装置は、上記第１の実施形態における自車両Ａ並びに制御演算部１１及び車線維持支援装置５０とほぼ同様の構成を有し、同様の機能を発揮するようになっている。このため、以下、これらの構成について異なる点のみを説明する。 [Second Embodiment]
(Constitution)
Next, a second embodiment of the present invention will be described with reference to FIGS. 31 and 32 with reference to FIGS. FIG. 31 is a block diagram of the control calculation unit 11 provided in the steering control device according to the present embodiment. FIG. 32 is a block diagram illustrating a configuration of the target reaction force current calculation unit 11B.
The own vehicle in the present embodiment and the control calculation unit and the lane keeping support device provided in the own vehicle have substantially the same configuration as the own vehicle A, the control computation unit 11 and the lane keeping support device 50 in the first embodiment. Have the same function. For this reason, only the differences between these configurations will be described below.
　図３１及び図３２に示すように、目標反力電流算出部１１Ｂは、上記実施の形態と異なり、軸力切替出力部１１Ｂｆを有していない。制御演算部１１は、遮断部１１Ｄと配分比率算出部１１Ｂｃｂとを備えた車線維持支援動作制限部５２を有している。車線維持支援動作制限部５２は、目標操舵反力の算出に用いる最終軸力の決定に用いるパラメータである配分比率ＧＦに基づいて、車線維持支援コントローラ１５の動作を制限するようになっている。車線維持支援コントローラ１５の動作の制限には、車線維持支援コントローラ１５の出力信号が目標反力電流算出部に入力するのを遮断することや、車線維持支援コントローラ１５の動作を停止状態とすることが含まれる。当該停止状態には、車線維持支援コントローラ１５の不動作状態や、補正操舵反力演算部１５Ａ、補正操舵反力中心演算部１５Ｂ及び補正転舵角演算部１５Ｃのうち、少なくとも補正操舵反力演算部１５Ａを停止状態とすることが含まれる。
　上記第１の実施形態において説明したように、配分比率ＧＦは、フィードフォワード軸力とフィードバック軸力との軸力差分に基づく配分比率（軸力差分配分比率）ＧＦ１（図１５参照）と、横方向加速度に基づく配分比率（横Ｇ配分比率）ＧＦ２（図１６参照）と、操舵角に基づく操舵角速度の配分比率（角速度配分比率）ＧＦ３とに基づいて決定する。 As shown in FIGS. 31 and 32, the target reaction force current calculation unit 11B does not have the axial force switching output unit 11Bf unlike the above embodiment. The control calculation unit 11 includes a lane keeping assist operation restriction unit 52 including a blocking unit 11D and a distribution ratio calculation unit 11Bcb. The lane keeping assist operation restriction unit 52 restricts the operation of the lane keeping assist controller 15 based on the distribution ratio GF that is a parameter used for determining the final axial force used for calculating the target steering reaction force. In order to limit the operation of the lane keeping support controller 15, the output signal of the lane keeping support controller 15 is blocked from being input to the target reaction force current calculation unit, or the operation of the lane keeping support controller 15 is stopped. Is included. The stop state includes at least the corrected steering reaction force calculation among the non-operation state of the lane keeping support controller 15, the corrected steering reaction force calculation unit 15A, the correction steering reaction force center calculation unit 15B, and the corrected turning angle calculation unit 15C. This includes putting the unit 15A in a stopped state.
As described in the first embodiment, the distribution ratio GF is a distribution ratio (axial force difference distribution ratio) GF 1 (see FIG. 15) based on the axial force difference between the feedforward axial force and the feedback axial force. It is determined based on a distribution ratio (lateral G distribution ratio) GF 2 (see FIG. 16) based on the lateral acceleration and a steering angular speed distribution ratio (angular speed distribution ratio) GF 3 based on the steering angle.
　図３１に示すように、車線維持支援動作制限部５２に設けられた遮断部１１Ｄは、車線維持支援コントローラ１５の出力信号が入力するようになっている。当該出力信号には、例えば最終目標補正操舵反力τＹ＊と、補正操舵反力中心値ΔＴｓｃと、最終目標補正転舵角θＹ＊とが含まれる。遮断部１１Ｄは、定常状態時では、入力した最終目標補正操舵反力τＹ＊及び補正操舵反力中心値ΔＴｓｃを目標反力電流算出部１１Ｂに出力し、入力した最終目標補正転舵角θＹ＊を目標転舵角演算部１１Ａの加算部１１Ａｂに出力するようになっている。 As shown in FIG. 31, the blocking unit 11 </ b> D provided in the lane keeping support operation restriction unit 52 receives an output signal of the lane keeping support controller 15. The output signal includes, for example, a final target corrected steering reaction force τY *, a corrected steering reaction force central value ΔTsc, and a final target corrected turning angle θY *. In the steady state, the blocking unit 11D outputs the input final target correction steering reaction force τY * and the correction steering reaction force central value ΔTsc to the target reaction force current calculation unit 11B, and the input final target correction steering angle θY *. Is output to the adder 11Ab of the target turning angle calculator 11A.
　また、遮断部１１Ｄは、配分比率算出部１１Ｂｃｂ（図３２参照）が出力する動作制限制御信号ＳＣが入力するようになっている。車線維持支援動作制限部５２は、動作制限制御信号ＳＣに基づいて車線維持支援コントローラ１５の動作を制限するようになっている。本実施形態では、遮断部１１Ｄは、動作制限制御信号ＳＣの信号レベルに基づいて、最終目標補正操舵反力τＹ＊、補正操舵反力中心値ΔＴｓｃ及び最終目標補正転舵角θＹ＊を目標反力電流算出部１１Ｂ及び加算部１１Ａｂに出力するか否かを決定するようになっている。遮断部１１Ｄは、動作制限制御信号ＳＣの信号レベルが例えばロウレベルの場合には最終目標補正操舵反力τＹ＊等を目標反力電流算出部１１Ｂ等に出力し、当該信号レベルが例えばハイレベルの場合には最終目標補正操舵反力τＹ＊等を目標反力電流算出部１１Ｂ等に出力しないようになっている。また、動作制限制御信号ＳＣは、最終目標補正操舵反力τＹ＊、補正操舵反力中心値ΔＴｓｃ及び最終目標補正転舵角θＹ＊毎にそれぞれ設けられている。このため、車線維持支援動作制限部５２は、最終目標補正操舵反力τＹ＊、補正操舵反力中心値ΔＴｓｃ及び最終目標補正転舵角θＹ＊を出力するか否かを個別に制御できる。これにより、車線維持支援動作制限部５２は、補正操舵反力演算部１５Ａ、補正操舵反力中心演算部１５Ｂ及び補正転舵角演算部１５Ｃのそれぞれの動作を独立して制限できる。 In addition, the cut-off unit 11D is configured to receive the operation restriction control signal SC output from the distribution ratio calculation unit 11Bcb (see FIG. 32). The lane keeping support operation restriction unit 52 restricts the operation of the lane keeping support controller 15 based on the operation restriction control signal SC. In the present embodiment, the blocking unit 11D sets the final target corrected steering reaction force τY *, the corrected steering reaction force central value ΔTsc, and the final target corrected turning angle θY * based on the signal level of the operation restriction control signal SC. It is determined whether or not to output to the force / current calculation unit 11B and the addition unit 11Ab. When the signal level of the operation restriction control signal SC is, for example, a low level, the cutoff unit 11D outputs a final target correction steering reaction force τY * or the like to the target reaction force current calculation unit 11B or the like, and the signal level is, for example, a high level. In this case, the final target correction steering reaction force τY * or the like is not output to the target reaction force current calculation unit 11B or the like. The operation restriction control signal SC is provided for each final target corrected steering reaction force τY *, corrected steering reaction force center value ΔTsc, and final target corrected turning angle θY *. For this reason, the lane keeping assist operation restriction unit 52 can individually control whether or not to output the final target corrected steering reaction force τY *, the corrected steering reaction force central value ΔTsc, and the final target corrected turning angle θY *. Thereby, the lane keeping assist operation restriction unit 52 can independently restrict the operations of the corrected steering reaction force calculation unit 15A, the correction steering reaction force center calculation unit 15B, and the correction turning angle calculation unit 15C.
　ここで、車線維持支援コントローラ１５の車線維持支援機能が制御演算部１１の機能を妨げる問題のうち、本実施形態に関連する特有の問題点について説明する。
　車線維持支援装置５０は、自車両Ａの状態が安定し、かつ運転者の操作状態が安定している場合に、転舵角及び操舵反力制御を通して、自車両Ａの直進性能を向上する。ここで、自車両Ａの状態が安定している場合の一例は、限界高Ｇ状態又はタイヤすべり状態でない場合である。また、運転者の操作状態が安定している場合の一例は、運転者が早い操舵をしていない場合である。
　実際の走行時には、タイヤが滑りやすい路面状態などの路面情報を的確に運転者に伝えたい場合がある。しかしながら、車線維持支援装置５０が機能してしまうと、路面状態によらず自車両Ａは直進してしまう。このため、どのような路面状態にあるのかを運転者が気付き難いという問題がある。 Here, among the problems in which the lane keeping support function of the lane keeping support controller 15 interferes with the function of the control calculation unit 11, a specific problem related to the present embodiment will be described.
