JP2010052657A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device determining rotation intention of a driver and capable of starting control required for rotation at an early stage. <P>SOLUTION: The vehicle control device is provided with a rotation intention detector 2 for detecting rotation intention of the driver based on reaction force torque received from a road surface by a wheel at deviation direction of the wheel; and a brake control unit 3 for controlling an actuator 4 for performing rotation motion of the vehicle. The brake control unit 3 detects the rotation intention of the driver from the reaction force torque received from the road surface at deviation of the wheel by controlling drive of the actuator 4 based on the output of the rotation intention detector 2, starts the control from before the steering wheel operation of the driver or the vehicle state amount is generated, and performs the control at the timing in the early stage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device that detects a driver's intention to turn using reaction force torque that a wheel receives from a road surface when the vehicle is deflected, and controls the turning state of the vehicle.

  Conventionally, as this type of vehicle control device, there is a vehicle control device that determines a turning state of a vehicle based on a driver's steering operation or a state quantity generated in the vehicle, and stabilizes the turning state in cooperation with other vehicle behavior control devices. It is known (see, for example, Patent Document 1).

Japanese Patent No. 3588818 (paragraph 0019, FIG. 3)

  According to the technique disclosed in Patent Document 1, the turning state of the vehicle is determined based on whether or not the vehicle yaw rate or steering angle is generated, and the vehicle turns by controlling the gear ratio and the throttle opening. The state can be stabilized.

  However, since the control is started after the driver's steering operation or the vehicle state quantity is generated, there is a problem that the timing of the control is delayed and stable running is not always possible.

  Further, since the control timing is delayed, a large control amount is generated at the start of the control, and there is a problem that a shock occurs or the driver feels uncomfortable.

  In addition to this, a handle angle sensor, a yaw rate sensor, and a lateral acceleration sensor for determining the turning state of the vehicle are very expensive, which causes an increase in the cost of the vehicle control device.

  The present invention has been made to solve these problems, and provides a vehicle control device that can determine a driver's intention to turn and can quickly start control necessary for turning.

  The vehicle control apparatus according to the present invention includes a turning intention detecting unit that detects a driver's intention to turn based on a reaction force torque that the wheel receives from the road surface when the wheel is deflected, and a turn control that controls an actuator that controls the turning motion of the vehicle. The turning control means controls the driving of the actuator based on the output of the turning intention detecting means.

  According to the vehicle control device of the present invention, the driver's intention to turn is detected from the reaction force torque received from the road surface when the wheels are deflected, and the control is started before the driver's steering operation or the vehicle state quantity is generated. The control can be performed at an early timing, and stable running can be maintained before the vehicle becomes unstable.

  Preferred embodiments of a vehicle control device according to the present invention will be described below with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments.

Embodiment 1 FIG.
1 is a configuration diagram of a vehicle control apparatus according to Embodiment 1 of the present invention. In FIG. 1, an electric power steering controller 1 controls a steering assist electric motor, as will be described later, and outputs a steering torque signal Ts and a motor current signal Imtr to a turning intention detector 2 which is a turning intention detection means. To do. The turning intention detector 2 calculates a driver's turning intention index S based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and uses the turning intention index S as a turning control means. That is, it outputs to the brake controller 3. The brake controller 3 controls the actuator that controls the turning motion of the vehicle, that is, the brake actuator 4 based on the turning intention index S output from the turning intention detector 2.

  Next, the operation of the vehicle control device according to the first embodiment will be described. First, the electric power steering controller 1 will be described. FIG. 2 is a diagram for explaining an electric power steering apparatus for a vehicle including the electric power steering controller 1.

  In FIG. 2, the electric power steering device 20 detects a steering wheel 21, a wheel tire 22 to be steered according to the rotation of the steering wheel 21, a steering torque Thdl of the driver, and outputs a steering torque signal Ts. A torque sensor 23 for the means, an electric motor 24 for generating the steering assist torque Tassist, a current sensor 25 for the motor current detection means for detecting the current of the electric motor 24 and outputting the motor current signal Imtr, and detecting the traveling speed of the vehicle The vehicle speed sensor 26 serving as a vehicle speed detection means for outputting a vehicle speed signal Vh and the electric power steering controller 1 are used. Vsupply indicates the voltage supplied from the electric power steering controller 1 to the electric motor 24, and Talign indicates the road surface reaction torque.

