JP2002370667A - Vehicular steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular steering device for obtaining a steering feeling of proper resistant load in the vicinity of a rectilinearly advancing position, and capable of smoothly enlarging a steering angle without a sensor of incompatibility in a vehicle for adopting a steer-by-wire system. SOLUTION: A movement of a steering actuator is transmitted to a wheel so that a steering angle changes by the movement of the steering actuator driven according to rotation of an operation member without mechanically connecting the operation member to the wheel. A reaction force generating actuator for returning the operation member to the rectilinearly advancing position is controlled on the basis of the stored corresponding relationship. The corresponding relationship is determined so as to include the relationship that reaction force increases and decreases in response to an increase-decrease in a rotation quantity when the rotation quantity of the operation member is a preset quantity or more exceeding zero, and the reaction force becomes a specific value exceeding zero when the rotation quantity is less than the preset quantity, and a rotating speed is the preset value or more exceeding zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering system employing a so-called steer-by-wire system.

[0002]

2. Description of the Related Art In a vehicle employing a steer-by-wire system, an operation member simulating a steering wheel is not mechanically connected to a wheel, but a movement of a steering actuator driven in accordance with the rotation of the operation member is controlled. ,
The steering is transmitted to the wheels so that the steering angle changes according to the movement. Therefore, steering resistance and self-aligning torque based on the friction between the wheel and the road surface are not transmitted to the operation member.

[0003] Therefore, by applying a reaction force in the direction of returning the operation member to the straight traveling position, a steering wheel is given a steering feeling to a driver in the same manner as in a normal vehicle in which a steering wheel is mechanically connected to wheels. The operating member is returned to the straight traveling position. In order to apply the reaction force, a sensor that detects the rotation amount of the operation member and a reaction force actuator that generates a reaction force in accordance with the rotation amount detected by the sensor are used.

Conventionally, the magnitude of the reaction force is proportional to the amount of rotation of the operating member. That is, a sensor for detecting a rotation angle as a rotation amount of the operation member is provided, and as shown in FIG. 7, a voltage command value proportional to the detected rotation angle is applied to the reaction force actuator. Further, in order to secure play of the operating member in the vicinity of the straight traveling position, the voltage instruction value is set to zero when the rotation angle is smaller than a set amount (10 degrees in the illustrated example). Note that the rotation angle and the voltage instruction value are positive when steering left or right, and negative when steering left or right.

[0005]

When the voltage command value to the reaction force actuator near the straight-ahead position is zero, the operation of the operating member is too light near the straight-ahead position, and when the voltage exceeds the vicinity of the straight-ahead position, the reaction force suddenly decreases. The force is added and the operation becomes heavy. Therefore, the driver feels great discomfort.

Therefore, as shown in FIG. 8, it is conceivable to eliminate the range in which the indicated voltage value is zero and to apply the indicated voltage value proportional to the detected rotation angle to the reaction force actuator. However, the electric motor constituting the reaction force actuator does not rotate unless a certain voltage or more is applied due to its nature. Therefore, the operation of the operation member is too light in the vicinity of the straight-ahead position, and the reaction force is suddenly applied beyond the straight-ahead position, and the operation becomes heavy.

Therefore, as shown in FIG. 9, it is conceivable that the magnitude of the voltage instruction value at the beginning of the rotation of the operating member is set to a magnitude necessary for rotating the reaction force actuator. Accordingly, a reaction force can be generated by the reaction force actuator immediately after the operation member starts rotating. However, even when the operating member rotates slightly due to the driver's unwillingness to steer near the straight-ahead position, the reaction force increases due to the increase in the rotation angle of the operating member. The operation member is rotated in the direction of action.

Further, since the reaction force exerted by the conventional reaction force actuator acts in a direction for returning the operating member to the straight-ahead position, when the driver intentionally rotates the operating member toward the straight-ahead position, the operation member is operated. Does not have any resistance. Therefore, when performing sharp steering in the direction opposite to the current steering direction, the operation of the operating member becomes extremely light up to near the straight-ahead position, while a reaction force is suddenly added when the steering member goes beyond the straight-ahead position. . Therefore, the fluctuation of the force required for the operation becomes extremely large, and the driver feels great discomfort.

