JP2009154648A - Rear wheel steering angle control device and rear wheel steering angle control method of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To early improve stabilization in vehicle behavior, by properly performing rear wheel steering angle control in response to vehicle behavior, by minimizing a control start delay when a vehicle travels forward, by surely prohibiting the rear wheel steering angle control in response to vehicle behavior when the vehicle is backing. <P>SOLUTION: A front wheel steering angle and the vehicle behavior such as a yaw rate are detected, and coincidence (coincidence of plus and minus signs) between the direction of the detected front wheel steering angle and the direction of the vehicle behavior is determined, and the rear wheel steering angle control in response to vehicle behavior by gain smaller than steady gain is performed until a determination of the coincidence continues for a first predetermined time and continues for a second predetermined time longer than the first predetermined time. When the determination of the coincidence continues for the second predetermined time or more, the rear wheel steering angle control in response to vehicle behavior by the steady gain is performed. The rear wheel steering angle control in response to vehicle behavior is stopped in nonesuch case. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle rear wheel steering angle control device and a rear wheel steering angle control method, and more particularly to a vehicle behavior corresponding rear wheel steering angle that sets a rear wheel steering angle according to vehicle behavior such as yaw rate and lateral acceleration of a vehicle body. The present invention relates to a rear wheel steering angle control device and a rear wheel steering angle control method for performing control.

  In a four-wheeled vehicle such as an automobile, a hub carrier (knuckle) that supports the left and right rear wheels is connected to the vehicle body including an electric or hydraulic linear actuator on the way, and the rear wheel A rear wheel steering device that changes the toe angle separately on the left and right is known (for example, Patent Document 1).

As a rudder angle control rule for such a rear wheel steering device, the yaw rate and lateral acceleration of the vehicle are detected, a control target value of the rear wheel rudder angle is set according to the detected yaw rate and lateral acceleration, and the rear wheel rudder is controlled. A control law for controlling the angle (toe angle) to be the rear wheel steering angle control target value is known (for example, Patent Document 2). This control is referred to as rear wheel steering angle control corresponding to vehicle behavior.
Japanese Patent Laid-Open No. 9-30438 JP-A-5-208681

  It is preferable that the vehicle behavior-compatible rear wheel steering angle control is started quickly to improve the stability of the vehicle behavior during forward traveling, and the vehicle behavior-compatible rear wheel steering angle control is always performed during forward traveling.

  However, when the vehicle moves backward, the front wheel rudder angle direction (left-right direction) determined by the steering wheel operation conflicts with the forward yaw rate direction or lateral acceleration direction (left-right direction). When the rear wheel steering angle control is performed, the vehicle behavior becomes unstable, and the natural steering feeling may be impaired. For this reason, it is preferable that the vehicle behavior corresponding rear wheel steering angle control is performed only during forward traveling.

  The problem to be solved by the present invention is that the rear wheel steering angle control corresponding to the vehicle behavior is not performed when the vehicle is moving backward, and the rear wheel steering angle control corresponding to the vehicle behavior is appropriately performed by minimizing the control start delay when the vehicle is traveling forward. It is to improve the stability of vehicle behavior.

  A vehicle rear wheel steering angle control device according to the present invention is a rear wheel steering angle control device that performs vehicle behavior-compatible rear wheel steering angle control that sets a rear wheel steering angle according to the behavior of the vehicle, A steering angle detection means for detecting, a vehicle behavior detection means for detecting the behavior of the vehicle, a direction of the front wheel steering angle detected by the steering angle detection means, and a direction of the vehicle behavior detected by the vehicle behavior detection means. A match is determined, the match determination continues for a first predetermined time, and it is temporarily determined that the vehicle is traveling forward until a second predetermined time longer than the first predetermined time elapses. When the vehicle travels forward for more than the second predetermined time, the forward gain determining means for determining that the vehicle is traveling forward, and the forward gain when the forward determination means makes a temporary determination for forward travel, the steady gain Rear wheel rudder for vehicle behavior with smaller gain When the forward travel decision is determined, control of the rear wheel steering angle corresponding to the vehicle behavior by the steady gain is performed, and when neither forward provisional decision nor final decision is made, the vehicle behavior is determined. Vehicle behavior corresponding rear wheel steering angle control means for stopping the corresponding rear wheel steering angle control.

