JP2001088723A - Steering device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain generation of feeling of disorder given to a driver when the driver feels a different steering auxiliary force to a deviation of same horizontal position. SOLUTION: A reference control torque T0 is set acording to an escape from a target locus by multiplying a future lateral deviation dyl by a control gain K in Step S7. A road surface frictional coefficient μ is estimationwise computed from a vehicle speed V in Step S8. Self-aligning compensation torque T1 is computed from the coefficient μ, the vehicle speed V and a steering angel δin Step S9. A total control torque is set by adding the reference torque T0 to the SAT compensation torque T1 in Step S10. A total control torque T is output to a steering actuator 7 in Step S11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering apparatus for a vehicle that assists in steering a steering apparatus so that a traveling locus of the vehicle approaches a target locus.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 7-81602 describes a method of calculating a lateral deviation of a vehicle with respect to a reference position of a road and a deflection angle of the vehicle with respect to a road ahead based on image information captured by a camera. A key plane system that sets a target steering angle so as to reduce both the deviation and the declination and assists the steering is described.

[0003]

However, in the above prior art, the self-aligning torque (the turning mechanism is intended to return to the straight running state) depending on the running conditions such as the vehicle speed and the steering angle and the running environment such as straight running and turning. Since the same steering assist force is applied despite different torques, for example, the steering felt by the driver when the steering assist force is applied in the same direction as the self-aligning torque or when the steering assist force is applied in the opposite direction. There is a possibility that the assisting force is different and the driver feels strange.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle steering apparatus that suppresses a driver's discomfort caused by feeling different steering assist forces for the same lateral position deviation.

[0005]

In order to achieve the above object, a steering apparatus for a vehicle according to the present invention comprises: a steering assist means for applying a steering assist force to a steering apparatus of a vehicle; Lateral position detecting means for detecting a lateral position, traveling state detecting means for detecting a traveling state related to a self-aligning torque acting on a steering mechanism of the own vehicle,
Control means for controlling the steering assist means so that the lateral position approaches a predetermined traveling locus, based on the lateral position and the traveling state detected by the lateral position detecting means and the traveling state detecting means, The control means corrects the control amount to the steering assist means in accordance with the magnitude and direction of the self-aligning torque for the same lateral position deviation.

Preferably, when the lateral position deviation occurs in the same direction as the steering angle, the control means reduces the control amount for the same lateral position deviation amount as the steering angle increases.

Preferably, when the deviation of the lateral position occurs in the direction opposite to the steering angle,
As the steering angle increases, the control amount for the same lateral position deviation amount increases.

Preferably, when the lateral position deviation occurs in the same direction as the steering angle, the control means reduces the control amount for the same lateral position deviation amount as the vehicle speed increases.

[0009] Preferably, when the deviation of the lateral position occurs in a direction opposite to a steering angle, the control means may include:
As the vehicle speed increases, the control amount for the same lateral position deviation amount increases.

[0010]

As described above, according to the first aspect of the present invention, for the same lateral position deviation amount, the control amount to the steering assist means is controlled according to the magnitude and direction of the self-aligning torque. By performing the correction, it is possible to suppress the driver's discomfort caused by feeling different steering assist forces for the same lateral position deviation.

According to the second aspect of the present invention, when a lateral position deviation occurs in the same direction as the steering angle, the larger the steering angle, the smaller the control amount for the same lateral position deviation amount is. By feeling a large steering assist force in the same direction as the direction in which the self-aligning torque acts, it is possible to suppress a sense of discomfort given to the driver.

According to the third aspect of the invention, when a lateral position deviation occurs in the direction opposite to the steering angle, the larger the steering angle is, the larger the control amount for the same lateral position deviation amount is. It is possible to assist the driver's steering in the direction opposite to the direction in which the self-aligning torque acts.

According to the fourth aspect of the invention, when a lateral position deviation occurs in the same direction as the steering angle, the higher the vehicle speed, the smaller the control amount for the same lateral position deviation amount is. By feeling a large steering assist force in the same direction as the direction in which the lining torque acts, it is possible to suppress a sense of incongruity to the driver caused by feeling a large steering assist force.