[0009]

A steering apparatus for a vehicle according to the present invention comprises an operating member, a steering actuator driven in accordance with the rotation of the operating member, and mechanically connecting the operating member to wheels. A mechanism that transmits the movement to the wheels so that the steering angle changes in accordance with the movement of the steering actuator, and a reaction force actuator that generates a reaction force acting in a direction to return the operation member to the straight-ahead position. And means for determining the amount of rotation of the operating member from the straight traveling position, means for determining the rotational speed of the operating member, and means for controlling the reaction force actuator based on the stored correspondence. If the magnitude of the rotation amount is equal to or greater than the set amount exceeding zero, the magnitude of the reaction force increases or decreases in accordance with the increase or decrease of the rotation amount, and the magnitude of the rotation amount is less than the set amount. hand, One, the magnitude of the rotation speed when it is higher than the set value greater than zero is defined to include a relationship that the magnitude of the reaction force is a constant value greater than zero. It is preferable that the set amount of the rotation amount of the operation member is set in advance so as to correspond to the play amount of the operation member in the vicinity of the straight traveling position. It is preferable that the set value of the magnitude of the rotation speed is set so as to correspond to a minute rotation speed when the operation member is rotated by the driver's assistance without steering intention. According to the present invention, when the magnitude of the rotation amount of the operation member is equal to or larger than the set amount exceeding zero, the magnitude of the reaction force increases or decreases in accordance with the increase or decrease of the rotation amount, so that the distance between the wheel and the road surface is reduced. A reaction force corresponding to friction can be provided. When the magnitude of the rotation amount of the operation member is less than the set amount, and when the magnitude of the rotation speed is equal to or greater than the set value exceeding zero, the magnitude of the reaction force is fixed to exceed zero, The operation of the operation member does not become too light near the straight traveling position, and it is possible to prevent the driver from feeling great discomfort.

The reaction force actuator is capable of generating a return resistance force acting in a direction opposite to the direction in which the operation member is returned to the straight traveling position, and determines whether the rotation amount is increasing or decreasing. Is provided, and the correspondence relationship is that when the magnitude of the rotation amount is less than the set amount, and the rotation amount increases, and the magnitude of the rotation speed is equal to or more than the set value. The reaction force having a constant magnitude is generated by the reaction force actuator, and the magnitude of the rotation amount is less than the set amount,
When the amount of rotation decreases and the magnitude of the rotation speed is equal to or greater than the set value, a return resistance force having a constant magnitude exceeding a predetermined zero is generated by the reaction force actuator. Preferably, it is defined to include the relationship. As a result, a steering feeling of an appropriate weight can be obtained near the straight traveling position regardless of the steering direction.

When the magnitude of the rotation amount is the set amount, the magnitude of the reaction force is such that the magnitude of the rotation amount is less than the set amount and the magnitude of the rotation speed is the set amount. It is preferable that the magnitude of the reaction force is equal to or greater than a constant value when the value is not less than the value. Thereby, when operating the operation member beyond the position in the vicinity of the straight traveling, the reaction force is prevented from fluctuating, and a smooth steering feeling can be obtained. Further, when the magnitude of the rotation amount is less than the set amount and the magnitude of the rotation speed is equal to or more than the set value, the magnitude of the constant reaction force and the magnitude of the constant return resistance force. Are preferably equal to each other. Thus, when operating the operating member at a position in the vicinity of the straight traveling, it is possible to prevent the force acting in the direction that hinders the operation from fluctuating, and to obtain a smooth steering feeling.

