JP4581651B2 - Vehicle steering system - Google Patents

Description

  The present invention belongs to the technical field of a steering apparatus for a vehicle by a steer-by-wire system.

In the conventional steer-by-wire system, the road surface condition is estimated from the current that flows through the steering actuator, and the steering reaction force actuator is driven according to the estimated road surface condition, giving the driver a fine road surface feeling. (For example, refer to Patent Document 1).
JP 2003-252224 A

However, in the above-described conventional vehicle steering apparatus, the road surface condition is estimated from the current value of the steering actuator and reflected in the steering reaction force, so the turning angle is accurately adjusted to the target turning angle. When the turning torque changes due to the influence of robust control, the change is generated as it is as a steering reaction force. Therefore, there is a problem in that the driver feels uncomfortable because the steering reaction torque increases even when the road surface load does not fluctuate, such as when the vehicle is turning in a steered state.

  The present invention has been made paying attention to the above-mentioned problem, and the purpose thereof is to suppress excessive fluctuations in the steering reaction torque associated with the robust control of the steering actuator so as not to give the driver a sense of incongruity. An object of the present invention is to provide a vehicular steering apparatus.

In order to achieve the above object, in the present invention,
A steering unit that is mechanically separated from the steering unit that receives the steering input of the driver and steers the steered wheels so as to achieve a target turning angle according to the steering state;
Steering torque detection means for detecting the steering torque of the steering unit;
Steering reaction force applying means for applying a steering reaction force torque to the steering unit in accordance with the steering torque;
Steering reaction force correction means for correcting the steering reaction force torque corresponding to the turning torque to be small when the turning torque is a value equal to or greater than a preset threshold value and increases ;
It is characterized by providing.

Therefore, in the vehicle steering apparatus of the present invention, when the turning torque is equal to or greater than the threshold value and increases, the reflection rate to the steering reaction force torque corresponding to the turning torque is reduced. By doing so, the excessive fluctuation | variation of a steering reaction force torque can be suppressed, and the discomfort given to a driver | operator can be prevented.

  Hereinafter, an embodiment for realizing a vehicle steering system of the present invention will be described based on Examples 1 and 2 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram illustrating a vehicle steering apparatus according to a first embodiment. The vehicle steering apparatus according to the first embodiment includes a steering section (1), a steering section (2), a mechanical backup 10, and a controller. A drive circuit unit (hereinafter referred to as a control unit) 11 and a vehicle state parameter sensor 14 are provided.

  The steering section (1) includes a steering wheel angle sensor 1, a steering torque sensor (steering torque detecting means) 2, a steering reaction force actuator (steering reaction force applying means) 3, and a steering reaction force actuator angle sensor 4.

  The handle angle sensor 1 detects a handle angle (steering angle) from the rotation angle of the steering shaft 15. The steering torque sensor 2 detects the driver's steering torque input to the steering shaft 15. As the steering reaction force actuator 3, for example, a DC brushless motor is used, and a steering reaction force torque is applied to the steering shaft 15 by a motor output. The steering reaction force actuator angle sensor 4 detects the motor rotation angle of the steering reaction force actuator 3.

  The steered portion (2) includes a steered actuator 5, a steered actuator angle sensor 6, a steered torque sensor (steered torque detecting means) 7, a pinion angle sensor (steered angle detecting means) 8, and a tie rod axial force sensor 9 It has.

  As the turning actuator 5, for example, a DC brushless motor is used. By rotating the pinion shaft 16 by the motor output, the steering rack 17 slides in the vehicle width direction, and the steered wheels 13, 13 are steered. The The turning actuator angle sensor 6 detects the motor rotation angle of the turning actuator 5. The turning torque sensor 7 detects turning torque that is input torque to the pinion shaft 16. The pinion angle sensor 8 detects the rotation angle of the pinion shaft 16. The tie rod axial force sensor 9 detects the road load from the input torque to the left and right tie rods 18 and 18.

