JP5218028B2 - Vehicle steering control device and vehicle steering control method - Google Patents

Description

  The present invention relates to a vehicle steering control device and a vehicle steering control method that include a steering actuator that steers steering wheels and a steering reaction force actuator that applies a steering reaction force to steering.

2. Description of the Related Art Conventionally, there is a vehicle steering apparatus that includes a steering actuator that steers and drives a wheel according to an operation of the operation member without mechanically connecting the operation member (steering wheel) to the wheel (for example, Patent Document 1). reference).
In this vehicle steering apparatus, an operation reaction force of the operation member including a reaction force component corresponding to the operation amount of the operation member and a reaction force component corresponding to the steering angle deviation is calculated. Here, the steering angle deviation is a value obtained by subtracting the actual steering angle of the wheel from the indicated steering angle corresponding to the operation amount of the operation member. When the vehicle behavior is not unstable, the reaction force actuator is controlled to generate the calculated operation reaction force. On the other hand, when the vehicle behavior is unstable, the steering actuator is driven to automatically steer the wheels regardless of the operation amount of the operation member so that the vehicle behavior is stabilized, and the calculated operation reaction force The reaction force actuator is controlled so as to generate an operation reaction force obtained by subtracting a reaction force component corresponding to the steering angle deviation.
JP 2001-30931 A

However, in the vehicle steering device described in Patent Document 1, when the vehicle behavior is not unstable, the reaction force component corresponding to the operation amount of the operation member and the reaction force component corresponding to the steering angle deviation are obtained. When the operation reaction force is generated and the vehicle behavior is unstable, the operation reaction force is generated by subtracting the reaction force component corresponding to the steering angle deviation from the operation reaction force. For this reason, if the vehicle behavior becomes unstable when there is an operation reaction force corresponding to the steering angle deviation, the reaction force component corresponding to the steering angle deviation is lost, giving the driver a sense of incongruity.
Therefore, an object of the present invention is to provide a vehicle steering control device and a vehicle steering control method capable of appropriately applying a steering reaction force without causing a driver to feel uncomfortable.

  In order to solve the above-described problem, the vehicle steering control device according to the present invention has a configuration in which the steering and the steering mechanism that steers the steered wheels are mechanically separated, and the steered angle of the steered wheels is Automatic turning control for driving and controlling the turning actuator is performed so that the second turning command angle calculated based on the traveling state of the host vehicle is obtained. At this time, the road surface reaction force corresponding to the second turning command angle generated by the automatic turning control is estimated. Then, the steering reaction force actuator is driven and controlled so that a steering reaction force equivalent to a reaction force deviation obtained by subtracting the estimated road surface reaction force estimated from the detected actual road surface reaction force is applied to the steering wheel.

  According to the vehicle steering control device of the present invention, the road surface reaction force generated by the automatic turning control is not fed back as the steering reaction force. Therefore, the steering reaction force for the automatic turning is not input to the steering. As a result, the driver does not feel uncomfortable or uncomfortable. Further, since the road surface reaction force generated by the driver's steering is fed back as the steering reaction force, a feeling of steering can be ensured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<< First Embodiment >>
"Constitution"
FIG. 1 is an overall configuration diagram in which a vehicle steering control device according to the present invention is applied to a steer-by-wire system.
As shown in FIG. 1, the steering wheel 1 operated by the driver is mechanically separated from the steering mechanism 10 (steering mechanism) that steers the left and right front wheels 11R and 11L (steering wheels). The steering shaft 2 is a rotating shaft of the steering wheel 1 connected to the steering wheel 1 and rotates together with the steering wheel 1. The steering shaft 2 includes a steering angle sensor 3 (steering angle detection means) that detects a rotation angle (that is, a steering angle) of the steering shaft 2, a steering torque sensor 4 that detects torque input to the steering shaft 2, and A reaction force motor 5 (steering reaction force actuator) that applies torque to the steering shaft 2 is provided. The reaction force motor 5 is for applying a steering reaction force to the steering wheel 1 by applying a torque to the steering shaft 2, and is constituted by a brushless motor or the like.

  The pinion shaft 7 is connected to the steering mechanism 10 and steers the left and right front wheels 11R and 11L as the pinion shaft 7 rotates. A steering motor 8 (steering actuator) capable of steering the left and right front wheels 11R and 11L via the steering mechanism 10 by rotating and driving the pinion shaft 7 to the pinion shaft 7, and left and right front wheels 11R, A turning angle sensor 9 (steering angle detecting means) for detecting a turning angle of 11L is provided. The steered motor 8 is constituted by a brushless motor or the like, similarly to the reaction force motor 5. Since the steered motor 8 and the pinion shaft 7 are mechanically connected, the steered angle sensor 9 detects the steered angle of the left and right front wheels 11R and 11L by detecting the rotational angle of the steered motor 8. can do.

The steering shaft 2 and the pinion shaft 7 are configured to be mechanically connectable by a backup clutch 6. The backup clutch 6 is connected when an abnormality occurs in the steer-by-wire system, and the driver can steer the left and right front wheels 11R and 11L directly when the steering wheel 1 is steered.
The axial force sensor 12 is provided at the hub portion of the left and right front wheels 11R and 11L. The axial force sensor 12 detects an axial force F applied to the rack of the steering mechanism 10 (reaction force from the road surface input to the left and right front wheels 11R and 11L).

The front recognition sensor 13 is for detecting the position of the host vehicle in the traveling lane. The front recognition sensor 13 includes a CCD camera 13a and a camera controller 13b. The camera controller 13b detects a lane mark by detecting a lane mark by edge detection or the like on a captured image in front of the host vehicle captured by the CCD camera 13a. Further, the camera controller 13b calculates a lateral displacement y that is a position in the lane width direction from the center of the traveling lane of the host vehicle and a yaw angle φ that is an angle with respect to the lane based on the detected lane mark.
The steering controller 14, the steering reaction force controller 15, and the front recognition sensor 13 are communicably connected via a communication line 16 and transmit / receive data to / from each other.
If the detection values detected by the various sensors have left and right directions, the left direction is a positive value.

(Configuration of steering controller)
The steering controller 14 inputs the steering angle θ of the steering wheel 1 detected by the steering angle sensor 3 and the lateral displacement y and yaw angle φ calculated by the front recognition sensor 13.
The steering controller 14 calculates an input command angle θs that is a steering command angle (first steering command angle) corresponding to the steering angle θ input by the driver. Further, the turning controller 14 calculates an automatic turning command angle θa (second turning command angle) for automatically turning so that the host vehicle travels in the center of the travel lane. Then, the turning controller 14 calculates a drive command value for the turning motor 8 so that the actual turning angle θt matches the command turning angle (= θs + θa). The steered motor 8 is driven based on the calculated drive command value, and the left and right front wheels 11R, 11L are steered. In this way, the steering operation is performed.

