JP4442270B2 - Vehicle steering system - Google Patents

Description

  The present invention belongs to the technical field of a so-called steer-by-wire vehicle steering apparatus in which a steering operation means and a steering apparatus are mechanically separated.

A conventional vehicle steering apparatus estimates self-aligning torque, elastic resistance torque, inertia torque, and the like from outputs from a vehicle speed sensor, a steering angle sensor, a tie rod displacement sensor, and the like, and based on these estimated values, a target steering reaction force is estimated. Is calculated. Then, the steering reaction force motor is controlled so that this target steering reaction force is obtained, and the road surface reaction force applied to the steered wheels from the road surface is reflected in the steering reaction force (see, for example, Patent Document 1).
JP-A-10-226346

  However, the ideal steering reaction force differs between a driver who uses information from the steering reaction force for steering operation and a driver who does not use the information. That is, since the ideal steering reaction force characteristic differs depending on the driver, the conventional technique has a problem that an optimum steering reaction force according to the steering characteristic of the driver is not added.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a vehicle steering apparatus capable of applying an optimum steering reaction force according to the steering characteristics of the driver.

In order to achieve the above-described object, in the vehicle steering device of the present invention, a steering device that steers steered wheels and a steering operation means mechanically separated from the steering device,
A steering actuator for driving the steering device;
A steering reaction force actuator that applies a steering reaction force to the steering operating means,
Steering angle detection means for detecting a steering angle of the steering operation means;
Steering torque detecting means for detecting the steering torque of the driver;
Road surface reaction force detecting means for detecting a road surface reaction force applied to the steering wheel from the road surface;
In a vehicle steering apparatus comprising:
Storage means for storing the relationship between the steering angle and the steering torque as a steering history;
Driver characteristic determination means for determining whether the distribution tendency of the steering angle with respect to the steering torque is in direct proportion or in inverse proportion when the relationship between the steering angle and the steering torque in the stored steering history is plotted in two-dimensional coordinates ;
When it is determined that the steering angle distribution tendency with respect to the steering torque is in direct proportion, the steering reaction force characteristic of the steering reaction force actuator is changed so that the steering reaction force reflecting the detected road surface reaction force is applied. A steering reaction force characteristic changing means for changing a steering reaction force characteristic of the steering reaction force actuator so that a steering reaction force that does not reflect the detected road reaction force is applied when it is determined to be inversely proportional ;
Is provided.

In the present invention, for the driver using the information of the steering reaction force , the steering information more than necessary can be prevented when traveling on the low μ road by transmitting the road surface information to the driver. On the other hand, by not transmitting road surface information to the driver who does not utilize the steering reaction force information, it is possible to prevent steering more than necessary when traveling on a low μ road .

Hereinafter, the best mode for carrying out the vehicle steering system of the present invention will be described based on Example 1 and Reference Examples 1 to 3 .

First, the configuration will be described.
FIG. 1 is an overall configuration diagram of a vehicle steering apparatus including the steer-by-wire system according to the first embodiment.
The vehicle steering apparatus according to the first embodiment includes a steering wheel 101, a steering reaction force actuator 102, a steering torque sensor 103, a steering angle sensor 104, a front wheel 105 (left front wheel 105L, right front wheel 105R), and rack axial force. A sensor 106 (106L, 106R), a steering gear 107, a turning actuator 108, a turning angle sensor 109, a control device 110, and a vehicle speed sensor 111 are provided.

The steering torque sensor 103 detects torque (steering torque) generated between the steering wheel 101 and the steering reaction force actuator 102. The steering angle sensor 104 detects an operation amount by which the steering wheel 101 is operated. The rack axial force sensor 106 detects the force in the rack axial direction of the steering rack. The vehicle speed sensor 111 detects the vehicle speed of the vehicle. The turning angle sensor 109 detects the turning angle of the front wheel 105.

