JP2008308079A - Car body slip angle control device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize the car body slip angle sensible to a driver. <P>SOLUTION: Such a car body slip angle gain Gβ as to make difference between the vehicle advance direction and the vehicle longitudinal direction insensible to the driver is computed using a formula based on a yaw angular speed gain Gr predetermined in accordance with the car speed, a vehicle longitudinal direction distance x from a reference position of the driver's eye to the border between the driver's view and the dead angle, and the car speed v detected by a car speed sensor 12. The steering angle for each of front and rear wheels of the vehicle is controlled by a steering angle control part 28 to provide the car body slip angle obtained by the computed car body slip angle gain Gβ. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle body slip angle control device and program, and more particularly, to a vehicle body slip angle control device and program for controlling a vehicle body slip angle of a vehicle.

Conventionally, as a characteristic setting method in an active front and rear wheel steering control vehicle in which characteristics of a vehicle body slip angle and a yaw angular velocity can be arbitrarily set from a steering angle of a driver, “side slip zeroing control” is known (Non-Patent Document 1). ). In this side slip zeroing control, the rear wheel rudder angle with respect to the front wheel rudder angle is controlled so that the vehicle body slip angle is always 0, so that ideal vehicle characteristics with excellent maneuverability can be obtained.
Kayaba Industry Co., Ltd., “Automotive Steering System and Maneuverability”, P196, Sankaido, 1996

  However, the technique described in Non-Patent Document 1 has a problem that the driver feels uncomfortable because the vehicle motion is optimized as mechanical characteristics.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle body slip angle control device and program capable of optimizing the vehicle body slip angle felt by the driver.

  In order to achieve the above object, a vehicle body slip angle control device according to the present invention includes a vehicle speed sensor that detects a vehicle speed, a yaw angular velocity gain that is predetermined according to the vehicle speed, and a vehicle front-rear direction to a boundary between a driver's field of view and a blind spot. A vehicle body slip angle at which the driver does not feel a deviation between the vehicle traveling direction and the vehicle longitudinal direction based on the distance in the direction and the vehicle speed detected by the vehicle speed sensor, or a vehicle body slip angle gain for obtaining the vehicle body slip angle. Calculation means for calculating, and control means for controlling the vehicle such that the vehicle body slip angle calculated by the calculation means or the vehicle body slip angle gain obtained from the vehicle body slip angle gain is obtained. .

  According to the vehicle body slip angle control device of the present invention, the vehicle speed is detected by the vehicle speed sensor, and the vehicle longitudinal direction to the boundary between the driver's field of view and the blind spot is determined by the calculation means according to the vehicle speed. The vehicle body slip angle at which the driver does not feel the difference between the vehicle traveling direction and the vehicle front-rear direction or the vehicle body slip angle gain for obtaining the vehicle body slip angle is calculated based on the vehicle distance and the vehicle speed detected by the vehicle speed sensor. .

  Then, the vehicle is controlled by the control means so that the vehicle body slip angle calculated by the calculation means or the vehicle body slip angle obtained from the vehicle body slip angle gain is obtained.

  Thus, by calculating the vehicle body slip angle at which the driver does not feel the difference between the vehicle traveling direction and the vehicle front-rear direction, or the vehicle body slip angle gain for obtaining the vehicle body slip angle, and controlling the vehicle, The body slip angle you feel can be optimized.

Calculating means according to the present invention, the below (1), it is possible to calculate the vehicle body slip angle gain G _beta.

Where k is a constant, x is a distance in the vehicle front-rear direction from a reference position determined according to the position of the driver's eye to the boundary between the driver's field of vision and blind spot, and G _γ is a yaw angular velocity gain determined in advance according to the vehicle speed. , V are vehicle speeds detected by a vehicle speed sensor.

  Further, the control means according to the present invention can control the steering angles of the front and rear wheels of the vehicle based on the vehicle body slip angle or the vehicle body slip angle gain calculated by the calculation means and the steering angle of the steering. As a result, the steering angle of the front and rear wheels of the vehicle can be controlled to optimize the vehicle body slip angle felt by the driver.