According to the fifth aspect of the present invention, when a lateral position deviation occurs in the direction opposite to the steering angle, the greater the vehicle speed, the greater the control amount for the same lateral position deviation amount. It is possible to assist the driver's steering in the direction opposite to the direction in which the lining torque acts.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example in which a vehicle steering apparatus according to the present invention is mounted on a typical automobile will be described in detail with reference to the accompanying drawings.

The vehicle steering system according to the present embodiment sets a current travel locus and a target locus of an automobile, and forcibly returns (converges) to the target locus when the travel locus deviates from the target locus. A steering assist force is applied to the steering device, a steering assist force is forcibly applied to the steering device so as not to perform a steering operation in a departure direction when a state likely to deviate from the target trajectory is detected, It includes one that applies a steering assist force to the steering device so as to trace, or one that automatically controls the steering device so as to trace the target trajectory. [First Embodiment] FIG. 1 is a diagram showing a system configuration of a vehicle equipped with a vehicle steering system according to a first embodiment.

In the automobile 1 shown in FIG. 1, reference numeral 2 denotes a controller for controlling the entire steering system. Reference numeral 3 denotes a CCD (Charge Coupled) for imaging an imaging area 3F in front of the automobile 1.
Device) An imaging device such as a camera. 6 is a car 1
The vehicle speed sensor detects the vehicle speed of the vehicle. Reference numeral 7 denotes an example of a mechanism for actually steering the vehicle 1, which is a steering actuator such as a motor for driving a steering shaft connected to a steering wheel 8 so as to apply a steering assist force, and 9 denotes a wheel speed v of the vehicle 1. The wheel speed sensor 11 for detecting is a steering angle sensor for detecting the steering of the steering wheel by the driver.

Reference numeral 10 denotes preceding road information (for example, obstacles (stopped vehicles, scattered cargo, etc.) on the road ahead of the vehicle) obtained from roads around the own vehicle (transmission / reception facilities provided on the road). The vehicle-to-vehicle communication device receives information on a traveling road environment when the vehicle is running, information on a following traveling state such as whether the vehicle is traveling in a row while maintaining a predetermined inter-vehicle distance with a preceding vehicle.

FIG. 2 is a control block diagram of the vehicle steering system according to the first embodiment. Each block shown inside the controller 2 expresses a control operation performed by the controller 2 by a flow of an input signal. I have. The actual control process by the controller 2
According to software stored in an OM (not shown) or the like,
It is executed by a CPU (not shown) (details will be described later). FIG. 3 shows a vehicle 1 traveling on a curved road and a vehicle traveling road R.
FIG. 5 is a diagram for explaining a positional relationship with the suffix; FIG. 4 is a diagram illustrating the positional relationship between the vehicle 1 traveling on a straight road and the vehicle traveling road R.

As shown in FIG. 2, the controller 2 estimates the target trajectory Y1 to which the automobile 1 should travel, based on the image of the front image pickup area 3F taken by the CCD camera 3 by a general method, Detection of the deviation dy0 and yaw angle yaw, detection of the vehicle speed V by the vehicle speed sensor, detection of the steering angle δ by the steering angle sensor, detection of the wheel v by the wheel speed sensor, and estimation calculation of the forward gaze distance L from the vehicle speed V are performed. Further, the controller 2
The road friction coefficient μ is estimated from the wheel speed v, and the self-aligning (SAT) correction torque T1 is calculated from the road friction coefficient μ, the vehicle speed V, and the steering angle δ. Further, the controller 2 calculates a future lateral deviation dy1 from the target trajectory Y1, the lateral deviation dy0, the yaw angle yaw, and the forward fixation distance L, sets a control gain K from a control gain map (not shown), and sets the future lateral deviation dy1. Control torque T according to deviation of target locus from control gain K
In addition to setting 0, the SAT correction torque T1 is added to the reference control torque T0 to set the total torque T to be output to the steering actuator 7.

During traveling on a curved road shown in FIG. 3, the current lateral position y0 of the vehicle, the current lateral position Y0 of the target locus (center of the lane), and the lateral position of the vehicle after the vehicle arrival time T in the global coordinate system. Assuming that the position is y1 and the lateral position of the target locus is Y1, the deviation (future lateral deviation) dy1 between the target locus after the vehicle arrival time T and the lateral position of the own vehicle is calculated as follows. Note that the vehicle arrival time T represents an estimated time required for the host vehicle to reach the forward fixation point.