  A vehicle rear wheel rudder angle control device according to the present invention is a vehicle rear wheel rudder angle control device that performs vehicle behavior corresponding rear wheel rudder angle control for setting a rear wheel rudder angle in accordance with the behavior of the vehicle. A steering angle detecting means for detecting an angle, a vehicle behavior detecting means for detecting the behavior of the vehicle, a vehicle speed detecting means for detecting the vehicle speed, and a counter accessed every predetermined time, and detected by the vehicle speed detecting means When the vehicle speed is equal to or higher than a predetermined value and the direction of the front wheel steering angle detected by the steering angle detection means and the direction of the vehicle behavior detected by the vehicle behavior detection means match, the counter is Incrementing, if the direction does not match, the count is decremented or reset, and if the vehicle speed detected by the vehicle speed detection means is less than a predetermined value, regardless of whether the direction matches or does not match The counter is reset, and if the count value of the counter is greater than or equal to the first predetermined value and less than the second predetermined value greater than the first predetermined value, it is temporarily determined that the vehicle is traveling forward. When the count value of the counter is equal to or greater than the second predetermined value, forward determination means for determining that the vehicle is traveling forward and temporary determination for forward traveling are made by the forward determination means. In this case, the rear wheel steering angle control corresponding to the vehicle behavior is performed with a gain smaller than the steady gain, and when the forward traveling determination is determined, the rear wheel steering angle control corresponding to the vehicle behavior based on the steady gain is performed, and the forward traveling steering control is performed. A vehicle behavior-compatible rear wheel steering angle control means for stopping the vehicle behavior-compatible rear wheel steering angle control when neither the provisional determination nor the final determination is made.

  A vehicle rear wheel rudder angle control method according to the present invention is a rear wheel rudder angle control method for performing vehicle behavior-compatible rear wheel rudder angle control in which a rear wheel rudder angle is set according to vehicle behavior, The behavior of the vehicle is detected, the coincidence between the detected direction of the front wheel steering angle and the direction of the vehicle behavior is determined, and the coincidence determination continues for a first predetermined time and is longer than the first predetermined time. Vehicle behavior corresponding rear wheel steering angle control is performed with a gain smaller than the steady gain until the predetermined time continues, and if the coincidence determination continues for the second predetermined time or more, the vehicle behavior corresponding rear wheel steering with the steady gain is performed. Angle control is performed, and if none of them is detected, the vehicle behavior corresponding rear wheel steering angle control is stopped.

  The vehicle behavior referred to in the present invention is a behavior of a vehicle having directionality in the left-right direction of the vehicle, such as the yaw rate of the vehicle body, the lateral acceleration acting on the vehicle body, and the like.

  According to the vehicle rear wheel rudder angle control device and the rear wheel rudder angle control method according to the present invention, the coincidence determination between the direction of the front wheel rudder angle and the direction of the vehicle behavior continues for a first predetermined time. The vehicle behavior rear wheel steering angle control is started with a gain smaller than the steady gain until a second predetermined time longer than the time elapses, and if the coincidence determination continues for the second predetermined time or more, the vehicle behavior based on the steady gain Since the corresponding rear wheel rudder angle control is performed, the vehicle behavior corresponding rear wheel rudder angle control is started by minimizing the risk of forward misjudgment during forward traveling and minimizing the control start delay, and the coincidence determination is second. If the vehicle continues for a predetermined time or more, the rear wheel steering angle control corresponding to the vehicle behavior using the steady gain is performed because there is no possibility of erroneous determination of forward travel. And, the rear wheel steering angle control corresponding to the vehicle behavior is not performed when the vehicle moves backward. As a result, the rear wheel steering angle control corresponding to the vehicle behavior is appropriately performed, and the stabilization of the vehicle behavior is improved.

  Hereinafter, embodiments of a rear wheel steering angle control device and a rear wheel steering angle control method according to the present invention will be described with reference to FIGS.

  First, a four-wheeled vehicle to which a rear wheel steering angle control device and a rear wheel steering angle control method according to the present invention are applied will be described with reference to FIG.