  In addition, the control means according to the present invention uses the gain K of the rear wheel steering angle with respect to the front wheel steering angle determined based on the above equation (1) to set the rear wheel steering angle δr according to the following equation (2). Can be controlled.

However, δ _f is the rudder angle of the front wheel according to the steering angle of the driver, v is the vehicle speed detected by the vehicle speed sensor, x is a reference position determined according to the position of the driver's eyes, and the driver's field of view and blind spot The distance in the vehicle longitudinal direction to the boundary, m is the vehicle mass, C _f is the front wheel cornering power, C _r is the rear wheel cornering power, l is the wheelbase length, l _f is the distance between the front axle and the vehicle center of gravity, and l _r is This is the distance between the rear axle and the vehicle center of gravity.

  As a result, the steering angle of the rear wheel of the vehicle can be controlled to optimize the vehicle body slip angle felt by the driver.

  The yaw angular velocity gain can be determined in advance so as to increase as the vehicle speed increases in the low speed range, to be constant or substantially constant in the medium speed range, and to decrease as the vehicle speed increases in the high speed range.

  The program according to the present invention is based on the yaw angular velocity gain determined according to the vehicle speed, the distance in the vehicle longitudinal direction to the boundary between the driver's field of vision and the dead angle, and the vehicle speed detected by the vehicle speed sensor that detects the vehicle speed. A vehicle body slip angle at which the driver does not feel a difference between the vehicle traveling direction and the vehicle longitudinal direction, or a vehicle body slip angle gain for obtaining the vehicle body slip angle, and the vehicle body calculated by the calculation unit It is characterized by functioning as a control means for controlling a control mechanism for controlling a steering angle of a vehicle wheel so that a slip angle or a vehicle body slip angle obtained from the vehicle body slip angle gain can be obtained.

  According to the program of the present invention, the vehicle front-rear direction from the reference position determined according to the driver's eye position to the boundary between the driver's field of view and the blind spot is determined by the calculation means according to the vehicle speed and the reference position determined according to the driver's eye position. The vehicle body slip angle at which the driver does not feel the difference between the vehicle traveling direction and the vehicle front-rear direction or the vehicle body slip angle gain for obtaining the vehicle body slip angle is calculated based on the vehicle distance and the vehicle speed detected by the vehicle speed sensor. .

  And the control mechanism which controls the steering angle of the wheel of a vehicle is controlled by the control means so that the vehicle body slip angle obtained from the vehicle body slip angle calculated by the calculation means or the vehicle body slip angle gain is obtained.

  As described above, the vehicle body slip angle at which the driver does not feel the difference between the vehicle traveling direction and the vehicle front-rear direction or the vehicle body slip angle gain for obtaining the vehicle body slip angle is calculated to control the steering angle of the vehicle wheels. Thus, the vehicle body slip angle felt by the driver can be optimized.

  As described above, according to the vehicle slip angle control device and program of the present invention, the vehicle slip angle at which the driver does not feel the difference between the vehicle traveling direction and the vehicle longitudinal direction, or the vehicle slip for obtaining the vehicle slip angle. By calculating the angular gain and controlling the vehicle, the vehicle slip angle felt by the driver can be optimized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a case where the present invention is applied to a vehicle control device for an active front and rear wheel steering control vehicle that can arbitrarily set characteristics of a vehicle body slip angle and a yaw angular velocity from a steering angle will be described as an example.

  First, as shown in FIG. 2, rotation about each axis when the vehicle motion axis is the x axis from the center of gravity toward the front of the vehicle, the y axis toward the left of the vehicle, and the z axis upward in the vertical direction. The angular velocities are defined as roll angular velocity, pitch angular velocity, and yaw angular velocity, respectively.

  As shown in FIG. 1, the vehicle control apparatus 10 according to the first embodiment includes a vehicle speed sensor 12 that detects a vehicle speed and a steering angle sensor 14 that detects a steering angle of a steering.