FIG. 2 is a control block diagram illustrating a configuration of the steering controller 14.
As shown in FIG. 2, the steering controller 14 includes an input command angle calculation unit 141 (first steering command angle calculation unit) and an automatic steering command angle calculation unit 142 (second steering command angle calculation unit). And a command turning angle calculation unit 143 and a motor drive control unit 144.
The input command angle calculation unit 141 inputs the steering angle θ detected by the steering angle sensor 3. Then, an input command angle θs that is a steering command angle corresponding to the steering angle θ is calculated. The input command angle θs is calculated based on a predetermined ratio (gear ratio) between the steering angle θ and the input command angle θs.

  The automatic steering command angle calculation unit 142 inputs the lateral displacement y and yaw angle φ of the host vehicle output from the front recognition sensor 13. Then, an automatic steering command angle θa for calculating the lateral displacement y and the yaw angle φ to “0” is calculated. The automatic steering command angle θa is obtained by, for example, adding a value obtained by multiplying the lateral displacement y and a predetermined gain Z1 to a value obtained by multiplying the yaw angle φ and the predetermined gain Z2 (θa = Z1 · y + Z2 · φ). .

The command turning angle calculation unit 143 adds the input command angle θs calculated by the input command angle calculation unit 141 and the automatic turning command angle θa calculated by the automatic turning command angle calculation unit 142. The added result (θs + θa) is output to the motor drive control unit 144 as a command turning angle.
The motor drive control unit 144 turns based on the deviation between the actual turning angle θt detected by the turning angle sensor 9 and the command turning angle so that the actual turning angle θt becomes the command turning angle (θs + θa). The rudder motor 8 is driven and controlled.
Specifically, the motor drive control unit 144 performs a drive command value (current command) of the steered motor 8 by rudder angle servo control that performs control calculation so that the actual steered angle follows the commanded steered angle with a predetermined response characteristic. Value).

FIG. 3 is a block diagram of the steering angle servo control.
As shown in FIG. 3, the steering angle servo system is configured by a method using a robust model matching method, for example. In this method, a current command value for realizing a predetermined normative response characteristic with respect to the command turning angle is calculated by a model matching compensator for matching with a predetermined desired characteristic. Further, a compensation current corresponding to the disturbance component is calculated by a robust compensator. As a result, it is possible to realize a control system with excellent disturbance resistance in which the actual turning angle can follow the normal response characteristic even when a disturbance occurs.

(Configuration of steering reaction force controller)
The steering reaction force controller 15 is an actual turning angle θt detected by the turning angle sensor 9, a road surface reaction force (actual road surface reaction force) F detected by the axial force sensor 12, and an automatic turning calculated by the turning controller 14. The command angle θa is input.
The steering reaction force controller 15 calculates the steering reaction force applied to the steering wheel 1. Next, the steering reaction force controller 15 calculates a drive command value for the reaction force motor 5 for applying the calculated steering reaction force, and the reaction force motor 5 is driven based on the calculated drive command value. In this way, the reaction force motor 5 is driven to apply a steering reaction force to the steering wheel 1.

Here, the steering reaction force applied to the steering wheel 1 has a magnitude corresponding to the actual road surface reaction force F. However, in the present embodiment, the steering reaction force corresponding to the road surface reaction force generated by the automatic steering is not fed back to the steering wheel 1.
FIG. 4 is a control block diagram showing the configuration of the steering reaction force controller 15.
The steering reaction force controller 15 includes a proportional gain calculation unit 151, a corrected road surface reaction force calculation unit 152, a feedback road surface reaction force calculation unit 153, and a motor drive control unit 154.

The proportional gain calculation unit 151 inputs the actual turning angle θt detected by the turning angle sensor 9 and the road surface reaction force F detected by the axial force sensor 12.
First, the relationship between the actual turning angle θt and the actual road surface reaction force F when automatic turning is not performed is approximated by the following equation using the proportional gain K.
F = K · θt (1)
Then, the proportional gain calculation unit 151 calculates the proportional gain K based on the following equation (2) obtained by modifying the above equation (1).
K = F / θt (2)

The corrected road surface reaction force calculation unit 152 inputs the proportional gain K calculated by the proportional gain calculation unit 151 and the automatic turning command angle θa calculated by the turning controller 14. Based on the proportional gain K and the automatic turning command angle θa, the corrected road reaction force calculation unit 152 calculates a road surface reaction force Fa corresponding to the automatic turning command angle (θa).
Fa = K · θa (3)

The feedback road surface reaction force calculation unit 153 subtracts the road reaction force Fa for the automatic turning calculated by the correction road surface reaction force calculation unit 152 from the road surface reaction force F detected by the axial force sensor 12 and feeds back as a steering reaction force. Calculate road surface reaction force _FFB .
F _FB = F− (K · θa) (4)
By the way, as shown in the following equation, the actual road surface reaction force F when the automatic steering is performed is equal to the road surface reaction force Fs corresponding to the command angle (θs) by the driver, and the command angle by the automatic steering ( This is the sum of the road surface reaction force Fa corresponding to θa).
F = Fs + Fa = (K · θs) + (K · θa) (5)

Therefore, the feedback road surface reaction force F _FB calculated based on the above equation (4) corresponds to the road surface reaction force Fs corresponding to the command angle (θs) by the driver.
The motor drive control unit 154 drives and controls the reaction force motor 5 so that the feedback road surface reaction force F _FB calculated by the feedback road surface reaction force calculation unit 153 is applied as a steering reaction force. At this time, the actual current (actual current) supplied to the reaction force motor 5 detected by the motor current sensor 5a is monitored, and the reaction force motor 5 is driven and controlled.

Specifically, the motor drive control unit 154 calculates a current target value for realizing the feedback road surface reaction force F _FB (torque), and detects the actual current actually supplied to the reaction force motor with the current sensor 5a. Then, feedback control is performed by outputting a drive command value based on the deviation between the actual current and the target current value so that the detected actual current and the target current value match. Thus, the drive control is performed so that the reaction force motor 5 outputs the feedback road surface reaction force F _FB .

<Operation>
Next, the operation of the first embodiment will be described.
FIG. 5 is a flowchart showing a steering reaction force control processing procedure executed by the steering reaction force controller 15.
It is assumed that the vehicle is currently traveling along the lane in the center of the travel lane. At this time, the front recognition sensor 13 outputs the lateral displacement y = 0 and the yaw angle φ = 0 from the center of the traveling lane of the vehicle to the steering controller 14. Since the vehicle is traveling in the center of the traveling lane, it is not necessary to activate the automatic steering control for lane keeping. Therefore, the turning controller 14 calculates the automatic turning command angle θa to “0” by the automatic turning command angle calculation unit 142 of FIG. Therefore, the command turning angle calculated by the command turning angle calculation unit 143 is equal to the input command angle θs corresponding to the steering wheel operation amount of the driver.

