CN-121536176-B - Wheel speed difference control method and system, whole vehicle controller, electric vehicle and medium

CN121536176BCN 121536176 BCN121536176 BCN 121536176BCN-121536176-B

Abstract

The disclosure relates to a wheel speed difference control method and system, a whole vehicle controller, an electric vehicle and a medium. The wheel speed difference control method comprises the steps of obtaining a current vehicle speed, a current wheel speed and a current actual output torque of a motor, calculating a wheel speed difference between a driving wheel and a follower wheel according to the current wheel speed, judging whether a torque pull-back function is activated according to the current vehicle speed and the wheel speed difference, determining a target anti-drag torque according to the current actual output torque of the motor and a pull-back coefficient under the condition that the torque pull-back function is activated, and requesting the target anti-drag torque to a motor controller. The method and the device can monitor the wheel speed difference trend in real time, and stably reduce the wheel speed difference before the ABS false triggering through the request strategy of intelligently adjusting the anti-dragging torque, so that the energy recovery process is ensured to be continuous and efficient, and the driving texture is improved.

Inventors

LI HAN
CAO HAO
WANG QI
ZHANG XIANG
WANG YUHAO
LIU BO
CHEN LUMING
CHENG MINGLIANG
WEI AOFENG
SHEN PENGFEI

Assignees

江苏国创新能源商用车创新技术有限公司

Dates

Publication Date: 20260508
Application Date: 20260120

Claims (17)