  The mechanical backup 10 mechanically connects the steering shaft 15 and the pinion shaft 16 to enable steering by the driver when the steer-by-wire system does not operate normally due to a failure of the steering actuator 5 or the like. For example, an electromagnetic clutch is used.

  A vehicle state parameter sensor (a vehicle state amount detection unit including a vehicle speed detection unit) 14 detects parameters indicating the vehicle state amount, such as a vehicle speed, a yaw rate of the vehicle, a lateral acceleration, and a vehicle body slip angle.

  The control unit 11 sets the target steering angle of the steered wheels 13 and 13 based on the detected values of the steering wheel angle sensor 1, the steering torque sensor 2, and the vehicle state parameter sensor 14, and is detected by the pinion angle sensor 8. A command current is output to the steering actuator 5 such that the steering angle matches the set target steering angle. Subsequently, the turning torque input to the turning section (2) is detected from the detected value of the turning torque sensor 7, and a steering reaction torque corresponding to the turning torque is added to the steering shaft 15.

  When the steer-by-wire system is operating normally, the control unit 11 keeps the clutch of the mechanical backup 10 in a released state, and puts the clutch into an engaged state when a failure is detected in the system.

FIG. 2 is a steering control block diagram of the control unit 11.
The target rudder angle calculation unit 11a calculates a target rudder angle based on the steering wheel angle from the steering wheel angle sensor 1 and each parameter (vehicle speed, lateral speed, yaw rate, etc.) from the vehicle state parameter sensor 14.

  Deviations between the target rudder angle and the actual rudder angle detected by the pinion angle sensor 8 are input to the PID controllers (proportional controller 11b, differential controller 11c, and integral controller 11d). The added value of the output of each controller 11b, 11c, 11d is supplied to the steering actuator 5 as a command current.

Next, the operation will be described.
[Steering reaction force control processing]
FIG. 3 is a flowchart showing the flow of the steering reaction force control process executed by the control unit 11 of the first embodiment, and each step will be described below.

  In step S1, it is determined from the detected value of the steering wheel angle sensor 1 and the detected value of the turning torque sensor 7 whether corner turning is constant and the turning torque is large. If YES, the process proceeds to step S3. If NO, the process proceeds to step S2. Here, when the output of the steering wheel angle sensor 1 is constant for a predetermined time and the detected value of the turning torque sensor 7 is equal to or greater than a preset threshold value, the corner turning is constant and the turning torque is Judge that it is big. Note that the steering torque may be detected by the tie rod axial force sensor 9.

In step S2, the steering reaction force torque (target value) corresponding to the steering torque is set using the following formula (1), and the normal control for reflecting the steering reaction force torque in the steering reaction force torque is performed, and the process proceeds to return. .
T = G ₀ × Ta (1)
Here, G ₀ is a gain constant, and Ta is a steering torque.

In step S3, it is determined whether or not the steering torque has increased from the deviation (steering angle deviation) between the actual steering angle of the steered wheels 13 and 13 obtained from the detection value of the pinion angle sensor 8 and the target steering angle. to decide. If YES, the process proceeds to step S4, in the case of NO, the process proceeds to step S 2.

In step S4, the target value of the steering reaction force torque is corrected (corresponding to the steering reaction force correction means) according to the rate of increase of the steering torque, and reflected in the steering reaction force torque, and the process proceeds to step S5. Here, the steering reaction torque is obtained from the following equation (2).
T = G ₀ × G ₁ × Ta (2)

G ₁ is a correction gain, which is set based on the map shown in FIG. As shown in FIG. 4, the correction gain G ₁ is set according to the change rate (ΔTa / Δt) of the turning torque, and is set to be a smaller value as the change rate (increase rate) becomes larger. . When the rate of change is zero, the correction gain G ₁ = 1, and therefore equation (2) matches equation (1) during normal control.

Further, the horizontal axis in FIG. 4 can be replaced with a reduction rate of deviation between the target rudder angle and the actual rudder angle. That is, when the decrease rate of the deviation is large, the correction gain G ₁ is decreased, and the correction gain G ₁ is increased as the decrease rate of the deviation is decreased.