The steering reaction force actuator 102 generates a steering reaction force on the steering wheel 101 that transmits the operation of the driver. The steered actuator 108 generates a force for operating the steering gear 107 to steer the front wheels 105.

The control device 110 includes a control amount for generating a turning angle for the front wheels 105 based on detection values of the steering torque sensor 103, the steering angle sensor 104, the rack axial force sensor 106, and the vehicle speed sensor 111, and a steering reaction force actuator. A control amount for causing the steering reaction force to be generated in 102 is calculated.

  With the above-described configuration, it is possible to realize a so-called steer-by-wire function that can arbitrarily change the characteristic of the turning angle in response to a driver's operation input.

  FIG. 2 is a control block diagram of the control device 110 according to the first embodiment. The control device 110 calculates driver characteristic determination means 110a, steering reaction force characteristic change means 110b, steering reaction force calculation means 110c, and steering reaction force command value calculation. Means 110d are provided.

  The driver characteristic determination unit 110a receives the outputs of the steering angle sensor 104 and the steering torque sensor 103, determines whether the driver changes the steering amount according to the change in the steering reaction force due to the change in the road surface μ, and the steering reaction force. Output to the characteristic changing means 110b.

  The steering reaction force characteristic changing unit 110b sets a steering reaction force characteristic such that an appropriate steering reaction force according to the driver characteristic is calculated, and outputs the steering reaction force characteristic to the steering reaction force calculation unit 110c. The steering reaction force calculating means 110c calculates the steering reaction force from the vehicle speed sensor 111, the steering angle sensor 104, and the rack axial force sensor 106 based on the steering reaction force characteristic set by the steering reaction force characteristic changing means 110b, and the steering reaction force is calculated. It outputs to force command value calculation means 110d.

The steering reaction force command value calculation unit 110 d calculates a control amount to be output to the steering reaction force actuator 102 from the target steering reaction force obtained from the steering reaction force calculation unit 110 c and the current steering torque obtained from the steering torque sensor 103. . The steering reaction force actuator 102 generates a steering reaction force based on a command value obtained from the control device 110.

Next, the operation will be described.
[Driver characteristic change control processing]

  FIG. 3 is a flowchart showing the flow of the driver characteristic change control process executed by the control device 110 according to the first embodiment. Each step will be described below.

  In step 301, the present system is activated by an ignition switch or the like of the vehicle, and the process proceeds to step 302.

  In step 302, the counter N that counts the number of data for determining the steering characteristics of the driver is reset (= 0), and the process proceeds to step 303.

In step 303, the steering angle θ from the steering angle sensor 104, and inputs the steering torque T from the steering torque sensor 103, the process proceeds to step 304.

In step 304, it is determined whether or not the absolute value of the steering angle θ is smaller than the first threshold θ _th0 . If YES, the process proceeds to step 305. If NO, the process proceeds to step 306.

In step 305, θ _{max is set} to θ _th0, and the process _proceeds to step 306.

In step 306, it is determined whether the absolute value of the steering angle is equal to or greater than θ _max . If YES, the process proceeds to step 307. If NO, the process proceeds to step 308.

In step 307, the current absolute value of the steering angle is set to θ _max , and the process proceeds to step 303.

In step 308, it is determined whether or not θ _max is larger than the second threshold value θ _th1 (> θ _th0 ). If YES, the process proceeds to step 309, and if NO, the process proceeds to step 303.

In step 309, the values of the steering angle θ and the steering torque T are stored in the memory, the counter N is incremented, θ _max is reset, and the process proceeds to step 310.

In step 310, determines whether a counter N threshold N _th. If yes, then go to step 311; if no, go to step 303.

  In step 311, the N pieces of data collected so far are processed to determine the steering characteristics of the driver, and the process proceeds to step 312.

  In step 312, the steering reaction force characteristic is changed so as to adjust the steering reaction force corresponding to the rack axial force based on the determination result in 311, and the process proceeds to step 302.

