JP4956782B2 - Vehicle steering control device - Google Patents

Description

  The present invention belongs to the technical field of a steering control device for a vehicle that gives an auxiliary steering angle that can achieve desired vehicle characteristics to a steered wheel.

Conventionally, an auxiliary steering angle is given to a steering angle of a driver's steering wheel via a transmission ratio variable actuator that is operated by an electric motor, and a transmission ratio between the steering angle of the steering wheel and the steered wheel steering angle (the rotation ratio) is changed. As a technique for changing (steering angle / steering angle), for example, a technique described in Patent Document 1 is disclosed. In the technique described in this publication, when the control amount corresponding to the control deviation, which is the difference between the target turning state and the actual turning state, is obtained, the control gain is changed according to the control deviation, the vehicle speed, or the steering speed. Yes. As a result, the steering rigidity is secured while suppressing the oscillation of the steering system.
JP 2000-351382 A

  However, when the control gain is reduced, there is a problem that a follow-up delay (steady deviation) of the variable transmission ratio actuator occurs in a small steering angle region in the initial stage of steering, causing a sense of response delay and insufficient reaction force.

  The present invention has been made paying attention to the above-mentioned problems, and an object of the present invention is to provide a vehicle steering control device having good responsiveness and steering rigidity.

In order to achieve the above-described object, in the vehicle steering control device of the present invention , the transmission angle can be changed by adding or subtracting the rotation angle with respect to the steering angle of the steering wheel and expressing the relationship with the steered wheel steering angle. A transmission ratio variable actuator, a transmission ratio variable control means for controlling the transmission ratio variable actuator by setting a command value so as to obtain a desired transmission ratio according to an operation state of the steering wheel, a direction of the operation force, and the transmission Command value correcting means for correcting the command value so that the command value becomes larger when the relationship with the rotation direction of the ratio variable actuator is the same direction than when the ratio variable actuator is in the reverse direction .

  In the vehicle steering control device of the present invention, the command value is corrected based on the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator, so that responsiveness and steering rigidity can be improved.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

[System configuration of vehicle steering control device]
FIG. 1 is a system configuration diagram of the steering control device according to the first embodiment. A steering wheel 2 that is rotatably supported on the vehicle body side and connected to the steering wheel 1 is connected to the steering wheel 1 that is steered by the driver.

  The steering shaft 2 is provided with a steering angle sensor 8 that detects the steering angle Θ, and outputs the steering angle Θ to the control unit 100. Further, on the steered wheel 20 side of the steering angle sensor 8, a transmission ratio variable actuator 3 for changing a transmission ratio (ratio of the steering steering angle Θ to the front wheel turning angle) is provided. The transmission ratio variable actuator 3 is provided with a front wheel motor 3a, and the transmission ratio is changed by adding or subtracting the rotation angle θmf of the front wheel motor 3a with respect to the steering angle Θ.

  The front wheel motor 3 a is provided with an encoder 10, and the rotation angle θmf of the front wheel motor 3 a is output to the control unit 100. A pinion 4 is provided on the steered wheel 20 side of the transmission ratio variable actuator 3, and the steered wheel 20 is steered by moving the rack shaft 5 left and right in the axial direction by a so-called rack and pinion mechanism. A vehicle speed sensor 7 is provided, and the detected vehicle speed VSP is output to the control unit 100.

[Control unit control configuration]
FIG. 2 is a block diagram showing the configuration of the control unit 100. The control unit 100 includes a rotation angle target value calculation unit 110, a rotation angle target value correction unit 120, and a steering angle servo control unit 130.

In the rotation angle target value calculation unit 110, a target value generation unit that generates a target yaw rate based on the detected values Θ and VSP of the steering angle sensor 8 and the vehicle speed sensor 7, and a target front wheel steering angle θ ^* based on the target yaw rate ^. calculating a, the target front wheel steering angle is constructed from the target output value generating unit that outputs a target rotation angle Shitamf ^* of the front wheel motor 3a in accordance with the theta ^*, the target front wheel steering angle to a rotation angle target value correcting section 120 theta ^* The rotation angle target value θmf ^* of the motor 3a corresponding to is output.