The lane keeping assist device 50 improves the straight traveling performance of the host vehicle A through the turning angle and the steering reaction force control when the state of the host vehicle A is stable and the operation state of the driver is stable. Here, an example of the case where the state of the host vehicle A is stable is a case where the vehicle is not in the limit high G state or the tire slip state. An example of the case where the driver's operation state is stable is a case where the driver is not steering quickly.
In actual driving, there are cases where it is desired to accurately convey to the driver road surface information such as a road surface condition in which tires are slippery. However, if the lane keeping assist device 50 functions, the host vehicle A goes straight regardless of the road surface condition. For this reason, there is a problem that it is difficult for the driver to notice what the road surface state is.
　路面状態を的確に運転者に伝えたい状況は、最終軸力におけるフィードバック軸力ＴＦＢの配分比率が高い領域である。図１５、図１６及び図１８に示すように、最終軸力におけるフィードバック軸力ＴＦＢの配分比率が高い領域は、配分比率ＧＦ１、配分比率ＧＦ２及び配分比率ＧＦ３の設定値が相対的に低い領域である。すなわち、配分比率ＧＦ１が第１４設定値よりも第１３設定値に近い値、配分比率ＧＦ２が第１６設定値よりも第１５設定値に近い値、配分比率ＧＦ３が第２０設定値よりも第２１設定値に近い値に設定する領域である。 The situation where it is desired to accurately convey the road surface condition to the driver is a region where the distribution ratio of the feedback axial force TFB in the final axial force is high. As shown in FIG. 15, FIG. 16, and FIG. 18, in the region where the distribution ratio of the feedback axial force TFB in the final axial force is high, the set values of the distribution ratio GF 1 , the distribution ratio GF 2 and the distribution ratio GF 3 are relative. It is a very low area. That is, the distribution ratio GF 1 is closer to the thirteenth set value than the fourteenth set value, the distribution ratio GF 2 is closer to the fifteenth set value than the sixteenth set value, and the distribution ratio GF 3 is greater than the twentieth set value. Is also an area set to a value close to the 21st set value.
　そこで、本実施形態では、配分比率算出部１１Ｂｃｂは、配分比率ＧＦ１、配分比率ＧＦ２及び配分比率ＧＦ３の設定値のうちの最小値が予め設定した閾値よりも小さいか否かを判断するようになっている。配分比率算出部１１Ｂｃｂは、当該最小値が当該閾値よりも小さいと判断した場合には、車線維持支援コントローラ１５の動作を制限するために、信号レベルがハイレベルの動作制限制御信号ＳＣを遮断部１１Ｄに出力する。一方、配分比率算出部１１Ｂｃｂは、当該最小値が当該閾値よりも大きいと判断した場合には、車線維持支援コントローラ１５の動作を制限する必要がないため、信号レベルがロウレベルの動作制限制御信号ＳＣを遮断部１１Ｄに出力する。遮断部１１Ｄは、動作制限制御信号ＳＣの信号レベルがハイレベルの場合には、最終目標補正操舵反力τＹ＊、補正操舵反力中心値ΔＴｓｃ及び最終目標補正転舵角θＹ＊を目標反力電流算出部１１Ｂ及び加算部１１Ａｂに出力しないようにする。これにより、目標反力電流算出部１１Ｂが出力する目標反力電流や目標転舵電流演算部１１Ｃが出力する目標転舵電流は、車線維持支援装置５０が算出する補正分を含まなくなる。このため、自車両Ａの車両直進機能は制限されるので、操舵制御装置は、路面情報を的確に運転者に伝えることができる。 Therefore, in the present embodiment, the distribution ratio calculation unit 11Bcb determines whether or not the minimum value among the set values of the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 is smaller than a preset threshold value. It is like that. When it is determined that the minimum value is smaller than the threshold value, the distribution ratio calculation unit 11Bcb blocks the operation restriction control signal SC having a high signal level in order to restrict the operation of the lane keeping support controller 15. To 11D. On the other hand, when the distribution ratio calculation unit 11Bcb determines that the minimum value is larger than the threshold value, it is not necessary to limit the operation of the lane keeping support controller 15, and thus the operation restriction control signal SC having a low signal level. Is output to the blocking unit 11D. When the signal level of the operation restriction control signal SC is high, the blocking unit 11D sets the final target correction steering reaction force τY *, the correction steering reaction force central value ΔTsc, and the final target correction turning angle θY * as the target reaction force. Do not output to the current calculation unit 11B and the addition unit 11Ab. Accordingly, the target reaction force current output by the target reaction force current calculation unit 11B and the target turning current output by the target turning current calculation unit 11C do not include the correction amount calculated by the lane keeping assist device 50. For this reason, since the vehicle straight-ahead function of the own vehicle A is limited, the steering control device can accurately convey the road surface information to the driver.
　軸力差分は、路面μの変化、すなわちタイヤすべりの指標となる。このため、車線維持支援動作制限部５２は、車線維持支援コントローラ１５の動作制限の判断に配分比率ＧＦ１を用いることにより、当該判断に路面状態を反映させることができる。
　また、車線維持支援動作制限部５２は、補正操舵反力演算部１５Ａのみの動作を制限してもよいし、補正操舵反力演算部１５Ａ、補正操舵反力中心演算部１５Ｂ及び補正転舵角演算部１５Ｃのいずれの動作も制限してもよい。
　さらに、車線維持支援動作制限部５２は、車線維持支援コントローラ１５の動作自体を停止することにより車線維持支援コントローラ１５の動作を制限するように構成してもよい。 The axial force difference is an indicator of a change in road surface μ, that is, a tire slip. Therefore, lane keeping assistance operation limiting portion 52, by using the distribution ratio GF 1 to determine the operating limits of the lane keeping assist controller 15, it is possible to reflect the road surface condition on the determination.
Further, the lane keeping assist operation restriction unit 52 may restrict the operation of only the corrected steering reaction force calculation unit 15A, the corrected steering reaction force calculation unit 15A, the corrected steering reaction force center calculation unit 15B, and the corrected turning angle. Any operation of the calculation unit 15C may be limited.
Further, the lane keeping support operation restriction unit 52 may be configured to restrict the operation of the lane keeping support controller 15 by stopping the operation of the lane keeping support controller 15 itself.
（動作その他）
　本実施形態による操舵制御装置の動作は、上記第１の実施形態による操舵制御装置の動作とほぼ同様であるため、異なる点を簡述する。
　本実施形態における目標操舵反力演算部１１Ｂは、軸力切替出力部を有していないため、車線維持支援装置５０が作動状態か否かに関わらず、フィードバック軸力ＴＦＢ及びフィードフォワード軸力ＴＦＦに基づいて、最終軸力を算出する。また、操舵制御装置では、配分比率算出部１１Ｂｃｂは、配分比率ＧＦ１、配分比率ＧＦ２及び配分比率ＧＦ３の設定値を設定する際に、これらの設定値のうちの最小値が予め設定した閾値よりも小さいと判断したら、遮断部１１Ｄを介して車線維持支援コントローラ１５の動作を制限する。 (Operation other)
Since the operation of the steering control device according to the present embodiment is substantially the same as the operation of the steering control device according to the first embodiment, the differences will be briefly described.
Since the target steering reaction force calculation unit 11B in the present embodiment does not have an axial force switching output unit, the feedback axial force TFB and the feedforward axial force regardless of whether the lane keeping assist device 50 is in an operating state or not. Based on TFF , the final axial force is calculated. In the steering control device, when the distribution ratio calculation unit 11Bcb sets the setting values of the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 , a minimum value among these setting values is set in advance. If it is determined that it is smaller than the threshold value, the operation of the lane keeping assist controller 15 is limited via the blocking unit 11D.
　本実施形態では、図１のステアリングホイール１２がステアリングホイールを構成する。図１の転舵モータ６が転舵アクチュエータを構成する。図１の転舵電流検出部５Ｃが転舵電流検出部を構成する。図１１の電流軸力算出部１１Ｂｂａが電流軸力算出部を構成する。図１１のブレンド軸力算出部１１Ｂｂｂが横Ｇ軸力算出部を構成する。図３及び図１１のフィードバック軸力算出部１１Ｂｂがフィードバック軸力算出部を構成する。図３及び図１４のフィードフォワード軸力算出部１１Ｂａがフィードフォワード軸力算出部を構成する。図３の目標反転電流演算部１１Ｂが操舵反力算出部を構成する。図１の反力モータ４が反力アクチュエータを構成する。図１の車線維持支援コントローラ１５が車線維持支援部を構成する。図３１及び図３２の遮断部１１Ｄ及び配分比率算出部１１Ｂｃｂが線維持支援動作制限部を構成する。図３１の遮断部１１Ｄが遮断部を構成する。 In this embodiment, the steering wheel 12 in FIG. 1 constitutes a steering wheel. The steering motor 6 in FIG. 1 constitutes a steering actuator. The steered current detector 5C in FIG. 1 constitutes a steered current detector. The current axial force calculation unit 11Bba in FIG. 11 constitutes a current axial force calculation unit. The blend axial force calculator 11Bbb in FIG. 11 constitutes a lateral G-axis force calculator. The feedback axial force calculation unit 11Bb in FIGS. 3 and 11 constitutes a feedback axial force calculation unit. The feedforward axial force calculation unit 11Ba shown in FIGS. 3 and 14 constitutes a feedforward axial force calculation unit. The target reverse current calculation unit 11B in FIG. 3 constitutes a steering reaction force calculation unit. The reaction force motor 4 in FIG. 1 constitutes a reaction force actuator. 1 constitutes a lane keeping support unit. The blocking unit 11D and the distribution ratio calculation unit 11Bcb in FIGS. 31 and 32 constitute a line maintenance support operation limiting unit. The blocking part 11D in FIG. 31 constitutes a blocking part.