Dy1 = Y1-y1 = (ΔY + Y0) − (y0−yaw × L) = ΔY + (Y0−y0) + yaw × L = ΔY + (dy0 + yaw × L) where L = T × V, ΔY is the amount of change in the lateral position of the target locus. Further, while traveling on a straight road shown in FIG. 4, the deviation (future lateral deviation) dy1 between the target locus after the vehicle arrival time T and the lateral position of the own vehicle is calculated as follows. You. In FIG. 4, the same reference numerals as those in FIG. 3 are referred to.

Dy1 = Y1-y1 = Y0− (y0−yaw × L) = (ΔY−y0) + yaw × L = (dy0 + yaw × L) where L = T × V, Y1 = Y0 The characteristic curve set in the control gain map may be set such that the control gain K increases as the lateral deviation dy1 increases in the future.

Next, the control procedure of the controller 2 will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 5 is a flowchart showing a control procedure of the vehicle steering system according to the first embodiment. FIG. 6 is a diagram showing the relationship between the deviation direction of the future lateral deviation dy1, the steering direction, the sign of the reference control torque, the sign of the self-aligning torque, and the total control torque.

As shown in FIG. 5, in step S1, the controller 2 stores the image picked up by the CCD camera 3, the detection signals from the vehicle speed sensor 6, the wheel speed sensor 9 and the steering angle sensor 11 in a RAM (not shown). Store and update to the latest one.

In step S2, a forward fixation distance L, which is the distance from the driver's viewpoint to the front fixation point, is estimated and calculated.
Here, the point where the driver gazes ahead is generally
It is known that the slower the vehicle speed, the closer it is, and the faster it is, the farther it is. Therefore, the forward fixation distance L is
A look-up table (LUT) is stored in advance in a ROM or the like (not shown) for a characteristic curve of the front gaze distance L that increases according to the vehicle speed V.
And the LUT may be obtained by referring to the LUT according to the vehicle speed V detected by the vehicle speed sensor 6.

In step S3, the lateral deviation dy0 is detected, in step S4, the yaw angle yaw is detected, in step S5, the target locus Y1 is estimated and calculated, and in step S6, the future lateral deviation is calculated.
dy1, that is, a deviation between the target trajectory Y1 and the estimated travel trajectory y1 is calculated. The future lateral deviation dy1 is defined as + for a rightward shift and − for a leftward shift with respect to the center of the lane.

In step S7, a reference control torque T0 according to the deviation of the target locus is set by multiplying the future lateral deviation dy1 by the control gain K (T0 = dy1 × K, where K is a negative number). The reference control torque T0 is defined as + for the right rotation torque and-for the left rotation torque.

In step S8, a road surface friction coefficient μ is estimated and calculated from the wheel speed v.

In step S9, the road surface friction coefficient μ, the vehicle speed
A self-aligning (SAT) correction torque T1 is calculated from V and the steering angle δ (T1 = K1 * δ * V * μ, where K1 is a positive number). The SAT correction torque T1 is proportional to the steering angle δ, the vehicle speed V, and the road surface friction coefficient μ. Here, the steering angle δ is + for right steering and − for left steering.

In step S10, the reference torque T0 is set to SA.
The total control torque T is set by adding the T correction torque T1 (T = T0 + T1).

In step S11, a total control torque T is output to the steering actuator 7.

In the first embodiment, as shown in FIG. 6, when a future lateral deviation dy1 occurs in the same direction as the steering angle δ, the larger the steering angle δ, the more the same direction as the steering assist force applying direction. Since a large self-aligning torque acts (in the direction opposite to the steering angle δ), the self-aligning correction torque T1 is subtracted from the reference control torque T0, so that the total control torque T is corrected to be small.

The future lateral deviation dy in the direction opposite to the steering angle δ
When 1 occurs, the larger the steering angle δ, the larger the self-aligning torque acts in the direction opposite to the direction in which the steering assist force is applied (in the same direction as the steering angle δ), so the self-aligning correction is applied to the reference control torque T0. Correction is made so that the total control torque T is increased by adding the torque T1.