Then, the motor drive control unit 144 drives and controls the steered motor 8 so that the actual steered angle θt matches the command steered angle (= θs).
The proportional gain calculator 151 of the steering reaction force controller 15 inputs the actual turning angle θt detected by the turning angle sensor 9 and the road surface reaction force F detected by the axial force sensor 12. Further, the corrected road surface reaction force calculation unit 152 of the steering reaction force controller 15 inputs the automatic turning command angle θa = 0 calculated by the turning controller 14 (step S1).

Based on the actual turning angle θt and the actual road surface reaction force F, the proportional gain calculation unit 151 calculates a proportional gain K indicating the relationship between the steering angle and the road surface reaction force based on the equation (2). (Step S2). Further, the corrected road surface reaction force calculating unit 152 calculates the automatic turning shunting road surface reaction force Fa based on the equation (3) based on the calculated proportional gain K and the automatic turning command angle θa (step) S3). At this time, since θa = 0, Fa = 0. That is, the road surface reaction force for automatic steering is not generated. Therefore, the feedback road surface reaction force F _FB becomes F _FB = F based on the above equation (4) (step S4).

Thus, the road surface reaction force F actually generated is a road surface reaction force corresponding to the input command angle θs by the driver. For this reason, in this case, correction by the automatic turning shunting road surface reaction force Fa is not performed, and the detected actual road surface reaction force F is directly fed back as a steering reaction force.
The motor drive control unit 154 sets the feedback road surface reaction force F _FB (= F) as a steering reaction force command value. Then, a drive command value for the reaction force motor 5 is calculated according to the steering reaction force command value (step S5). Next, the calculated drive command value is output to the reaction force motor 5 (step S6). As a result, a steering reaction force corresponding to the actual road surface reaction force F is applied to the steering wheel 1.

  In addition, it is assumed that the driver performs a steering operation and the vehicle deviates leftward from the center of the traveling lane. In this case, the front recognition sensor 13 calculates the lateral displacement y corresponding to the amount of deviation in the left direction from the center of the traveling lane of the vehicle and the yaw angle φ that is the angle in the vehicle longitudinal direction with respect to the lane. Then, the automatic turning command angle calculation unit 142 of the turning controller 14 automatically turns the vehicle (for turning rightward) to return the vehicle to the center of the traveling lane based on the lateral displacement y and the yaw angle φ. The command angle θa is calculated. Therefore, the command turning angle calculated by the command turning angle calculation unit 143 is the sum of the driver's input command angle θs and the automatic turning command angle θa.

The motor drive control unit 143 drives and controls the steered motor 8 so that the actual steered angle θt becomes the command steered angle (= θs + θa). Thereby, the front wheels 11R and 11L are steered rightward.
In this case, the steering reaction force controller 15 uses the corrected road surface reaction force calculating unit 152 to calculate the automatic turning shunting road surface reaction force Fa based on the automatic turning command angle θa based on the equation (3) ( Step S3). Then, the feedback road surface reaction force calculation unit 153 calculates a result obtained by subtracting the automatic steering branch road surface reaction force Fa from the actual road surface reaction force F as a feedback road surface reaction force F _FB (step S4).

The motor drive control unit 154 sets the feedback road surface reaction force F _FB (= F−Fa) as a steering reaction force command value. Then, a drive command value for the reaction force motor 5 is calculated according to the steering reaction force command value (step S5). Next, the calculated drive command value is output to the reaction force motor 5 (step S6). Thereby, a steering reaction force is applied to the steering wheel 1. At this time, the steering reaction force to be applied is equivalent to the road surface reaction force generated by the turning corresponding to the input command angle θs.

Next, the steering reaction force applied to the steering wheel 1 will be described with reference to FIGS. FIG. 6 is a diagram illustrating a steering reaction force applied during automatic steering control in the present embodiment. FIG. 7 is a diagram illustrating a general steering reaction force applied during automatic steering control.
When the driver performs a steering operation in the right direction, a driver input steering angle indicated by the symbol a is generated on the steering wheel 1. The steering angle sensor 3 detects the driver input steering angle a as the steering angle θ.

At this time, assuming that a lateral displacement y in the left direction has occurred in the vehicle, the front wheels 11R and 11L have a right turning angle b corresponding to the driver input steering angle a and automatic turning control. A rightward turning angle c for setting the lateral displacement y and the yaw angle φ to 0 is generated.
Here, the turning angle b is a turning angle corresponding to the input command angle θs. The turning angle c is a turning angle corresponding to the automatic turning command angle θa. The turning angle sensor 9 detects the turning angle (b + c) as the actual turning angle θt.

Therefore, the reaction force from the road surface input to the front wheels 11R and 11L is the sum of the road surface reaction force d corresponding to the turning angle b and the road surface reaction force e corresponding to the turning angle c. The axial force sensor 12 detects a road surface reaction force (d + e) as an actual road surface reaction force F.
A steering reaction force f is applied to the steering wheel 1. The steering reaction force f corresponds to a road surface reaction force obtained by subtracting a road surface reaction force e generated by a turning angle c corresponding to the automatic steering command angle θa from the actual road surface reaction force (d + e). In other words, the steering reaction force f corresponds to the road surface reaction force d generated by the turning angle b corresponding to the input command angle θs.

Thus, in this embodiment, the steering reaction force corresponding to the road surface reaction force e generated by the turning angle c is not fed back to the steering wheel 1.
On the other hand, when the steering reaction force corresponding to the actual road surface reaction force F is applied to the steering wheel 1 as it is, an excess steering reaction force is applied to the steering wheel 1 as shown in FIG.
As described above, when the front wheels 11R and 11L are steered by automatic steering for lane keeping, a corresponding road surface reaction force e is generated. The actual road surface reaction force F detected by the axial force sensor 12 at this time is the sum of the road surface reaction force d corresponding to the driver input steering angle a and the road surface reaction force e.

  Therefore, if the steering reaction force corresponding to the actual road surface reaction force F is fed back as it is, a steering reaction force greater than the steering reaction force f corresponding to the road surface reaction force d is applied to the steering wheel 1. In other words, when the steering reaction force corresponding to the actual road surface reaction force F is fed back as it is, the change in the steering reaction force corresponding to the change in the turning angle by the automatic turning is made even though the driver is not performing the steering operation. It occurs in the steering wheel 1 and makes the driver feel uncomfortable and uncomfortable.