When the amount of rotation decreases and the rotational speed of the operating member is equal to or greater than a set value greater than the set value, the return resistance force having a magnitude exceeding a predetermined zero is set to the aforementioned value. It is preferably generated by a reaction actuator. It is preferable that the set value of the rotation speed is set so as to correspond to the sudden steering state. In this way, when performing sharp steering in the direction opposite to the current steering direction, the return resistance force is applied to the operation member by the reaction force actuator until the operation member returns to the straight traveling position, and the operation of the operation member becomes extremely light. Can be prevented. Further, even if the reaction force actuator generates a reaction force when the steering is performed beyond the straight traveling position, it is possible to prevent the fluctuation of the force required for the operation from becoming large and prevent the driver from feeling uncomfortable.

When the magnitude of the rotation amount is less than the set amount and the magnitude of the rotation speed is less than the set value, the generation of the force by the reaction force actuator is canceled. preferable. As a result, it is possible to prevent a reaction force and a return resistance force from acting on the operation member when the operation member rotates at a slight speed by the driver's assistance without steering intention. On the contrary, it is possible to prevent the operation member from rotating.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A steering apparatus for a vehicle shown in FIG. 1 includes an operating member 1 simulating a steering wheel, and a steering actuator 2 driven in accordance with the rotation of the operating member 1.
And a steering gear 3 for transmitting the movement to the wheels 4 so that the steering angle is changed according to the movement of the steering actuator 2 without mechanically connecting the operation member 1 to the wheels 4. A reaction force actuator 19 is provided for generating a reaction force acting in a direction for returning the operation member 1 to the straight traveling position and a return resistance force acting in a direction opposite to the direction for returning the operation member 1 to the straight traveling position.

The steering actuator 2 can be constituted by an electric motor such as a known brushless motor. The steering gear 3 is constituted by a motion converting mechanism such as a ball screw mechanism for converting the rotational motion of the output shaft of the steering actuator 2 into a linear motion of the steering rod 7. The movement of the steering rod 7 is transmitted to the wheel 4 via the tie rod 8 and the knuckle arm 9, and the toe angle of the wheel 4 changes. As the steering gear 3, a known gear can be used, and the configuration is not limited as long as the movement of the steering actuator 2 can be transmitted to the wheels 4 so that the steering angle changes. In addition,
In a state where the steering actuator 2 is not driven,
The wheel alignment is set so that the wheels 4 can return to the straight traveling position by the self-aligning torque.

The operating member 1 is connected to a rotating shaft 10 rotatably supported by the vehicle body. The output shaft of the reaction force actuator 19 is integrated with the rotating shaft 10. The reaction force actuator 19
Can be constituted by an electric motor such as a brushless motor.

As means for determining the amount of rotation of the operating member 1 from the straight position, an angle sensor 11 for detecting the rotation angle δh of the operating member 1 from the straight position is provided. As means for detecting the steering angle δ of the vehicle, a steering angle sensor 13 constituted by a potentiometer for detecting the operation amount of the steering rod 7 is provided. A speed sensor 14 for detecting the vehicle speed V is provided. The angle sensor 11, the steering angle sensor 13, and the speed sensor 14 are connected to a control device 20 constituted by a computer.
The control device 20 determines whether the rotation angle δh is increasing or decreasing from the detected value of the rotation angle δh detected in time series, and obtains the rotation speed R of the operation member 1 by calculation.

The control device 20 controls the steering actuator 2 via a drive circuit 22. For example, the relationship between the rotation angle δh of the operation member 1, the vehicle speed V, and the target steering angle is determined and stored in advance, and the driving circuit 22 is connected via the drive circuit 22 so as to eliminate the deviation between the steering angle δ and the target steering angle. The driving signal of the steering actuator 2 is output. The relationship between the rotation angle δh, the vehicle speed V, and the target steering angle is determined by decreasing the target steering angle corresponding to the rotation angle δh as the vehicle speed V increases.
The turning performance at low speed and the running stability at high speed can be improved. The control method of the steering actuator 2 is not particularly limited as long as the steering actuator 2 is driven according to the rotation of the operation member 1. For example, a yaw rate sensor of the vehicle is provided and the operation is performed. The relationship between the rotation angle δh of the member 1 and the target yaw rate is predetermined and stored, and a drive signal of the steering actuator 2 is output via the drive circuit 22 so as to eliminate the deviation between the detected yaw rate and the target yaw rate. Is also good.