[Driver characteristic change control operation]
When the driver is steering further, in the flowchart of FIG. 3, the flow of step 301 → step 302 → step 303 → step 304 → step 305 → step 306 → step 307 → step 303 is repeated, In 307, the process of setting θmax to | θ | is repeated.

When the driver is turning back or holding the steering wheel, the flow from step 30 6 → step 308 → step 309 → step 310 → step 303 is repeated until the counter N reaches the threshold value N _th . In step 309, the values of the steering angle θ and the steering torque T are stored in the memory.

When the counter N reaches the threshold value N _th , the flow proceeds from step 310 to step 311 to step 312 to 302. In step 311, the steering characteristic of the driver is determined from the N data stored so far. In step 312, the steering reaction force characteristic is changed so as to adjust the steering reaction force corresponding to the rack axial force.

[Determination of driver steering characteristics]
In the first embodiment, as shown in FIG. 4, the relationship between the steering torque and the steering angle is plotted two-dimensionally, and the driver's steering characteristics are determined from the tendency of the driver's steering history.

  At this time, the steering characteristic of the driver tends to have a characteristic that the steering angle becomes smaller as the steering torque characteristic for the same steering angle becomes lighter as in the group A in FIG. When the steering torque characteristic with respect to the same steering angle becomes light, it can be divided into a tendency to have a characteristic that the steering angle becomes large.

  Here, since it is considered that the driver of the A group is a driver who predicts that the road surface μ is decreased when the steering reaction force becomes small, the steering reaction reflecting the road surface reaction force is included in such a driver. It is desirable to add force characteristics. In addition, since the driver of the group B steers more when the steering reaction force becomes smaller (additional steering), there is a risk of overcutting on a low μ road and a delay in counter steer. Therefore, it is desirable to add a steering reaction force characteristic that does not reflect the road surface reaction force to such a driver.

[Problems of conventional control]
In the shift-by-wire system described in Japanese Patent Laid-Open No. 10-226346, self-aligning torque terms, elastic resistance torque terms, and inertial resistance torque terms are estimated based on detection results of a vehicle speed sensor, a steering angle sensor, and a tie rod displacement sensor. The target value of the reaction force torque is obtained from these estimated values, and the reaction force motor (steering reaction force actuator) is controlled to obtain this target value.

  However, since the ideal steering reaction force characteristic varies depending on the driver's steering characteristic, there is a problem that an appropriate steering reaction force according to the driver's steering characteristic cannot be applied particularly in a state where the road surface μ is low.

In other words, the driver using the steering reaction force information in the steering operation accurately grasps the road surface state from the steering reaction force . For example, the tire does not produce a force on a low μ road, so the steering torque becomes lighter. , "If you turn the steering wheel any more, the tire force will be too small, and if the rear wheel slips, the amount to cut in the reverse direction will increase to hit the counter" No more than that.

  However, when the steering reaction force similar to that on the dry road surface is applied even when the road surface μ is low due to the steer-by-wire, the driver determines that the vehicle still grips, and turns the steering wheel to steer. As a result, counter steer delay, unnecessary understeer may occur.

On the other hand, a driver who does not use steering reaction force information for steering operation does not estimate the grip state of the tire from the steering reaction force information.In general, when the steering wheel becomes light on a low μ road, the steering wheel is turned off until it becomes heavy. to continue. As a result, understeer appears intensely or countersteer diverges with a delay.

[Steering reaction force characteristics change action according to driver's steering characteristics]
On the other hand, in the vehicle steering apparatus according to the first embodiment, the driver's steering characteristics are determined from the tendency of the driver's steering history shown in FIG. 4, and the steering reaction force characteristics are changed in accordance with the steering characteristics. The optimum steering reaction force according to the steering characteristic can be added.

  In other words, for drivers who use information on steering reaction force, a steering reaction force characteristic that reflects the road surface reaction force is added, and the road surface information is transmitted to the driver, thereby preventing unnecessary steering. ing.