  In addition, the vehicle control device 10 includes a yaw angular velocity gain calculation unit 16 that calculates a yaw angular velocity gain according to the vehicle speed from the vehicle speed sensor 12 based on predetermined characteristics of the vehicle speed and the yaw angular velocity gain, and a yaw angular velocity gain. Based on the yaw angular velocity gain calculated by the calculation unit 16 and the vehicle speed from the vehicle speed sensor 12, the driver does not feel the difference between the vehicle traveling direction and the vehicle longitudinal direction, that is, the vehicle body slip angle that the driver feels is zero. And a vehicle body slip angle gain calculating unit 18 for calculating a vehicle body slip angle gain for obtaining an angle. The yaw angular velocity gain is a gain of the yaw angular velocity with respect to the steering angle, and the vehicle body slip angle gain is a gain of the vehicle body slip angle with respect to the steering angle.

  In addition, the vehicle control device 10 controls the vehicle body to be controlled so that the vehicle body slip angle felt by the driver is 0 based on the steering angle from the steering angle sensor 14 and the vehicle body slip angle gain calculated by the vehicle body slip angle gain calculation unit 18. A target vehicle body slip angle calculation unit 20 that calculates the slip angle, and a yaw angular velocity calculation unit 22 that calculates the yaw angular velocity based on the steering angle from the steering angle sensor 14 and the yaw angular velocity gain calculated by the yaw angular velocity gain calculation unit 16. And.

  The vehicle control device 10 includes a front wheel actuator 24 for controlling the steering angle of the front wheel of the vehicle, a rear wheel actuator 26 for controlling the steering angle of the rear wheel of the vehicle, the vehicle speed from the vehicle speed sensor 12, and the target vehicle body slip. Based on the vehicle body slip angle that is the control target calculated by the angle calculation unit 20 and the yaw angular velocity calculated by the yaw angular velocity calculation unit 22, the steering angle of each of the front and rear wheels is 0 as the vehicle slip angle felt by the driver. A steering angle control unit 28 that controls the driving of the front wheel actuator 24 and the rear wheel actuator 26 is provided so as to obtain the steering angles of the front and rear wheels for obtaining a vehicle body slip angle.

  The whole or each of the yaw angular velocity gain calculating unit 16, the vehicle body slip angle gain calculating unit 18, the target vehicle body slip angle calculating unit 20, the yaw angular velocity calculating unit 22, and the steering angle control unit 28 of the present embodiment is one microcomputer. Various programs including a program for realizing a steering control processing routine to be described later are stored in the memory of the microcomputer.

  Next, a description will be given of the vehicle body slip angle when the vehicle body slip angle felt by the driver is 0 and the driver does not feel the difference between the vehicle longitudinal direction and the vehicle traveling direction.

First, how the driver senses the vehicle body slip angle and the appropriate value will be described. FIG. 3 is a diagram showing a speed vector of the driver's front field of view while turning at a vehicle speed of 144 km / h (40 m / s) and a lateral acceleration of 3 m / s ² . Further, a trace line when a vehicle body slip angle equivalent to a 2WS (two-wheel steering) vehicle is attached and a trace line when the vehicle body slip angle = 0 are shown.

  The entry angle when the trace line with a vehicle body slip angle equivalent to 2WS vehicles enters the boundary between the driver's forward view and the blind spot formed by the hood or instrument panel, that is, the direction when the trace line disappears from view The corners are positive and the driver feels that the longitudinal direction of the vehicle is inward with respect to the trace line.

  On the other hand, the entry angle of the trace line when the vehicle body slip angle = 0 is negative and the vehicle front-rear direction is outside the trace line even though the vehicle body slip angle at the center of gravity is 0. I feel it is suitable. That is, the driver feels a difference between the vehicle longitudinal direction and the vehicle traveling direction.

  This indicates that the vehicle body slip angle felt visually by the driver is different from the vehicle body slip angle at the center of gravity, and in order to realize a comfortable vehicle motion based on human motion sensing characteristics, It is important to pay attention to the vehicle body slip angle felt by the driver and to design so as not to feel the deviation between the vehicle longitudinal direction and the vehicle traveling direction.

  Here, in order to derive an appropriate value of the vehicle body slip angle visually sensed in the steady turning state, an experiment using a visual simulator excluding information other than vision and a transient response of turning is performed, and the experimental result shown in FIG. 4 is obtained. It was.