The control device 20 stores a predetermined correspondence relationship among the rotation angle δh of the operation member 1, the increase / decrease of the rotation angle δh, the rotation speed R, the magnitude of the reaction force, and the magnitude of the return resistance force. I do. In the present embodiment, the relationship shown in FIG. 2 and the relationship shown in FIG. 3 are stored as the corresponding relationship.

FIG. 2 shows the relationship between the rotation angle δh and the voltage command value to the reaction force actuator 19, and the rotation angle δh
The values of h and the voltage instruction value are positive when the operating member 1 is located on one side of the left and right sides of the straight traveling position, and negative when the operating member 1 is located on the other side. When the magnitude of the rotation angle δh is equal to or greater than a predetermined set amount (10 degrees in the illustrated example) exceeding zero, the voltage instruction value is assumed to increase and decrease in proportion to the increase and decrease of the rotation angle δh. If less, the voltage reading is zero.

FIG. 3 shows the relationship between the rotation speed R of the operating member 1 and the command value for applying a voltage to the reaction force actuator 19 when the magnitude of the rotation angle δh is smaller than the set value. The rotation speed R and the voltage addition instruction value are positive when the vehicle is steered to one of the left and right sides, and negative when the vehicle is steered to the other side. When the magnitude of the rotation speed R is less than a predetermined set value exceeding zero, the voltage addition instruction value is set to zero. It is preferable that the set value of the magnitude of the rotation speed R is set so as to correspond to a minute rotation speed when the operating member 1 is rotated by the driver's assistance without steering intention. 10 degrees / second. The set value of the magnitude of the rotational speed R may be, for example, the magnitude of the minimum rotational speed that can be calculated from the detected value of the rotational angle sampled by the control device 20. In this case,
When the magnitude of the rotation speed R is zero, the magnitude of the rotation speed R becomes smaller than the set value. When the rotation speed R is equal to or higher than the set value, the magnitude of the voltage addition instruction value is set to a predetermined constant value (2.5 V in the illustrated example). The magnitude of the constant value is made equal to the magnitude of the voltage instruction value when the magnitude of the rotation angle δh is the above-mentioned set amount in the relationship shown in FIG.

The control device 20 controls the drive circuit 23 based on the stored correspondence so as to generate a reaction force or a return resistance corresponding to the determined rotation angle δh, the increase or decrease of the rotation angle δh, and the rotation speed R. Via the reaction force actuator 19
Control. Thereby, the reaction force corresponding to the voltage instruction value corresponding to the rotation angle δh satisfying the relationship shown in FIG.
The reaction force actuator 19 generates a reaction force or a return resistance according to the voltage addition instruction value corresponding to the rotation speed R that satisfies the relationship shown in FIG. That is, when the magnitude of the rotation angle δh is equal to or greater than the set amount, the magnitude of the reaction force increases or decreases in response to the increase or decrease of the rotation angle δh, and the magnitude of the rotation angle δh Is less than the set amount, and the rotation angle δ
When h increases and the magnitude of the rotation speed R is equal to or greater than the set value, a reaction force having a constant value exceeding zero is generated by the reaction force actuator 19, and the rotation angle δh Is smaller than the set amount, the rotation angle δh is reduced, and the rotation speed R
Is greater than or equal to the set value, it is determined to include a relationship in which a return resistance force of a certain magnitude exceeding a predetermined zero is generated by the reaction force actuator 19. In addition, the magnitude of the reaction force when the magnitude of the rotation angle δh is the set amount, and the magnitude of the rotation angle δh is less than the set amount, and the magnitude of the rotation speed R is The magnitude of the constant reaction force when the value is equal to or larger than the set value is equal to the magnitude of the constant return resistance force.
Further, when the magnitude of the rotation angle δh is less than the set amount and the magnitude of the rotation speed R is less than the set value, the reaction force actuator 19 generates the reaction force and the return resistance force. Is canceled.