The rotation angle target value correction unit 120 corrects the rotation angle target value θmf ^* output from the rotation angle target value calculation unit 110 based on the detected values Θ and VSP of the steering angle sensor 8 and the vehicle speed sensor 7, and rotates after the correction. The angle target value θmfh ^* is output to the rudder angle servo control unit 130.

よって、前輪モータ３ａに出力される指令電流値Ｉ_θは、偏差eと、比例ゲインPと、微分ゲインDと、積分ゲインIとから下記式により算出される。

尚、各ゲインはチューニング定数である。 The steering angle servo control unit 130 outputs a current command value to the front wheel motor 3a of the variable transmission ratio actuator 3 based on the corrected rotation angle target value θmfh ^* output from the rotation angle target value correction unit 120, and the front wheel motor 3a. Servo control is performed between Specifically, the deviation e between the corrected rotation angle target value θmfh ^* and the actual rotation angle θmf is calculated by the following equation.

Thus, the command current value I _theta output to the front wheels motor 3a, and the deviation e, a proportional gain P, a derivative gain D, is calculated by the following equation from the integral gain I.

Each gain is a tuning constant.

ここで、

である。 Next, the calculation contents of the target value generation unit and the target output value generation unit will be described.
[Vehicle model calculation]
The vehicle parameter calculation executed by the vehicle model calculation unit 111 will be described.
In general, assuming a two-wheel model, the yaw rate of the vehicle can be expressed by the following equation (1).

here,

It is.

但し、

となる。 When the transfer function of the yaw rate for the front wheel steering is obtained from the state equation, the following equation (3) is obtained.

However,

It becomes.

である。 The yaw rate transfer function is (3)

It is.

here,

が求められる。 From the above, vehicle parameters

Is required.

[Target value calculation]
The target yaw rate is obtained from the vehicle speed and vehicle parameters. The target yaw rate and the target yaw angular acceleration are expressed by the following formula (6).

ただし、yrate_gain_map，yrate_omegn_map，yrate_zeta_map，yrate_zero_mapは前輪操舵用チューニングパラメータである。 Here, the parameter of the target yaw rate is expressed by the following equation (7).

However, yrate_gain_map, yrate_omegn_map, yrate_zeta_map, and yrate_zero_map are front wheel steering tuning parameters.

よって、目標前輪舵角θ^*を下記式(9)により算出する。

[Target front wheel turning angle calculation]
When the target front wheel steering angle θ ^* is calculated from the target yaw rate, it can be obtained from the following equation (8).

Therefore, the target front wheel steering angle θ ^* is calculated by the following equation (9).

When the target front wheel steering angle theta ^* is calculated by the above, the target rotation angle of the target front wheel steering angle theta ^* transfer ratio variable actuator 3 in accordance with the (front wheel motor 3a) θmf ^* is calculated. By the above-described calculation, control for adding the control steering angle to the steering angle Θ is performed in the low vehicle speed region, and control for subtracting the control steering angle from the steering angle Θ is performed in the high vehicle speed region. In particular, in the extremely low vehicle speed region close to the stop of the vehicle (during garage entry or the like), the most control steering angle is added. Further, although the yaw rate control is used in the first embodiment, the lateral speed control may be used, and the target front wheel steering angle may be calculated based on a map in which a gain or the like is set in advance, and is not particularly limited.

[Rotation angle target value correction unit]
Next, the control content of the rotation angle target value correction unit 120 will be described based on the flowchart of FIG.

[Reading process of steering angle and vehicle speed]
In step S1, the driver's steering angle Θ and vehicle speed VSP are read from the steering angle sensor 8 and the vehicle speed sensor 7.

[Rotation angle target value calculation processing]
In step S2, the rotation angle target value θmf ^* calculated by the rotation angle target value calculation unit 110 is read.
In step S2 ′, it is determined whether or not the absolute value of the steering angle Θ is smaller than the first threshold value. If smaller, the process proceeds to step S3. Otherwise, the process proceeds to step S14 (steering angle servo control process). Specifically, the first threshold value represents a very small steering angle region (eg, ± 10 °). In this way, by correcting in the very small steering angle region, it is possible to suppress problems such as response delay due to actuator follow-up delay from straight forward to the initial stage of steering, and deterioration of steering rigidity due to small initial reaction force rise. To do. Further, since the correction can be made in other areas, for example, the fluctuation is prevented from occurring even when the correction direction is switched by turning after the steering wheel 1 is largely turned.