In addition, in order to apply a steering reaction force for automatic turning, torque (steering reaction force) to be rotated in a direction opposite to the direction in which automatic steering is desired is input to the steering wheel 1.
On the other hand, in this embodiment, it is set as the structure which does not feed back only the steering reaction force equivalent to the road surface reaction force generate | occur | produced by automatic steering. Therefore, the driver does not feel uncomfortable or uncomfortable. Further, torque is not input to the steering wheel 1 in the direction opposite to that of the automatic turning by the steering reaction force for the automatic turning.

Further, since the road surface reaction force corresponding to the input command angle θs by the driver is fed back as the steering reaction force, the driver can feel the road surface reaction force change as the steering reaction force change when performing the steering operation. A feeling can be secured.
Further, a feedback road surface reaction force F _FB is calculated by subtracting the estimated automatic turning branch surface reaction force Fa from the detected actual road surface reaction force F. Therefore, when the actual road surface reaction force F includes a reaction force component other than the road surface reaction force Fs corresponding to the input command angle θs and the automatic turning branching road surface reaction force Fa, the road surface reaction force can be appropriately fed back. it can. Therefore, for example, even when the vehicle rides on the curb, a steering reaction force according to the vehicle behavior can be applied.

  In the present embodiment, the front wheels 11R and 11L constitute steering wheels, and the steering mechanism 10 constitutes a steering mechanism. The reaction force motor 5 constitutes a steering reaction force actuator, and the turning motor 8 constitutes a turning actuator. Further, the steering angle sensor 3 constitutes a steering angle detection means, and the axial force sensor 12 constitutes a road surface reaction force detection means.

The input command angle calculation unit 141 constitutes a first steering command angle calculation unit, the automatic steering command angle calculation unit 142 constitutes a second steering command angle calculation unit, and the motor drive control unit 144 turns the steering. It constitutes a control means. Further, the proportional gain calculation unit 151 and the corrected road surface reaction force calculation unit 152 constitute a road surface reaction force estimation unit, and the feedback road surface reaction force calculation unit 153 and the motor drive control unit 154 constitute a steering reaction force control unit.
Further, the proportional gain calculation unit 151 constitutes a first gain calculation unit, and the corrected road surface reaction force calculation unit 152 constitutes a first gain multiplication unit.

"effect"
(1) The steering angle detection means detects the steering angle of the steering. The first turning command angle calculation means calculates a first turning command angle that is a turning angle based on the steering angle detected by the steering angle detection means. The second turning command angle calculation means calculates a second turning command angle that is a turning angle based on the traveling state of the host vehicle. The turning control means is configured to change the turning actuator based on the first turning command angle calculated by the first turning command angle calculating means and the second turning command angle calculated by the second turning command angle calculating means. Drive control. The road surface reaction force estimation means estimates an estimated road surface reaction force that is a road surface reaction force generated in response to the second turning command angle. The road surface reaction force detecting means detects an actual road surface reaction force input from the road surface to the steering mechanism. The steering reaction force control means applies a steering reaction force equivalent to a reaction force deviation obtained by subtracting the estimated road surface reaction force estimated by the road surface reaction force estimation means from the actual road surface reaction force detected by the road surface reaction force detection means to the steering. The steering reaction force actuator is driven and controlled.

Thereby, it can be set as the structure which does not feed back the road surface reaction force which generate | occur | produces by automatic steering control as a steering reaction force. Therefore, the steering reaction force change based on the turning angle change by the automatic turning is not generated in the steering wheel 1. As a result, the driver does not feel uncomfortable or uncomfortable.
Further, since the road surface reaction force generated by the driver's steering is fed back as the steering reaction force, a feeling of steering can be ensured.

  Furthermore, since the steering reaction force to be fed back by subtracting the estimated road surface reaction force from the actual road surface reaction force is calculated, the steering reaction force according to the vehicle behavior can be applied. This is particularly effective when the actual road surface reaction force includes a road surface reaction force generated by the driver's steering and a road surface reaction force component other than the road surface reaction force corresponding to the target turning angle.

(2) The steered angle detection means detects the steered wheel steered angle. The turning control means includes a command turning angle obtained by adding together the first turning command angle calculated by the first turning command angle calculating means and the second turning command angle calculated by the second turning command angle calculating means. The steered actuator is driven and controlled so that the steered angles detected by the steered angle detecting means coincide.
Thereby, the turning angle corresponding to the steering by the driver and the turning angle corresponding to the traveling state can be generated in the steered wheels.

(3) The first gain calculating means calculates a first gain indicating a proportional relationship between the actual turning angle of the steered wheels and the actual road surface reaction force. The first gain multiplication means multiplies the first gain calculated by the first gain calculation means and the second turning command angle calculated by the second turning command angle calculation means. The road surface reaction force estimation means estimates the multiplication result of the first gain multiplication means as a road surface reaction force corresponding to the second turning command angle.
Therefore, it is possible to estimate the automatic steering shunt surface reaction force relatively easily.
(4) The steering reaction force is estimated so that a road reaction force generated by the automatic steering control is estimated and a steering reaction force equivalent to a reaction force deviation obtained by subtracting the estimated road reaction force from the detected actual road reaction force is applied to the steering. Drive and control the actuator.
Therefore, the steering reaction force can be appropriately applied without causing the driver to feel uncomfortable or uncomfortable.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described.
In the second embodiment, in the first embodiment described above, when the automatic steering command angle θa is larger than a predetermined angle, the steering reaction force is set so that the driver can recognize that automatic steering is being performed. It is something to be granted.

"Constitution"
FIG. 8 is a control block diagram showing the configuration of the steering reaction force controller 15.
The steering reaction force controller 15 of the second embodiment has the same configuration as the steering reaction force controller 15 shown in FIG. 4 except that a correction gain calculation unit 155 and a correction unit 156 are added in FIG. 4 described above. Have Therefore, here, the description will focus on the different parts.
The correction gain calculation unit 155 inputs the automatic turning command angle θa calculated by the turning controller 14. Then, the correction gain calculator 155 calculates the correction gain K ₁ based on the automatic steering command angle θa. The correction gain K ₁ is a gain for correcting the automatic turning shunt road surface reaction force Fa calculated by the correction road surface reaction force calculation unit 152.

The correction gain calculator 155 calculates the correction gain K ₁ with reference to the correction gain calculation map shown in FIG. The correction gain calculation map has an automatic turning command angle θa on the horizontal axis and a correction gain K ₁ on the vertical axis. The correction gain calculation map is set so that the correction gain K ₁ = 1 is calculated when the automatic steering command angle θa is equal to or smaller than the predetermined angle α (first steering command angle threshold). Further, the correction gain calculation map is set so that when the automatic steering command angle θa is larger than the predetermined angle α, the correction gain K ₁ is proportionally larger from “1” as the automatic steering command angle θa is larger. .