The control procedure of the reaction force actuator 19 will be described with reference to the flowchart of FIG. First, a detected value of the rotation angle δh of the operation member 1 is read (step 1), and it is determined whether or not the magnitude of the rotation angle δh is equal to or greater than a set amount (10 degrees) exceeding zero (step 2). If the magnitude of the rotation angle δh is equal to or greater than the set amount, the voltage instruction value V1 corresponding to the rotation angle δh according to the relationship shown in FIG. A reaction force acting in the returning direction is generated (step 3), and the process returns to step 1. If the magnitude of the rotation angle δh is less than the set amount, the rotation speed R of the operating member 1 is calculated based on the rotation angle δh obtained in time series (step 4), and the magnitude of the rotation speed R is zero. Is determined (step 5). If the rotation speed R is equal to or larger than the set value, a voltage addition instruction value V2 having a fixed size shown in FIG. 3 is applied to the reaction force actuator 19 (step 6), and the process returns to step 1. The voltage addition instruction value V2 of a certain magnitude shown in FIG. 3 is a positive value when the steering is performed in one direction to the left and right, and is a negative value when the steering is performed to the other side in the left and right. Therefore, the control device 20 determines whether the rotation angle δh is increasing or decreasing. When the rotation angle δh is increasing, the control device 20 has a certain size acting in a direction to return the operating member 1 to the straight traveling position. The reaction force is generated by the reaction force actuator 19. When the rotation angle δh decreases, the reaction force actuator 19 generates a return resistance force of a predetermined constant magnitude acting in a direction opposite to the direction of returning the operation member 1 to the straight traveling position. . In step 5, the rotation speed R
Is smaller than the set value, the reaction force actuator 1
The voltage applied to 9 is set to zero, the generation of the reaction force or the restoring force is canceled (step 7), and the process returns to step 1. Note that a sensor for detecting the applied voltage or the applied current to the reaction force actuator 19 may be provided, and the feedback control may be performed based on the detected value so that the applied voltage becomes the target value.

According to the above-described embodiment, when the magnitude of the rotation angle δh of the operation member 1 is equal to or larger than the set amount exceeding zero, the magnitude of the reaction force increases or decreases in accordance with the increase or decrease of the rotation angle δh. A reaction force corresponding to the friction between the wheel 4 and the road surface can be provided. When the magnitude of the rotation angle δh of the operation member 1 is smaller than the set amount and the magnitude of the rotation speed R is equal to or larger than the set value exceeding zero, the magnitude of the reaction force is set to a constant value exceeding zero. Therefore, the operation of the operation member 1 does not become too light in the vicinity of the straight traveling position, and it is possible to prevent the driver from feeling great discomfort. When the magnitude of the rotation angle δh is smaller than the set amount, an appropriate steering feeling can be obtained regardless of the steering direction by applying a reaction force or a return resistance force. The magnitude of the reaction force when the magnitude of the rotation angle δh is the set amount is equal to the magnitude of the constant reaction force and the return resistance force when the magnitude of the rotation angle δh is less than the set amount. Since the operation members 1 are equalized, when the operation member 1 is operated beyond the position in the vicinity of the straight traveling position, the reaction force can be prevented from fluctuating, and a smooth steering feeling can be obtained. A smooth steering feeling can be obtained by preventing a force acting in a direction that hinders operation from fluctuating. When the magnitude of the rotation angle δh of the operation member 1 is smaller than the set amount and the magnitude of the rotation speed R is smaller than the set value, the generation of the reaction force or the return resistance force is released, so that the driver When the operating member 1 rotates at a slight speed by supporting the hand without intention of steering, it is possible to prevent the operating member 1 from rotating against the driver's intention.