Further, in FIG. 4, the characteristic A of the correction gain G ₁ is linearly interpolated. However, as shown in B, it can be set by an arbitrary curve.

  In step S5, it is determined whether or not to continue the steering reaction torque correction control. If YES, the process proceeds to return, and if NO, the process proceeds to step S2. Here, the correction control is stopped when the turning torque is equal to or less than the start condition (the threshold value of step S1) or the deviation is zero. The correction control is also stopped when the target rudder angle starts to move again.

  In step S5, the correction control is stopped when the deviation between the target turning angle and the actual turning angle is open even though there is no steering input from the driver. That is, the object of the present invention is to prevent a sense of discomfort associated with servo control during steering. If the deviation between the target steering angle and the actual steering angle is open, this means that the vehicle motion and road surface conditions have changed and the load has increased. It is necessary to tell the driver.

[Angle servo control of steering actuator]
First, an angle servo that is a controller of a general steering actuator will be described.
FIG. 5 illustrates the turning angle δ and the steering reaction force in a time series when the stepwise target turning angle δ ^* is given to the turning actuator in the turning angle servo control. Each state indicates a difference in response due to a difference in load input to the steering actuator 5 (FIGS. 5 (I) and (II)). Note that t1 is the time when the target rudder angle is step-inputted.

When the steering actuator is controlled, generally, an angle robust servo control is performed such that the actual steering angle δ follows a certain target steering angle δ ^* without a steady deviation. The initial follow-up control places importance on the rise of the actual steering angle δ, and therefore performs control using elements such as a proportional term and a differential term. Specific examples are the proportional controller 11b and the differential controller 11c shown in FIG.

Following control after the initial stage is performed using an integral element for the purpose of reducing the deviation between the target steering angle δ ^* and the actual steering angle δ. Specific examples include I control and disturbance observer (integral controller 11d in FIG. 5).

As shown in FIG. 5 (I), when the load is low, the deviation between the road surface load and the steering torque is small, so the angle servo gives a smooth actual steering angle response with little deviation from the target steering angle δ ^* . Show. However, in a high load state, the response changes from a low load state.

In FIG. 5 (II), as a control operation, first, a proportional and differential terms are used to start up at once. Here, when a high load resistance force (disturbance) from the outside is applied to the controlled object, the tracking of the angle becomes dull at a certain point, and a deviation Δd occurs. At this point, the integral term starts to move, and the control is such that the actual steering angle δ gradually approaches the target steering angle δ ^* (the steering torque increases, and thus becomes a large value with respect to the road load). ).

  Basically, since the integral term is an accumulation operation, the operation is generally slow even when compared with the proportional or differential term.

Next, how the servo control operates in an actual vehicle traveling scene will be described with reference to FIGS.
When the driver turns around a certain corner, the driver rotates the handle 12 to a predetermined position. In consideration of the driver's steering operation and vehicle parameters (vehicle speed, lateral acceleration, yaw rate, etc.), the target rudder angle calculation unit 11a in the control unit 11 sets command values to the controllers 11b, 11c, and 11d. Ask. These command values are generally given as target steering angles. Then, a command current (or command voltage) that reduces the deviation between the target rudder angle and the actual rudder angle is generated, and the steering actuator 5 is controlled.

When traveling with a certain load, for example, when turning at a high lateral acceleration, the initial response portion alone cannot sufficiently follow the target rudder angle δ ^* , and the steering actuator 5 is operated from the road surface. Since the momentary balance is caused by the load, a deviation d remains between the target rudder angle δ ^* and the actual rudder angle δ. Thereafter, an integral term is activated to cancel the influence of this load and to make the actual steering angle δ coincide with the target steering angle δ ^* .

  In this way, the steer-by-wire steering actuator 5 operates to realize the function of “turning” the vehicle.