（本実施形態の効果）
（１）制御演算部１１は、操舵反力の算出に用いるパラメータに基づいて、車線維持支援コントローラ１５の動作を制限する。
　このような構成によれば、操舵反力演算部は、操舵反力の演算に車線維持支援部が算出する補正分を含めなくなる。これにより、車線維持支援機能が操舵制御を妨げるのを防止できる。また、操舵制御装置は、路面情報を的確に運転者に伝えることができる。
（２）当該パラメータは、フィードフォワード軸力算出部１１Ｂａが算出したフィードフォワード軸力ＴＦＦとフィードバック軸力算出部１１Ｂｂが算出したフィードバック軸力ＴＦＢとを配分する比率である配分比率を含んでいる。
　このような構成によれば、路面情報を的確に運転者に伝えることができる。
（３）当該配分比率は、配分比率ＧＦ１、配分比率ＧＦ２及び配分比率ＧＦ３に基づいて決定する。
　このような構成によれば、路面情報を的確に運転者に伝えることができる。 (Effect of this embodiment)
(1) The control calculation unit 11 restricts the operation of the lane keeping support controller 15 based on parameters used for calculating the steering reaction force.
According to such a configuration, the steering reaction force calculation unit does not include the correction amount calculated by the lane keeping support unit in the calculation of the steering reaction force. This can prevent the lane keeping assist function from interfering with the steering control. In addition, the steering control device can accurately convey the road surface information to the driver.
(2) The parameters include distribution ratio is a ratio to distribute the feedback axial force T FB feedforward axial force feedforward axial force calculating unit 11Ba is calculated T FF and the feedback axial force calculating unit 11Bb is calculated Yes.
According to such a configuration, road surface information can be accurately transmitted to the driver.
(3) The distribution ratio is determined based on the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 .
According to such a configuration, road surface information can be accurately transmitted to the driver.
（４）制御演算部１１は、配分比率ＧＦ１、配分比率ＧＦ２及び配分比率ＧＦ３のうちの最小値が予め設定した閾値よりも小さい場合には車線維持支援コントローラ１５の動作を制限し、当該最小値が当該閾値以上の場合には車線維持支援コントローラ１５の動作を制限しない。
　このような構成によれば、路面状態等の情報を含むフィードバック軸力ＴＦＢが操舵反力に反映されやすい場合に車線維持支援コントローラ１５の動作を制限できる。これにより、路面情報を的確に運転者に伝えることができる。
（５）制御演算部１１は、車線維持支援コントローラ１５に備えられた補正操舵反力演算部１５Ａの動作を制限する。
　このような構成によれば、操舵反力の制御量に直接寄与する最終目標補正操舵反力を付与せずに、操舵反力を算出できる。 (4) The control calculation unit 11 restricts the operation of the lane keeping support controller 15 when the minimum value of the distribution ratio GF 1 , the distribution ratio GF 2, and the distribution ratio GF 3 is smaller than a preset threshold value, When the minimum value is equal to or greater than the threshold value, the operation of the lane keeping support controller 15 is not limited.
According to such a configuration, the operation of the lane keeping assist controller 15 can be limited when the feedback axial force TFB including information such as the road surface condition is easily reflected in the steering reaction force. Thereby, road surface information can be accurately conveyed to the driver.
(5) The control calculation unit 11 limits the operation of the corrected steering reaction force calculation unit 15 </ b> A provided in the lane keeping support controller 15.
According to such a configuration, the steering reaction force can be calculated without applying the final target correction steering reaction force that directly contributes to the control amount of the steering reaction force.
（６）制御演算部１１は、補正操舵反力中心演算部１５Ｂ及び補正転舵角演算部１５Ｃの動作を制限する。
　このような構成によれば、操舵反力の制御量に寄与する補正分を付与せずに、操舵反力を算出できる。
（７）制御演算部１１は、最終目標補正転舵角θＹ＊、最終目標補正操舵反力τＹ＊及び補正操舵反力中心値ΔＴｓｃの少なくともいずれか１つが制御演算部１１に入力するのを遮断して車線維持支援コントローラ１５の動作を制限する遮断部を有する。
　このような構成によれば、車線維持支援コントローラ１５の作動状態は継続したままで、操舵反力の制御量に寄与する補正分を付与せずに、操舵反力を算出できる。
（８）車線維持支援コントローラ１５の動作の制限は、車線維持支援コントローラ１５の動作の停止が含まれる。
　このような構成によれば、操舵反力の制御量に寄与する補正分を付与せずに、操舵反力を算出できる。 (6) The control calculation unit 11 restricts the operations of the corrected steering reaction force center calculation unit 15B and the corrected turning angle calculation unit 15C.
According to such a configuration, the steering reaction force can be calculated without providing a correction amount that contributes to the control amount of the steering reaction force.
(7) The control calculation unit 11 blocks at least one of the final target correction turning angle θY *, the final target correction steering reaction force τY *, and the correction steering reaction force central value ΔTsc from being input to the control calculation unit 11. The lane keeping support controller 15 has a blocking unit that restricts the operation.
According to such a configuration, the steering reaction force can be calculated without giving a correction amount that contributes to the control amount of the steering reaction force while the operation state of the lane keeping assist controller 15 is continued.
(8) The limitation of the operation of the lane keeping support controller 15 includes the stop of the operation of the lane keeping support controller 15.
According to such a configuration, the steering reaction force can be calculated without providing a correction amount that contributes to the control amount of the steering reaction force.
〔第３の実施形態〕
　次に、本発明の第３の実施形態について図１から図２９を参照しつつ、図３３から図３５を用いて説明する。まず、図３３及び図３４を用いて本実施形態による操舵制御装置の概略構成について説明する。図３３は、目標反力電流算出部１１Ｂの構成を表すブロック図である。図３４は、フリクション演算部１１Ｂｇが事前フリクションを算出する際に参照する制御マップＭ１１を示す図である。
　本実施形態における自車両並びに当該自車両に備えられた制御演算部及び車線維持支援装置は、上記第１の実施形態における自車両Ａ並びに制御演算部１１及び車線維持支援装置５０とほぼ同様の構成を有し、同様の機能を発揮するようになっている。このため、以下、これらの構成について異なる点のみを説明する。 [Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. 33 to 35 with reference to FIGS. First, a schematic configuration of the steering control device according to the present embodiment will be described with reference to FIGS. 33 and 34. FIG. 33 is a block diagram illustrating a configuration of the target reaction force current calculation unit 11B. FIG. 34 is a diagram illustrating a control map M11 that is referred to when the friction calculation unit 11Bg calculates pre-friction.
The own vehicle in the present embodiment and the control calculation unit and the lane keeping support device provided in the own vehicle have substantially the same configuration as the own vehicle A, the control computation unit 11 and the lane keeping support device 50 in the first embodiment. Have the same function. For this reason, only the differences between these configurations will be described below.
　図３３に示すように、目標反力電流算出部１１Ｂは、上記実施の形態と異なり、軸力切替出力部１１Ｂｆを有していない。
　目標反力電流算出部１１Ｂは、第１操舵反力を補正する補正値に基づいて操向輪１３（図１参照）の転舵に伴って発生するフリクションを演算するフリクション演算部１１Ｂｇを有している。
　ここで、第１操舵反力は、事前目標操舵反力読み出し部１１Ｂｄａが読み出した事前目標操舵反力である。また、補正値は、最終軸力の算出に用いる補正操舵反力中心値ΔＴｓｃと最終目標補正操舵反力τＹ＊とを含んでいる。すなわち、事前目標操舵反力を補正する補正値は、当該事前目標操舵反力に加算する補正値（最終目標補正操舵反力τＹ＊）だけでなく、当該事前目標操舵反力の読み出しに用いる最終軸力の算出に用いる補正値（補正操舵反力中心値ΔＴｓｃ）も含む。 As shown in FIG. 33, the target reaction force current calculation unit 11B does not have the axial force switching output unit 11Bf unlike the above embodiment.
The target reaction force current calculation unit 11B includes a friction calculation unit 11Bg that calculates the friction generated when the steered wheel 13 (see FIG. 1) is steered based on the correction value for correcting the first steering reaction force. ing.