The present invention is not limited to the above embodiment. For example, when the rotation angle δh of the operation member 1 decreases and the magnitude of the rotation speed R of the operation member 1 is equal to or greater than the set value larger than the above set value, regardless of the magnitude of the rotation angle δh, The reaction force actuator 19 may generate a return resistance force having a magnitude exceeding a predetermined zero. FIG.
The rotation speed R when the rotation angle δh is decreasing
Force Actuator 1 that Generates the Size of the Motor and the Return Resistance
9 shows an example of the relationship with the magnitude of the drive current of No. 9. In the present embodiment, if the rotation speed R is 400 degrees / second or more, a return resistance is generated. In this case, as shown in the flowchart of FIG. 6, first, the control device 20 reads the detected value of the rotation angle δh of the operation member 1 (step 1), and the rotation angle δh increases or decreases from the straight traveling position. Is determined (step 2). If the rotation angle δh has not increased or changed, it is determined whether or not the magnitude of the rotation angle δh is equal to or greater than a set amount (10 degrees) exceeding zero (step 3). If the magnitude of the rotation angle δh is equal to or greater than the set amount, the voltage instruction value V1 corresponding to the rotation angle δh according to the relationship shown in FIG. A reaction force acting in the returning direction is generated (Step 4), and Step 1 is performed.
Return to If the magnitude of the rotation angle δh is less than the set amount, the rotation speed R of the operating member 1 is calculated based on the rotation angle δh obtained in time series (step 5), and the magnitude of the rotation speed R becomes zero. Is determined (step 6). If the rotation speed R is equal to or greater than the set value, a voltage addition instruction value V2 having a certain size shown in FIG. 3 is applied to the reaction force actuator 19 (step 7), and the process returns to step 1. When the magnitude of the rotation speed R is less than the set value in Step 6, the voltage applied to the reaction force actuator 19 is set to zero, the generation of the reaction force or the return resistance force is canceled (Step 8), and the process returns to Step 1. . If the rotation angle δh has decreased from the straight traveling position in step 2, the rotation speed R of the operating member 1 is calculated based on the rotation angle δh obtained in time series (step 9), and the magnitude of the rotation speed R is calculated as described above. It is determined whether the value is equal to or greater than a set value (400 degrees / second) (step 1).
0). If the rotation speed R is less than the set value, step 3
If it is equal to or greater than the set value, the reaction force actuator 19 is driven so that a drive current satisfying the relationship shown in FIG.
1) Return to step 1. Thereby, when performing a rapid steering in the direction opposite to the current steering direction, the return resistance force is applied to the operation member 1 by the reaction force actuator 19 until the operation member 1 returns to the straight traveling position, and the operation of the operation member 1 is extremely light. In addition, when steering is performed beyond the straight traveling position, even if a reaction force is applied to the operation member 1 by the reaction force actuator 19, it is possible to prevent the fluctuation of the force required for operation from increasing, and Can be prevented from feeling uncomfortable. Others are the same as the above embodiment.

In the above embodiment, when the rotation speed R of the operating member 1 is lower than the set value, the generation of the reaction force is canceled.
When the rotation amount is smaller than the set amount, a constant reaction force may be generated regardless of the rotation speed. Further, the relationships shown in FIGS. 2, 3 and 5 are merely examples and the present invention is not limited to these. In addition, each set amount, set value, and specific numerical value of a constant value are appropriately set to arbitrary values. do it.

