Vehicle control method, vehicle and computer readable storage medium

Abstract

The invention provides a vehicle control method, a vehicle and a computer readable storage medium, and relates to the technical field of vehicles, the method is applied to the vehicle with four-wheel steering and front and rear axle independent driving, when a pivot steering mode of the vehicle is activated, front and rear wheels are controlled to steer to respective corresponding target angles in the same direction, and the vehicle is controlled to steer to the target angles. Controlling front and rear drive motors to output torques with the same magnitude and opposite directions to obtain transverse and longitudinal accelerations of the vehicle, determining the magnitude relationship between the transverse and longitudinal accelerations and a preset acceleration threshold value, and adjusting the torques output by the front and rear drive motors, the rotation angles of front and rear wheels and the yaw velocity of the vehicle according to the magnitude relationship. The longitudinal force borne by the front shaft and the rear shaft in the longitudinal direction is the same in magnitude and opposite in direction, and the transverse force borne by the front shaft and the rear shaft in the transverse direction forms a pair of force couples. In-situ steering of the vehicle can be achieved, and the problem that turning around is difficult on a narrow road is solved.

Claims

1. A control method for a vehicle, the vehicle including a front axle, a rear axle, a front drive motor for driving the front axle, and a rear drive motor for driving the rear axle, characterized in that, the control method includes: When the in-situ steering mode of the vehicle is activated, controlling the front wheels and the rear wheels to steer in the same direction to their respective target steering angles; Controlling the front drive motor to output a first torque and controlling the rear drive motor to output a second torque; wherein, the magnitudes of the first torque and the second torque are the same and the directions are opposite; Obtaining the lateral acceleration and the longitudinal acceleration of the vehicle; Determining the magnitude relationship between the lateral acceleration and the longitudinal acceleration and a preset acceleration threshold; Adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw angular velocity of the vehicle according to the magnitude relationship, so that the magnitude of the first longitudinal force received by the front axle in the longitudinal direction is the same as and the direction is opposite to the magnitude of the second longitudinal force received by the rear axle in the longitudinal direction, and the first lateral force received by the front axle in the lateral direction and the second lateral force received by the rear axle in the lateral direction form a couple.

2. The control method according to claim 1, characterized in that, the adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw angular velocity according to the magnitude relationship includes: When the magnitude relationship is that both the lateral acceleration and the longitudinal acceleration are greater than the preset acceleration threshold, reducing the first torque and increasing the second torque so that the longitudinal acceleration reaches the preset acceleration threshold; When the longitudinal acceleration reaches the preset acceleration threshold, obtaining the lateral acceleration again; Judging whether the laterally re-acquired acceleration reaches the preset acceleration threshold to obtain a first judgment result; Performing torque control on the front drive motor and the rear drive motor according to the first judgment result, and performing steering angle control on the front wheels and the rear wheels, so that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force, and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; and, Judging whether the yaw angular velocity reaches a preset angular velocity; If not, when the yaw angular velocity is greater than the preset angular velocity, reducing the first torque and the second torque based on a preset torque adjustment ratio, or when the yaw angular velocity is less than the preset angular velocity, increasing the first torque and the second torque based on the preset torque adjustment ratio so that the yaw angular velocity reaches the preset angular velocity.

3. The control method according to claim 2, characterized in that, the performing torque control on the front drive motor and the rear drive motor according to the first judgment result, and performing steering angle control on the front wheels and the rear wheels includes: When the first judgment result is that the lateral acceleration reaches the preset acceleration threshold, control the front drive motor to continuously output the reduced first torque, the rear drive motor to continuously output the increased second torque, and keep the steering angles of the front wheels and the rear wheels unchanged; When the first judgment result is that the lateral acceleration does not reach the preset acceleration threshold, adjust the first torque, the second torque, and the steering angles of the front wheels and the rear wheels respectively so that the lateral acceleration reaches the preset acceleration threshold.

4. The control method according to claim 1, wherein, the adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that the longitudinal acceleration is greater than the preset acceleration threshold and the lateral acceleration reaches the preset acceleration threshold, increase the steering angles of the front wheels and the rear wheels, and decrease the first torque and the second torque so that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force, and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; and, judge whether the yaw rate reaches a preset angular velocity; if not, then when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio, or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio so that the yaw rate reaches the preset angular velocity.

5. The control method according to claim 1, wherein, the adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that the longitudinal acceleration is greater than the preset acceleration threshold and the lateral acceleration is less than the preset acceleration threshold, increase the steering angle of the front wheels and decrease the steering angle of the rear wheels so that the longitudinal acceleration reaches the preset acceleration threshold; when the longitudinal acceleration reaches the preset acceleration threshold, obtain the lateral acceleration again; judge whether the laterally-accelerated value obtained again reaches the preset acceleration threshold to obtain a second judgment result; perform torque control on the front drive motor and the rear drive motor, and perform steering angle control on the front wheels and the rear wheels according to the second judgment result so that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force, and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; and, judge whether the yaw rate reaches a preset angular velocity; If not, when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio, or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio, so that the yaw rate reaches the preset angular velocity.