Here, the first steering reaction force is the preliminary target steering reaction force read by the preliminary target steering reaction force reading unit 11Bda. Further, the correction value includes a corrected steering reaction force center value ΔTsc and a final target correction steering reaction force τY * used for calculating the final axial force. That is, the correction value for correcting the preliminary target steering reaction force is not only the correction value (final target correction steering reaction force τY *) to be added to the preliminary target steering reaction force, but also the final value used for reading the preliminary target steering reaction force. It also includes a correction value (corrected steering reaction force central value ΔTsc) used for calculating the axial force.
　車線維持支援コントローラ１５（図２参照）は、事前目標操舵反力読み出し部１１Ｂｄａが読み出した事前目標操舵反力を補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊で補正することにより、自車両Ａが走行車線から逸脱せずに走行するのを支援するようになっている。
　フリクション演算部１１Ｂｇは、フリクション演算前段部１１Ｂｇａと、フリクション演算後段部１１Ｂｇｂとを有している。フリクション演算前段部１１Ｂｇａは、ステアリングホイール１２の操舵角δから算出した操舵角速度ｄδ／ｄｔと、自車両Ａの車速Ｖとに基づく事前フリクションを演算するようになっている。 The lane keeping support controller 15 (see FIG. 2) corrects the prior target steering reaction force read by the prior target steering reaction force reading unit 11Bda with the corrected steering reaction force central value ΔTsc and the final target corrected steering reaction force τY *. The vehicle A is supported to travel without departing from the traveling lane.
The friction calculation unit 11Bg includes a friction calculation pre-stage unit 11Bga and a friction calculation post-stage unit 11Bgb. The friction calculation pre-stage unit 11Bga calculates a prior friction based on the steering angular velocity dδ / dt calculated from the steering angle δ of the steering wheel 12 and the vehicle speed V of the host vehicle A.
　ここで、図３４を用いて事前フリクションの演算方法について説明する。
　図３４は、制御マップＭ１１を表すグラフである。
　事前フリクションの演算方法としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応した事前フリクションを制御マップＭ１１から読み出す方法を採用できる。制御マップＭ１１としては、例えば、操舵角速度ｄδ／ｄｔの絶対値に対応した事前フリクションを登録したマップがある。具体的には、図３４に示すように、制御マップＭ１１は、車速Ｖ毎に設定される。各制御マップＭ１１は、操舵角速度ｄδ／ｄｔが０である場合に事前フリクションを第２２設定値（例えば、０．０）に設定する。また、制御マップＭ１１は、操舵角速度ｄδ／ｄｔの絶対値が第６設定操舵角速度ｄδ６／ｄｔ（＞０）以上の範囲では、操舵角速度ｄδ／ｄｔの大きさにかかわらず事前フリクションを第２３設定値（一定値）に設定する。さらに、制御マップＭ１１は、操舵角速度ｄδ／ｄｔが０．０以上で且つ操舵角速度ｄδ／ｄｔの絶対値が第６設定操舵角速度ｄδ６／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値に応じて事前フリクションを直線的に増加させる。具体的には、各制御マップＭ１１は、操舵角速度ｄδ／ｄｔの絶対値が０以上で且つ第６設定操舵角速度ｄδ６／ｄｔ未満の範囲では、操舵角速度ｄδ／ｄｔの絶対値と事前フリクションとの関係を表す一次関数に従って事前フリクションを設定する。一次関数は、操舵角速度ｄδ／ｄｔの絶対値が０である場合に事前フリクションを第２２設定値（０．０）とし、操舵角速度ｄδ／ｄｔの絶対値が第６設定操舵角速度ｄδ６／ｄｔである場合に事前フリクションを第２３設定値（０＜第２３設定値）に設定する。これにより、事前フリクション演算前段部１１Ｂｇａは、操舵角速度ｄδ／ｄｔの絶対値が第６設定操舵角速度ｄδ６／ｄｔ未満である場合には、操舵角速度ｄδ／ｄｔの絶対値が大きいほど事前フリクションの絶対値を大きくする。また、事前フリクション演算前段部１１Ｂｇａは、操舵角速度ｄδ／ｄｔの絶対値が第６設定操舵角速度ｄδ６／ｄｔ以上である場合には、操舵角速度ｄδ／ｄｔの大きさにかかわらず、事前フリクションの絶対値を予め定めた一定値とする。第６設定値は、車速Ｖが増加するほど高い値に設定される。 Here, the prior friction calculation method will be described with reference to FIG.
FIG. 34 is a graph showing the control map M11.
As a method for calculating the preliminary friction, for example, a method of reading the preliminary friction corresponding to the absolute value of the steering angular velocity dδ / dt from the control map M11 can be employed. As the control map M11, for example, there is a map in which pre-friction corresponding to the absolute value of the steering angular velocity dδ / dt is registered. Specifically, as shown in FIG. 34, the control map M11 is set for each vehicle speed V. Each control map M11 sets the prior friction to the 22nd set value (for example, 0.0) when the steering angular velocity dδ / dt is 0. Further, the control map M11 shows that the prior friction is the 23rd in the range where the absolute value of the steering angular velocity dδ / dt is not less than the sixth set steering angular velocity dδ 6 / dt (> 0) regardless of the magnitude of the steering angular velocity dδ / dt. Set to a set value (constant value). Further, the control map M11 indicates that the absolute value of the steering angular velocity dδ / dt is within a range where the steering angular velocity dδ / dt is 0.0 or more and the absolute value of the steering angular velocity dδ / dt is less than the sixth set steering angular velocity dδ 6 / dt. The pre-friction is increased linearly according to Specifically, in each control map M11, the absolute value of the steering angular velocity dδ / dt and the prior friction are obtained when the absolute value of the steering angular velocity dδ / dt is not less than 0 and less than the sixth set steering angular velocity dδ 6 / dt. Pre-friction is set according to a linear function that expresses the relationship. In the linear function, when the absolute value of the steering angular velocity dδ / dt is 0, the prior friction is set to the 22nd set value (0.0), and the absolute value of the steering angular velocity dδ / dt is the sixth set steering angular velocity dδ 6 / dt. Is set to the 23rd set value (0 <23rd set value). As a result, when the absolute value of the steering angular velocity dδ / dt is less than the sixth set steering angular velocity dδ 6 / dt, the pre-friction calculation pre-stage unit 11Bga increases the pre-friction as the absolute value of the steering angular velocity dδ / dt increases. Increase the absolute value. Further, the pre-friction calculation pre-stage unit 11Bga, when the absolute value of the steering angular velocity dδ / dt is equal to or larger than the sixth set steering angular velocity dδ 6 / dt, regardless of the magnitude of the steering angular velocity dδ / dt, The absolute value is a predetermined constant value. The sixth set value is set to a higher value as the vehicle speed V increases.
　図３３に戻って、事前フリクション演算前段部１１Ｂｇａは、制御マップＭ１１を用いて得た事前フリクションをフリクション演算後段部１１Ｂｇｂに出力する。
　フリクション演算後段部１１Ｂｇｂには、当該事前フリクションの他に、目標操舵反力が入力する。目標操舵反力は、事前目標操舵反力を最終目標補正操舵反力τＹ＊で補正した操舵反力である。すなわち、目標操舵反力は、第１操舵反力を補正値で補正した第２操舵反力に相当する。
　フリクション演算後段部１１Ｂｇｂは、入力した目標操舵反力に基づく係数を算出する。当該係数の算出は、例えば目標操舵反力に当該係数を関連づけた制御マップから読み出す方法を採用できる。フリクション演算後段部１１Ｂｇｂは、入力した事前フリクションに目標操舵反力から得られる係数を乗算してフリクションを算出する。このように、フリクション演算部１１Ｂｇは、目標操舵反力から得られる係数に基づいて、フリクションを演算するようになっている。 Returning to FIG. 33, the pre-friction calculation pre-stage unit 11Bga outputs the pre-friction obtained using the control map M11 to the friction calculation post-stage unit 11Bgb.
In addition to the preliminary friction, the target steering reaction force is input to the friction calculation post-stage portion 11Bgb. The target steering reaction force is a steering reaction force obtained by correcting the prior target steering reaction force with the final target correction steering reaction force τY *. That is, the target steering reaction force corresponds to the second steering reaction force obtained by correcting the first steering reaction force with the correction value.
The friction calculation post-stage unit 11Bgb calculates a coefficient based on the input target steering reaction force. For the calculation of the coefficient, for example, a method of reading from a control map in which the coefficient is associated with the target steering reaction force can be employed. The friction calculation post-stage unit 11Bgb calculates the friction by multiplying the input prior friction by a coefficient obtained from the target steering reaction force. As described above, the friction calculation unit 11Bg calculates the friction based on the coefficient obtained from the target steering reaction force.