[0027]

According to the present invention, in a vehicle employing a steer-by-wire system, a steering feeling of an appropriate weight can be obtained in the vicinity of a straight-ahead position, and the steering angle can be smoothly increased without feeling uncomfortable. Accordingly, it is possible to provide a vehicle steering device that does not rotate the operation member against the driver's intention and can provide a smooth steering feeling even when the steering direction is changed by sudden steering.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of a vehicle steering system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a rotation angle of an operation member and a voltage instruction value to a reaction force actuator in the vehicle steering system according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a rotation speed of an operation member and a voltage addition instruction value to a reaction force actuator in the vehicle steering system according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a control procedure of a reaction force actuator in the vehicle steering system according to the embodiment of the present invention;

FIG. 5 is an example of a relationship between the magnitude of the rotation speed when the rotation angle of the operating member is reduced and the magnitude of the drive current of the reaction force actuator that generates the restoring force in the steering apparatus for a vehicle according to a modification of the embodiment of the present invention. Figure showing

FIG. 6 is a flowchart showing a control procedure of a reaction force actuator in a vehicle steering system according to a modification of the embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between a rotation angle of an operation member and a voltage instruction value to a reaction force actuator in a conventional vehicle steering apparatus.

FIG. 8 is a diagram showing a relationship between a rotation angle of an operation member and a voltage instruction value to a reaction force actuator in a vehicle steering system of a comparative example.

FIG. 9 is a diagram illustrating a relationship between a rotation angle of an operation member and a voltage instruction value to a reaction force actuator in a vehicle steering apparatus of a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operating member 2 Steering actuator 3 Steering gear 4 Wheel 11 Angle sensor 19 Reaction force actuator 20 Control device

Claims (6)

[Claims] An operating member, a steering actuator driven in accordance with the rotation of the operating member, and a steering angle corresponding to the movement of the steering actuator without mechanically connecting the operating member to wheels. As a result, a mechanism for transmitting the movement to the wheels, a reaction force actuator for generating a reaction force acting in a direction for returning the operation member to the straight traveling position, and a rotation amount of the operation member from the straight traveling position. Means for determining the rotational speed of the operating member, and means for controlling the reaction force actuator based on the stored relationship, the correspondence being a set amount whose magnitude of rotation exceeds zero. When it is above, the magnitude of the reaction force increases / decreases in accordance with the increase / decrease of the rotation amount, the magnitude of the rotation amount is less than the set amount, and the magnitude of the rotation speed becomes zero. Settings beyond When it is higher, the vehicle steering system the magnitude of the reactive force is defined to include the relation of a constant value greater than zero. 2. The magnitude of the reaction force when the magnitude of the rotation amount is the set amount is such that the magnitude of the rotation amount is less than the set amount and the magnitude of the rotation speed is The vehicle steering system according to claim 1, wherein the magnitude of the reaction force is equal to or greater than a predetermined value when the value is equal to or greater than the set value. 3. The reaction force actuator is capable of generating a return resistance force acting in a direction opposite to a direction for returning the operation member to the straight traveling position, and determines whether the rotation amount is increasing or decreasing. Means is provided, wherein the correspondence is such that the magnitude of the rotation amount is less than the set amount, the rotation amount increases, and the magnitude of the rotation speed is equal to or greater than the set value. At the time, the reaction force having a constant magnitude is generated by the reaction force actuator, and the magnitude of the rotation amount is less than the set amount,
When the amount of rotation decreases and the magnitude of the rotation speed is equal to or greater than the set value, a return resistance force having a constant magnitude exceeding a predetermined zero is generated by the reaction force actuator. The vehicle steering apparatus according to claim 1, wherein the vehicle steering apparatus is defined to include a relationship. 4. When the magnitude of the rotation amount is less than the set amount and the magnitude of the rotation speed is equal to or more than the set value, the magnitude of the constant reaction force and the constant return resistance The vehicle steering apparatus according to claim 3, wherein the magnitudes of the forces are equal to each other. 5. When the rotation amount decreases and the rotation speed of the operation member is equal to or greater than a set value greater than the set value, the return resistance force exceeds a predetermined zero. The vehicle steering apparatus according to claim 3, wherein the force is generated by the reaction force actuator. 6. When the magnitude of the rotation amount is less than the set amount and the magnitude of the rotation speed is less than the set value, the generation of the force by the reaction force actuator is cancelled. A vehicle steering apparatus according to any one of claims 1 to 5.