  On the other hand, for drivers who do not use information on steering reaction force, a steering reaction force characteristic that does not reflect the road surface reaction force is added, and the steering reaction force is made to be close to that during dry driving, so that the driver is neutral in steering. By making it easy to convey the position and adding a large steering reaction force, it is possible to prevent further unnecessary steering.

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

  (1) A driver characteristic determination unit 110a that determines the driver's steering characteristic from the tendency of the driver's steering history, and the steering reaction force characteristic of the steering reaction force actuator 102 is changed according to the determination result of the driver characteristic determination unit 110a. Since the steering reaction force characteristic changing means 110b is provided, the optimum steering reaction force can be added according to the steering characteristic of the driver.

(2) Since the steering reaction force characteristic changing means 110b changes the steering reaction force characteristic corresponding to the road surface reaction force applied to the front wheels 105 from the road surface, the steering reaction force characteristic change unit 110b does not grasp the driver as the driver who grasps the road surface condition from the change in the steering reaction force. Appropriate steering reaction force can be applied to both drivers.

  (3) Since the driver characteristic determination unit 110a determines the steering characteristic based on the relationship between the steering angle of the steering wheel 101 and the steering torque, the driver changes the steering reaction force based on the relationship between the steering angle and the steering reaction force. Therefore, it is possible to determine whether or not the driver grasps the road surface, and an appropriate steering reaction force according to the steering characteristics of the driver can be added.

  (4) Since the driver characteristic determination unit 110a determines the steering characteristic based on the tendency of the steering history when the maximum steering angle is equal to or greater than a predetermined value, the steering characteristic in a situation where the driver's steering characteristic appears relatively remarkably. It is possible to determine whether the driver is more accurately grasping the road surface condition.

(5) The steering reaction force characteristic changing unit 110b adds or subtracts the amount corresponding to the road surface reaction force applied from the road surface to the front wheel 105 according to the determination result of the driver characteristic determination unit 110a. An appropriate steering reaction force can be applied to both the driver who grasps the driver and the driver who does not grasp the driver.
[Reference Example 1]

The configuration of the reference example 1 is different from the configuration of the first embodiment in that a car navigation system is provided as a means for collecting road curvature information. Parts are denoted by the same reference numerals and description thereof is omitted.

Figure 5 is an overall configuration diagram of a vehicle steering apparatus having a steer-by-wire system of Reference Example 1, a vehicle steering apparatus of Reference Example 1, in addition to the configuration of the first embodiment shown in FIG. 1, the road curvature information A car navigation system 112 for collecting the vehicle is provided.

FIG. 6 is a control block diagram of the control device 110 of the reference example 1. The road curvature information from the car navigation system 112 is input to the driver characteristic determination unit 110a. Based on the steering angle and the road curvature, the driver characteristic determination unit 110a determines whether the driver changes the steering amount in accordance with the change in the steering reaction force due to the change in the road curvature.

Further, the steering reaction force characteristic changing unit 110b changes the steering reaction force characteristic so that the amount corresponding to the road surface reaction force applied to the front wheels 105 from the road surface continuously varies according to the determination result of the driver characteristic determination unit 110a. To do.

Next, the operation will be described.
[Driver characteristic change control processing]
FIG. 7 is a flowchart showing the flow of the driver characteristic change control process executed by the control device 110 of the reference example 1 , and each step will be described below. Steps 701, 702, and 709 to 712 perform the same processing as steps 301, 302, and 309 to 312 of the flowchart shown in FIG.

  In step 703, the steering angle θ is input from the steering angle sensor 104, the steering torque T is input from the steering torque sensor 103, and the road curvature ρ (reciprocal of the radius of the curved road) is input from the car navigation system 112, and the process proceeds to step 704.