Next, the effect of the rudder angle servo on the driver will be described.
FIG. 6 shows a turning angle response when a stepwise target turning angle δ ^* is given to the turning actuator, turning torque Ta applied to the turning actuator, and steering in the turning angle servo control. The state of the reaction force torque T is illustrated in time series. The step input time is t1. As an actual example, it is a state (steady turn) in which the corner is turned with the handle held at a certain angle.

As described above, when the driver steers, the value of the steering torque Ta increases, and this load causes a deviation Δd between the target steering angle δ ^* of the angle servo of the steering actuator and the actual steering angle δ. Then, the state is instantaneously balanced and the state is maintained as a rudder (interval of time t2-t3 in FIG. 6).

  By the way, the load here means a load that can move the steered actuator even when a load is applied to the steered actuator, and the steered wheel steer is fixed by a curb or the like. It does not mean load.

Subsequently, the integral term operates the steered actuator so as to reduce the deviation Δd between the target rudder angle δ ^* and the actual rudder angle δ (section from time t3 to t4 in FIG. 6).

  On the other hand, the steering reaction force torque T increases from the time t1 to the time t2 when the initial response stops, and becomes a constant value in the section of the time t2-t3. From the viewpoint of the driver, it is felt that the place where the actual steering angle δ stops is the reaction force when the steering wheel angle is constant.

  However, after this (time t3−t4), the steered actuator is moved due to the integral term, so the steered torque Ta moves (increase ΔTa), and therefore the steering reaction torque Ta also fluctuates excessively. (Fluctuation amount ΔT in FIG. 4). That is, the steering reaction torque T is increased by the integral term even though the road load does not change. Since the steering reaction force control reads a subtle change in the road surface, the fluctuation of the steering reaction force torque T is exerted and the steering feeling of the driver is deteriorated.

[Steering reaction force correcting action of embodiment 1]
On the other hand, in the vehicle steering apparatus of the first embodiment, when the turning torque Ta becomes equal to or greater than the threshold value during steering, the steering reaction force torque T corresponding to the turning torque Ta is corrected to be small. By doing so, the deterioration of the steering feeling accompanying the servo control of the turning angle is prevented.

When the steering torque Ta is equal to or greater than the threshold value, the deviation Δd between the target steering angle δ ^* to the steering actuator 5 and the actual steering angle δ increases, and the influence on the steering reaction torque T also increases. However, when the steering torque Ta is small, the deviation Δd is hard to occur and the influence on the steering reaction torque T is small. Therefore, the influence of the steering reaction torque T is reduced by dividing the steering torque Ta at a threshold value or more.

Here, the threshold value is a value such that a deviation Δd between the target steering angle δ ^* to the steering actuator 5 and the actual steering angle δ is generated, and this value depends on the torque generation characteristics of the steering actuator 5. It is determined.

FIG. 7 is a diagram showing the steering reaction force correcting action of the first embodiment. Similarly to FIG. 6, the turning angle response when the stepwise target turning angle δ ^* is given to the turning actuator 5 and The states of the steering torque Ta and the steering reaction torque T applied to the steering actuator 5 at that time are illustrated in time series.

At time t2, the actual steering angle δ responds to the target steering angle δ ^* input in a stepwise manner. Immediately after this (time t3), the integral term that reduces the deviation starts to move.

  In the first embodiment, the increase amount ΔT of the steering reaction force torque T is suppressed to be small by correcting the steering reaction force torque T to be small corresponding to a certain rate of change (ΔTa / Δt) of the steering torque Ta. . That is, it is possible to reduce the fluctuation of the steering reaction torque T due to the integral term during turning keeping.

  Here, it can be said that the change rate (ΔTa / Δt) of the steering torque is the same as the change rate (Δδ / Δt) of the angle servo, and it can also be determined by the change rate of the angle servo. Therefore, the smaller the change rate (Δδ / Δt) of the angle servo, the smaller the influence of the change in the steering reaction torque due to the integral term.