  Next, the operation of the electric power steering controller 1 will be described. FIG. 3 is a diagram showing an operation flow of the electric power steering controller 1, but the processing from step S31 to step S34 is the same as that of a general electric power steering controller.

  First, the steering torque signal Ts and the vehicle speed signal Vh are input (step S31). Next, the target current Itag of the electric motor 24 is determined based on the steering torque signal Ts and the vehicle speed signal Vh (step S32). Here, the target current Itag is generally determined according to a map as shown in FIG. FIG. 4 is a map in which the horizontal axis is the steering torque signal Ts, the vertical axis is the target current Itag of the electric motor 24, and the vehicle speed signal Vh is a parameter.

  Next, the motor current signal Imtr is input (step S33), and the motor supply voltage Vsupply is controlled so that the motor current signal Imtr matches the target current Ittag (step S34). In this way, the electric power steering controller 1 controls the steering assist torque Tassist.

  The electric power steering controller 1 according to the present embodiment further outputs a steering torque signal Ts and a motor current signal Imtr to the turning intention detector 2 for turning control (step S35).

Next, the turning intention detector 2 will be described. As described above, the turning intention detector 2 according to the present embodiment receives the steering torque signal Ts and the motor current signal Imtr, calculates the deflection torque Tstr of the wheel based on the formula 1 shown below, The turning intention index S is output to the brake controller 3.
Turning intention index S = wheel deflection torque Tstr
= Steering torque signal Ts + steering assist torque Tassist
-Mechanism friction torque Tfric
= Steering torque signal Ts + motor current signal Imtr * Kt
-Mechanical friction torque Tfric (Equation 1)

  In Equation 1, Kt represents a conversion constant from the motor current Imtr to the steering assist torque Tassist, and Tfric represents the friction torque of the steering mechanism. The deflection torque Tstr in the turn is a reaction force torque that the wheel receives from the road surface, that is, a road surface reaction force torque. The road surface reaction force torque is calculated from the total torque of the driver's steering torque Ts and the steering assist torque Tassist of the electric power steering device 20. Is equal to a value obtained by subtracting the friction torque Tfric of the steering mechanism, the steering torque Ts is detected by a torque sensor 23 mounted on the electric power steering device 20, and the steering assist torque Tassist is obtained from a motor current signal Imtr generated in the electric motor 24. Detected. The friction torque Tfric of the steering mechanism is a parameter that varies depending on the vehicle speed Vh, and is a value obtained by calculation or the like if the vehicle speed Vh can be detected.

  Here, the characteristic of the deflection torque Tstr of the wheel as the turning intention index S will be described with reference to FIG. FIG. 5 is a comparison of the deflection torque Tstr of the wheel and the phase of the steering wheel angle (actual steering angle), yaw rate, and lateral acceleration when turning from straight running to turning. When the wheel is deflected for turning, the wheel rotates about the kingpin. When the driver intends to turn and generates the steering torque Ts, a current flows through the electric motor 24 constituting the electric power steering device 20 according to the steering torque Ts, and the steering assist torque Tassist is generated. Then, the deflection torque Tstr for deflecting the wheel is obtained from the total torque of the steering torque Ts and the steering assist torque Tassist. When the deflection torque Tstr exceeds the friction Tμ between the tire 22 and the road surface, the torque is actually switched. Rudder is started (actual rudder angle is generated). Then, due to the steering of the wheels, a lateral force is generated in the tire 22, a movement in the yaw direction and the lateral direction is generated in the vehicle, and a yaw rate and a lateral acceleration are finally generated. Based on such a principle, according to the wheel deflection torque Tstr, the driver's intention to turn can be detected earlier than using the steering wheel angle, yaw rate sensor, and lateral acceleration sensor.

  In the present embodiment, the example in which the deflection torque (road surface reaction torque) is obtained from the steering torque, the assist current, and the vehicle speed has been described. However, a load cell mounted on a torque sensor attached to the kingpin shaft, an axle bearing, or the like. Even if it is detected by a sensor signal such as, a similar effect can be obtained.

  Next, the brake controller 3 and the brake actuator 4 will be described. FIG. 6 is a flowchart showing the operation of the brake controller 3. First, the turning intention index S output from the turning intention detector 2 is input (step S61), and the target deceleration Dtag is determined based on the turning intention index S (step S62). Next, the target brake pressure Ptag of the brake actuator 4 is calculated based on the target deceleration Dtag (step S63). Then, drive control of the brake actuator 4 is performed based on the calculated target brake pressure Ptag (step S64). The brake controller 3 repeats the processes in steps S61 to S64 every predetermined period.