In step 704, it is determined whether or not the absolute value | ρ | of the road curvature is smaller than the threshold value ρ _th0 . If YES, the process proceeds to step 705. If NO, the process proceeds to step 706.

In step 705, ρ _{max is set} to ρ _th0, and the process _proceeds to step 706.

In step 706, the absolute value of road curvature | [rho | determines whether it is [rho _max or more. If YES, the process proceeds to step 707, and if NO, the process proceeds to step 708.

In step 707, the absolute value of the current road curvature is set to ρ _max , and the process proceeds to step 703.

In step 708, it is determined whether or not ρ _max is larger than a second threshold ρ _th1 that is larger than ρ _th0 . If YES, the process proceeds to step 709, and if NO, the process proceeds to step 703.

  The driver characteristic change control action based on the flowchart of FIG. 7 is the same as that in which the steering angle θ in the flowchart of FIG. 3 is replaced with the road curvature ρ, and the actual road curvature is obtained in step 711 by the above processing. The steering characteristic of the driver having a high correlation with ρ can be obtained, and the steering characteristic can be estimated with high accuracy.

Next, the effect will be described.
In the vehicle steering apparatus of Reference Example 1 , in addition to the effects (1) and (2) of the first embodiment, the effects listed below can be obtained.

  (6) Since the driver characteristic determination unit 110a determines the steering characteristic based on the relationship between the steering angle of the steering wheel 101 and the road curvature, the driver determines the change in the steering reaction force from the relationship between the steering angle and the road curvature. It can be determined whether or not the driver grasps the road surface, and an appropriate steering reaction force according to the steering characteristics of the driver can be added.

  (7) Since the driver characteristic determination unit 110a determines the steering characteristic based on the tendency of the steering history when the road curvature on which the vehicle is traveling exceeds a predetermined value, the driver's steering characteristic is relatively remarkable. Steering characteristics can be determined in the situation that appears, and it can be determined whether or not the driver is more accurately grasping the road surface condition.

(8) The steering reaction force characteristic changing unit 110b continuously changes the amount corresponding to the road surface reaction force applied from the road surface to the front wheel 105 according to the determination result of the driver characteristic determination unit 110a. Therefore, an appropriate steering reaction force can be applied to both the driver who grasps the road surface condition and the driver who does not grasp the road surface condition.
[Reference Example 2]

The vehicle steering device of Reference Example 2 is different from Example 1 in that the steering characteristics of the driver are determined based on the relationship between the steering angle and the vehicle yaw rate, and other configurations are the same as those of Example 1. The description of the configuration is omitted.

Figure 8 is an overall configuration diagram of a vehicle steering apparatus having a steer-by-wire system of Reference Example 2, the vehicle steering apparatus of Reference Example 2, in addition to Example 1, a yaw rate sensor for detecting yaw rate of the vehicle 113 is provided.

FIG. 9 is a control block diagram of the control device 110 of the reference example 2. The yaw rate of the vehicle detected by the yaw rate sensor 113 is input to the driver characteristic determination unit 110a. Based on the steering angle and the yaw rate, the driver characteristic determination unit 110a determines whether the driver changes the steering amount in accordance with the change in the steering reaction force due to the change in the yaw rate.

Next, the operation will be described.
[Driver characteristic change control processing]
FIG. 10 is a flowchart showing the flow of the driver characteristic change control process executed by the control device 110 of Reference Example 2 , and each step will be described below. Step 1001, step 1002, and step 1009 to step 1012 perform the same processing as step 301, step 302, and step 309 to step 312 of the flowchart shown in FIG.

  In step 1003, the steering angle θ is input from the steering angle sensor 104, the steering torque T is input from the steering torque sensor 103, and the yaw rate ψ ′ of the vehicle is input from the yaw rate sensor 113, and the process proceeds to step 1004.

In step 1004, it is determined whether the absolute value of the yaw rate | ψ ′ | is smaller than the threshold value _ψ′th0 . If YES, the process moves to step 1005. If NO, the process moves to step 1006.