  The four-wheel vehicle 1 of the present embodiment includes left and right front wheels 4L and 4R and left and right rear wheels 6L and 6R. The front wheels 4L and 4R are fitted with tires 3L and 3R, respectively, suspended by the vehicle body 2 by left and right front suspensions 7L and 7R, and attached to the vehicle body 2 by knuckles 7aL and 7aR so as to be turnable. The rear wheels 6L and 6 are fitted with tires 5L and 5R, respectively, suspended by the vehicle body 2 by left and right rear suspensions 8L and 8R, and attached to the vehicle body 2 by knuckles 8aL and 8aR so as to be turnable.

  The four-wheel vehicle 1 includes a front wheel steering device 10 that directly steers the left and right front wheels 4L and 4R by steering the steering wheel 11. The front wheel steering device 10 includes a pinion 13 that is integrally connected to a steering wheel 11 via a steering shaft 12 and a tooth portion that meshes with the pinion 13 so as to be able to reciprocate in the vehicle width direction. And a rack and pinion mechanism having a rack shaft 14. Both ends of the rack shaft 14 are connected to the left and right knuckles 7aL and 7aR via tie rods 15. The left and right front wheels 4L, 4R are steered (turned) when the rack shaft 14 moves in the vehicle width direction by the rotation operation of the steering wheel 11.

  The steering shaft 12 is provided with a steering angle sensor 26 that detects the steering angle of the steering wheel 11 corresponding to the actual steering angle of the front wheels 4L, 4R. Thereafter, the steering angle sensor 26 outputs a sensor signal indicating the actual front wheel steering angle δr.

  The four-wheeled vehicle 1 is a rear wheel steering device (rear wheel toe angle varying device) 20 having one end connected to the vehicle body 2 and the other end connected to the knuckle 8aL of the left rear wheel 6L. And a right linear actuator 21R having one end connected to the vehicle body 2 and the other end connected to the knuckle 8aR of the right rear wheel 6R. The left and right linear actuators 21L and 21R are electrically operated or hydraulic, and expand and contract by a linear operation to individually change the toe angles of the left and right rear wheels 6L and 6R. In the rear wheel steering device 20 configured as described above, the rear wheels can be steered by changing the toe angles of the left and right rear wheels 6L and 6R by the left and right linear actuators 21L and 21R.

  The left and right linear actuators 21L and 21R are controlled by a rear wheel steering control device (ECU) 30. The rear wheel steering control device 30 is of an electronic control type including a microcomputer, and receives a sensor signal indicating the actual front wheel steering angle from the front wheel steering angle sensor 26 from a vehicle speed sensor 24 that detects the vehicle speed V of the four-wheeled vehicle 1. A sensor signal indicating the vehicle speed is input from a yaw rate sensor 25 that detects the yaw rate of the vehicle body 2, and a sensor signal indicating the yaw rate of the vehicle body 2 is input. For example, the control target rear steering angle of the left and right rear wheels is calculated according to the yaw rate corresponding rear wheel steering angle control law.

  The sensor signal of the front wheel steering angle sensor 26 reverses the sign of the front wheel steering angle, and the sensor signal of the yaw rate sensor 25 reverses the sign of the yaw rate. In the present embodiment, the positive and negative signs of the sensor signal of the front wheel steering angle sensor 26 and the sensor signal of the yaw rate sensor 25 are both “positive” when facing right and “negative” when facing left. . As a result, the front wheel steering angle and the yaw rate direction can be determined based on the signs of the sensor signals of the steering angle sensor 26 and the yaw rate sensor 25.

  The rear wheel steering angle control device 30 converts the control target rear steering angle into the control target stroke amount of the linear actuators 21L and 21R, and linear actuators 21L and 21R from the stroke sensors 23L and 23R provided in the linear actuators 21L and 21R. The sensor signal indicating the actual stroke amount is input, and the control target signal is output to each of the linear actuators 21L and 21R so that the control deviation between the control target stroke amount and the actual stroke amount becomes zero.

  Thus, feedback control is performed so that the toe angles (rear wheel rudder angles) of the left and right rear wheels 6L and 6R become the target rear steering angle (rear wheel rudder angle control target value).

  Next, details of the rear wheel steering angle control device 30 according to the present embodiment will be described with reference to FIG.