  Here, for example, if the target deceleration Dtag is set so as to increase as the turning intention index S increases, control is performed with a small deceleration when the driver performs steering with a light steering torque such as a lane change. When a strong steering torque is applied such as emergency avoidance, optimal control is performed as necessary, such as a large deceleration.

  Furthermore, if braking force distribution control means is provided in the brake controller 3 and the setting is made so that the target brake pressure Ptag is largely distributed by the brake actuator on the inside of the turn or on the front wheels, the turning moment of the vehicle can be controlled more optimally. Become.

  As described above, the vehicle control apparatus according to the first embodiment detects the driver's intention to turn based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and at the time of turning The brake control is performed. As a result, the intention to turn can be detected earlier than in the prior art, and vehicle control can be performed without any early start of control or uncomfortable feeling.

  In addition, since the signal obtained from the electric power steering controller 1 is used in place of a conventional sensor such as a steering angle, a yaw rate sensor, or a lateral acceleration sensor, the cost of the vehicle control device can be reduced.

  The method for setting the target deceleration Dtag and the target brake pressure Ptag based on the turning intention index S described in the first embodiment is merely an example, and does not limit the turning control method by the brake system.

Embodiment 2. FIG.
Next, a vehicle control device according to Embodiment 2 of the present invention will be described. FIG. 7 is a configuration diagram of the vehicle control device according to the second embodiment. In FIG. 7, the electric power steering controller 1 controls the steering assist electric motor and outputs the steering torque signal Ts and the motor current signal Imtr to the turning intention detector 2 which is a turning intention detecting means. The turning intention detector 2 calculates the driver's turning intention index S based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and uses the turning intention index S as driving force control means. Is output to the driving force controller 73. The driving force controller 73 controls the engine 74 or the driving force distribution actuator 75 which is a driving force distribution control unit based on the turning intention index S output from the turning intention detector 2.

  Here, a general reciprocating engine will be used as the engine 74, but the description is the same for a vehicle such as an electric vehicle that uses a motor as a drive source. The drive force distribution actuator 75 distributes the drive torque generated by the engine 74 to the left and right wheels and the front and rear wheels using a differential gear capable of controlling the restraint force, a multi-plate clutch or the like (not shown). Slip differential gear) and electronic control center differential gear.

  Next, the operation of the vehicle control device according to the second embodiment will be described. The operations of the electric power steering controller 1 and the turning intention detector 2 are the same as those in the first embodiment, and the description thereof will be omitted, and the driving force controller 73, the engine 74, and the driving force distribution actuator 75 will be described.

  FIG. 8 is a flowchart showing the operation of the driving force controller 73. First, the turning intention index S output from the turning intention detector 2 is input (step S81), and the target deceleration Dtag and the target yaw rate Ytag are determined based on the turning intention index S (step S82). Next, based on the target deceleration Dtag and the target yaw rate Ytag, the driving torque reduction amount DTtag of the engine 74 and the left and right torque distribution amount DStag of the driving force distribution actuator 75 are calculated (step S83). Based on the calculated drive torque reduction amount DTtag, the drive torque of the engine is reduced, and the drive control of the drive force distribution actuator 75 is performed based on the left / right torque distribution amount DStag (step S84). The driving force controller 73 repeats the processes in steps S81 to S84 every predetermined period.

Here, for example, if the target deceleration Dtag is set so as to increase as the turning intention index S increases, control is performed with a small deceleration when the driver performs steering with a light steering torque such as a lane change. When a strong steering torque such as emergency avoidance is applied, a large deceleration is performed, and optimum drive control is performed as necessary.

  Further, for example, if the target yaw rate Ytag is set to be larger as the turning intention index S is larger, the turning moment of the vehicle can be optimally controlled, for example, the driving torque of the wheels outside the turning is increased in accordance with the driver's intention to turn. It becomes like this.

  As described above, the vehicle control apparatus according to the second embodiment detects the driver's intention to turn based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and at the time of turning The driving force control is performed. As a result, the intention to turn can be detected earlier than in the prior art, and vehicle control can be performed without any early start of control or uncomfortable feeling. In addition, since the signal obtained from the electric power steering controller 1 is used in place of a conventional sensor such as a steering angle, a yaw rate sensor, or a lateral acceleration sensor, the cost of the vehicle control device can be reduced.