　フリクション演算後段部１１Ｂｇｂは、算出した当該フリクションを目標反力電流算出部１１Ｂに設けられた加算部１１Ｂｈに出力する。加算部１１Ｂｈは、フリクション演算部１１Ｂｇが出力したフリクションと、目標操舵反力とを加算して、目標反力電流演算部１１Ｂｅに出力する。目標反力電流演算部１１Ｂｅは、フリクションが付加された目標操舵反力に基づいて、目標反力電流を演算する。目標反力電流演算部１１Ｂｅは、目標反力電流を反力モータ駆動部３Ｄ（図２参照）に出力する。 The friction calculation post-stage unit 11Bgb outputs the calculated friction to the addition unit 11Bh provided in the target reaction force current calculation unit 11B. The adder 11Bh adds the friction output by the friction calculator 11Bg and the target steering reaction force, and outputs the result to the target reaction force current calculator 11Be. The target reaction force current calculation unit 11Be calculates a target reaction force current based on the target steering reaction force to which friction is added. The target reaction force current calculation unit 11Be outputs the target reaction force current to the reaction force motor drive unit 3D (see FIG. 2).
　ここで、車線維持支援コントローラ１５の車線維持支援機能が制御演算部１１の機能を妨げる問題のうち、本実施形態に関連する特有の問題点について説明する。
　ステア・バイ・ワイヤシステムにおける反力制御には、操舵反力すなわちフィードバック軸力に応じたフリクション項が存在する。当該フリクション項は操舵反力が大きくなるほど大きくなる。上記第１の実施形態における特有の問題点において図２９を用いて説明したように、車線維持支援制御をしている場合には、操舵反力に補正操舵反力中心値を加算するため、同じ操舵角位置であっても、車線維持支援制御をしていない場合と比較して、操舵反力が小さくなる。これに対し、フリクション項は、補正操舵反力中心値を加算する前の操舵反力で算出されるため、操舵反力に対するフリクション項が過剰になる。これにより、良好な操舵感が得られないという問題が生じる。 Here, among the problems in which the lane keeping support function of the lane keeping support controller 15 interferes with the function of the control calculation unit 11, a specific problem related to the present embodiment will be described.
In the reaction force control in the steer-by-wire system, there is a friction term corresponding to the steering reaction force, that is, the feedback axial force. The friction term increases as the steering reaction force increases. As described with reference to FIG. 29 regarding the specific problem in the first embodiment, when the lane keeping assist control is being performed, the correction steering reaction force central value is added to the steering reaction force, and thus the same. Even at the steering angle position, the steering reaction force is smaller than when the lane keeping assist control is not performed. On the other hand, since the friction term is calculated by the steering reaction force before adding the corrected steering reaction force central value, the friction term for the steering reaction force becomes excessive. This causes a problem that a good steering feeling cannot be obtained.
　本実施形態におけるフリクション演算部１１Ｂｇは、補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊を考慮した目標操舵反力に基づく係数を事前フリクションに乗算して操向輪１３の転舵に伴って発生するフリクションを演算するようになっている。
　図３５は、操舵角速度とフリクション項との関係を示すグラフである。横軸は操舵角速度の絶対値を示し、縦軸はフリクション項を示している。曲線ε０は、補正操舵反力中心値ΔＴｓｃを考慮（車線維持支援制御分を考慮）した場合の操舵角速度に対するフリクション項の特性を表している。曲線ε１は、補正操舵反力中心値ΔＴｓｃを考慮していない場合の操舵角速度に対するフリクション項の特性を表している。すなわち、曲線ε０によって表す特性は、フリクション演算部１１Ｂｇが出力するフリクションの特性に相当している。曲線ε１によって表す特性は、事前フリクションの特性に相当している。
　図３５に示すように、補正操舵反力中心値ΔＴｓｃを考慮した場合には、補正操舵反力中心値ΔＴｓｃを考慮していない場合と比較して、フリクション項は低減する。これにより、本実施形態における制御演算部１１は、補正操舵反力中心値ΔＴｓｃにより操舵反力が小さくなっても、操舵反力の低減分に応じてフリクション項も小さくできるので、フリクションが過剰になるのを防止して、良好な操舵感を得られる。 The friction calculation unit 11Bg in this embodiment multiplies the pre-friction by a coefficient based on the target steering reaction force in consideration of the corrected steering reaction force central value ΔTsc and the final target correction steering reaction force τY *, and steers the steered wheels 13. The friction generated along with this is calculated.
FIG. 35 is a graph showing the relationship between the steering angular velocity and the friction term. The horizontal axis indicates the absolute value of the steering angular velocity, and the vertical axis indicates the friction term. A curve ε0 represents a characteristic of the friction term with respect to the steering angular velocity when the corrected steering reaction force central value ΔTsc is taken into consideration (considering the lane keeping assist control). A curve ε1 represents the characteristic of the friction term with respect to the steering angular velocity when the corrected steering reaction force central value ΔTsc is not taken into consideration. That is, the characteristic represented by the curve ε0 corresponds to the characteristic of the friction output by the friction calculation unit 11Bg. The characteristic represented by the curve ε1 corresponds to the characteristic of the prior friction.
As shown in FIG. 35, when the corrected steering reaction force central value ΔTsc is taken into consideration, the friction term is reduced as compared with the case where the corrected steering reaction force central value ΔTsc is not taken into consideration. As a result, even if the steering reaction force is reduced by the corrected steering reaction force central value ΔTsc, the control calculation unit 11 in the present embodiment can reduce the friction term in accordance with the reduction amount of the steering reaction force. It is possible to obtain a good steering feeling.
（動作その他）
　本実施形態による操舵制御装置の動作は、上記第１の実施形態による操舵制御装置の動作とほぼ同様であるため、異なる点を簡述する。
　本実施形態における目標操舵反力演算部１１Ｂは、軸力切替出力部を有していないため、車線維持支援装置５０が作動状態か否かに関わらず、フィードバック軸力ＴＦＢ及びフィードフォワード軸力ＴＦＦに基づいて、最終軸力を算出する。また、操舵制御装置では、目標反転電流演算部１１Ｂは、補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊を考慮した目標操舵反力に基づく係数に基づいて、操向輪１３の転舵に伴って発生するフリクションを演算する。続いて、目標反転電流演算部１１Ｂは、演算したフリクションと目標操舵反力とを加算して目標反転電流を算出する。 (Operation other)
Since the operation of the steering control device according to the present embodiment is substantially the same as the operation of the steering control device according to the first embodiment, the differences will be briefly described.
Since the target steering reaction force calculation unit 11B in the present embodiment does not have an axial force switching output unit, the feedback axial force TFB and the feedforward axial force regardless of whether the lane keeping assist device 50 is in an operating state or not. Based on TFF , the final axial force is calculated. Further, in the steering control device, the target reversal current calculation unit 11B is based on a coefficient based on the target steering reaction force in consideration of the corrected steering reaction force center value ΔTsc and the final target correction steering reaction force τY *. Friction generated with turning is calculated. Subsequently, the target reverse current calculation unit 11B calculates the target reverse current by adding the calculated friction and the target steering reaction force.
　本実施形態では、図１のステアリングホイール１２がステアリングホイールを構成する。図１の転舵モータ６が転舵アクチュエータを構成する。図１の転舵電流検出部５Ｃが転舵電流検出部を構成する。図１１の電流軸力算出部１１Ｂｂａが電流軸力算出部を構成する。図１１のブレンド軸力算出部１１Ｂｂｂが横Ｇ軸力算出部を構成する。図３及び図１１のフィードバック軸力算出部１１Ｂｂがフィードバック軸力算出部を構成する。図３及び図１４のフィードフォワード軸力算出部１１Ｂａがフィードフォワード軸力算出部を構成する。図３の目標反転電流演算部１１Ｂが操舵反力算出部を構成する。図１の反力モータ４が反力アクチュエータを構成する。図１の車線維持支援コントローラ１５が車線維持支援部を構成する。図３５のフリクション演算部１１Ｂｇがフリクション演算部を構成する。図３５のフリクション演算前段部１１Ｂｇａがフリクション演算前段部を構成する。図３５のフリクション演算後段部１１Ｂｇｂがフリクション演算後段部を構成する。事前目標操舵反力読み出し部１１Ｂｄａが読み出した事前目標操舵反力が第１操舵反力を構成する。また、最終軸力の算出に用いる補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊が補正値を構成する。 In this embodiment, the steering wheel 12 in FIG. 1 constitutes a steering wheel. The steering motor 6 in FIG. 1 constitutes a steering actuator. The steered current detector 5C in FIG. 1 constitutes a steered current detector. The current axial force calculation unit 11Bba in FIG. 11 constitutes a current axial force calculation unit. The blend axial force calculator 11Bbb in FIG. 11 constitutes a lateral G-axis force calculator. The feedback axial force calculation unit 11Bb in FIGS. 3 and 11 constitutes a feedback axial force calculation unit. The feedforward axial force calculation unit 11Ba shown in FIGS. 3 and 14 constitutes a feedforward axial force calculation unit. The target reverse current calculation unit 11B in FIG. 3 constitutes a steering reaction force calculation unit. The reaction force motor 4 in FIG. 1 constitutes a reaction force actuator. 1 constitutes a lane keeping support unit. The friction calculation unit 11Bg in FIG. 35 constitutes a friction calculation unit. The friction calculation pre-stage unit 11Bga in FIG. 35 constitutes the friction calculation pre-stage unit. The friction calculation post-stage part 11Bgb of FIG. 35 constitutes the friction calculation post-stage part. The pre-target steering reaction force read by the pre-target steering reaction force reading unit 11Bda constitutes the first steering reaction force. Further, the correction steering reaction force central value ΔTsc and the final target correction steering reaction force τY * used for calculating the final axial force constitute a correction value.