In the same direction as the steering angle δ, the future lateral deviation dy1
When the vehicle speed V increases, a larger self-aligning torque acts in the same direction as the direction in which the steering assist force is applied (in the direction opposite to the steering angle δ), so that the self-aligning correction torque is changed from the reference control torque T0. Correction is made so that T1 is subtracted and the total control torque T becomes smaller. When a lateral deviation dy1 is generated in the direction opposite to the steering angle δ in the future, as the vehicle speed V increases, a larger self-aligning torque acts in the direction opposite to the direction in which the steering assist force is applied (in the same direction as the steering angle δ). Therefore, the self-aligning correction torque T1 is added to the reference control torque T0, so that the total control torque T is corrected so as to increase.

Therefore, when a steering assist force is to be applied in the same direction as the lateral deviation dy1 in the future, the control torque T is reduced, so that a large steering assist force is sensed in the same direction as the action direction of the self-aligning torque. It is possible to suppress a sense of discomfort given to the driver.

When a steering assist force is applied in the direction opposite to the lateral deviation dy1 in the future, the control torque T is increased to assist the driver in steering in the direction opposite to the direction in which the self-aligning torque acts. it can. [Second Embodiment] In the second embodiment, the road-to-vehicle communication device 1
The direction of the disturbance such as a cross wind (in the case of a cross wind, the direction of the base point of the cross wind with respect to the own vehicle) and the magnitude are detected from the road information obtained from 0, and the control torque is applied when the steering assist force is applied in the same direction as the disturbance. By reducing T, it is possible to suppress a sense of discomfort to the driver caused by feeling a large steering assist force in the same direction as the disturbance. When the steering assist force is applied in the direction opposite to the disturbance, the control torque T is increased to assist the driver in steering against the disturbance.

FIG. 7 is a control block diagram of the vehicle steering system according to the second embodiment.

As shown in FIG. 7, the controller 2 calculates a target trajectory Y1 to be advanced by the car 1 based on the image of the front image pickup area 3F picked up by the CCD camera 3 by a general method. Detection of deviation dy0 and yaw angle yaw, detection of vehicle speed V by vehicle speed sensor, forward gaze distance L from vehicle speed V
Is calculated. Also, the controller 2 is a road-vehicle communication device 1.
The direction and magnitude of the disturbance are detected from the road information obtained from 0, and the rightward control gain is obtained from the direction and magnitude of the disturbance.
Set KR and left control gain KL. Further, the controller 2
Is the target trajectory Y1, lateral deviation dy0, yaw angle yaw, forward gaze distance
A future lateral deviation dy1 is calculated from L, and a control torque T to be output to the steering actuator 7 is set from the future lateral deviation dy1, the rightward control gain KR, and the leftward control gain KL.

FIGS. 8 and 9 are flowcharts showing a control procedure of the vehicle steering system according to the second embodiment. FIG.
Is a rightward control gain map based on the direction and magnitude of the crosswind. FIG. 11 is a leftward control gain map based on the direction and magnitude of the crosswind.

As shown in FIG. 8, in step S21,
The controller 2 stores the image captured by the CCD camera 3, the detection signals from the vehicle speed sensor 6, the wheel speed sensor 9 and the steering angle sensor 11, and the road information obtained from the road-vehicle communication device 10 in a RAM (not shown). Update to the latest.

In step S22, a forward fixation distance L, which is the distance from the driver's viewpoint to the front fixation point, is estimated and calculated. Here, it is known that the point at which the driver gazes forward is generally directed closer as the vehicle speed is slower, and farther away as the vehicle speed is faster. Therefore, the forward fixation distance L
Is obtained by previously storing a characteristic curve of the front gaze distance L that becomes longer according to the vehicle speed V in a ROM (not shown) or the like using a look-up table (L
UT), and the LUT is stored in the vehicle speed sensor 6.
May be obtained by referring to the vehicle speed V detected by the above.

In step S23, a lateral deviation dy0 is detected,
In step S24, the yaw angle yaw is detected, and in step S2
In step 5, the target trajectory Y1 is estimated and calculated, and in step S26, the future lateral deviation dy1, that is, the deviation between the target trajectory Y1 and the estimated travel trajectory y1 is calculated. The future lateral deviation dy1 is defined as + for a rightward deviation from the center of the lane and-for a leftward deviation.

In step S27, the direction of the cross wind is detected as a disturbance from the road information of the road-to-vehicle communication device 10.

In step S28, the direction F of the cross wind is detected as a disturbance from the road information of the road-to-vehicle communication device 10.