  The method for setting the target deceleration Dtag, the target yaw rate Ytag, the drive torque reduction amount DTtag, and the left-right torque distribution amount DStag based on the turning intention index S described in the second embodiment is an example, and the turning control method using the driving force It is not intended to limit.

Embodiment 3 FIG.
Next, a vehicle control device according to Embodiment 3 of the present invention will be described. FIG. 9 is a configuration diagram of the vehicle control device according to the third embodiment. In FIG. 9, the electric power steering controller 1 controls the electric motor for steering assist, and outputs the steering torque signal Ts and the motor current signal Imtr to the turning intention detector 2 which is a turning intention detecting means. The turning intention detector 2 calculates a driver's turning intention index S based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and the turning intention index S is obtained by suspension control means. Output to a certain suspension controller 93. The suspension controller 93 controls the suspension actuator 94 based on the turning intention index S output from the turning intention detector 2. Here, the suspension actuator 94 is an attenuation control actuator that controls the flow rate of the damper, an electronic stabilizer that controls the torsion amount of the stabilizer, or the like.

  Next, the operation of the vehicle control device according to the third embodiment will be described. The operations of the electric power steering controller 1 and the turning intention detector 2 are the same as those in the first embodiment, and the description thereof will be omitted, and the suspension controller 93 and the suspension actuator 94 will be described.

  FIG. 10 is a flowchart showing the operation of the suspension controller 93. First, the turning intention index S output from the turning intention detector 2 is input (step S1001), and the target turning degree YGtag is determined based on the turning intention index S (step S1002). Next, the control amount QStag of the suspension actuator 94 is calculated based on the target turning degree YGtag (step S1003). Based on the calculated control amount QStag, drive control of the suspension actuator 94 is performed (step S1004). The suspension controller 93 repeats the processes in steps S1001 to S1004 at predetermined intervals.

Here, for example, the larger the turning intention index S is set, the larger the target turning degree YGtag becomes, and the attenuation of the suspension outside the turning is increased and the attenuation of the suspension inside the turning is reduced according to the target turning degree YGtag. If the suspension control amount QStag is set as described above, the control with the roll amount suppressed optimally according to the driver's intention to turn is performed.

  Furthermore, if a suspension distribution control means is provided and the suspension control amount QStag is set so as to largely distribute the suspension attenuation of the front wheels, the pitch during deceleration in preparation for turning can be suppressed.

  As described above, the vehicle control apparatus according to the third embodiment detects the driver's intention to turn based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and at the time of turning Suspension control is performed. This makes it possible to detect turning intentions earlier than before, and not only enables early control start and vehicle control without a sense of incongruity, but also replaces sensors such as the conventional handle angle, yaw rate sensor, lateral acceleration sensor, etc. Since the signal obtained from the electric power steering controller 1 is used, the cost of the vehicle control device can be reduced.

  The method for setting the target turning degree YGtag and the suspension control amount QStag based on the turning intention index S described in the present embodiment is merely an example, and the turning control method by the suspension system is not limited.

Embodiment 4 FIG.
Next, a vehicle control device according to Embodiment 4 of the present invention will be described. FIG. 11 is a configuration diagram of the vehicle control device according to the fourth embodiment. In FIG. 11, the electric power steering controller 1 controls the electric motor for steering assist, and outputs the steering torque signal Ts and the motor current signal Imtr to the turning intention detector 2 which is a turning intention detecting means. The turning intention detector 2 calculates the driver's turning intention index S based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and the turning intention index S is converted into the deflection controller 113. Output to. The deflection controller 113 controls the deflection actuator 114 serving as a steering control unit based on the turning intention index S output from the turning intention detector 2. Here, the deflection actuator 114 is a steer-by-wire or 4WS mechanism that performs deflection of a wheel by a motor.

  Next, the operation of the vehicle control device according to the fourth embodiment will be described. The operations of the electric power steering controller 1 and the turning intention detector 2 are the same as those in the first embodiment, and a description thereof will be omitted. The deflection controller 113 and the deflection actuator 114 will be described.

  FIG. 12 is a flowchart showing the operation of the deflection controller 113. First, the turning intention index S output from the turning intention detector 2 is input (step S1201), and the target yaw rate Ytag is determined based on the turning intention index S (step S1202). Next, the control amount Qtag of the deflection actuator 114 is calculated based on the target yaw rate Ytag (step S1203). Based on the calculated control amount Qtag, drive control of the deflection actuator 114 is performed (step S1204). The deflection controller 113 repeats the processes in steps S1201 to S1204 at predetermined intervals.