  The rear wheel rudder angle control device 30 includes a forward determination unit 31 and a yaw rate-compatible rear wheel rudder angle control unit 32.

  The advance determination unit 31 includes a code match counter 33 that is accessed every predetermined time. The forward determination unit 31 has a vehicle speed detected by the vehicle speed sensor 24 equal to or greater than a predetermined value (stop to extremely low vehicle speed), and a positive / negative sign of a sensor signal output from the front wheel steering angle sensor 26 and a sensor signal output from the yaw rate sensor. The sign coincidence counter 33 is incremented and the sensor output by the front wheel rudder angle sensor 26 is output when the sign of the front wheel rudder coincides with that of the front wheel rudder angle and the direction of the yaw rate. If the sign of the signal does not match the sign of the sensor signal output from the yaw rate sensor, that is, if the direction of the front wheel steering angle does not match the direction of the yaw rate, the sign match counter 33 is decremented or zeroed. When the vehicle speed detected by the vehicle speed sensor 24 is less than the predetermined value, the sign of the sensor signal matches or does not match, that is, the front wheel rudder Match the orientation and yaw orientation of, regardless of the discrepancy, reset to zero the sign coincidence counter 33.

  When the count value of the sign match counter 33 is equal to or greater than the FB permission count value (first predetermined value) and less than the forward determination count value (second predetermined value) greater than the FB permission count value, Then, it is temporarily determined that the vehicle is traveling forward. In other words, the flag setting that is temporarily determined to advance the vehicle is performed. The FB permission means that the feedback control of the yaw rate compatible rear wheel steering angle is permitted.

  When the count value of the code coincidence counter 33 is equal to or greater than the forward determination count value (second predetermined value), the forward determination unit 31 determines that the vehicle is traveling forward. In other words, it is determined that the vehicle is moving forward and flagging is performed.

  Since the count value of the code coincidence counter 33 is updated every predetermined time, the count value indicates the passage of time in the condition establishment state. Accordingly, the forward determination unit 31 continues the first predetermined time (FB permission OK time) in which the direction of the front wheel rudder angle and the direction of the yaw rate coincide with each other, and the second determination time is longer than the first predetermined time. Until a predetermined time (forward fixed time) elapses, it is temporarily determined that the vehicle is traveling forward. If the coincidence determination continues for a second predetermined time or more, the vehicle is traveling forward. It will be determined.

  The yaw rate corresponding rear wheel rudder angle control unit 32 performs feedback compensation for yaw rate corresponding rear wheel rudder angle control with a gain (feedback compensation control gain) smaller than the steady-state gain when the forward determination unit 31 temporarily determines forward traveling. When the determination of forward traveling is made, the yaw rate corresponding rear wheel steering angle control by the steady gain is performed by the feedback compensation control method. If neither the provisional determination of the forward running nor the final determination is made, that is, the determination that the vehicle is not moving forward, in other words, the vehicle is moving backward. In the case of determination, the yaw rate corresponding rear wheel steering angle control is not performed or is stopped. The gain here is the gain of feedback compensation control.

  As described above, the coincidence determination between the direction of the front wheel rudder angle and the direction of the yaw rate continues for the first predetermined time, and until the second predetermined time longer than the first predetermined time elapses, that is, forward travel Prior to the final determination, it is temporarily determined that the vehicle is traveling forward, and by this temporary determination, the yaw rate compatible rear wheel steering angle control is started with a gain smaller than the steady gain. Limiting the risk of erroneous forward determination, the rear wheel steering angle control corresponding to the yaw rate is started. As a result, yaw rate compatible rear wheel rudder angle control is started quickly, and stabilization of the vehicle behavior is quickly improved.

  When the coincidence determination continues for the second predetermined time or longer, yaw rate corresponding rear wheel steering angle control is performed with a steady gain, assuming that there is no possibility of erroneous determination of forward movement due to drift during reverse movement or the like. And, when the vehicle is reversing, yaw rate compatible rear wheel steering angle control is not performed.

  As a result, yaw rate-compatible rear wheel rudder angle control is appropriately performed, and the vehicle behavior is stabilized and improved.

  Next, an example of a processing routine for rear wheel steering angle control according to the present embodiment will be described with reference to the flowchart shown in FIG. The processing routine is repeatedly executed at predetermined intervals by time interruption.