In step S29, a rightward control gain KR and a leftward control gain KL are set based on the direction and magnitude of the crosswind from the crosswind control gain maps shown in FIGS.

Here, as a characteristic curve set in the rightward control gain map shown in FIG. 10, the magnitude of the crosswind is constant up to a predetermined value A in the left and right direction, and the control gain KR increases as the size increases in the leftward direction thereafter. If the control gain KR is set to decrease as the value increases in the right direction,
The rightward control gain KR increases as the crosswind to the left increases, so that the rightward control torque T generated by the steering actuator 7 increases. Conversely, the rightward control gain KR decreases as the crosswind to the right increases, so that the rightward control torque T generated by the steering actuator 7 decreases.

As a characteristic curve set in the leftward control gain map shown in FIG. 11, the magnitude of the crosswind is constant up to a predetermined value A in the left and right direction, and then the control gain KL decreases as the size increases in the leftward direction. If the control gain KL is set so as to increase as it increases in the right direction, the control gain KL in the left direction increases as the crosswind in the right direction increases, so that the control torque in the left direction generated by the steering actuator 7 is increased. T increases. Conversely, the leftward control gain KL decreases as the crosswind to the left increases, so that the control torque T generated by the steering actuator 7 decreases.

Therefore, when the steering assist force is applied in the same direction as the cross wind, the control torque T is reduced to reduce
A sense of discomfort to the driver caused by feeling a large steering assist force in the same direction as the disturbance is suppressed. When the steering assist force is applied in the direction opposite to the crosswind, the control torque T is increased to assist the driver in steering against disturbance.

In step S30 shown in FIG. 9, it is determined whether or not the vehicle shifts rightward by determining whether or not the future lateral deviation dy1 is a positive value (dy1> 0?).

If the future lateral deviation dy1 is a positive value in step S30 (YES in step S30), the flow advances to step S31, and if it is a negative value or otherwise (N in step S30).
O) Go to step S32.

In step S31, since the vehicle shifts rightward, the control torque T is set by multiplying the future lateral deviation dy1 by the leftward control gain KL (T = dy1 × KL).

On the other hand, in step S32, the future lateral deviation dy
By determining whether or not 1 is a negative value, it is determined whether or not the vehicle shifts leftward (dy1 <0?).

If the future lateral deviation dy1 is a negative value in step S32 (YES in step S32), the vehicle shifts to the left in step S33, so that the future lateral deviation dy1 is multiplied by the rightward control gain KR. Set the control torque T (T = d
y1 x KR).

If the future lateral deviation dy1 is not a negative value in step S32 (NO in step S32), it is determined that the future lateral deviation dy1 is zero, and the routine returns without intervening in the steering assist control.

In step S34, a control torque T is output to the steering actuator 7. [Third Embodiment] In the third embodiment, at the time of setting the control torque T, the direction and magnitude of a disturbance such as a cross wind are detected based on road information obtained from the road-to-vehicle communication device 10, and are set in the same direction as the disturbance. When the steering assist force is applied, the degree of intervention in the steering assist control is reduced (the width of the dead zone is widened to make it difficult to intervene in the control), so that a large steering assist force is sensed in the same direction as the disturbance. The discomfort to the elderly. Further, when the steering assist force is applied in the direction opposite to the disturbance, the degree of intervention in the steering assist control is increased (the dead zone width is narrowed to facilitate the intervention in the control), so that the steering of the driver against the disturbance is performed. To help.

FIG. 12 is a control block diagram of the vehicle steering system according to the third embodiment.

As shown in FIG. 12, the controller 2 comprises a CCD
Based on the image of the front imaging area 3F captured by the camera 3, estimation of the target trajectory Y1 to which the car 1 should travel, detection of the lateral deviation dy0 and yaw angle yaw, by a general method,
Detection of vehicle speed V by vehicle speed sensor, distance of gaze ahead from vehicle speed V
Perform the estimation calculation of L. The controller 2 detects the direction and magnitude of the disturbance based on the road information obtained from the road-to-vehicle communication device 10 and determines the rightward dead zone width based on the direction and magnitude of the disturbance.
Set WR and left dead zone width WL. Further, the controller 2
Calculate the future lateral deviation dy1 from the target trajectory Y1, lateral deviation dy0, yaw angle yaw, and forward fixation distance L, and calculate future lateral deviation dy1 and control gain.
A control torque T to be output to the steering actuator 7 is set from K, the right dead zone width WR, and the left dead zone width WL.