[Steering force estimation process]
In step S3, the driver's steering torque is estimated from the steering angle Θ and the vehicle speed VSP. In estimating the steering torque of the driver, for example, the front wheel slip angle generated on the front wheel 20 can be estimated from the vehicle model, the road surface reaction force corresponding to the slip angle is estimated, and driving based on these estimation logics is performed. It is estimated how much steering torque the person is generating. For this estimation method, steering angular velocity, vehicle behavior (yaw rate, lateral acceleration), and four-wheel wheel speed may be used. Further, when a torque sensor is provided, a torque sensor signal may be detected, and is not particularly limited.

[Judgment processing of normal efficiency / reverse efficiency]
In step S4, the transmission ratio variable actuator 3 (front wheel motor 3a) faces the reaction force from the estimated steering torque and the direction of the actual rotation angle of the transmission ratio variable actuator 3 (front wheel motor 3a) (sign of angular velocity). It is determined whether the moving direction (= positive efficiency) or the moving direction (= reverse efficiency) from the reaction force. FIG. 4 is an efficiency diagram showing the relationship of the output torque with respect to the actuator current flowing through the front wheel motor 3a. When the output torque is high with respect to the actuator current, the efficiency is reverse, indicating that the efficiency is good. On the other hand, when the output torque is low with respect to the actuator current, the efficiency is positive and the efficiency is poor. Therefore, the deviation of the actual rotation angle θmf with respect to the rotation angle target value θmf ^* of the variable transmission ratio actuator 3 (front wheel motor 3a) is likely to occur in the normal efficiency, and the deviation is smaller in the reverse efficiency.

[Judgment processing for control of adding and switching back off]
In steps S5 and S8, the transmission ratio variable actuator 3 (front wheel motor 3a) is calculated from the estimated steering torque and the direction of rotation angle target value θmf ^* (sign of rotation angular velocity) of the transmission ratio variable actuator 3 (front wheel motor 3a). It is determined whether or not the direction is controlled to be increased or decreased.

  Note that the direction to increase is the side to add to the steering angle Θ of the driver, so it is so-called quick control. When the steering wheel 1 is increased, the transmission ratio variable actuator 3 (front wheel motor 3a) is also turned off. When the steering wheel 1 is turned back, the transmission ratio variable actuator 3 (front wheel motor 3a) is also controlled to turn back. On the other hand, the direction to switch back is so-called slow control because it is the side to subtract from the steering angle Θ of the driver, and when the steering wheel 1 is increased, the transmission ratio variable actuator 3 (front wheel motor 3a) is switched off. When the steering wheel 1 is turned back, the transmission ratio variable actuator 3 (front wheel motor 3a) is controlled to be increased.

  Here, the relationship between the increase / return control and the efficiency will be described. An example will be described in which control is performed on a given rotation angle target value without considering normal efficiency and reverse efficiency.

In the case of rounding control, the steady-state deviation of the transmission ratio variable actuator 3 (front wheel motor 3a) is such that the actual rotation angle θmf decreases as viewed from the absolute value of the rotation angle target value θmf ^* . FIG. 7 is a diagram illustrating actuator followability during quick control without considering efficiency. When the steering angle increases, the efficiency is positive during the quick control and the followability is poor, so the absolute value of the actual rotation angle θmf is smaller than the rotation angle target value θmf ^* . On the other hand, when the steering angle decreases, the reverse efficiency is achieved during the quick control, and the followability is good, so the actual rotation angle θmf follows the rotation angle target value θmf ^* .

On the other hand, in the case of the switchback control, the steady-state deviation is in the direction in which the actual rotation angle θmf increases as viewed from the absolute value of the rotation angle target value θmf ^* . In consideration of this characteristic, it is determined whether the correction direction of the target value is increased or decreased. FIG. 8 is a diagram illustrating actuator followability during slow control without considering efficiency. When the steering angle increases, the reverse efficiency is obtained during the slow control, and the followability is good, so the actual rotation angle θmf follows the rotation angle target value θmf ^* . On the other hand, when the steering angle decreases, the efficiency is positive during slow control and the followability is poor, so the absolute value of the actual rotation angle θmf is larger than the rotation angle target value θmf ^* . Therefore, the target value is corrected according to the efficiency.