  In the experiment, an image of a subject traveling on a course of a constant radius (200R) is shown to the subject, and the vehicle body slip angle is changed as a parameter. The vehicle body slip angle was investigated when there was no discrepancy between the vehicle direction and the vehicle traveling direction. The broken line in FIG. 4 represents the vehicle body slip angle characteristic of the 2WS vehicle, and the vehicle longitudinal direction changes from outward to inward as the vehicle speed increases. That is, the vehicle body slip angle changes from positive to negative.

  In addition, the vehicle body slip angle (see the one-dot chain line in FIG. 4) at which the vehicle body slip angle visually sensed by the driver is 0 varies according to the vehicle speed under the condition that the turning radius is constant. Without a negative constant value.

  In the result of the experiment by the visual simulator, the body slip angle that the subject felt to be an appropriate value was almost the same as the body slip angle at which the approach angle = 0, and when the body slip angle at which the approach angle = 0. It is considered that the vehicle body slip angle that the driver feels visually is 0, and the driver does not feel a deviation between the vehicle longitudinal direction and the vehicle traveling direction.

  Next, the relationship between the trace line and the front view when the vehicle body slip angle is 0 will be described with reference to FIG. The approach angle θ of the trace line when the vehicle body slip angle becomes 0 is expressed by the following equation (3).

  However, x is the distance in the vehicle front-rear direction from the reference position (for example, the eye position) based on the position of the driver's eyes to the boundary between the driver's front view and the blind spot formed by the view being blocked by the hood or instrument panel, R is a turning radius.

  Θ represented by the above (3) is the vehicle body slip angle when the vehicle body slip angle felt visually by the driver is 0 and “approach angle = 0”.

  Next, a method of calculating the vehicle body slip angle gain for obtaining the vehicle body slip angle when the vehicle body slip angle felt by the driver is zero will be described.

  First, the vehicle body slip angle when the vehicle body slip angle felt by the driver is zero can be expressed by the above equation (3) without depending on the vehicle speed. Further, since the turning radius R is sufficiently larger than the distance x to the boundary between the driver's forward field of vision and blind spot, the turning line approach angle is expressed around x represented by the following equation (4). Consider first-order approximation based on the Taylor expansion of equation (3) above.

ここで、θを表わす上記（３）式は、以下の（５）式で表わすことができる。

Here, the above equation (3) representing θ can be represented by the following equation (5).

また、θは以下の（６）式で近似することができる。

Θ can be approximated by the following equation (6).

ところで、ｆ（ｘ）´は以下の（７）式で表わすことができる。

By the way, f (x) ′ can be expressed by the following equation (7).

  In the above equation (7), f (0) and g (0) are both indefinite 0/0. For this reason, the following theorem (8) and (9) are obtained by applying the theorem of the capital.

したがって、上記(７)式〜(９)式より、以下の（１０）式、（１１）式が得られる。

Therefore, the following expressions (10) and (11) are obtained from the expressions (7) to (9).

  Further, from the above equations (6), (10), and (11), θ can be approximated by the following equation (12).

  As in the above equation (12), the vehicle body slip angle when the vehicle body slip angle felt by the driver is 0 can be approximated to a value that is proportional to the distance to the boundary between the front field of view and the dead angle and inversely proportional to the turning radius. .

  The turning radius R can be expressed by the following equation (13) using the vehicle speed v and the yaw angular velocity r.

  From the above equations (12) and (13), the vehicle body slip angle gain Gβ for obtaining the vehicle body slip angle when the vehicle body slip angle felt by the driver is 0 is calculated using the yaw angular velocity gain Gr as follows: It can be expressed by equation (14).

  An example of the relationship between the yaw angular velocity gain and the vehicle body slip angle gain calculated based on the above equation (12) is shown in FIGS. 6 (A) and 6 (B). As shown in FIG. 6A, the characteristic of the yaw angular velocity gain with respect to the vehicle speed is determined so as to increase as the vehicle speed increases in the low speed range, to be constant in the medium speed range, and to decrease as the vehicle speed increases in the high speed range. It has been. Further, as shown in FIG. 6B, the vehicle body slip angle gain has a negative constant value in a low speed range where the yaw angular velocity gain increases in proportion to the vehicle speed, and asymptotically approaches 0 in a vehicle speed region higher than that. It has become.

