CN-121973644-A - Vehicle steering control method, vehicle and storage medium

CN121973644ACN 121973644 ACN121973644 ACN 121973644ACN-121973644-A

Abstract

The present disclosure relates to a vehicle steering control method, a vehicle and a storage medium, and relates to the technical field of vehicles, wherein the vehicle is provided with a first steering system, the first steering system does not include a steering motor, a driving motor in the first steering system does not directly enable wheels to rotate, so that two front wheels are loaded with front axle yaw torque by applying opposite driving torque to the driving motor corresponding to the front wheels, resistance and friction are overcome by the front axle yaw torque, and in order to prevent the front wheels from loading the front axle yaw torque to cause the movement of a vehicle body, the vehicle is firstly stationary by controlling two rear wheels before controlling the front wheels, so that the vehicle can realize in-situ rotation of the wheels based on differential control of four motors in a stationary state.

Inventors

JIANG TINGLONG
LI JIAN
ZHOU ZHIJUN
XIONG WEI

Assignees

比亚迪股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260402

Claims (10)

1. A vehicle steering control method, characterized in that the vehicle is provided with a first steering system that does not include a steering motor, the method comprising: in response to a vehicle entering a steering-in-place mode, acquiring steering information of a steering wheel, front wheel rotation angle information and rear wheel speed information of the vehicle, wherein the steering is performed by using the first steering system in the steering-in-place mode; applying a driving torque to a driving motor corresponding to a rear wheel based on a speed deviation between an actual speed and a target speed of the rear wheel determined from the rear wheel speed information to make the rear wheel stationary; And under the condition that the rear wheels are determined to be stationary, applying driving torques with opposite directions to the driving motors corresponding to the two front wheels on the basis of the front wheel steering deviation determined by the steering wheel steering information and the front wheel steering angle information so as to control the vehicle to steer in place according to the steering wheel steering information.
2. The vehicle steering control method according to claim 1, characterized in that before acquiring steering wheel steering information, front wheel rotation angle information, and rear wheel speed information of the vehicle in response to the vehicle entering a in-situ steering mode, the method further comprises: And acquiring the speed information of the vehicle, and prompting the vehicle to enter a steering-in-place mode when the vehicle is determined to be stationary according to the speed information.
3. The vehicle steering control method according to claim 2, characterized in that the vehicle is further provided with a second steering system including a steering motor, and the acquiring of the vehicle speed information of the vehicle includes: And acquiring speed information of the vehicle in response to detecting that the second steering system fails.
4. The vehicle steering control method according to claim 1, characterized in that the applying of the driving torque to the driving motor corresponding to the rear wheel based on a speed deviation between an actual speed of the rear wheel and a target speed determined from the rear wheel speed information includes: Determining the actual speed of the rear wheel according to the wheel speed information of the rear wheel; PID calculation is carried out based on the difference value between the target speed and the actual speed of the rear wheel, so as to obtain the control quantity of the driving motor corresponding to the rear wheel; and applying a driving torque to a driving motor corresponding to the rear wheel based on the control amount.
5. The vehicle steering control method according to claim 1, characterized in that the applying of the driving torques in opposite directions to the driving motors for the two front wheels based on the front wheel steering deviation determined from the steering wheel steering information and the front wheel steering angle information includes: determining the actual turning angle of the front wheels according to the turning angle information of the front wheels, and determining the target turning angle of the wheels according to the turning information of the steering wheel; PID calculation is carried out based on the difference between the wheel target rotation angle and the front wheel actual rotation angle, so that a front axle yaw torque control quantity is obtained; the yaw torque control quantity of the front axle is evenly distributed, so that the respective wheel end torque control quantity of the two front wheels is obtained; and applying a driving torque with the magnitude of the wheel end torque control quantity to a driving motor corresponding to the front wheel close to the steering direction, and applying a driving torque with the magnitude of the wheel end torque control quantity to a driving motor corresponding to the front wheel far away from the steering direction.
6. The vehicle steering control method according to claim 1, characterized in that the determining that the rear wheel is stationary includes: And detecting the current speed of the vehicle in response to receiving the valid control state flag bit, and determining that the rear wheel is stationary if the valid control state flag bit indicates that the rear wheel is stationary and the vehicle is stationary based on the current speed of the vehicle.
7. The vehicle steering control method according to claim 1 or 5, characterized in that after applying opposite driving torques to the driving motors corresponding to the two front wheels, the method further comprises: The driving torque of the driving motor corresponding to the front wheel is transmitted through the guiding mechanism, so that the front wheel moves according to the guiding movement track, wherein the guiding mechanism comprises a suspension rod system movement mechanism and/or a chassis steering trapezoid mechanism, and the guiding mechanism is used for limiting the movement track of the front wheel steering angle.
8. The vehicle steering control method according to claim 7, characterized in that the vehicle includes a position sensor that is disposed on the guide mechanism and outputs position information of the guide mechanism; the front wheel steering angle information obtaining step comprises the following steps: acquiring position information of the guide mechanism, wherein the position information indicates the displacement of the guide mechanism; and acquiring front wheel steering angle information of the vehicle according to the mapping relation between the displacement of the guide mechanism and the wheel steering angle.
9. A vehicle, characterized in that the vehicle comprises: the steering wheel angle sensor is used for acquiring the steering wheel angle information; the rotation angle sensor is used for acquiring the front wheel rotation angle information; the brake controller is used for acquiring the wheel speed information of the rear wheel; a motor controller for controlling the driving motor; a vehicle control unit for executing the vehicle steering control method according to any one of claims 1 to 8.
10. A computer-readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the vehicle steering control method of any one of claims 1 to 8.