[Target value correction amount calculation processing]
In step S6, step S7, step S9 and step S10, the determination result of the normal efficiency / reverse efficiency and increase / return determined in steps S4 and S5, and the rotation angle of the transmission ratio variable actuator 3 (front wheel motor 3a). A target value correction amount Δθ is calculated from the target value θmf ^* . The correction amount Δθ is set in advance using a map from the efficiency diagram shown in FIG. There are a total of four maps of the correction amount Δθ, and the absolute value of the correction amount differs depending on whether the efficiency is normal or reverse, and whether it is increased or decreased depending on whether it is increased or decreased. For the selected map, a correction amount Δθ is calculated according to the magnitude of the rotation angle target value θmf ^* .

FIG. 5 is a normal efficiency and reverse efficiency map when raising the rotation angle target value θmf ^* . When the efficiency is normal, the raising amount is set large, and when the efficiency is reverse, the raising amount is set small. FIG. 6 is a normal efficiency and reverse efficiency map when bulking the rotation angle target value θmf ^* . When the efficiency is normal, the bulk reduction amount is set large, and when the efficiency is reverse, the bulk reduction amount is set small. As shown in FIGS. 5 and 6, a second threshold value is set for each of the target value raising and lowering amounts. This second threshold value is a value of a degree of movement (about ± 3 °) when the vehicle is steered at the neutral position. In the vicinity of the 0 point where the absolute value of the steering angle Θ or the rotation angle target value θmf ^* is smaller than the second threshold value, it is smoothly changed to prevent control hunting.

[Target value correction amount change rate restriction processing]
In step S11 and step S12, when the calculated correction amount Δθ is added to the rotation angle target value θmf ^* , the correction amount changes when the steering condition and the traveling condition change. Specifically, when the correction amount Δθ changes suddenly by switching back and forth between the normal efficiency and the reverse efficiency by turning the steering wheel 1 or when the vehicle speed is changed from the state in which the quick control is executed at the low vehicle speed. A case where the state is changed to a state where the slow control is executed due to the increase is considered.

  In order to prevent a sudden change in the correction amount at this time, a limit value of the correction amount change rate is set, and the previous correction amount is compared with the correction amount calculated this time. When the correction amount change rate exceeds a preset threshold value, the correction amount is changed to the correction amount limited by the limit value, and otherwise, the correction amount calculated this time is output as it is.

[Calculation of corrected rotation angle target value]
In step S13, adds the correction amount to the calculated target rotation angle θmf ^*, calculates a corrected target rotation angle θmfh ^*. In step S14, the steering angle servo control is executed so that the calculated rotation angle target value θmfh ^* after correction is obtained.

(Operation by target value correction control processing)
FIG. 9 is a diagram illustrating actuator followability during quick control when the rotation angle target value is corrected according to efficiency. During quick control, increasing the target value increase on the positive efficiency side and decreasing the target value increase on the reverse efficiency side allows the actual rotation angle θmf to follow the rotation angle target value θmf ^* before correction well. You can see that

FIG. 10 is a diagram illustrating actuator followability during slow control when the rotation angle target value is corrected according to efficiency. During slow control, the actual rotation angle θmf is good for the uncorrected rotation angle target value θmf ^* by reducing the target value increase amount on the reverse efficiency side and increasing the target value increase amount on the positive efficiency side. You can see that it follows.

Hereafter, it enumerates about the effect of a present Example.
(1) The transmission angle variable actuator 3 capable of changing the transmission ratio representing the relationship with the steered angle of the steered wheel 20 by adding or subtracting the rotation angle θmf to the steering angle Θ of the steering wheel 1 and the operation of the steering wheel A control unit 100 (transmission ratio variable control means) that controls the transmission ratio variable actuator 3 by setting a rotation angle target value θmf ^* that is a command value so as to obtain a desired transmission ratio according to the state, and the direction of the operating force And a rotation angle target value correction unit 120 (command value correction means) for correcting the rotation angle target value θmf ^* based on the relationship between the rotation ratio of the transmission ratio variable actuator 3 and the rotation direction of the transmission ratio variable actuator 3. Therefore, since the command value is corrected based on the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator, the responsiveness and steering rigidity can be enhanced. In particular, it becomes possible to improve the actuator followability when the rotation angle target value is small as in the case of minute steering, and it is possible to suppress problems such as a sense of delay in response and insufficient rise of reaction force.