  Note that the vehicle body slip angle gain represented by the above equation (14) represents the vehicle body slip angle characteristic at which the vehicle body slip angle felt by the driver during steady turning is zero, and is adjusted near this vehicle body slip angle gain. Can be used as a design parameter for improving the steering transient response.

  Next, the operation of the vehicle control device 10 according to the first embodiment will be described. Hereinafter, a case where the vehicle is in a steady turn will be described as an example.

  In the vehicle control device 10, a steering angle control processing routine shown in FIG. 4 is executed. First, in step 100, the vehicle speed is detected by the vehicle speed sensor 12, and in step 102, the yaw angular velocity gain calculating unit 16 detects the vehicle speed based on the characteristics of the yaw angular velocity gain shown in FIG. The yaw angular velocity gain according to the vehicle speed is calculated.

  In step 104, based on the vehicle speed detected in step 100 and the yaw angular velocity gain calculated in step 102 by the vehicle body slip angle gain calculation unit 18, the equation (14) is used to calculate the driver's speed. A vehicle body slip angle gain for obtaining a vehicle body slip angle when the felt slip angle is 0 is calculated. Note that the distance from the reference position of the driver's eye to the boundary between the driver's forward view and the blind spot formed by the hood or instrument panel is obtained in advance and stored in a memory (not shown). A value stored in advance in the memory may be used.

  In step 106, the steering angle is detected by the steering angle sensor 14, and in step 108, the target vehicle slip angle calculation unit 20 detects the vehicle body slip angle gain Gβ calculated in step 104 and the step 106. Based on the steering angle δsw, the vehicle body slip angle β when the slip angle felt by the driver is zero is calculated using the following equation (15).

ただし、Ｔｓは時定数である。

However, Ts is a time constant.

  In the next step 110, based on the yaw angular velocity gain Gr calculated in step 102 and the steering angle δsw detected in step 106 by the yaw angular velocity calculation unit 22, the following equation (16) is used to calculate the yaw. An angular velocity r is calculated.

  In step 112, the rudder angle control unit 28, based on the vehicle speed v detected in step 100, the vehicle body slip angle β calculated in step 108, and the yaw angular velocity r calculated in step 110, The following (17) is used to calculate the steering angle δf of the front wheels for obtaining the vehicle body slip angle when the slip angle felt by the driver is 0, and the driver feels using the following equation (18): A steering angle δr of the rear wheel for obtaining the vehicle body slip angle when the slip angle becomes 0 is calculated.

Where m is the vehicle mass, C _f is the front wheel cornering power, C _r is the rear wheel cornering power, l is the wheelbase length, l _f is the distance between the front axle and the vehicle center of gravity, and l _r is the distance between the rear axle and the vehicle center of gravity. Distance.

  In step 114, the front wheel actuator 24 and the rear wheel actuator are driven by the rudder angle control unit 28 so that the front and rear wheel steering angles calculated in step 114 are the same. The wheel steering angle is controlled, and the steering angle control processing routine is terminated.

  By the steering angle control processing routine, the steering angle of the front wheels and the steering angle of the rear wheels are controlled, and the azimuth at the position where the trace line during steady turning, i.e., the vehicle locus of the driver position disappears from the driver's front field of view. The vehicle body slip angle is controlled to be 0, and the vehicle body slip angle felt by the driver can be set to 0.

  As described above, according to the vehicle control device according to the first embodiment, the vehicle body slip angle when the driver does not feel the difference between the vehicle traveling direction and the vehicle front-rear direction is calculated, and the calculated vehicle body slip is calculated. By controlling the steering angle of each of the front and rear wheels of the vehicle so as to be an angle, the vehicle body slip angle felt by the driver can be optimized.

  Further, the driver feels the vehicle body slip angle from the front field of view, and by setting the vehicle body slip angle that the driver feels from the front field of view to 0, the vehicle front-rear direction and the vehicle traveling direction coincide with each other, and the driver can easily drive. Vehicle motion can be realized.