The correction unit 156 receives the automatic turning branch surface reaction force Fa calculated by the correction road surface reaction force calculation unit 152 and the correction gain K ₁ calculated by the correction gain calculation unit 155. Then, the corrected automatic steering shunt surface reaction force Fa ′ is calculated by multiplying the automatic steering shunt surface reaction force Fa by the correction gain K ₁ (Fa ′ = K ₁ · Fa).
Further, the feedback road surface reaction force calculation unit 153 calculates the feedback road surface reaction force F _FB by subtracting the corrected automatic steering branch road surface reaction force Fa ′ from the actual road surface reaction force F.
F _FB = F−Fa ′ = F−K ₁ (K · θa) (6)

<Operation>
Next, the operation of the second embodiment will be described.
FIG. 10 is a flowchart showing a steering reaction force control processing procedure executed by the steering reaction force controller 15.
It is assumed that the vehicle has greatly deviated leftward from the center of the driving lane. In this case, the front recognition sensor 13 calculates the lateral displacement y and the yaw angle φ corresponding to the amount of deviation in the left direction from the center of the traveling lane of the vehicle. Then, the automatic turning command angle calculation unit 142 of the turning controller 14 automatically turns the vehicle (for turning rightward) to return the vehicle to the center of the traveling lane based on the lateral displacement y and the yaw angle φ. The command angle θa is greatly calculated.

Then, the motor drive control unit 144 controls the driving of the steering motor 8 so that the actual turning angle θt becomes the command turning angle (= θs + θa). Thereby, the front wheels 11R and 11L are steered rightward.
The steering reaction force controller 15 inputs the actual turning angle θt detected by the turning angle sensor 9 and the road surface reaction force F detected by the axial force sensor 12 in the proportional gain calculation unit 151. The corrected road surface reaction force calculation unit 152 and the correction gain calculation unit 155 input the automatic turning command angle θa calculated by the turning controller 14 (step S1).

Based on the actual turning angle θt and the actual road surface reaction force F, the proportional gain calculation unit 151 calculates a proportional gain K indicating the relationship between the steering angle and the road surface reaction force based on the equation (2). (Step S2). Further, the corrected road surface reaction force calculating unit 152 calculates the automatic turning shunting road surface reaction force Fa based on the equation (3) based on the calculated proportional gain K and the automatic turning command angle θa (step) S3).
Next, the correction gain calculator 155 calculates the correction gain K ₁ based on the automatic steering command angle θa. At this time, if the automatic steering command angle θa is larger than the predetermined angle α (Yes in step S11), the correction gain K ₁ is calculated to be a value larger than “1” based on the correction gain calculation map of FIG. (Step S12).

Therefore, the correction unit 156 increases and corrects the automatic turning shunting road surface reaction force Fa calculated by the correction road surface reaction force calculation unit 152 (step S14).
Then, the feedback road surface reaction force calculation unit 153 calculates a result obtained by subtracting the automatic turning branching road surface reaction force Fa ′ after the increase correction from the actual road surface reaction force F as a feedback road surface reaction force F _FB (step S15).

The motor drive control unit 154 sets the feedback road surface reaction force F _FB (= F−Fa ′) as a steering reaction force command value. Then, a drive command value for the reaction force motor 5 is calculated according to the steering reaction force command value (step S5). Next, the calculated drive command value is output to the reaction force motor 5 (step S6). Thereby, a steering reaction force is applied to the steering wheel 1.
Thus, when the automatic turning command angle θa is large (when θa> α), the correction amount of the road surface reaction force to be fed back as the steering reaction force is increased by correcting the automatic turning branching surface reaction force Fa. Enlarge. As a result, the steering wheel can be turned in the direction in which automatic steering is performed, and the driver can recognize that automatic steering is being performed by a change in the steering reaction force.

When the automatic turning command angle θa is large, the vehicle behavior is also increased by the automatic turning. Therefore, in this case, it is better to make the driver recognize that automatic steering is being performed. In addition, since the steering reaction force can be applied to the steering wheel 1 in the steering direction in which automatic steering is performed, automatic steering can be assisted.
On the other hand, when the automatic turning instruction angle θa is equal to or less than the predetermined angle α is set to (No at step S11), and the correction gain K _{1 "1"} (step S13). Therefore, the automatic turning shunting road surface reaction force Fa is not corrected.

Thus, when the automatic steering command angle θa is small (when θa ≦ α), the automatic steering shunting surface reaction force Fa is not fed back as a steering reaction force. This prevents the driver from recognizing that automatic steering is being performed. Therefore, the troublesomeness given to the driver can be eliminated.
In the present embodiment, the correction gain calculation unit 155 and the correction unit 156 constitute an estimated road surface reaction force correction unit.

"effect"
(5) The estimated road surface reaction force correcting means increases and corrects the estimated road surface reaction force to be subtracted from the actual road surface reaction force when the second turning command angle is larger than a predetermined first turning command angle threshold value.
Thus, when the amount of automatic turning is large, the driver can recognize that automatic turning is being performed. Moreover, since a steering wheel can be turned in the direction which performs automatic steering, automatic steering can be assisted.

<< Third Embodiment >>
Next, a third embodiment of the present invention will be described.
In the third embodiment, the road surface reaction force with respect to automatic steering is more accurately estimated in the second embodiment described above.
"Constitution"
FIG. 11 is a control block diagram showing the configuration of the steering reaction force controller 15.
The steering reaction force controller 15 of the third embodiment includes the tangential gain calculation unit 157, the second correction road surface reaction force calculation unit 158, the second feedback road surface reaction force calculation unit 159, and the feedback road surface reaction force calculation unit in FIG. 8 described above. Except for adding 160, it has the same configuration as the steering reaction force controller 15 shown in FIG. Therefore, here, the description will focus on the different parts.

In the following description, the corrected road surface reaction force calculation unit 152 in FIG. 8 is renamed to the first corrected road surface reaction force calculation unit 152, and the feedback road surface reaction force calculation unit 153 is renamed to the first feedback road surface reaction force calculation unit 153. . Then, the automatic turning branch surface reaction force calculated by the first correction road surface reaction force calculation unit 152 is defined as a first automatic turning branch surface reaction force Fa1. Further, the feedback road surface reaction force calculated by the first feedback road surface reaction force calculation unit 153 is _defined as a first feedback road surface reaction force F _FB1 .

  The tangential gain calculation unit 157 inputs the actual turning angle θt detected by the turning angle sensor 9 and the actual road surface reaction force F detected by the axial force sensor 12. Then, the current actual turning angle θt (x), the actual turning angle θt (x−1) detected before one sampling, the current actual road surface reaction force F (x), and the actual road surface detected before one sampling. Based on the reaction force F (x−1), the tangential gain L is calculated.