Description

Vehicle steering control method, vehicle and storage medium Technical Field The disclosure relates to the technical field of automobiles, and in particular relates to a vehicle steering control method, a vehicle and a storage medium. Background With the continued advancement of automotive technology, steering systems have undergone an evolution from mechanical hydraulic assistance to full electronic control as a core component of vehicle handling. Currently, steering technologies of vehicles mainly include technical routes such as mechanical hydraulic power steering (Hydraulic Power Steering, HPS), electro hydraulic power steering (Electro-Hydraulic Power Steering, EHPS), electric power steering (Electric Power Steering, EPS), steer-By-Wire (SBW), and four-wheel steering (Four-WHEEL STEERING,4 WS), and each technology has unique advantages and limitations. From the technical development, the electric power steering gradually becomes mainstream due to the characteristics of high efficiency, energy saving and easy integration, and the electric power steering can directly drive a steering column or a rack through a motor, so that proper power assistance can be provided according to the speed and the steering angle, and the driving comfort and safety are remarkably improved. The occurrence of the steering-by-wire technology marks the progress of the steering system to complete electronization and intellectualization, the steering-by-wire cancels the traditional mechanical connection, steering control is realized through electronic signals, the response speed and the control precision are further improved, but the problems of high cost and reliability still limit the large-scale application, and particularly the redundant design of the steering-by-wire system, and the redundant hardware which is not subjected to heterogeneous design has the safety risk of common failure. The four-wheel drive differential steering technology realizes steering by simultaneously controlling the driving torque of front wheels or rear wheels, remarkably improves the steering stability and steering flexibility of vehicle running, and particularly has excellent performance during high-speed running and parking. However, four wheel drive differential steering is accomplished by rotating the left and right drive wheels at different speeds, and at ‌ in-situ stationary ‌, no effective steering torque is generated, and the front wheels cannot be controlled to steer while the vehicle is stationary. Disclosure of Invention The disclosure provides a vehicle steering control method, a vehicle and a storage medium, which are used for solving the problem that a four-wheel drive differential steering technology cannot steer under the condition that the vehicle is stationary. In order to achieve the above object, a first aspect of the present disclosure provides a vehicle steering control method, the vehicle being provided with a first steering system that does not include a steering motor, the method comprising: in response to a vehicle entering a steering-in-place mode, acquiring steering information of a steering wheel, front wheel rotation angle information and rear wheel speed information of the vehicle, wherein the steering is performed by using the first steering system in the steering-in-place mode; Applying a driving torque to a driving motor corresponding to the rear wheel based on a speed deviation between an actual speed and a target speed of the rear wheel determined from the rear wheel speed information to make the rear wheel stationary; And under the condition that the rear wheels are determined to be stationary, applying driving torques with opposite directions to the driving motors corresponding to the two front wheels on the basis of the front wheel steering deviation determined by the steering wheel steering information and the front wheel steering angle information so as to control the vehicle to steer in place according to the steering wheel steering information. Optionally, before acquiring the steering wheel steering information, the front wheel steering angle information, and the rear wheel speed information of the vehicle in response to the vehicle entering the in-situ steering mode, the method further comprises: And acquiring the speed information of the vehicle, and prompting the vehicle to enter a steering-in-place mode when the vehicle is determined to be stationary according to the speed information. Optionally, the vehicle is further configured with a second steering system, the second steering system includes a steering motor, and the acquiring the vehicle speed information of the vehicle includes: And acquiring speed information of the vehicle in response to detecting that the second steering system fails. Optionally, the applying the driving torque to the driving motor corresponding to the rear wheel based on the speed deviation between the actual speed of the rear wheel and the target speed determined by the wheel