（本実施形態の効果）
（１）フリクション演算部１１Ｂｇは、操舵反力を補正する補正値に基づいて操向輪１３の転舵に伴って発生するフリクションを演算する。
　このような構成によれば、操舵反力に対するフリクション項が過剰になるのを防止できる。これにより、車線維持支援機能が操舵制御を妨げるのを防止できる。また、良好な操舵感が得られる。
（２）当該補正値は、補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊とを含む。
　このような構成によれば、操舵反力に対するフリクション項が過剰になるのを防止できる。
（３）フリクション演算部１１Ｂｇは、補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊で補正された操舵反力から得られる係数に基づいて、フリクションを演算する。
　このような構成によれば、操舵反力に対するフリクション項が過剰になるのを防止できる。 (Effect of this embodiment)
(1) The friction calculation unit 11Bg calculates the friction generated when the steered wheels 13 are steered based on the correction value for correcting the steering reaction force.
According to such a configuration, it is possible to prevent the friction term for the steering reaction force from becoming excessive. This can prevent the lane keeping assist function from interfering with the steering control. Further, a good steering feeling can be obtained.
(2) The correction value includes a corrected steering reaction force center value ΔTsc and a final target correction steering reaction force τY *.
According to such a configuration, it is possible to prevent the friction term for the steering reaction force from becoming excessive.
(3) The friction calculator 11Bg calculates the friction based on the coefficient obtained from the steering reaction force corrected by the corrected steering reaction force central value ΔTsc and the final target correction steering reaction force τY *.
According to such a configuration, it is possible to prevent the friction term for the steering reaction force from becoming excessive.
（４）フリクション演算部１１Ｂｇは、ステアリングホイール１２の操舵角δから算出した操舵角速度ｄδ／ｄｔと、自車両Ａの車速Ｖとに基づく事前フリクションを演算するフリクション演算前段部１１Ｂｇａと、事前フリクションと係数とに基づいて、フリクションを演算するフリクション演算後段部１１Ｂｇｂとを有する。
　この構成によれば、操舵反力を補正する補正量を操向輪１３の転舵に伴って発生するフリクションの演算に反映できる。これにより、操舵反力に対するフリクション項が過剰になるのを防止できる。
（５）目標反力電流演算部１１Ｂｅは、補正操舵反力中心値ΔＴｓｃ及び最終目標補正操舵反力τＹ＊で補正された目標操舵反力と、フリクション演算部１１Ｂｇが演算したフリクションとに基づいて、目標反力電流を演算する。
　この構成によれば、操舵反力に対する適切なフリクション項に基づいて、目標反転電流を演算できる。これにより、良好な操舵感が得られる。 (4) The friction calculation unit 11Bg includes a friction calculation pre-stage unit 11Bga that calculates pre-friction based on the steering angular velocity dδ / dt calculated from the steering angle δ of the steering wheel 12 and the vehicle speed V of the host vehicle A; And a friction calculation post-stage unit 11Bgb for calculating the friction based on the coefficient.
According to this configuration, the correction amount for correcting the steering reaction force can be reflected in the calculation of the friction generated when the steered wheel 13 is steered. This can prevent the friction term for the steering reaction force from becoming excessive.
(5) The target reaction force current calculation unit 11Be is based on the target steering reaction force corrected by the corrected steering reaction force central value ΔTsc and the final target correction steering reaction force τY *, and the friction calculated by the friction calculation unit 11Bg. The target reaction force current is calculated.
According to this configuration, the target reverse current can be calculated based on an appropriate friction term for the steering reaction force. Thereby, a favorable steering feeling can be obtained.
１　ステアリングホイール角度センサ
３Ｄ　反力モータ駆動部
４　反力モータ
５Ｃ　転舵電流検出部
５Ｄ　転舵モータ駆動部
６　転舵モータ
１１Ｂ　目標反力電流算出部
１１Ｂａ　フィードフォワード軸力算出部
１１Ｂｂ　フィードバック軸力算出部
１１Ｂｂｅ　フィードバック軸力算出実行部
１１Ｂｃ　最終軸力算出部
１１Ｂｆ　軸力切替出力部
１１Ｂｃｂ　配分比率算出部
１１Ｄ　遮断部
１１Ｂｇ　フリクション演算部
１２　ステアリングホイール
１４Ａ　車速センサ
１４Ｂ　横Ｇセンサ
１４Ｃ　ヨーレートセンサ
１５　車線維持支援部
１５Ａ　補正操舵反力演算部
１５Ｂ　補正操舵反力中心演算部
１５Ｃ　補正転舵角演算部
５０　車線維持支援装置 DESCRIPTION OF SYMBOLS 1 Steering wheel angle sensor 3D Reaction force motor drive part 4 Reaction force motor 5C Steering current detection part 5D Steering motor drive part 6 Steering motor 11B Target reaction force electric current calculation part 11Ba Feedforward axial force calculation part 11Bb Feedback axial force calculation Unit 11Bbe feedback axial force calculation execution unit 11Bc final axial force calculation unit 11Bf axial force switching output unit 11Bcb distribution ratio calculation unit 11D blocking unit 11Bg friction calculation unit 12 steering wheel 14A vehicle speed sensor 14B lateral G sensor 14C yaw rate sensor 15 lane keeping support unit 15A Correction steering reaction force calculation unit 15B Correction steering reaction force center calculation unit 15C Correction turning angle calculation unit 50 Lane keeping support device

Claims (17)

  1. 　操向輪と機械的に分離したステアリングホイールと、
    　前記ステアリングホイールの操作量に応じて前記操向輪を転舵する転舵アクチュエータと、
    　前記転舵アクチュエータの転舵電流を検出する転舵電流検出部と、
    　前記転舵電流に基づいてステアリングラックの軸力を算出する電流軸力算出部と、
    　前記電流軸力算出部が算出した前記ステアリングラックの軸力に基づいて、フィードバック軸力を算出するフィードバック軸力算出部と、
    　前記ステアリングホイールの操舵角に基づいて、フィードフォワード軸力を算出するフィードフォワード軸力算出部と、
    　前記フィードフォワード軸力算出部が算出した前記フィードフォワード軸力と前記フィードバック軸力算出部が算出した前記フィードバック軸力とに基づいて、操舵反力を算出する操舵反力算出部と、
    　前記ステアリングホイールに前記操舵反力を付与する反力アクチュエータと、
    　前記車両が走行車線から逸脱せずに走行するのを支援する車線維持支援部と
    　を備え、
    　前記操舵反力算出部は、前記車線維持支援部が作動状態と判定した場合には、前記フィードバック軸力を用いずに前記フィードフォワード軸力に基づいて前記操舵反力を算出すること
    　を特徴とする操舵制御装置。     A steering wheel mechanically separated from the steering wheel;
    A steered actuator for steering the steered wheel in accordance with an operation amount of the steering wheel;
    A steering current detector for detecting a steering current of the steering actuator;
    A current axial force calculator that calculates the axial force of the steering rack based on the steering current;
    A feedback axial force calculation unit that calculates a feedback axial force based on the axial force of the steering rack calculated by the current axial force calculation unit;
    A feedforward axial force calculation unit that calculates a feedforward axial force based on a steering angle of the steering wheel;
    A steering reaction force calculation unit for calculating a steering reaction force based on the feedforward axial force calculated by the feedforward axial force calculation unit and the feedback axial force calculated by the feedback axial force calculation unit;
    A reaction force actuator for applying the steering reaction force to the steering wheel;
    A lane maintenance support unit that supports the vehicle traveling without departing from the driving lane,
    The steering reaction force calculation unit calculates the steering reaction force based on the feedforward axial force without using the feedback axial force when it is determined that the lane keeping assisting unit is in an operating state. A steering control device.
  2. 　前記軸力切替出力部は、前記車両の車速と、前記ステアリングホイールの操舵角とに基づいて、前記作動状態か否かを判定すること
    　を特徴とする請求項１記載の操舵制御装置。     The steering control device according to claim 1, wherein the axial force switching output unit determines whether or not the vehicle is in the operating state based on a vehicle speed of the vehicle and a steering angle of the steering wheel.
  3. 　前記作動状態には、前記車線維持支援部が前記車両の走行支援を制御可能な状態である待機状態と、前記車線維持支援部が前記車両の走行支援の制御中であるオン状態とが含まれること
    　を特徴とする請求項１又は２に記載の操舵制御装置。     The operating state includes a standby state in which the lane keeping support unit can control the driving support of the vehicle, and an on state in which the lane keeping support unit is controlling the driving support of the vehicle. The steering control device according to claim 1 or 2, wherein
  4. 　前記操舵反力算出部は、前記フィードフォワード軸力算出部が出力する前記フィードフォワード軸力と、前記フィードバック軸力算出部が出力する前記フィードバック軸力とが入力し、前記車線維持支援部が作動していない非作動状態では前記フィードバック軸力を出力し、前記作動状態では前記フィードフォワード軸力を出力する軸力切替出力部を有すること
    　を特徴とする請求項１から３までのいずれか一項に記載の操舵制御装置。     The steering reaction force calculation unit receives the feedforward axial force output from the feedforward axial force calculation unit and the feedback axial force output from the feedback axial force calculation unit, and the lane keeping assist unit operates. 4. The apparatus according to claim 1, further comprising: an axial force switching output unit that outputs the feedback axial force in a non-operating state and outputs the feedforward axial force in the operating state. 5. The steering control device described in 1.