FIGS. 13 and 14 are flowcharts showing the control procedure of the vehicle steering system according to the third embodiment. FIG. 15 is a rightward dead zone width map based on the direction and magnitude of the crosswind. FIG. 16 is a leftward dead zone width map based on the direction and magnitude of the crosswind.

As shown in FIG. 13, in a step S41, the controller 2 controls the image taken by the CCD camera 3,
The detection signals from the vehicle speed sensor 6, the wheel speed sensor 9, and the steering angle sensor 11, and the road information obtained from the road-to-vehicle communication device 10 are stored in a RAM (not shown) and updated to the latest one.

In step S42, a forward fixation distance L, which is the distance from the driver's viewpoint to the front fixation point, is estimated and calculated. Here, it is known that the point at which the driver gazes forward is generally directed closer as the vehicle speed is slower, and farther away as the vehicle speed is faster. Therefore, the forward fixation distance L
Is obtained by previously storing a characteristic curve of the front gaze distance L that becomes longer according to the vehicle speed V in a ROM (not shown) or the like using a look-up table (L
UT), and the LUT is stored in the vehicle speed sensor 6.
May be obtained by referring to the vehicle speed V detected by the above.

In step S43, the lateral deviation dy0 is detected,
In step S44, the yaw angle yaw is detected, and in step S4
In step S5, the target trajectory Y1 is estimated, and in step S46, the future lateral deviation dy1, that is, the deviation between the target trajectory Y1 and the estimated travel trajectory y1, is calculated. The future lateral deviation dy1 is defined as + for a rightward deviation from the center of the lane and-for a leftward deviation.

In step S47, the direction of the cross wind is detected as a disturbance from the road information of the road-vehicle communication device 10.

In step S48, the direction F of the cross wind is detected as a disturbance from the road information of the road-to-vehicle communication device 10.

In step S49, the rightward dead zone width WKR and the leftward dead zone width WL are determined based on the direction and magnitude of the crosswind from the crosswind deadband maps shown in FIGS.
Set.

Here, the characteristic curve set in the rightward dead zone width map shown in FIG. 15 is that the size of the crosswind is constant up to a predetermined value B in the left and right direction, and the dead zone width WR becomes smaller as the size becomes larger leftward thereafter. If the dead zone width WR is set to be larger as it increases to the right, the right dead zone width WR becomes smaller as the crosswind to the left increases, so that it is necessary to intervene in the steering assist control to the right. It will be cool. Conversely, the rightward dead zone width WR increases as the crosswind to the right increases, making it difficult to intervene in the steering assist control to the right.

The characteristic curve set in the leftward control gain map shown in FIG. 16 shows that the magnitude of the crosswind is constant up to a predetermined value B in the left-right direction, and the dead zone width WL increases as the size increases leftward thereafter. If the dead zone width WL is set to be smaller as it increases in the right direction, the larger the crosswind in the right direction, the smaller the dead zone width in the left direction.Thus, it becomes easier to intervene in the steering assist control in the left direction. . Conversely, the leftward dead zone width WL increases as the crosswind to the left increases, so that it becomes difficult to intervene in the steering assist control to the left.

Therefore, when the steering assist force is applied in the same direction as the crosswind, it is difficult to intervene in the control, thereby suppressing a feeling of discomfort to the driver given by feeling the large steering assist force in the same direction as the disturbance. . Further, when the steering assist force is applied in the direction opposite to the crosswind, the driver assists the steering against the disturbance by facilitating the intervention in the control.

In step S50 shown in FIG. 14, it is determined whether or not the own vehicle shifts rightward by determining whether or not the future lateral deviation dy1 is a positive value (dy1> 0?).

If the future lateral deviation dy1 is a positive value in step S50 (YES in step S50), the flow advances to step S51, and if it is a negative value or otherwise (N in step S50).
O) Go to step S52.

In step S51, since the vehicle shifts rightward, the control torque T is set by multiplying a value obtained by subtracting the leftward dead zone width WL from the future lateral deviation dy1 by the control gain K (T = (dy1 -WL) × K).

On the other hand, in step S52, the future lateral deviation dy
By determining whether or not 1 is a negative value, it is determined whether or not the vehicle shifts leftward (dy1 <0?).