In step 1005, ψ ′ _{max is set} to ψ ′ _th0, and the process _proceeds to step 1006.

In step 1006, the absolute value of the yaw rate | [psi '| is [psi' determines whether a _max or more. If YES, the process moves to step 1007, and if NO, the process moves to step 1008.

In Step 1007, the absolute value of the current yaw rate is set to ψ ′ _max , and the process proceeds to Step 1003.

In step 1008, it is determined whether or not ψ ′ _max is larger than a second threshold value ψ ′ _th1 larger than ψ ′ _th0 . If YES, the process moves to step 1009, and if NO, the process moves to step 1003.

  The driver characteristic change control operation based on the flowchart of FIG. 10 is the same as that in which the steering angle θ of the flowchart of FIG. 3 is replaced with the yaw rate ψ ′. By the above processing, in step 1011, the actual yaw rate ψ Steering characteristics of the driver with a high correlation with 'can be obtained, and the steering characteristics can be estimated with high accuracy.

Next, the effect will be described.
In the vehicle steering device of Reference Example 2 , in addition to the effects (1) and (2) of the first embodiment, the effects listed below can be obtained.

( 9 ) Since the driver characteristic determining means 110a determines the steering characteristic based on the relationship between the steering angle of the steering wheel 101 and the yaw rate of the vehicle, the driver determines the change in the steering reaction force from the relationship between the steering angle and the yaw rate. It can be determined whether or not the driver grasps the road surface, and an appropriate steering reaction force according to the steering characteristics of the driver can be added.

( 10 ) The driver characteristic determining means 110a determines the steering characteristic based on the tendency of the steering history when the maximum value of the yaw rate exceeds a predetermined value. The characteristics can be determined, and it can be determined whether or not the driver knows the road surface condition more accurately.
[Reference Example 3]

The vehicle steering apparatus of Reference Example 3 differs from Example 1 in that the steering characteristics of the driver are determined based on the relationship between the steering angle and the force applied in the rack axial direction of the steering rack. Since the configuration is the same as that of the first embodiment, description of the configuration is omitted.

FIG. 11 is a control block diagram of the control device 110 of Reference Example 3. The force in the rack axial direction of the steering rack detected by the rack axial force sensor 106 is input to the driver characteristic determining unit 110a. Based on the steering angle and the rack axial force, the driver characteristic determination unit 110a determines whether the driver changes the steering amount in accordance with the change in the steering reaction force due to the change in the rack axial force.

Next, the operation will be described.
[Driver characteristic change control processing]
FIG. 12 is a flowchart showing the flow of the driver characteristic change control process executed by the control device 110 of Reference Example 3 , and each step will be described below. Step 1201, step 1202, and step 1209 to step 1212 perform the same processing as step 301, step 302, and step 309 to step 312 of the flowchart shown in FIG.

  In step 1203, the steering angle θ is input from the steering angle sensor 104, the steering torque T is input from the steering torque sensor 103, and the rack axial force F is input from the rack axial force sensor 106, and the process proceeds to step 1204.

In step 1204, it is determined whether or not the absolute value | F | of the rack axial force F is smaller than the threshold value _Fth0 . If YES, the process proceeds to step 1205. If NO, the process proceeds to step 1206.

In step 1205, F _{max is set} to F _th0, and the process _proceeds to step 1206.

In step 1206, it is determined whether or not the absolute value | F | of the rack axial force F is equal to or greater than _Fmax . If YES, the process proceeds to step 1207, and if NO, the process proceeds to step 1208.

In step 1207, the current absolute value of the rack axial force F is set to F _max , and the process proceeds to step 1203.

In step 1208, it is determined whether F _max is greater than a second threshold value F _{th1 that is} greater than F _th0 . If YES, the process proceeds to step 1209, and if NO, the process proceeds to step 1203.