  5. 　操向輪と機械的に分離したステアリングホイールと、
    　前記ステアリングホイールの操作量に応じて前記操向輪を転舵する転舵アクチュエータと、
    　前記転舵アクチュエータの転舵電流を検出する転舵電流検出部と、
    　前記転舵電流に基づいてステアリングラックの軸力を算出する電流軸力算出部と、
    　前記電流軸力算出部が算出した前記ステアリングラックの軸力に基づいて、フィードバック軸力を算出するフィードバック軸力算出部と、
    　前記ステアリングホイールの操舵角に基づいて、フィードフォワード軸力を算出するフィードフォワード軸力算出部と、
    　前記フィードフォワード軸力算出部が算出した前記フィードフォワード軸力と前記フィードバック軸力算出部が算出した前記フィードバック軸力とに基づいて、操舵反力を算出する操舵反力算出部と、
    　前記ステアリングホイールに前記操舵反力を付与する反力アクチュエータと、
    　前記車両が走行車線から逸脱せずに走行するのを支援する車線維持支援部と、
    　前記操舵反力の算出に用いるパラメータに基づいて、前記車線維持支援部の動作を制限する車線維持支援動作制限部と
    　を有することを特徴とする操舵制御装置。     A steering wheel mechanically separated from the steering wheel;
    A steered actuator for steering the steered wheel in accordance with an operation amount of the steering wheel;
    A steering current detector for detecting a steering current of the steering actuator;
    A current axial force calculator that calculates the axial force of the steering rack based on the steering current;
    A feedback axial force calculation unit that calculates a feedback axial force based on the axial force of the steering rack calculated by the current axial force calculation unit;
    A feedforward axial force calculation unit that calculates a feedforward axial force based on a steering angle of the steering wheel;
    A steering reaction force calculation unit for calculating a steering reaction force based on the feedforward axial force calculated by the feedforward axial force calculation unit and the feedback axial force calculated by the feedback axial force calculation unit;
    A reaction force actuator for applying the steering reaction force to the steering wheel;
    A lane keeping support unit for assisting the vehicle to travel without departing from the traveling lane;
    A steering control device, comprising: a lane keeping support operation restriction unit that restricts the operation of the lane keeping support unit based on a parameter used for calculating the steering reaction force.
  6. 　前記パラメータは、前記フィードフォワード軸力算出部が算出した前記フィードフォワード軸力と前記フィードバック軸力算出部が算出した前記フィードバック軸力とを配分する比率である配分比率を含むこと
    　を特徴とする請求項５記載の操舵制御装置。     The parameter includes a distribution ratio that is a ratio of distributing the feedforward axial force calculated by the feedforward axial force calculation unit and the feedback axial force calculated by the feedback axial force calculation unit. Item 6. The steering control device according to Item 5.
  7. 　前記配分比率は、前記フィードフォワード軸力と前記フィードバック軸力との軸力差分に基づく軸力差分配分比率と、前記横方向加速度に基づく横Ｇ配分比率と、前記操舵角に基づく操舵角速度の角速度配分比率とに基づいて決定すること
    　を特徴とする請求項６記載の操舵制御装置。     The distribution ratio includes an axial force difference distribution ratio based on an axial force difference between the feedforward axial force and the feedback axial force, a lateral G distribution ratio based on the lateral acceleration, and an angular velocity of a steering angular velocity based on the steering angle. The steering control device according to claim 6, wherein the steering control device is determined based on the distribution ratio.
  8. 　前記車線維持支援動作制限部は、
    　前記軸力差分配分比率、前記横Ｇ配分比率及び前記角速度配分比率のうちの最小値が予め設定した閾値よりも小さい場合には前記車線維持支援部の動作を制限し、前記最小値が前記閾値以上の場合には前記車線維持支援部の動作を制限しないこと
    　を特徴とする請求項７記載の操舵制御装置。     The lane keeping support operation restriction unit is
    When the minimum value among the axial force difference distribution ratio, the lateral G distribution ratio, and the angular velocity distribution ratio is smaller than a preset threshold value, the operation of the lane keeping support unit is limited, and the minimum value is the threshold value. In the above case, the operation of the lane keeping assist unit is not limited.
  9. 　前記車線維持支援部は、
    　前記操向輪の転舵角を補正する補正転舵角を演算する補正転舵角演算部と、
    　前記操舵反力を補正する補正操舵反力を演算する補正操舵反力演算部と、
    　前記ステアリングホイールの位置が前記操舵反力の中立位置となるように補正する補正操舵反力中心値を演算する補正操舵反力中心演算部と
    　を有し、
    　前記車線維持支援動作制限部は、前記補正操舵反力演算部の動作を制限すること
    　を特徴とする請求項５から８までのいずれか一項に記載の操舵制御装置。     The lane keeping support section
    A correction turning angle calculation unit for calculating a correction turning angle for correcting the turning angle of the steering wheel;
    A correction steering reaction force calculation unit for calculating a correction steering reaction force for correcting the steering reaction force;
    A correction steering reaction force center calculation unit for calculating a correction steering reaction force center value for correcting the steering wheel position to be a neutral position of the steering reaction force;
    The steering control device according to any one of claims 5 to 8, wherein the lane keeping assist operation restriction unit restricts the operation of the correction steering reaction force calculation unit.
  10. 　前記車線維持支援動作制限部は、前記補正転舵角演算部及び前記補正操舵反力中心演算部の動作を制限すること
    　を特徴とする請求項９記載の操舵制御装置。     The steering control device according to claim 9, wherein the lane keeping assist operation restriction unit restricts operations of the correction turning angle calculation unit and the correction steering reaction force center calculation unit.
  11. 　前記車線維持支援動作制限部は、前記補正転舵角、前記補正操舵反力及び前記補正操舵反力中心値の少なくともいずれか１つが前記操舵反力算出部に入力するのを遮断して前記車線維持支援部の動作を制限する遮断部を有すること
    　を特徴とする請求項９又は１０に記載の操舵制御装置。     The lane keeping assist operation restriction unit blocks the lane from blocking at least one of the corrected turning angle, the corrected steering reaction force, and the corrected steering reaction force central value from being input to the steering reaction force calculation unit. The steering control device according to claim 9 or 10, further comprising a blocking unit that restricts the operation of the maintenance support unit.
  12. 　前記車線維持支援部の動作の制限は、前記車線維持支援部の動作の停止が含まれること
    　を特徴とする請求項５から１１までのいずれか一項に記載の操舵制御装置。     The steering control device according to any one of claims 5 to 11, wherein the restriction of the operation of the lane keeping support unit includes a stop of the operation of the lane keeping support unit.
  13. 　操向輪と機械的に分離したステアリングホイールと、
    　前記ステアリングホイールの操作量に応じて前記操向輪を転舵する転舵アクチュエータと、
    　前記転舵アクチュエータの転舵電流を検出する転舵電流検出部と、
    　前記転舵電流に基づいてステアリングラックの軸力を算出する電流軸力算出部と、
    　前記電流軸力算出部が算出した前記ステアリングラックの軸力に基づいて、第１操舵反力を算出する操舵反力算出部と、
    　前記第１操舵反力を補正して、車両が走行車線から逸脱せずに走行するのを支援する車線維持支援部と、
    　前記第１操舵反力を補正する補正値に基づいて前記操向輪の転舵に伴って発生するフリクションを演算するフリクション演算部と、
    　前記第１操舵反力を前記補正値で補正した第２操舵反力を前記ステアリングホイールに付与する反力アクチュエータと
    　を有することを特徴とする操舵制御装置。     A steering wheel mechanically separated from the steering wheel;
    A steered actuator for steering the steered wheel in accordance with an operation amount of the steering wheel;
    A steering current detector for detecting a steering current of the steering actuator;
    A current axial force calculator that calculates the axial force of the steering rack based on the steering current;
    A steering reaction force calculation unit for calculating a first steering reaction force based on the axial force of the steering rack calculated by the current axial force calculation unit;
    A lane keeping support unit that corrects the first steering reaction force and assists the vehicle traveling without departing from the traveling lane;
    A friction calculation unit that calculates the friction generated when the steered wheels are steered based on a correction value for correcting the first steering reaction force;
    And a reaction force actuator that applies a second steering reaction force obtained by correcting the first steering reaction force with the correction value to the steering wheel.