In each of the above-described configurations, the rotation angle target value θmf ^* is corrected based on the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator 3, and the actual transmission ratio is corrected before the rotation angle target value θmf ^*. It is synonymous with following.

(2) When the transmission ratio variable actuator 3 adds the rotation angle, the rotation angle target value θmf ^* is increased and corrected. Therefore, it is possible to improve the actuator follow-up performance at the time of additional control (during quick control).

(3) When the transmission ratio variable actuator 3 is subtracting the rotation angle, the rotation angle target value θmf ^* is corrected to decrease. Therefore, it is possible to improve the actuator followability at the time of switching back control (during slow control). In particular, by using both (2) and (3) above, it is possible to ensure good actuator followability regardless of quick control or slow control.

(4) When the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator 3 is the same direction, the correction amount is made larger than that in the reverse direction. That is, on the positive efficiency side, the efficiency of the output characteristics is poor with respect to the control input (current), and the deviation of the actual rotation angle θmf from the rotation angle target value θmf ^* tends to occur. For this reason, the followability of the transmission ratio variable actuator 3 is deteriorated. At this time, the followability can be improved by increasing the target value. On the other hand, on the reverse efficiency side, the efficiency of the output characteristics is high with respect to the control input (current), so the followability is not so bad. If the target value is corrected to the same extent as the normal efficiency side, the followability to the target value is worsened Let For this reason, when it comes to the reverse efficiency side, a favorable followability can be ensured in the entire region by setting the correction amount small.

(5) The rotation angle target value θmf ^* is corrected when the steering angle Θ is equal to or smaller than the first threshold value. Therefore, it is possible to suppress problems such as a feeling of response delay due to an actuator follow-up delay in the initial stage of steering from a straight line and a small rise in initial reaction force. Further, since it is possible to prevent correction in other areas, for example, it is possible to prevent fluctuations caused by switching of the correction direction due to turning after the steering wheel 1 is largely turned.

(6) When the steering angle Θ or the rotation angle target value θmf ^* is less than or equal to the second threshold value, the correction amount Δθ is made smaller as the rotation angle target value θmf ^* is smaller. Therefore, even when the forward efficiency side and the reverse efficiency side of the variable transmission ratio actuator 3 change, it becomes possible to gradually change the correction amount, and good follow-up even when switching back by lane change or the like Sex can be secured.

Next, Example 2 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 11 is a characteristic diagram showing the relationship between the vehicle speed VSP and the yaw rate gain. The yaw rate gain is the ratio of the yaw rate of the vehicle to the steering angle (steering angle). As shown in FIG. 11, the yaw rate gain characteristic of a vehicle generally has a peak around 100 km / h. That is, the yaw rate generated with respect to the steering angle (steering angle) tends to increase in the process of increasing the vehicle speed in the vicinity of 100 km / h from the stop state. On the other hand, in the process of further increasing the vehicle speed from around 100 km / h, the yaw rate generated with respect to the steering angle (steering angle) tends to decrease.
In other words, it can be said that in the region where the yaw rate gain of the vehicle is high, the influence of the actuator follow-up delay is greatly reflected in the vehicle behavior.

  Therefore, in order to set the correction amount Δθ in consideration of the yaw rate gain characteristic, when setting the raising amount or the lowering amount in steps S6, S7, S9, S10, a correction gain set according to the vehicle speed is applied. (Δθ × k).

  FIG. 12 is a diagram illustrating the relationship of the correction gain k with respect to the vehicle speed. In the vehicle speed region where the yaw rate gain is low, the vehicle characteristic is a region with low responsiveness, so the correction gain k is set small, and in the vehicle speed region where the yaw rate gain is large, the vehicle characteristic is a region with high responsiveness. The gain k is set large. In other words, when the yaw rate gain is large, the correction amount Δθ is set larger than when the yaw rate gain is small.