  In the above embodiment, the case where the steering angles of the front and rear wheels are controlled has been described as an example. However, the present invention is not limited to this, and the vehicle slip angle felt by the driver is 0 by other vehicle control. Control may be performed so as to obtain the vehicle body slip angle.

  Next, a second embodiment will be described. In addition, about the part of the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the second embodiment, the vehicle body slip angle gain for obtaining the vehicle body slip angle when the vehicle body slip angle felt by the driver is 0 is calculated, and the vehicle body slip angle is not obtained without obtaining the vehicle body slip angle as a control target. The difference from the first embodiment is that the steering angle of each of the front and rear wheels is controlled based on the gain.

  As shown in FIG. 8, the vehicle control device 210 according to the second embodiment includes a vehicle speed sensor 12, a steering angle sensor 14, a yaw angular velocity gain calculation unit 16, a vehicle body slip angle gain calculation unit 18, and a front wheel. The actuator 24, the rear wheel actuator 26, the vehicle speed from the vehicle speed sensor 12, the steering angle from the steering angle sensor 14, the vehicle body slip angle gain calculated by the vehicle body slip angle gain calculation unit 18, and the yaw angular velocity gain calculation unit 16 Based on the calculated yaw angular velocity gain, the front wheel actuator 24 and the rear wheel actuator 26 are driven so that the front and rear wheel steering angles are obtained to obtain the vehicle body slip angle when the vehicle body slip angle felt by the driver is zero. And a rudder angle control unit 228 to be controlled.

  Next, a steering angle control processing routine according to the second embodiment will be described with reference to FIG. In addition, about the process similar to 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  First, at step 100, the vehicle speed is detected by the vehicle speed sensor 12, and at step 102, the yaw angular velocity gain calculation unit 16 calculates the yaw angular velocity gain according to the vehicle speed. At the next step 104, the vehicle body slip angle gain calculation unit. 18, based on the vehicle speed detected in step 100 and the yaw angular velocity gain calculated in step 102, the vehicle body slip angle gain for obtaining the vehicle body slip angle when the slip angle felt by the driver is zero is calculated. To do.

  In step 106, the steering angle is detected by the steering angle sensor 14, and in step 250, the steering speed control unit 228 detects the vehicle speed v detected in step 100, and the vehicle body slip angle gain Gβ calculated in step 104. On the basis of the yaw angular velocity gain Gr calculated in step 102 and the steering angle δsw detected in step 106, the vehicle body when the slip angle felt by the driver is 0 using the following equation (19) The front wheel rudder angle δf for obtaining the slip angle is calculated, and the rear wheel rudder angle δr for obtaining the vehicle body slip angle when the slip angle felt by the driver is zero using the following equation (20). Is calculated.

However, Ts is the time constant, m is the vehicle mass, C _f is a front wheel cornering power, C _r is the rear wheel cornering power, l is a wheel base length, l _f is the distance between the front axle and the center of gravity of the vehicle, l _r is the rear axle And the center of gravity of the vehicle.

  In step 114, the front wheel actuator 24 and the rear wheel actuator 26 are driven by the rudder angle control unit 228 so that the rudder angle calculated in step 250 is obtained. And the steering angle control processing routine is terminated.

  As described above, according to the vehicle control device according to the second embodiment, the vehicle body slip angle gain for obtaining the vehicle body slip angle when the driver does not feel the difference between the vehicle traveling direction and the vehicle front-rear direction is obtained. By calculating and controlling the steering angles of the front and rear wheels of the vehicle based on the calculated vehicle body slip angle gain, the vehicle body slip angle felt by the driver can be optimized.

  Further, in order to control the steering angle of each of the front and rear wheels of the vehicle based on the vehicle body slip angle gain without calculating the vehicle body slip angle when the driver does not feel the deviation between the vehicle traveling direction and the vehicle front-rear direction. The processing speed can be improved.

  Next, a third embodiment will be described. In addition, about the part of the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The third embodiment is different from the first embodiment in that only the steering angle of the rear wheels is controlled.