  14. 　前記車線維持支援部は、
    　前記第１操舵反力を補正する補正操舵反力を演算する補正操舵反力演算部と、
    　前記ステアリングホイールの位置が前記第１操舵反力の中立位置となるように補正する補正操舵反力中心値を演算する補正操舵反力中心演算部と
    　を備え、
    　前記補正値は、前記補正操舵反力と前記補正操舵反力中心値とを含むこと
    　を特徴とする請求項１３記載の操舵制御装置。     The lane keeping support section
    A corrected steering reaction force calculation unit for calculating a corrected steering reaction force for correcting the first steering reaction force;
    A correction steering reaction force center calculation unit for calculating a correction steering reaction force center value for correcting the steering wheel position to be a neutral position of the first steering reaction force;
    The steering control device according to claim 13, wherein the correction value includes the correction steering reaction force and the correction steering reaction force central value.
  15. 　前記フリクション演算部は、前記第２操舵反力から得られる係数に基づいて、前記フリクションを演算すること
    　を特徴とする請求項１３又は１４に記載の操舵制御装置。     The steering control device according to claim 13 or 14, wherein the friction calculation unit calculates the friction based on a coefficient obtained from the second steering reaction force.
  16. 　前記フリクション演算部は、
    　前記ステアリングホイールの操舵角から算出した操舵角速度と、前記車両の車速とに基づく事前フリクションを演算するフリクション演算前段部と、
    　前記事前フリクションと前記係数とに基づいて、前記フリクションを演算するフリクション演算後段部と
    　を有すること
    　を特徴とする請求項１５記載の操舵制御装置。     The friction calculator is
    A friction calculation pre-stage unit that calculates a prior friction based on the steering angular velocity calculated from the steering angle of the steering wheel and the vehicle speed of the vehicle;
    The steering control device according to claim 15, further comprising: a friction calculation post-stage unit that calculates the friction based on the preliminary friction and the coefficient.
  17. 　前記第２操舵反力と、前記フリクション演算部が演算した前記フリクションとに基づいて、前記反力アクチュエータを駆動する電流の目標値である目標反力電流を演算する目標反力電流演算部をさらに有すること
    　を特徴とする請求項１３から１６までのいずれか一項に記載の操舵制御装置。     A target reaction force current calculation unit for calculating a target reaction force current that is a target value of a current for driving the reaction force actuator based on the second steering reaction force and the friction calculated by the friction calculation unit; The steering control device according to any one of claims 13 to 16, characterized by comprising:
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016133182A1 (en) * 2015-02-19 2016-08-25 本田技研工業株式会社 Vehicle
US9694819B2 (en) 2015-02-19 2017-07-04 Honda Motor Co., Ltd. Vehicle
US9725014B2 (en) 2013-07-31 2017-08-08 Honda Motor Co., Ltd. Vehicle
JPWO2016162902A1 (en) * 2015-04-09 2017-10-19 日産自動車株式会社 Lane maintenance support device
CN109552401A (en) * 2017-09-27 2019-04-02 株式会社捷太格特 Vehicle console device
CN109572803A (en) * 2017-09-27 2019-04-05 株式会社捷太格特 Vehicle console device
CN110091912A (en) * 2018-01-30 2019-08-06 株式会社捷太格特 Steering controller
WO2022189022A1 (en) 2021-03-09 2022-09-15 Robert Bosch Gmbh Apparatus and method for influencing and/or operating a steering system, and steering system, in particular for a vehicle
DE102021202285A1 (en) 2021-03-09 2022-09-15 Robert Bosch Gesellschaft mit beschränkter Haftung Device and method for influencing vehicle behavior
US11603132B2 (en) 2019-05-15 2023-03-14 Nissan Motor Co., Ltd. Steering control method and steering control device
WO2023148883A1 (en) * 2022-02-03 2023-08-10 株式会社ジェイテクト Steering control device and steering control method

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2023005140A (en) 2021-06-28 2023-01-18 トヨタ自動車株式会社 Vehicle control system and vehicle control method
JP2023032089A (en) 2021-08-26 2023-03-09 トヨタ自動車株式会社 steering system

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000108914A (en) * 1998-10-02 2000-04-18 Toyota Motor Corp Steering control device
JP2003175853A (en) * 2001-12-10 2003-06-24 Nissan Motor Co Ltd Steering controller
JP2004034923A (en) * 2002-07-08 2004-02-05 Toyota Central Res & Dev Lab Inc Steering control
JP2004189119A (en) * 2002-12-12 2004-07-08 Mitsubishi Electric Corp Vehicular steering device
JP2006137215A (en) * 2004-11-10 2006-06-01 Toyota Motor Corp Steering reaction force control device of steer by wire type steering device
JP2006218888A (en) * 2005-02-08 2006-08-24 Jtekt Corp Steering device for vehicle
JP2007050743A (en) * 2005-08-17 2007-03-01 Toyota Motor Corp Wheel lateral force estimating device and steering reaction force controlling device
JP2008013123A (en) * 2006-07-07 2008-01-24 Nissan Motor Co Ltd Lane maintenance assistant device
JP2010030504A (en) * 2008-07-30 2010-02-12 Nissan Motor Co Ltd Vehicle steering controller and vehicle steering control method
JP2011184023A (en) * 2010-03-11 2011-09-22 Isuzu Motors Ltd Power steering device
JP2011201366A (en) * 2010-03-24 2011-10-13 Toyota Motor Corp Controller for vehicle
JP2012240456A (en) * 2011-05-16 2012-12-10 Nissan Motor Co Ltd Vehicular steering device and steering control method

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3807262B2 (en) * 2001-07-12 2006-08-09 日産自動車株式会社 Lane tracking control device
JP3884369B2 (en) * 2002-11-15 2007-02-21 株式会社ジェイテクト Steering control device

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000108914A (en) * 1998-10-02 2000-04-18 Toyota Motor Corp Steering control device
JP2003175853A (en) * 2001-12-10 2003-06-24 Nissan Motor Co Ltd Steering controller
JP2004034923A (en) * 2002-07-08 2004-02-05 Toyota Central Res & Dev Lab Inc Steering control
JP2004189119A (en) * 2002-12-12 2004-07-08 Mitsubishi Electric Corp Vehicular steering device
JP2006137215A (en) * 2004-11-10 2006-06-01 Toyota Motor Corp Steering reaction force control device of steer by wire type steering device
JP2006218888A (en) * 2005-02-08 2006-08-24 Jtekt Corp Steering device for vehicle
JP2007050743A (en) * 2005-08-17 2007-03-01 Toyota Motor Corp Wheel lateral force estimating device and steering reaction force controlling device
JP2008013123A (en) * 2006-07-07 2008-01-24 Nissan Motor Co Ltd Lane maintenance assistant device
JP2010030504A (en) * 2008-07-30 2010-02-12 Nissan Motor Co Ltd Vehicle steering controller and vehicle steering control method
JP2011184023A (en) * 2010-03-11 2011-09-22 Isuzu Motors Ltd Power steering device
JP2011201366A (en) * 2010-03-24 2011-10-13 Toyota Motor Corp Controller for vehicle
JP2012240456A (en) * 2011-05-16 2012-12-10 Nissan Motor Co Ltd Vehicular steering device and steering control method

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9725014B2 (en) 2013-07-31 2017-08-08 Honda Motor Co., Ltd. Vehicle
WO2016133182A1 (en) * 2015-02-19 2016-08-25 本田技研工業株式会社 Vehicle
US9694819B2 (en) 2015-02-19 2017-07-04 Honda Motor Co., Ltd. Vehicle
US10220836B2 (en) 2015-02-19 2019-03-05 Honda Motor Co., Ltd. Vehicle
JPWO2016162902A1 (en) * 2015-04-09 2017-10-19 日産自動車株式会社 Lane maintenance support device
CN109552401A (en) * 2017-09-27 2019-04-02 株式会社捷太格特 Vehicle console device
CN109572803A (en) * 2017-09-27 2019-04-05 株式会社捷太格特 Vehicle console device
CN109572803B (en) * 2017-09-27 2022-07-19 株式会社捷太格特 Vehicle control device
JP2019131014A (en) * 2018-01-30 2019-08-08 株式会社ジェイテクト Steering control device
JP7047412B2 (en) 2018-01-30 2022-04-05 株式会社ジェイテクト Steering control device
CN110091912A (en) * 2018-01-30 2019-08-06 株式会社捷太格特 Steering controller
US11603132B2 (en) 2019-05-15 2023-03-14 Nissan Motor Co., Ltd. Steering control method and steering control device
WO2022189022A1 (en) 2021-03-09 2022-09-15 Robert Bosch Gmbh Apparatus and method for influencing and/or operating a steering system, and steering system, in particular for a vehicle
DE102021202278A1 (en) 2021-03-09 2022-09-15 Robert Bosch Gesellschaft mit beschränkter Haftung Device and method for influencing and/or operating a steering system and steering system, in particular for a vehicle
DE102021202285A1 (en) 2021-03-09 2022-09-15 Robert Bosch Gesellschaft mit beschränkter Haftung Device and method for influencing vehicle behavior
WO2022189021A1 (en) 2021-03-09 2022-09-15 Robert Bosch Gmbh Apparatus and method for influencing a vehicle behaviour
WO2023148883A1 (en) * 2022-02-03 2023-08-10 株式会社ジェイテクト Steering control device and steering control method

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