  First, it is determined whether or not the vehicle speed is equal to or higher than a predetermined value (step S1). If the vehicle speed is not equal to or higher than the predetermined value, the count value C of the sign matching counter 33 is reset to zero, both the forward temporary determination flag Fb and the forward determination flag Fa are set to “0” (step S2), and the routine is terminated.

  If the vehicle speed is equal to or higher than the predetermined value, it is determined whether or not the forward confirmation flag Fa is “1” (step S3). When Fa = 1, it is a case where the forward travel confirmation determination has already been made, and in this case, the yaw rate compatible rear wheel steering angle control of the feedback compensation control method using the steady gain is continued (step S4). ).

  If Fa = 1 is not satisfied, it is next determined whether or not the forward temporary determination flag Fb is “1” (step S5). If Fb = 1 is not set, provisional determination of forward travel has not been made. In this case, the sign of the sensor signal output by the front wheel steering angle sensor 26 and the sensor output by the yaw rate sensor are next output. It is determined whether or not the sign of the signal matches (step S6). If the positive and negative signs match, the count value C of the sign match counter 33 is incremented (step S7). If the positive and negative signs do not match, the count value C of the sign match counter 33 is reset to zero (step S8). .

  Then, it is determined whether or not the count value C of the code match counter 33 has reached the FB permission count value (step S9). When the count value C of the sign coincidence counter 33 has not reached the FB permission count value, the yaw rate corresponding rear wheel steering angle control of the feedback compensation control method is not permitted and the control is not performed (step S10).

  On the other hand, if the count value C of the sign coincidence counter 33 has reached the FB permission count value, the feedback compensation control type yaw rate compatible rear wheel steering angle control is started with a gain smaller than the steady gain, and the forward running is temporarily determined. Is performed, the forward temporary determination flag Fb is set to “1” (step S11). The yaw rate-compatible rear wheel steering angle control gain may be corrected so as to approach a steady gain at a predetermined rate each time step S11 is executed.

If Fb = 1 in the determination in step S5, the provisional determination of forward travel has already been made. In this case, as in the process in step S6, the front wheel steering angle sensor 26 is It is determined whether or not the sign of the sensor signal to be output matches the sign of the sensor signal output from the yaw rate sensor (step S12). If the sign is the same, the count value C of the sign match counter 33 is incremented (step S13). If the sign is not matched, the count value C of the sign match counter 33 is reset to zero (step S14). .
Then, it is determined whether or not the count value C of the code coincidence counter 33 has reached the forward fixed count value (step S15). If the count value C of the code coincidence counter 33 has not reached the advance confirmation count value, the routine is terminated as it is.

  On the other hand, if the count value C of the sign coincidence counter 33 has reached the forward determination count value, it is assumed that the yaw rate corresponding rear wheel steering angle control of the feedback compensation control method is performed by the steady gain, and the forward traveling determination is determined. The advance determination flag Fa is set to “1” (step S16).

  By repeatedly executing the above processing routine, the yaw rate corresponding rear wheel rudder angle control is reliably prohibited when the vehicle is moving backward, and the yaw rate corresponding rear wheel rudder is minimized by minimizing the control start delay when the vehicle is traveling forward. The angle control is appropriately performed, and the stabilization of the vehicle behavior is improved at an early stage.

  Another example of the processing routine of the rear wheel steering angle control according to this embodiment will be described with reference to the flowchart shown in FIG. The processing routine is repeatedly executed at predetermined intervals by time interruption.

First, it is determined whether or not the vehicle speed is equal to or higher than a predetermined value (step S101). If the vehicle speed is not equal to or higher than the predetermined value, the count value C of the sign coincidence counter 33 is reset to zero, both the forward temporary determination flag Fb and the forward determination flag Fa are set to “0” (step S102), and the routine is terminated.

  If the vehicle speed is equal to or higher than the predetermined value, it is determined whether or not the reverse determination flag Fc is “1” (step S103). When Fc = 1, it is a case where it is already determined that the vehicle is traveling backwards. In this case, the routine is immediately terminated to continue the state in which the yaw rate-compatible rear wheel steering angle control is not performed. .