  The driver characteristic change control operation based on the flowchart in FIG. 12 is the same as that in which the steering angle θ in the flowchart in FIG. 3 is replaced with the rack axial force F. The steering characteristic of the driver having a high correlation with F can be obtained, and the steering characteristic can be estimated with high accuracy.

Next, the effect will be described.
In the vehicle steering device of Reference Example 3 , in addition to the effects (1) and (2) of the first embodiment, the effects listed below can be obtained.

( 11 ) Since the driver characteristic determining means 110a determines the steering characteristic based on the relationship between the steering angle of the steering wheel 101 and the rack axial force, the driver determines the steering reaction force based on the relationship between the steering angle and the rack axial force. It can be determined whether or not the driver grasps the road surface from the change, and an appropriate steering reaction force according to the steering characteristics of the driver can be added.

( 12 ) Since the driver characteristic determining means 110a determines the steering characteristic based on the tendency of the steering history when the rack axial force becomes a predetermined value or more, the steering characteristic in a situation where the steering characteristic of the driver appears relatively remarkably. It is possible to determine whether the driver is more accurately grasping the road surface condition.

1 is an overall configuration diagram of a vehicle steering apparatus including a steer-by-wire system according to a first embodiment. FIG. 3 is a control block diagram of the control device according to the first embodiment. 3 is a flowchart illustrating a flow of driver characteristic change control processing executed by the control device according to the first embodiment. It is a steering characteristic judgment map of a driver. It is a whole block diagram of the steering device for vehicles provided with the steer-by-wire system of the reference example 1 . It is a control block diagram of the control device of Reference Example 1 . 6 is a flowchart showing a flow of driver characteristic change control processing executed by the control device of Reference Example 1 ; Ru overall configuration diagram der of a vehicle steering apparatus having a steer-by-wire system of Reference Example 2. It is a control block diagram of the control device of Reference Example 2 . 10 is a flowchart showing a flow of driver characteristic change control processing executed by the control device of Reference Example 2 . It is a control block diagram of the control device of Reference Example 3 . 14 is a flowchart showing a flow of driver characteristic change control processing executed by the control device of Reference Example 3 ;

DESCRIPTION OF SYMBOLS 101 Steering wheel 102 Steering reaction force actuator 103 Steering torque sensor 104 Steering angle sensor 105 Front wheel 106 Rack axial force sensor 107 Steering gear 108 Steering actuator 109 Steering angle sensor 110 Controller 110a Driver characteristic judgment means 110b Steering reaction force characteristic change means 110c Steering reaction force calculation means 110d Steering reaction force command value calculation means 111 Vehicle speed sensor 112 Car navigation system 113 Yaw rate sensor

Claims (1)

Steering operation means mechanically separated from the steering device for steering the steered wheels;
A steering actuator for driving the steering device;
A steering reaction force actuator that applies a steering reaction force to the steering operating means,
Steering angle detection means for detecting a steering angle of the steering operation means;
Steering torque detecting means for detecting the steering torque of the driver;
Road surface reaction force detecting means for detecting a road surface reaction force applied to the steering wheel from the road surface;
In a vehicle steering apparatus comprising:
Storage means for storing the relationship between the steering angle and the steering torque as a steering history;
Driver characteristic determination means for determining whether the distribution tendency of the steering angle with respect to the steering torque is in direct proportion or in inverse proportion when the relationship between the steering angle and the steering torque in the stored steering history is plotted in two-dimensional coordinates ;
When it is determined that the steering angle distribution tendency with respect to the steering torque is in direct proportion, the steering reaction force characteristic of the steering reaction force actuator is changed so that the steering reaction force reflecting the detected road surface reaction force is applied. A steering reaction force characteristic changing means for changing a steering reaction force characteristic of the steering reaction force actuator so that a steering reaction force that does not reflect the detected road reaction force is applied when it is determined to be inversely proportional ;
A vehicle steering apparatus characterized by comprising:

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