  As shown in FIG. 10, the vehicle control device 310 according to the third embodiment includes a vehicle speed sensor 12, a steering angle sensor 14, a vehicle speed from the vehicle speed sensor 12, a rear wheel actuator 26, and a vehicle speed sensor 12. Based on the vehicle speed and the steering angle from the steering angle sensor 14, the driving of the rear wheel actuator 26 is controlled so that the steering angle of the rear wheel for obtaining the vehicle body slip angle at which the vehicle body slip angle felt by the driver becomes 0 is obtained. And a steering angle control unit 328.

  Next, a method for calculating the steering angle of the rear wheels to obtain the vehicle body slip angle when the vehicle body slip angle felt by the driver is zero will be described.

  First, the motion of a 4WS (4-wheel steering) vehicle can be described by the transfer function expressed by the following equation (21).

  However, Δ (s) and each of N1 (s) to N4 (s) are represented by the following formulas (22) to (26).

  Here, when the steady gain of the rear wheel steering angle δr with respect to the front wheel steering angle δf is K, it is expressed by the following equation (27).

  Further, the steady gain Gβ of the vehicle body slip angle with respect to the front wheel steering angle when the rear wheel steering angle is controlled and the steady gain Gr of the yaw angular velocity with respect to the front wheel steering angle are expressed by the following equations (28) and (29). The

  However, G1 is a steady gain of the vehicle body slip angle with respect to the front wheel steering angle, G2 is a steady gain of the vehicle body slip angle with respect to the rear wheel steering angle, G3 is a steady gain of the yaw angular velocity with respect to the front wheel steering angle, and G4 is a yaw angular velocity with respect to the rear wheel steering angle. Is a steady gain. G1 to G4 are represented by the following formulas (30) to (33).

  Here, in order to set the vehicle body slip angle felt by the driver to 0, it is necessary to establish the relationship of the above equation (14). The condition for setting the vehicle body slip angle felt by the driver to 0 is (14) It is represented by the following (34) by the equations (28) and (29).

  Further, when the above equation (34) is solved for K, K is represented by the following equation (35).

  Therefore, when the rear wheel steering angle is controlled so that the rear wheel steering angle δr represented by the following equation (36) is controlled with respect to the front wheel steering angle δf by the above equations (27) and (35), the driver The vehicle body slip angle can be reduced to zero.

  Next, a steering angle control processing routine according to the third embodiment will be described with reference to FIG. In addition, about the process similar to 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  First, in step 100, the vehicle speed is detected by the vehicle speed sensor 12, in step 106, the steering angle is detected by the steering angle sensor 14, and in step 350, the steering angle detected by the steering angle control unit 328 in the above step 106 is detected. Based on the above, the rudder angle of the front wheels is calculated.

  Then, in step 352, based on the vehicle speed v detected in step 100 and the steering angle δf of the front wheel calculated in step 350 by the rudder angle control unit 328, using the above equation (36), The steering angle δr of the rear wheel of the control target for obtaining the vehicle body slip angle when the sensed slip angle is 0 is calculated.

  In step 354, the steering angle control unit 328 controls the steering angle of the rear wheels by driving the rear wheel actuator 26 so that the steering angle calculated in the above step 352 is obtained. End the routine.

  The steering angle control processing routine controls the steering angle of the rear wheels with respect to the steering angle of the front wheels, and the azimuth of the position where the trace line during steady turning, that is, the vehicle locus of the driver position disappears from the driver's front view. The vehicle body slip angle can be controlled so that becomes zero, and the vehicle body slip angle felt by the driver can be zero.

  As described above, according to the vehicle control apparatus according to the third embodiment, the steering angle of the rear wheels for obtaining the vehicle body slip angle when the driver does not feel the deviation between the vehicle traveling direction and the vehicle longitudinal direction. And the vehicle slip angle sensed by the driver can be optimized by controlling the steering angle of the rear wheel of the vehicle so that the calculated steering angle is obtained.