  In a portion where the change rate (ΔTa / Δt) of the turning torque is large, as shown in FIG. 7A, this means that the change rate of the steering reaction torque is reduced. By doing so, the turning actuator 5 can reduce the influence of unnecessary changes, and can prevent deterioration in steering feeling. In the above description, the rate of change is used, but expressions such as lowering the gain are also agreed.

Next, the effect will be described.
In the vehicle steering apparatus according to the first embodiment, the following effects can be obtained.

(1) A steering unit that is mechanically separated from the steering unit (1) that receives the steering input of the driver, and steers the steered wheels 13 and 13 so that the target steering angle δ ^* according to the steering state is obtained. (2), a steering torque sensor 7 for detecting the steering torque Ta of the steering section (2), and a steering reaction force actuator for applying a steering reaction torque to the steering section (1) according to the steering torque Ta 3 and a steering reaction force correction means for correcting the steering reaction force torque T corresponding to the turning torque Ta to be small when the turning torque Ta is greater than or equal to a preset threshold value and increases. Therefore, excessive fluctuations in the steering reaction torque T associated with the robust control of the steering actuator 5 can be suppressed, and a sense of discomfort given to the driver can be prevented.

  (2) The steering reaction force correction means is proportional to the increase rate of the steering torque (ΔTa / Δt) in order to increase the correction amount of the steering reaction force torque as the increase rate of the steering torque (ΔTa / Δt) increases. Thus, excessive fluctuations that occur can be effectively suppressed.

  (3) Since the steering reaction force correction means increases the correction amount of the steering reaction force torque T as the steering angle deviation reduction rate is smaller, it is possible to effectively suppress excessive fluctuations that occur in proportion to the steering angle deviation. .

  The vehicle steering apparatus according to the second embodiment is an example in which the correction amount of the steering reaction torque is changed according to the frictional state of the road surface, the vehicle speed, the vehicle state quantity, the steering torque, and the like. Since it is the same as 1, description is abbreviate | omitted.

In the second embodiment, the start of movement of the integral term is detected, and the steering reaction torque correction control is started. After the start of the correction control, the steering reaction force torque (T _{1 in} FIG. 9) at the beginning of the movement of the integral term is stored, and the steering reaction force torque T is corrected so that the value T ₁ continues until the end of the correction control. .

[Control start judgment]
In the second embodiment, as in the first embodiment, the deviation between the actual steering angle δ and the target steering angle δ ^* is monitored (steering angle deviation calculating means) when the steering torque Ta is greater than or equal to the threshold value during steering. If the opening Δd of this value is greater than or equal to the threshold value after the elapse of a predetermined set time (section from time t2 to t3 in FIG. 8), the rate of change in the steering reaction torque is reduced. To do.

  Here, during the set time (time t2-t3), when a load that causes a steering angle deviation is input to the steered wheels 13, 13, the actual steering angle δ is set to the target steering angle input. It can be determined by the time when the movement slows down or the time constant of the control system. This set time can be defined because the angle servo has certain characteristics (rise time constant, convergence, etc.) with respect to the steady steering of the driver.

  Further, in the second embodiment, the regulation is performed with the passage of time after the steering operation by the driver is stopped (for example, the time constant of the integral controller 11d), and this is used as a trigger determination, and the change rate is changed (time t3-t4). ).

[Steering reaction force correction]
FIG. 9 is a diagram showing the steering reaction force correcting action of the second embodiment. In the second embodiment, the steering reaction force torque T _{1 at} which the integral term starts to be effective is stored, and the value T ₁ is stored until the correction control is completed. Since the steering reaction torque T is corrected so that the torque continues, the fluctuation of the steering reaction torque due to the influence of the integral term can be made zero.

[Correction of target reaction torque according to road friction]
When the road surface friction is low, the vehicle behavior greatly increases with respect to steering. Therefore, the correction amount of the steering reaction force torque T is reduced and the reaction force is set to be heavy to prevent the driver from excessive steering. The road surface friction can be estimated from a change in wheel speed. Further, it may be estimated from detection values of infrastructure information and raindrop sensors. Furthermore, the road surface μ may be detected using an infrared sensor (corresponding to friction estimation means).