FIG. 12 is a diagram showing the relationship between the actual turning angle θt and the actual road surface reaction force F. As shown in FIG. 12, the relationship between the actual turning angle θt and the actual road surface reaction force F is generally a non-linear relationship.
Therefore, in order to accurately estimate the automatic turning shunt surface reaction force Fa, a straight line slope L shown in the following equation is used. This inclination L is a road surface reaction force change rate indicating the change amount of the actual road surface reaction force F with respect to the change amount of the actual turning angle θt.
F (x) −F (x−1) = L · (θt (x) −θt (x−1)) (7)

The straight line represented by the above equation (7) corresponds to the straight line in FIG.
In the present embodiment, this straight line is considered as a tangent to point P in the figure. Here, the point P is a point on the characteristic line at the actual turning angle θt (x ′) that is intermediate between the actual turning angle θt (x) and the actual turning angle θt (x−1). The slope L of this straight line is defined as a tangential gain.
The tangential gain calculation unit 157 calculates the tangential gain L based on the following equation (8) obtained by modifying the above equation (7).
L = F (x) −F (x−1) / (θt (x) −θt (x−1)) (8)

The second corrected road surface reaction force calculation unit 158 receives the tangential gain L calculated by the tangential gain calculation unit 157 and the automatic turning command angle θa calculated by the turning controller 14. Then, the second corrected road surface reaction force calculation unit 158 calculates a road surface reaction force Fa2 corresponding to the automatic turning command angle θa based on the tangential gain L and the automatic turning command angle θa.
Fa2 = L · θa (9)
The second feedback road surface reaction force calculation unit 159 subtracts the road surface reaction force Fa2 calculated by the second correction road surface reaction force calculation unit 158 from the road surface reaction force F detected by the axial force sensor 12 to obtain the second feedback road surface reaction force F. Calculate _FB2 .
F _FB2 = F− (L · θa) (10)

The feedback road surface reaction force calculation unit 160 receives the proportional gain K, the tangential gain L, the automatic steering command angle θa, the first feedback road surface reaction force F _FB1, and the second feedback road surface reaction force F _FB2 .
When the tangential gain L is smaller than the proportional gain K (L <K), the feedback road surface reaction force F _FB is calculated based on the following equation.
F _FB = s ・ F _FB1 + (1−s) ・ F _FB2 ……… (11)
Here, s is a distribution gain for determining the distribution of the first feedback road surface reaction force F _FB1 and the second feedback road surface reaction force F _FB2 . The distribution gain s is calculated with reference to the distribution gain calculation map shown in FIG.

  The distribution gain calculation map has an automatic turning command angle θa on the horizontal axis and a distribution gain s on the vertical axis. The distribution gain calculation map is set so that the gain s is calculated to be “0” when the automatic steering command angle θa is smaller than the predetermined angle β1 (third steering command angle threshold). The distribution gain calculation map is set so that the gain s is calculated to be “1” when the automatic steering command angle θa is larger than the predetermined angle β2 (second steering command angle threshold). Further, in the distribution gain calculation map, when the automatic steering command angle θa is a predetermined angle β1 or more and β2 or less, the gain s is proportionally increased from “0” to “1” as the automatic steering command angle θa increases. Set to calculate.

That is, when θa <β1, the feedback road surface reaction force F _FB is equal to the second feedback road surface reaction force F _FB2 . When θa> β2, the feedback road surface reaction force F _FB is equal to the first feedback road surface reaction force F _FB1 .
When the tangential gain L is equal to or greater than the proportional gain K (L ≧ K), the feedback road surface reaction force F _FB is calculated based on the following equation.
F _FB = F _FB1 = F−K ₁ (K · θa) (12)

<Operation>
Next, the operation of the third embodiment will be described.
FIG. 14 is a flowchart showing a steering reaction force control processing procedure executed by the steering reaction force controller 15.
It is assumed that the vehicle deviates leftward from the center of the driving lane. In this case, the front recognition sensor 13 calculates the lateral displacement y and the yaw angle φ corresponding to the amount of deviation in the left direction from the center of the traveling lane of the vehicle. Then, the automatic turning command angle calculation unit 142 of the turning controller 14 automatically turns the vehicle (for turning rightward) to return the vehicle to the center of the traveling lane based on the lateral displacement y and the yaw angle φ. The command angle θa is calculated.

Then, the motor drive control unit 144 controls the driving of the steering motor 8 so that the actual turning angle θt becomes the command turning angle (= θs + θa). Thereby, the front wheels 11R and 11L are steered rightward.
The proportional gain calculation unit 151 and the tangential gain calculation unit 157 of the steering reaction force controller 15 input the actual turning angle θt detected by the turning angle sensor 9 and the road surface reaction force F detected by the axial force sensor 12. . Further, the first correction road surface reaction force calculation unit 152, the correction gain calculation unit 155, and the second correction road surface reaction force calculation unit 158 input the automatic steering command angle θa calculated by the steering controller 14 (step S1). .

Based on the actual turning angle θt and the actual road surface reaction force F, the proportional gain calculation unit 151 calculates a proportional gain K indicating the relationship between the steering angle and the road surface reaction force based on the equation (2). (Step S2). Further, the first corrected road surface reaction force calculation unit 152 calculates the automatic turning shunt road surface reaction force Fa1 by multiplying the calculated proportional gain K and the automatic turning command angle θa (step S3).
The correction gain calculator 155 calculates the correction gain K ₁ based on the automatic steering command angle θa. At this time, if the automatic steering command angle θa is equal to or smaller than the predetermined angle α (No in step S11), the correction gain K ₁ = 1 is set (step S13).

Therefore, the correction unit 156 sets the automatic turning branch surface reaction force Fa1 calculated by the corrected road surface reaction force calculation unit 152 as it is as the corrected automatic steering branch surface reaction force Fa1 ′ (step S14).
Then, the first feedback road surface reaction force calculation unit 153 calculates a result obtained by subtracting the automatic steering branch road surface reaction force Fa ′ from the actual road surface reaction force F as the first feedback road surface reaction force F _FB1 (step S15).

Further, the tangential gain calculation unit 157 calculates the road surface reaction force change rate indicating the change amount of the actual road surface reaction force F with respect to the change amount of the actual turning angle θt in one sampling period, based on the equation (8). Calculated as L (step S21).
The second corrected road surface reaction force calculating unit 158 calculates the automatic turning shunt road surface reaction force Fa2 by multiplying the calculated tangential gain L and the automatic turning command angle θa (step S22).
Then, the second feedback road surface reaction force calculation unit 159 calculates a result obtained by subtracting the automatic steering branch road surface reaction force Fa2 from the actual road surface reaction force F as a second feedback road surface reaction force F _FB2 (step S23).

At this time, it is assumed that the tangential gain L is smaller than the proportional gain K (Yes in step S24) and the automatic steering command angle θa is smaller than the predetermined angle β1 (Yes in step S25). In this case, the feedback road surface reaction force calculation unit 160 calculates “0” for the distribution gain s based on the distribution gain calculation map. Then, using this distribution gain s, the feedback road surface reaction force F _FB is calculated based on the equation (11). Therefore, the feedback road surface reaction force F _FB is equal to the second feedback road surface reaction force F _FB2 (step S26).