  If Fc = 1 is not satisfied, it is next determined whether or not the advance confirmation flag Fa is “1” (step S103). When Fa = 1, it is a case where the forward traveling confirmation has already been determined, and in this case, the yaw rate compatible rear wheel steering angle control of the feedback compensation control method using the steady gain is continued (step S105). ).

  If Fa = 1 is not satisfied, it is next determined whether or not the forward temporary determination flag Fb is “1” (step S106). If Fb = 1 is not set, provisional determination of forward travel has not been made. In this case, the sign of the sensor signal output by the front wheel steering angle sensor 26 and the sensor output by the yaw rate sensor are next output. It is determined whether or not the sign of the signal matches (step S107). If the positive and negative signs match, the count value C of the sign match counter 33 is incremented (step S108). If the positive and negative signs do not match, the count value C of the sign match counter 33 is decremented (step S109).

  Then, it is determined whether or not the count value C of the code match counter 33 has reached the FB permission count value (step S110). When the count value C of the code coincidence counter 33 has not reached the FB permission count value, the yaw rate corresponding rear wheel steering angle control of the feedback compensation control method is not permitted, and the control is not performed (step S111). Thereafter, it is determined whether or not the count value C of the code coincidence counter 33 has been reduced to the backward confirmation value (step S112). If the count value C of the code coincidence counter 33 has been reduced to the backward confirmation value, the backward confirmation flag Fc is set to “1” (step S113).

  On the other hand, if the count value C of the sign coincidence counter 33 has reached the FB permission count value, the feedback compensation control type yaw rate compatible rear wheel steering angle control is started with a gain smaller than the steady gain, and the forward running is temporarily determined. Is performed, the forward temporary determination flag Fb is set to “1” (step S114). The yaw rate-compatible rear wheel steering angle control gain may be corrected so as to approach the steady gain at a predetermined rate each time step S114 is executed.

If Fb = 1 in the determination in step S106, the provisional determination of forward travel has already been made, and in this case, as in the process in step S107, the front wheel steering angle sensor 26 is It is determined whether the sign of the sensor signal to be output matches the sign of the sensor signal output from the yaw rate sensor (step S113). If the positive and negative signs match, the count value C of the sign match counter 33 is incremented (step S114). If the positive and negative signs do not match, the count value C of the sign match counter 33 is decremented (step S115).
Then, it is determined whether or not the count value C of the code coincidence counter 33 has reached the forward fixed count value (step S116). If the count value C of the code coincidence counter 33 has not reached the advance confirmation count value, the routine is terminated as it is.

  On the other hand, if the count value C of the sign coincidence counter 33 has reached the forward determination count value, it is assumed that the yaw rate corresponding rear wheel steering angle control of the feedback compensation control method is performed by the steady gain, and the forward traveling determination is determined. Then, the advance confirmation flag Fa is set to “1” (step S117).

  Even when the above-described processing routine is repeatedly executed, yaw rate compatible rear wheel steering angle control is reliably prohibited when the vehicle is moving backward, and when the vehicle is traveling forward, the control start delay is minimized and the yaw rate compatible rear wheel is controlled. Steering angle control is performed appropriately, and stabilization of vehicle behavior is improved at an early stage.

  Note that the rear wheel steering angle control device and the rear wheel steering angle control method according to the present invention are similarly applied to rear wheel steering angle control corresponding to vehicle behavior such as lateral acceleration corresponding to yaw rate corresponding rear wheel steering angle control. The direction of the front wheel steering angle detected by the front wheel steering angle sensor 26 shown in FIG. 3 and the direction of the lateral acceleration detected by the lateral acceleration sensor 27 are coincident or inconsistent, depending on the yaw rate direction. As in the case, forward / backward movement of the vehicle may be determined.

1 is an overall configuration diagram showing one embodiment of a four-wheeled vehicle to which a rear wheel steering angle control device and a rear wheel steering angle control method according to the present invention are applied. 1 is a block diagram showing one embodiment of a rear wheel steering angle control device of a vehicle according to the present invention. It is a flowchart which shows an example of the processing routine of the rear-wheel steering angle control by the rear-wheel steering angle control apparatus of the vehicle by this invention. It is a flowchart which shows another example of the processing routine of the rear-wheel steering angle control by the rear-wheel steering angle control apparatus of the vehicle by this invention.