It is the schematic which shows the structure of the vehicle control apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the direction of each axis | shaft explaining vehicle motion. (A) The figure which shows the speed vector of the driver's front field of view in turning, and (B) The figure which shows the trace line when the vehicle body slip angle = 0, and the trace line when the vehicle body slip angle corresponding to 2WS vehicle is obtained. is there. It is a graph which shows the result of the experiment by a visual simulator. It is a figure for demonstrating the relationship between the trace line when a vehicle body slip angle becomes 0, and a front view. (A) The graph which shows the characteristic of the yaw angular velocity gain with respect to vehicle speed, (B) The graph which shows the characteristic of the vehicle body slip angle gain with respect to vehicle speed. It is a flowchart which shows the content of the steering angle control processing routine in the vehicle control apparatus which concerns on the 1st Embodiment of this invention. It is the schematic which shows the structure of the vehicle control apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the content of the steering angle control processing routine in the vehicle control apparatus which concerns on the 2nd Embodiment of this invention. It is the schematic which shows the structure of the vehicle control apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the content of the steering angle control processing routine in the vehicle control apparatus which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

10, 210, 310 Vehicle control device 12 Vehicle speed sensor 14 Steering angle sensor 16 Yaw angular velocity gain computing unit 18 Vehicle body slip angle gain computing unit 20 Target vehicle body slip angle computing unit 22 Yaw angular velocity computing unit 24 Front wheel actuator 26 Rear wheel actuators 28, 228 328 Rudder angle controller

Claims (6)

A vehicle speed sensor for detecting the vehicle speed;
Deviation between the vehicle traveling direction and the vehicle longitudinal direction based on the yaw angular velocity gain predetermined according to the vehicle speed, the distance in the vehicle longitudinal direction to the boundary between the driver's field of vision and the blind spot, and the vehicle speed detected by the vehicle speed sensor. Vehicle body slip angle that the driver does not feel, or vehicle body slip angle gain for obtaining the vehicle body slip angle;
Control means for controlling the vehicle so as to obtain the vehicle body slip angle calculated by the calculation means or the vehicle body slip angle gain obtained from the vehicle body slip angle gain;
A vehicle body slip angle control device. It said calculation means, by the equation shown below, the vehicle body slip angle control device according to claim 1, wherein for calculating the vehicle body slip angle gain G _beta.

Where k is a constant, x is a distance in the vehicle front-rear direction from a reference position determined according to the position of the driver's eye to the boundary between the driver's field of vision and blind spot, and G _γ is a yaw angular velocity gain determined in advance according to the vehicle speed. , V are vehicle speeds detected by the vehicle speed sensor.   The said control means controls the steering angle of each front-and-rear wheel of a vehicle based on the said vehicle body slip angle or the said vehicle body slip angle gain calculated by the said calculation means, and the steering angle of a steering. Car body slip angle control device. 3. The vehicle body slip angle control according to claim 2, wherein the control means controls the steering angle δr of the rear wheel according to the following formula using the gain K of the rear wheel steering angle with respect to the front wheel steering angle determined based on the equation (1). apparatus.

However, δ _f is the steering angle of the front wheel, v is the vehicle speed detected by the vehicle speed sensor, x is the vehicle longitudinal direction from the reference position determined according to the position of the driver's eyes to the boundary between the driver's field of view and the blind spot. distance, m is vehicle mass, C _f is a front wheel cornering power, C _r is the rear wheel cornering power, l is a wheel base length, l _f is the distance between the front axle and the center of gravity of the vehicle, l _r is the rear axle and the vehicle center of gravity Distance.   The yaw angular velocity gain is predetermined so as to increase as the vehicle speed increases in a low speed region, to be constant or substantially constant in a medium speed region, and to decrease as the vehicle speed increases in a high speed region. The vehicle body slip angle control device according to any one of the preceding claims. Computer
Based on the yaw angular velocity gain determined according to the vehicle speed, the distance in the vehicle longitudinal direction to the boundary between the driver's field of vision and the blind spot, and the vehicle speed detected by the vehicle speed sensor that detects the vehicle speed, A vehicle body slip angle at which the driver does not feel the deviation, or a vehicle body slip angle gain for obtaining the vehicle body slip angle, and the vehicle body slip angle calculated by the calculation unit or the vehicle body slip angle gain A program for functioning as a control means for controlling a control mechanism for controlling a steering angle of a vehicle wheel so as to obtain an obtained vehicle body slip angle.

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