The motor drive control unit 154 sets the feedback road surface reaction force F _FB (= F _FB2 ) as a steering reaction force command value. Then, a drive command value for the reaction force motor 5 is calculated according to the steering reaction force command value (step S5). Next, the calculated drive command value is output to the reaction force motor 5 (step S6). Thereby, a steering reaction force is applied to the steering wheel 1.
As described above, when the tangential gain L is smaller than the proportional gain K, the steering reaction force equivalent to the road surface reaction force corrected using the tangential gain L is fed back. Thereby, an automatic steering shunt surface reaction force can be estimated with high accuracy.

FIG. 15 is a diagram for explaining a method of calculating the automatic turning branch surface reaction force (corrected road surface reaction force).
Here, a case where the tangential gain L is smaller than the proportional gain K and the automatic steering command angle θa is smaller than the predetermined angle β1 will be described.
Reference sign A in the figure represents an automatic turning shunting surface reaction force (L · θa) calculated using the tangential gain L. Reference symbol C denotes an automatic turning shunt surface reaction force (K · θa) calculated using the proportional gain K. Reference numeral B is an actual automatic turning shunting surface reaction force (theoretical value).

  As can be seen from FIG. 15, compared with C corrected using the proportional gain K, A corrected using the tangential gain L is closer to the amount B actually desired to be corrected. Therefore, when the tangential gain L is smaller than the proportional gain K and the automatic turning command angle θa is smaller than the predetermined angle β1, it is more accurate to estimate the automatic turning shunt surface reaction force using the tangential gain L. Can be derived.

Next, when the vehicle greatly deviates from the center of the driving lane to the left, and the automatic turning command angle calculation unit 142 of the turning controller 14 calculates the automatic turning command angle θa that is equal to or greater than the predetermined angle β1. Will be described.
In this case, the feedback road surface reaction force calculation unit 160 of the steering reaction force controller 15 calculates the distribution gain s to a value greater than 1 based on the distribution gain calculation map (step S27). Then, using this distribution gain s, a feedback road surface reaction force F _FB is calculated based on the equation (11) (step S28).

At this time, the feedback road surface reaction force F _FB is calculated so as to become a value closer to the first feedback road surface reaction force F _FB1 as the automatic steering command angle θa is larger.
As can be seen from FIG. 15, the greater the automatic steering command angle θa, the closer the amount B to be actually corrected approaches C to be corrected using the proportional gain K. Therefore, when the tangential gain L is smaller than the proportional gain K and the automatic turning command angle θa is equal to or greater than the predetermined angle β1, the automatic turning shunt surface reaction force is estimated using the proportional gain K and the tangential gain L. . Furthermore, as the automatic steering command angle θa is larger, the automatic steering shunt surface reaction force is brought closer to the value estimated using the proportional gain K. Thereby, an accurate value can be derived.

Further, compared with the case where the automatic turning shunt reaction force is estimated using only the tangential gain L, the automatic turning shunt reaction force (corrected road reaction force) to be subtracted from the actual road reaction force F may be increased. it can. As a result, like the second embodiment described above, the driver can recognize that automatic steering is being performed. Further, it is possible to apply a steering reaction force in the direction in which it is desired to turn by automatic turning.
In the present embodiment, the tangential gain calculation unit 157 constitutes a second gain calculation unit, and the second corrected road surface reaction force calculation unit 158 constitutes a second gain multiplication unit.

"effect"
(6) The second gain calculation means calculates a second gain indicating a road surface reaction force change rate that is a change amount of the actual road surface reaction force with respect to a change amount of the actual turning angle of the steered wheel. The second gain multiplication means multiplies the second gain calculated by the second gain calculation means and the second turning command angle calculated by the second turning command angle calculation means. The road surface reaction force estimation means estimates the multiplication result of the second gain multiplication means as a road surface reaction force corresponding to the second turning command angle.
Thereby, even if the relationship between the actual turning angle and the actual road surface reaction force is non-linear, it is possible to accurately estimate the automatic steering shunt road surface reaction force.

(7) The road surface reaction force estimating means has a second gain calculated by the second gain calculating means that is smaller than the first gain calculated by the first gain calculating means and is calculated by the second turning command angle calculating means. When the second turning command angle is smaller than a predetermined second turning command angle threshold, the multiplication result of the second gain multiplication means is estimated as the road surface reaction force corresponding to the second turning command angle.
Thereby, the road surface reaction force generated by the automatic turning can be accurately estimated.

(8) The road surface reaction force estimation means has a second gain calculated by the second gain calculation means that is smaller than the first gain calculated by the first gain calculation means and is calculated by the second turning command angle calculation means. When the second turning command angle is greater than or equal to a predetermined third turning command angle threshold value that is greater than the second turning command angle threshold value, the road surface corresponding to the second turning command angle is the multiplication result of the first gain multiplication means. Estimated as reaction force.
Thereby, the road surface reaction force generated by the automatic turning can be accurately estimated. In addition, the driver can recognize that automatic steering is being performed. Furthermore, it is possible to apply a steering reaction force in a direction in which it is desired to turn by automatic turning.

(9) The road surface reaction force estimating means has a second gain calculated by the second gain calculating means that is smaller than the first gain calculated by the first gain calculating means and is calculated by the second turning command angle calculating means. When the second turning command angle is greater than or equal to the second turning command angle threshold and smaller than the third turning command angle threshold, the second turning command angle is based on the multiplication result of the first gain multiplication means and the multiplication result of the second gain multiplication means. The road surface reaction force corresponding to the two-turn steering command angle is estimated.
As a result, the larger the automatic steering command angle is, the larger the automatic steering branch road reaction force can be estimated, and the road reaction force generated by the automatic steering can be accurately estimated.

<Modification>
In each of the above-described embodiments, the case where the steering controller 14 performs lane keeping control for automatically turning the host vehicle so as to travel in the center of the traveling lane has been described. The present invention can be applied as long as steering control is performed. Such control includes, for example, vehicle behavior stabilization control. In the vehicle behavior stabilization control, first, a target vehicle behavior amount based on a driver's steering operation is calculated. Then, the actual vehicle behavior amount is automatically steered so as to approach the target vehicle behavior amount.
Also in this case, if the configuration is made such that the road surface reaction force generated by the vehicle behavior stabilization control is not fed back as the steering reaction force, the same effects as in the above embodiments can be obtained.