Explanation of symbols

4L, 4R Front wheel 6L, 6R Rear wheel 21L, 21R Linear actuator 23L, 23R Stroke sensor 24 Vehicle speed sensor 25 Yaw rate sensor 26 Steering angle sensor 27 Lateral acceleration sensor 30 Rear wheel steering angle control device 31 Advance determination unit 32 Rear wheel steering for yaw rate Angle control unit

Claims (3)

A rear wheel rudder angle control device for performing rear wheel rudder angle control corresponding to vehicle behavior for setting a rear wheel rudder angle according to the behavior of the vehicle,
Rudder angle detecting means for detecting the front wheel rudder angle;
Vehicle behavior detection means for detecting the behavior of the vehicle;
The coincidence between the direction of the front wheel rudder angle detected by the rudder angle detection means and the direction of the vehicle behavior detected by the vehicle behavior detection means is determined, and the coincidence determination continues for a first predetermined time. Until the second predetermined time longer than the predetermined time elapses, it is temporarily determined that the vehicle is traveling forward. If the coincidence determination continues for the second predetermined time or longer, the vehicle is traveling forward. Forward determination means for determining and confirming,
When the forward determination means makes a provisional determination of forward travel, the vehicle behavior-corresponding rear wheel steering angle control is performed with a gain smaller than the steady gain, and when the forward travel confirmation determination is made, the vehicle with the steady gain is determined. Vehicle behavior corresponding rear wheel rudder angle control means for performing behavior corresponding rear wheel rudder angle control and stopping the vehicle behavior corresponding rear wheel rudder angle control when neither forward provisional determination nor final determination is made. ,
A rear wheel rudder angle control device having a vehicle. A vehicle rear wheel rudder angle control device that performs vehicle behavior corresponding rear wheel rudder angle control for setting a rear wheel rudder angle according to the behavior of the vehicle,
Rudder angle detecting means for detecting the front wheel rudder angle;
Vehicle behavior detection means for detecting the behavior of the vehicle;
Vehicle speed detection means for detecting the vehicle speed;
Including a counter that is accessed every predetermined time, the vehicle speed detected by the vehicle speed detecting means is equal to or greater than a predetermined value, and detected by the direction of the front wheel steering angle detected by the steering angle detecting means and the vehicle behavior detecting means The counter is incremented when the vehicle behavior direction matches, and the count is decremented or reset when the vehicle behavior direction does not match, and the vehicle speed detected by the vehicle speed detecting means is If it is less than a predetermined value, the counter is reset regardless of whether the orientations match or not, and a second predetermined value that is greater than or equal to the first predetermined value and the count value of the counter is greater than the first predetermined value If it is less than the predetermined value, it is temporarily determined that the vehicle is traveling forward. If the count value of the counter is equal to or greater than the second predetermined value, the vehicle A deterministic determining advancement determining means that the traveling,
When the forward determination means makes a provisional determination of forward travel, the vehicle behavior-corresponding rear wheel steering angle control is performed with a gain smaller than the steady gain. When the forward travel confirmation determination is made, the vehicle with the steady gain is determined. Vehicle behavior corresponding rear wheel rudder angle control means for performing behavior corresponding rear wheel rudder angle control and stopping the vehicle behavior corresponding rear wheel rudder angle control when neither forward provisional determination nor final determination is made. ,
A rear wheel rudder angle control device having a vehicle. A rear wheel rudder angle control method for performing rear wheel rudder angle control corresponding to vehicle behavior that sets a rear wheel rudder angle according to the behavior of the vehicle,
The front wheel rudder angle and the vehicle behavior are detected, the coincidence between the detected direction of the front wheel rudder angle and the direction of the vehicle behavior is determined, the coincidence determination continues for a first predetermined time, and the first predetermined time Vehicle behavior-corresponding rear wheel steering angle control is performed with a gain smaller than the steady gain until it continues for a longer second predetermined time. If the coincidence determination continues for the second predetermined time or longer, the vehicle with the steady gain is used. A vehicle rear wheel rudder angle control method that performs behavior corresponding rear wheel rudder angle control and stops the vehicle behavior corresponding rear wheel rudder angle control when none of them is performed.

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