[Correction of target reaction torque according to vehicle speed]
It can be seen that as the vehicle speed increases, the road surface load increases with the self-aligning torque as an example. Therefore, by setting the steering reaction torque T to be heavier as the vehicle speed increases, the stability of steering in the high speed range is improved.

[Correction of target reaction torque according to lateral acceleration]
When the lateral acceleration of the vehicle increases, it can be understood that a high lateral acceleration turn is assumed. However, the behavior of the vehicle increases with respect to steering. Therefore, the greater the lateral acceleration, the smaller the correction amount of the steering reaction torque T and the reaction force. Setting it to be heavy prevents the driver from excessive steering.

[Correction of target reaction torque according to steering torque]
When the driver's steering torque is large, the vehicle is steered and the steering angle deviation is further increased. Therefore, in order to prevent the steering angle deviation from further increasing, the correction amount of the steering reaction force torque T is reduced to increase the reaction force. Therefore, excessive steering of the driver is prevented.

Next, the effect will be described.
In the vehicle steering apparatus of the second embodiment, the following effects can be obtained in addition to the effect (1) of the first embodiment.

(4) a pinion angle sensor 8 that detects the steered angle of the steered wheels 13 and 13, and a steered angle deviation calculating unit that calculates a steered angle deviation that is a deviation between the target steered angle δ ^* and the steered angle δ. The steering unit (2) determines a steering torque command value based on the integral value of the steering angle deviation, and the steering reaction force correction means is configured so that the steering angle deviation is equal to or greater than a predetermined angle. Since it is determined that the steering torque has increased when the above is continued, when the integral term works, the reflection rate to the steering reaction force can be reliably reduced, so the influence on the steering reaction force torque T is reduced, A driver's uncomfortable feeling can be reduced.

  (5) Provided with a road surface friction estimating means for estimating the friction state of the road surface on which the vehicle is traveling, the steering reaction force correcting means reduces the correction amount of the steering reaction force torque T as the road surface friction is lower. Excessive steering by the driver on the road is suppressed, and the vehicle behavior can be stabilized.

  (6) Vehicle speed detection means (vehicle state parameter sensor 14) for detecting the vehicle speed of the vehicle is provided, and the steering reaction force correction means reduces the correction amount of the steering reaction force torque T as the vehicle speed increases. Steering stability can be secured.

  (7) The vehicle state quantity detection means (vehicle state parameter sensor 14) for detecting the lateral acceleration is provided, and the steering reaction force correction means increases the lateral acceleration so that the correction amount of the steering reaction force torque T decreases. It is possible to prevent excessive steering of the driver during the lateral acceleration turning.

  (8) A steering torque sensor 2 for detecting the steering torque input by the driver to the steering unit (2) is provided, and the steering reaction force correction means increases the correction amount of the steering reaction force torque T as the steering torque increases. In order to reduce the size, excessive steering at the time of additional steering can be prevented.

(Other examples)
As mentioned above, although the vehicle steering device of the present invention has been described based on the first and second embodiments, the specific configuration is not limited to these embodiments, and it relates to each claim of the claims. Design changes and additions are allowed without departing from the scope of the invention.

  For example, instead of the tie rod axial force sensor, a configuration may be provided in which a rack axial force sensor or a means for estimating or detecting tire axial force equivalent is provided. Mechanical backup may be omitted.

  In the first and second embodiments, the PID controller is used. However, such a controller may be used as long as it has a function similar to this.

1 is an overall system diagram illustrating a vehicle steering apparatus according to a first embodiment. 3 is a steering control block diagram of a control unit 11. FIG. 3 is a flowchart illustrating a flow of a steering reaction force control process executed by a control unit 11 according to the first embodiment. It is a setting map of a correction gain G ₁ in response to the rate of change of the steering torque (ΔTa / Δt). In the turning angle servo control, the turning angle δ and the state of the steering reaction force when the stepwise target turning angle δ ^* is given to the turning actuator are illustrated in time series. In the turning angle servo control, the turning angle response when the stepwise target turning angle δ ^* is given to the turning actuator, the turning torque Ta applied to the turning actuator at that time, and the steering reaction torque T These states are illustrated in time series. It is a figure which shows the steering reaction force correction effect | action of Example 1. FIG. It is a figure which shows the determination method of Example 2. FIG. It is a figure which shows the steering reaction force correction effect | action of Example 2. FIG.