6. The control method according to claim 5, wherein, the torque control of the front drive motor and the rear drive motor according to the second judgment result, and the steering angle control of the front wheels and the rear wheels include: when the second judgment result is that the lateral acceleration reaches the preset acceleration threshold, keep the output torques of the front drive motor and the rear drive motor unchanged respectively, and keep the increased steering angle of the front wheels unchanged and the decreased steering angle of the rear wheels unchanged; when the second judgment result is that the lateral acceleration does not reach the preset acceleration threshold, adjust the first torque, the second torque, and the steering angles of the front wheels and the rear wheels respectively, so that the lateral acceleration reaches the preset acceleration threshold.

7. The control method according to claim 1, wherein, the adjustment of the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that the longitudinal acceleration reaches the preset acceleration threshold and the lateral acceleration is greater than or less than the preset acceleration threshold, judge whether the yaw rate reaches the preset angular velocity; If not, when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio, and reduce the steering angles of the front wheels and the rear wheels based on a preset steering angle adjustment value, or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio, and increase the steering angles of the front wheels and the rear wheels based on the preset steering angle adjustment value, so that the yaw rate reaches the preset angular velocity, the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force, and the absolute value of the first lateral force is the same as the absolute value of the second lateral force.

8. The control method according to claim 1, wherein, the adjustment of the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that both the longitudinal acceleration and the lateral acceleration reach the preset acceleration threshold, judge whether the yaw rate reaches the preset angular velocity; If so, control the first torque and the second torque to remain unchanged, and keep the steering angles of the front wheels and the rear wheels unchanged respectively; If not, when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio, or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio, so that the yaw rate reaches the preset angular velocity, the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force, and the absolute value of the first lateral force is the same as the absolute value of the second lateral force.

9. The control method according to claim 1, wherein, the adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that the longitudinal acceleration is less than the preset acceleration threshold and the lateral acceleration is greater than the preset acceleration threshold, reduce the steering angle of the front wheels and increase the steering angle of the rear wheels; judge whether it satisfies that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; if so, keep the output torques of the front drive motor and the rear drive motor unchanged respectively, keep the reduced steering angle of the front wheels unchanged and keep the increased steering angle of the rear wheels unchanged; if not, adjust the first torque, the second torque and the steering angles of the front wheels and the rear wheels respectively, so that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; and, judge whether the yaw rate reaches the preset angular velocity; if not, when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio, or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio, so that the yaw rate reaches the preset angular velocity.

10. The control method according to claim 1, wherein, the adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that the longitudinal acceleration is less than the preset acceleration threshold and the lateral acceleration reaches the preset acceleration threshold, reduce the steering angle of the front wheels and increase the first torque, or increase the steering angle of the rear wheels and reduce the second torque, so that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; and, judge whether the yaw rate reaches the preset angular velocity; If not, when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio; or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio, so that the yaw rate reaches the preset angular velocity.

11. The control method according to claim 1, wherein, the adjusting the first torque, the second torque, the steering angle of the front wheels, the steering angle of the rear wheels, and the yaw rate of the vehicle according to the magnitude relationship includes: when the magnitude relationship is that the longitudinal acceleration is less than the preset acceleration threshold and the lateral acceleration is less than the preset acceleration threshold, increase the first torque, reduce the steering angle of the front wheels, reduce the second torque, and increase the steering angle of the rear wheels, so that the absolute value of the first longitudinal force is the same as the absolute value of the second longitudinal force, and the absolute value of the first lateral force is the same as the absolute value of the second lateral force; and judge whether the yaw rate reaches a preset angular velocity; If not, when the yaw rate is greater than the preset angular velocity, reduce the first torque and the second torque based on a preset torque adjustment ratio; or when the yaw rate is less than the preset angular velocity, increase the first torque and the second torque based on the preset torque adjustment ratio, so that the yaw rate reaches the preset angular velocity.

12. The control method according to any one of claims 1 to 11, wherein, the controlling the front wheels and the rear wheels to steer in the same direction to their respective target steering angles when the in-situ steering mode of the vehicle is activated includes: when the in-situ steering mode of the vehicle is activated, obtain a preset in-situ steering direction; obtain the preset steering angles corresponding to the in-situ steering direction to obtain the respective target steering angles of the front wheels and the rear wheels; control the front wheels and the rear wheels to steer in the same direction to their respective target steering angles.

13. A vehicle, wherein, the vehicle includes: a memory for storing executable program code; a processor for calling and running the executable program code from the memory, so that the vehicle executes the control method of the vehicle according to any one of claims 1 to 12.

14. A computer-readable storage medium, wherein, the computer-readable storage medium stores a computer program, and when the computer program is executed, it implements the control method of the vehicle according to any one of claims 1 to 12.

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