If the future lateral deviation dy1 is a negative value in step S52 (YES in step S52), the value of the future lateral deviation dy1 minus the right dead zone width WR is subtracted from the future lateral deviation dy1 in step S53 because the vehicle shifts leftward in step S53. Is multiplied by a control gain K to set a control torque T (T = (dy1-WR) × K).

If the future lateral deviation dy1 is not a negative value in step S52 (NO in step S52), it is determined that the future lateral deviation dy1 is zero, and the routine returns without intervening in the steering assist control.

In step S54, a control torque T is output to the steering actuator 7.

The present invention can be applied to a modification or a modification of the above embodiment without departing from the gist of the invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system configuration of a vehicle equipped with a vehicle steering device according to a first embodiment.

FIG. 2 is a control block diagram of the vehicle steering system according to the first embodiment.

FIG. 3 is a diagram illustrating a positional relationship between an automobile 1 traveling on a curved road and a vehicle traveling road R.

FIG. 4 is a diagram illustrating a positional relationship between the vehicle 1 traveling on a straight road and a vehicle traveling road R.

FIG. 5 is a flowchart illustrating a control procedure of the vehicle steering system according to the first embodiment.

FIG. 6 is a diagram illustrating a relationship between a shift direction of a future lateral deviation dy1, a steering direction, a sign of a reference control torque, a sign of a self-aligning torque, and a total control torque in the first embodiment.

FIG. 7 is a control block diagram of a vehicle steering system according to a second embodiment.

FIG. 8 is a flowchart illustrating a control procedure of the vehicle steering system according to the second embodiment.

FIG. 9 is a flowchart illustrating a control procedure of the vehicle steering system according to the second embodiment.

FIG. 10 is a rightward control gain map based on the direction and magnitude of the crosswind.

FIG. 11 is a leftward control gain map based on the direction and magnitude of the crosswind.

FIG. 12 is a control block diagram of a vehicle steering system according to a third embodiment.

FIG. 13 is a flowchart illustrating a control procedure of the vehicle steering system according to the third embodiment.

FIG. 14 is a flowchart illustrating a control procedure of the vehicle steering system according to the third embodiment.

FIG. 15 is a rightward dead zone width map based on the direction and magnitude of crosswind.

FIG. 16 is a leftward dead zone width map based on the direction and magnitude of the crosswind.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automobile 2 Controller 3 CCD camera 6 Vehicle speed sensor 7 Steering actuator 9 Wheel speed sensor 10 Roadside-vehicle communication device 11 Steering angle sensor

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenichi Okuda 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Masafumi Yamamoto 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Masaki Chiba 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima F-term (reference) 3D032 CC04 CC08 DA03 DA23 DA24 DA27 DA32 DA71 DA82 DA88 DC08 DC22 DC40 DD02 DD06 EA01 EB11 GG01

Claims (5)

[Claims] 1. A steering assisting means for applying a steering assisting force to a steering device of a vehicle; a lateral position detecting means for detecting a lateral position of a host vehicle in a traveling lane; Traveling state detecting means for detecting a traveling state related to lining torque; and a lateral position and a traveling state detected by the lateral position detecting means and the traveling state detecting means, so that the lateral position approaches a predetermined traveling locus. Control means for controlling the steering assist means, wherein the control means corrects the control amount to the steering assist means according to the magnitude and direction of the self-aligning torque for the same lateral position deviation. A steering device for a vehicle. 2. The control means according to claim 1, wherein when the lateral position deviation occurs in the same direction as the steering angle, the control amount for the same lateral position deviation amount decreases as the steering angle increases. The vehicle steering apparatus according to claim 1, wherein 3. The control means according to claim 1, wherein when the lateral position deviation occurs in a direction opposite to a steering angle, the control amount for the same lateral position deviation amount increases as the steering angle increases. The vehicle steering apparatus according to claim 1, wherein 4. When the lateral position deviation occurs in the same direction as the steering angle, the control means may:
2. The vehicle steering system according to claim 1, wherein a control amount for the same lateral position deviation amount is reduced. 5. The control means according to claim 1, wherein when the lateral position deviation occurs in a direction opposite to a steering angle, the control amount for the same lateral position deviation amount increases as the vehicle speed increases. Item 2. The vehicle steering apparatus according to Item 1.