Explanation of symbols

1 Steering angle sensor 2 Steering torque sensor 3 Steering reaction force actuator 4 Steering reaction force actuator angle sensor 5 Steering actuator 6 Steering actuator angle sensor 7 Steering torque sensor 8 Pinion angle sensor 9 Tie rod axial force sensor 10 Mechanical backup 11 Controller & Drive circuit unit 12 Steering wheel 13 Steering wheel 14 Vehicle condition parameter sensor 15 Steering shaft 16 Pinion shaft 17 Steering rack 18 Tie rod

Claims (8)

A steering unit that is mechanically separated from the steering unit that receives the steering input of the driver and steers the steered wheels so as to achieve a target turning angle according to the steering state;
Steering torque detection means for detecting the steering torque of the steering unit;
Steering reaction force applying means for applying a steering reaction force torque to the steering unit in accordance with the steering torque;
Steering reaction force correction means for correcting the steering reaction force torque corresponding to the turning torque to be small when the turning torque is a value equal to or greater than a preset threshold value and increases ;
A vehicle steering apparatus comprising: The vehicle steering apparatus according to claim 1,
A turning angle detection means for detecting a turning angle of the steering wheel;
Rudder angle deviation calculating means for calculating a rudder angle deviation that is a deviation between the target steered angle and the steered angle, and
The steering unit determines a command value of the steering torque based on an integral value of the steering angle deviation,
The vehicle steering apparatus according to claim 1, wherein the steering reaction force correction means determines that the turning torque has increased when a state where the steering angle deviation is equal to or greater than a predetermined angle continues for a set time or longer. The vehicle steering apparatus according to claim 1 or 2,
The steering apparatus for a vehicle according to claim 1, wherein the steering reaction force correction means increases the correction amount of the steering reaction force torque as the increase rate of the steering torque increases. The vehicle steering apparatus according to claim 1 or 2,
A turning angle detection means for detecting a turning angle of the steering wheel;
Rudder angle deviation calculating means for calculating a rudder angle deviation that is a deviation between the target steered angle and the steered angle, and
The steering unit determines a command value of the steering torque based on an integral value of the steering angle deviation,
The steering apparatus for a vehicle according to claim 1, wherein the steering reaction force correction means increases the correction amount of the steering reaction force torque as the decrease rate of the steering angle deviation decreases. The vehicle steering apparatus according to any one of claims 1 to 4, wherein:
Road surface friction estimation means for estimating the friction state of the road surface on which the vehicle is running,
The steering apparatus for a vehicle according to claim 1, wherein the steering reaction force correction unit decreases the correction amount of the steering reaction force torque as the road surface friction is lower. The vehicle steering apparatus according to any one of claims 1 to 5,
Vehicle speed detection means for detecting the vehicle speed of the vehicle,
The steering apparatus for a vehicle according to claim 1, wherein the steering reaction force correction unit decreases the correction amount of the steering reaction force torque as the vehicle speed increases. The vehicle steering apparatus according to any one of claims 1 to 6, wherein:
Vehicle state quantity detecting means for detecting the lateral acceleration of the vehicle as the vehicle state quantity,
The steering apparatus for a vehicle according to claim 1, wherein the steering reaction force correction unit decreases the correction amount of the steering reaction force torque as the vehicle state amount increases. The vehicle steering apparatus according to any one of claims 1 to 7,
A steering torque detecting means for detecting a steering torque input by the driver to the steering unit;
The vehicle steering apparatus according to claim 1, wherein the steering reaction force correction unit reduces the correction amount of the steering reaction force torque as the steering torque increases.

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