  Thereby, the correction amount Δθ can be set in accordance with the change in the yaw response of the vehicle depending on the vehicle speed.

(Other examples)
As described above, the first and second embodiments have been described. In the first embodiment, when the amount of increase / decrease of the correction amount Δθ is calculated, the rotation angle target value is set, but it may be set for the steering angle Θ.

5 and 6, the gain of the target front wheel steering angle θ ^* with respect to the steering angle Θ may be changed, or the steering angle Θ itself that is the basis for calculating the target front wheel steering angle θ ^* may be changed. It may be corrected.

  In addition, although the change rate of the correction amount is limited in steps S11 and S12, the correction amount itself may have a hysteresis characteristic.

1 is an overall system diagram showing a steering control device of Embodiment 1. FIG. FIG. 3 is a control block diagram of a controller according to the first embodiment. 3 is a flowchart illustrating control contents of a rotation angle target value correction unit according to the first embodiment. It is an efficiency diagram showing the relationship of the output torque with respect to the actuator current which flows into the front-wheel motor of Example 1. It is the normal efficiency and reverse efficiency map at the time of raising with respect to the rotation angle target value of Example 1. FIG. It is a normal efficiency and reverse efficiency map at the time of lowering with respect to the rotation angle target value of Example 1. FIG. It is a figure showing the actuator followability at the time of quick control which does not consider efficiency. It is a figure showing the actuator followability at the time of slow control which does not consider efficiency. It is a figure showing the actuator tracking property at the time of quick control at the time of correct | amending a rotation angle target value according to the efficiency of Example 1. FIG. It is a figure showing the actuator tracking property at the time of slow control at the time of correcting a rotation angle target value according to the efficiency of Example 1. It is a characteristic view showing the relationship between a vehicle speed and a yaw rate gain. It is a figure showing the relationship of the correction gain k with respect to the vehicle speed of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering shaft 3a Front wheel motor 3 Variable transmission ratio actuator 7 Vehicle speed sensor 8 Steering angle sensor 20 Steering wheel
100 control unit
110 Rotation angle target value calculator
120 Rotation angle target value correction unit

Claims (8)

A transmission ratio variable actuator capable of changing the transmission ratio representing the relationship with the steering angle of the steered wheel by adding and subtracting the rotation angle with respect to the steering angle of the steering wheel;
A transmission ratio variable control means for setting a command value so as to obtain a desired transmission ratio according to the operation state of the steering wheel, and controlling the transmission ratio variable actuator;
When the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator is the same direction, command value correction means for correcting the command value to be larger than that in the reverse direction ;
A vehicle steering control device comprising: The vehicle steering control device according to claim 1,
The vehicle steering control device, wherein the command value correction means increases and corrects the command value when the relationship between the direction of the operation force and the rotation direction of the transmission ratio variable actuator is the same direction . The vehicle steering control device according to claim 1 or 2,
The vehicle steering control device, wherein the command value correction means corrects the command value to be decreased when the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator is opposite . The vehicle steering control device according to any one of claims 1 to 3 ,
The vehicle steering control device, wherein the command value correcting means is means executed when a steering angle is equal to or less than a first threshold value . The vehicle steering control device according to claim 4 ,
The command value correcting means is a means for reducing the correction amount as the rotation angle is smaller when the steering angle or the command value is equal to or smaller than a second threshold smaller than the first threshold . Steering control device. The vehicle steering control device according to any one of claims 1 to 5,
The vehicle steering control device, wherein the command value correction means sets a correction amount based on a vehicle speed . The vehicle steering control device according to any one of claims 1 to 5 ,
The vehicle steering control device, wherein the command value correction means sets the correction amount smaller when the yaw rate gain representing the yaw rate with respect to the steering angle is smaller than when the yaw rate gain is large . For the variable transmission ratio actuator that can change the transmission ratio that represents the relationship with the steering angle of the steered wheels by adding or subtracting the rotation angle to the steering angle of the steering wheel, the command value is set so that the desired transmission ratio is obtained. When outputting
When the relationship between the direction of the operating force and the rotation direction of the transmission ratio variable actuator is the same direction, the command value is corrected to be larger than that in the reverse direction, and the actual transmission ratio is set to the command value before correction. A vehicle steering control device characterized by being caused to follow.

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