It is a whole lineblock diagram showing an embodiment of a vehicle control device in the present invention. It is a control block diagram which shows the structure of a turning controller. It is a turning angle control block diagram in a turning controller. It is a control block diagram which shows the structure of the steering reaction force controller in 1st Embodiment. It is a flowchart which shows the steering reaction force control processing procedure performed with the steering reaction force controller in 1st Embodiment. It is a figure which shows the steering reaction force provided at the time of automatic steering control in this embodiment. It is a figure which shows the general steering reaction force provided at the time of automatic steering control. It is a control block diagram which shows the structure of the steering reaction force controller in 2nd Embodiment. It is a correction gain calculation map. It is a flowchart which shows the steering reaction force control processing procedure performed with the steering reaction force controller in 2nd Embodiment. It is a control block diagram which shows the structure of the steering reaction force controller in 3rd Embodiment. It is a figure which shows the relationship between an actual road surface reaction force and an actual turning angle. It is a distribution gain calculation map. It is a flowchart which shows the steering reaction force control processing procedure performed with the steering reaction force controller in 3rd Embodiment. It is a figure for demonstrating the calculation method of the feedback road surface reaction force.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering shaft 3 Steering angle sensor 4 Steering torque sensor 5 Reaction force motor 6 Backup clutch 7 Pinion shaft 8 Steering motor 9 Steering angle sensor 10 Steering mechanism 11R, 11L Front wheel 12 Axial force sensor 13 Forward recognition sensor 14 Roll Rudder controller 15 Steering reaction force controller 16 Communication line

Claims (9)

Steering that the driver steers,
A steering mechanism that is mechanically separated from the steering and steers the steered wheels;
A steering reaction force actuator for applying a steering reaction force to the steering;
A steering actuator that drives the steering mechanism;
Steering angle detection means for detecting the steering angle of the steering;
First turning command angle calculating means for calculating a first turning command angle that is a turning angle based on the steering angle detected by the steering angle detecting means;
Second turning command angle calculating means for calculating a second turning command angle that is a turning angle based on the traveling state of the host vehicle;
Based on the first turning command angle calculated by the first turning command angle calculating means and the second turning command angle calculated by the second turning command angle calculating means, the turning actuator that drives and controls the turning actuator is controlled. Rudder control means;
Road surface reaction force estimating means for estimating an estimated road surface reaction force that is a road surface reaction force generated in response to the second steering command angle;
Road surface reaction force detecting means for detecting an actual road surface reaction force input from the road surface to the steering mechanism;
The steering reaction is applied so that a steering reaction force equivalent to a reaction force deviation obtained by subtracting the estimated road surface reaction force estimated by the road surface reaction force estimation unit from the actual road surface reaction force detected by the road surface reaction force detection unit is applied to the steering. And a steering reaction force control means for driving and controlling the force actuator. A turning angle detection means for detecting a turning angle of the steering wheel;
The steering control means is a command steering obtained by adding together the first turning command angle calculated by the first turning command angle calculating means and the second turning command angle calculated by the second turning command angle calculating means. The vehicle steering control device according to claim 1, wherein the steering actuator is driven and controlled so that an angle coincides with a turning angle detected by the turning angle detection unit.   When the second steering command angle is larger than a predetermined first steering command angle threshold, the steering reaction force control means increases the estimated road reaction force correction that subtracts the estimated road reaction force to be subtracted from the actual road reaction force. The vehicle steering control device according to claim 1, further comprising means. First gain calculating means for calculating a first gain indicating a proportional relationship between the actual turning angle of the steered wheel and the actual road surface reaction force; the first gain calculated by the first gain calculating means; First gain multiplication means for multiplying the second steering command angle calculated by the rudder command angle calculation means,
The road surface reaction force estimation means estimates the multiplication result of the first gain multiplication means as a road surface reaction force corresponding to the second turning command angle. The vehicle steering control device described in 1. A second gain calculating means for calculating a second gain indicating a change rate of the road surface reaction force that is a change amount of the actual road surface reaction force with respect to a change amount of the actual turning angle of the steered wheel; and a calculation by the second gain calculation means Second gain multiplying means for multiplying the second gain and the second turning command angle calculated by the second turning command angle calculating means,
The road surface reaction force estimation means estimates the multiplication result of the second gain multiplication means as a road surface reaction force corresponding to the second turning command angle. The vehicle steering control device described in 1. A first gain calculating means for calculating a first gain indicating a proportional relationship between the actual turning angle of the steered wheel and the actual road surface reaction force; and an actual road surface reaction force with respect to a change amount of the actual steered wheel. The second gain calculating means for calculating the second gain indicating the road surface reaction force change rate that is the amount of change of the second gain, the second gain calculated by the second gain calculating means and the second turning command angle calculating means Second gain multiplication means for multiplying the second turning command angle,
The road surface reaction force estimating means calculates the second gain calculated by the second gain calculating means smaller than the first gain calculated by the first gain calculating means and calculated by the second turning command angle calculating means. When the second turning command angle is smaller than a predetermined second turning command angle threshold, the multiplication result of the second gain multiplying means is estimated as a road surface reaction force corresponding to the second turning command angle. The vehicle steering control device according to any one of claims 1 to 3. First gain multiplying means for multiplying the first gain calculated by the first gain calculating means and the second turning command angle calculated by the second turning command angle calculating means;
The road surface reaction force estimating means calculates the second gain calculated by the second gain calculating means smaller than the first gain calculated by the first gain calculating means and calculated by the second turning command angle calculating means. When the second turning command angle is greater than or equal to a predetermined third turning command angle threshold value that is greater than the second turning command angle threshold value, the multiplication result of the first gain multiplication means is used as the second turning command angle value. The vehicle steering control device according to claim 6, wherein the vehicle steering control device is estimated as a corresponding road surface reaction force.   The road surface reaction force estimating means calculates the second gain calculated by the second gain calculating means smaller than the first gain calculated by the first gain calculating means and calculated by the second turning command angle calculating means. When the second turning command angle is not less than the second turning command angle threshold and smaller than the third turning command angle threshold, the multiplication result of the first gain multiplication means and the multiplication result of the second gain multiplication means are The vehicle steering control device according to claim 6 or 7, wherein a road surface reaction force corresponding to the second turning command angle is estimated based on the vehicle steering control device. Detecting an actual road surface reaction force input to the steering mechanism mechanically separated from the steering wheel from the road surface;
Calculating a first turning command angle that is a turning angle based on the steering angle of the steering;
Calculating a second turning command angle that is a turning angle based on the traveling state of the host vehicle;
Based on the calculated first steering command angle and second steering command angle, driving the steering actuator that drives the steering mechanism; and
Estimating a road surface reaction force corresponding to the second steering command angle generated by the control;
Driving the steering reaction force actuator so that a steering reaction force equivalent to a reaction force deviation obtained by subtracting the estimated road reaction force estimated from the detected actual road surface reaction force is applied to the steering wheel. A vehicle steering control method.

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