  Here, for example, if the turning intention index S is larger, the target yaw rate Ytag is set to be larger, and if the deflection control amount Qtag is set according to the target yaw rate Ytag, the driver steers with a light steering torque by changing the lane or the like. Is controlled with a small control amount, but when strong steering torque is applied, such as emergency avoidance, turning control with a large control amount is performed, and optimal control is performed as necessary become.

As described above, the vehicle control apparatus according to the fourth embodiment detects the driver's intention to turn based on the steering torque signal Ts and the motor current signal Imtr output from the electric power steering controller 1, and at the time of turning The deflection control is performed. This makes it possible to detect turning intentions earlier than before, and not only enables early control start and vehicle control without a sense of incongruity, but also replaces sensors such as the conventional handle angle, yaw rate sensor, lateral acceleration sensor, etc. Since the signal obtained from the electric power steering controller 1 is used, the cost of the vehicle control device can be reduced.

  Note that the method for setting the target yaw rate Ytag and the deflection control amount Qtag based on the turning intention index S described in the present embodiment is merely an example, and the turning control method by the deflection system is not limited.

  The vehicle control device according to the present invention can be used as a vehicle control device that determines a driver's intention to turn and can quickly start control necessary for turning.

It is a block diagram of the vehicle control apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the electric power steering apparatus of the vehicle containing the electric power steering controller which concerns on Embodiment 1 of this invention. It is an operation | movement flowchart of the electric power steering controller which concerns on Embodiment 1 of this invention. 5 is a map for determining a target current in the electric power steering controller according to Embodiment 1 of the present invention. It is explanatory drawing which shows the phase relationship of the deflection torque which concerns on Embodiment 1 of this invention, a steering wheel angle (actual steering angle), a yaw rate, and a lateral acceleration. It is an operation | movement flowchart of the brake controller which concerns on Embodiment 1 of this invention. It is a block diagram of the vehicle control apparatus which concerns on Embodiment 2 of this invention. It is an operation | movement flowchart of the driving force controller which concerns on Embodiment 2 of this invention. It is a block diagram of the vehicle control apparatus which concerns on Embodiment 3 of this invention. It is an operation | movement flowchart of the suspension controller which concerns on Embodiment 3 of this invention. It is a block diagram of the vehicle control apparatus which concerns on Embodiment 4 of this invention. It is an operation | movement flowchart of the deflection | deviation controller which concerns on Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric power steering controller 2 Turning intention detector 3 Brake controller 20 Electric power steering device 21 Handle 22 Tire 23 Torque sensor 24 Electric motor 25 Current sensor 26 Vehicle speed sensor 73 Driving force controller 74 Engine 75 Driving force distribution actuator 93 Suspension Controller 94 Suspension 113 Deflection controller 114 Deflection actuator

Claims (8)

A turning intention detecting means for detecting a driver's intention to turn based on a reaction torque received by the wheel from the road surface when the wheel is deflected;
Turning control means for controlling an actuator for controlling turning movement of the vehicle;
With
The turning control means controls the drive of the actuator based on the output of the turning intention detection means.   The vehicle control apparatus according to claim 1, wherein the turning control unit includes a braking force control unit that controls a braking force of the vehicle.   The vehicle control apparatus according to claim 1, wherein the turning control means includes braking force distribution control means for distributing and controlling the braking force of the vehicle to each wheel.   The vehicle control apparatus according to claim 1, wherein the turning control unit includes a driving force control unit that controls a driving force of the vehicle.   The vehicle control apparatus according to claim 1, wherein the turning control means includes driving force distribution control means for distributing the driving force of the vehicle to at least front and rear or left and right wheels.   The vehicle control apparatus according to claim 1, wherein the turning control unit includes a suspension control unit that suppresses a roll motion and a pitch motion of the vehicle.   The vehicle control apparatus according to claim 1, wherein the turning control means includes a steering control means for controlling the deflection of the wheels. Steering torque detection means for detecting the steering torque of the driver;
An electric motor that assists the steering force of the driver;
Motor current detecting means for detecting a motor current of the electric motor;
Vehicle speed detecting means for detecting the traveling speed or wheel speed of the vehicle;
With
8. The reaction torque received by the wheel from the road surface is detected based on the output of the steering torque detection means, the output of the motor current detection means, and the output of the vehicle speed detection means. The vehicle control device according to any one of the above.

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