1. A wheel speed difference control method, comprising: Acquiring a current vehicle speed, a current wheel speed and a current actual output torque of a motor; Calculating the wheel speed difference between the driving wheel and the follower wheel according to the current wheel speed; Judging whether a torque pull-back function is activated or not according to the current vehicle speed and the wheel speed difference; under the condition that the torque pull-back function is activated, determining a target anti-drag torque according to the current actual output torque and a pull-back coefficient of the motor; Requesting the target counter-drag torque from a motor controller; Determining the magnitude of a torque up gradient according to the range of the target anti-tug torque under the condition that an energy recovery start signal is detected, wherein the torque up gradient is the magnitude of the target anti-tug torque increased within a preset time, and determining the magnitude of the torque up gradient according to the range of the target anti-tug torque comprises determining the magnitude of the torque up gradient to be a first torque up gradient under the condition that the target anti-tug torque is increased from 0 to a first preset torque, wherein the first torque up gradient is smaller than the preset torque up gradient; and increasing the target counter-drag torque according to the magnitude of the torque increasing gradient, wherein increasing the target counter-drag torque according to the magnitude of the torque increasing gradient comprises increasing the target counter-drag torque by using the first torque increasing gradient when the target counter-drag torque increases from 0 to the first predetermined torque.
2. The wheel speed difference control method according to claim 1, wherein: Determining the magnitude of the torque increasing gradient according to the range of the target anti-tug torque comprises determining the magnitude of the torque increasing gradient as a second torque increasing gradient when the target anti-tug torque increases from the first preset torque to a second preset torque, wherein the second preset torque is larger than the first preset torque, and the second torque increasing gradient is larger than the first torque increasing gradient; The increasing the target counter-drag torque according to the magnitude of the torque increasing gradient includes increasing the target counter-drag torque with the second torque increasing gradient if the target counter-drag torque increases from the first predetermined torque to the second predetermined torque.
3. The wheel speed difference control method according to claim 2, wherein: determining the magnitude of the torque up gradient according to the range of the target anti-drag torque comprises determining the magnitude of the torque up gradient as the first torque up gradient under the condition that the target anti-drag torque increases from the second preset torque; The increasing the target counter-drag torque according to the magnitude of the torque increasing gradient includes increasing the target counter-drag torque using the first torque increasing gradient.
4. The wheel speed difference control method according to any one of claims 1 to 3, further comprising: And under the condition that the torque back pulling function is not activated, executing the steps of determining the magnitude of the torque increasing gradient according to the range of the target back pulling torque and increasing the target back pulling torque according to the magnitude of the torque increasing gradient.
5. The wheel speed difference control method according to any one of claims 1 to 3, wherein the calculating of the wheel speed difference between the drive wheel and the follow-up wheel includes: Determining the wheel speed of the driving wheel according to the average value of the wheel speeds of the two driving wheels; determining the wheel speed of the follower according to the average value of the wheel speeds of the two follower wheels; And determining the wheel speed difference according to the difference between the wheel speed of the driving wheel and the wheel speed of the follow-up wheel.
6. The wheel speed difference control method according to any one of claims 1 to 3, wherein the pullback coefficient is greater than 0 and less than 1, The determining the target anti-dragging torque according to the current actual output torque and the pullback coefficient of the motor comprises the following steps: And determining the target anti-dragging torque according to the product of the current actual output torque of the motor and the pull-back coefficient.
7. The wheel speed difference control method according to any one of claims 1 to 3, wherein the determining whether to activate a torque pullback function according to the current vehicle speed and the wheel speed difference includes: Activating the torque pullback function if the current vehicle speed and the wheel speed difference satisfy an activation condition, wherein the activation condition includes any one of a first activation condition and a second activation condition, the first activation condition being that the current vehicle speed is less than a predetermined vehicle speed and an absolute value of the wheel speed difference is greater than a first predetermined wheel speed difference, the second activation condition being that the current vehicle speed is greater than or equal to a predetermined vehicle speed and an absolute value of the wheel speed difference is greater than a first predetermined proportion of the current vehicle speed, the first predetermined proportion being greater than 0 and less than 1; in the case where the current vehicle speed and the wheel speed difference do not satisfy the activation condition, the torque pullback function is not activated.
8. The wheel speed difference control method according to claim 7, further comprising: Under the condition that the torque pullback function is activated, judging whether to close the torque pullback function according to the current speed and the wheel speed difference; executing the step of determining the magnitude of the torque increasing gradient according to the range of the target anti-dragging torque and increasing the target anti-dragging torque according to the magnitude of the torque increasing gradient under the condition that the torque back-dragging function is closed; And under the condition that the torque pullback function is not closed, executing the step of determining the target anti-tug torque according to the current actual output torque and the pullback coefficient of the motor.
9. The wheel speed difference control method according to claim 8, wherein the determining whether to turn off the torque pullback function according to the current vehicle speed and the wheel speed difference includes: closing the torque pullback function in a case where the current vehicle speed and the wheel speed difference satisfy a closing condition, wherein the closing condition includes any one of a first closing condition that the current vehicle speed is smaller than a predetermined vehicle speed and an absolute value of the wheel speed difference is smaller than a second predetermined wheel speed difference, and a second closing condition that the current vehicle speed is equal to or greater than a predetermined vehicle speed and the absolute value of the wheel speed difference is smaller than a second predetermined ratio of the current vehicle speed that is greater than 0 and smaller than 1; In the case where the current vehicle speed and the wheel speed difference do not satisfy the closing condition, the torque pullback function is not turned off.
10. The wheel speed difference control method according to claim 9, wherein: the second predetermined wheel speed difference is less than the first predetermined wheel speed difference; the second predetermined ratio is less than the first predetermined ratio.
11. The wheel speed difference control method according to any one of claims 1 to 3, wherein the energy recovery start signal includes at least one of an accelerator pedal release signal and a brake pedal tip-in signal.
12. A vehicle control unit comprising: The parameter acquisition module is configured to acquire the current vehicle speed, the current wheel speed and the current actual output torque of the motor; A wheel speed difference calculation module configured to calculate a wheel speed difference between a driving wheel and a follower wheel from the current wheel speed; the pull-back judging module is configured to judge whether to activate a torque pull-back function according to the current vehicle speed and the wheel speed difference; the reverse dragging torque determining module is configured to determine target reverse dragging torque according to current actual output torque of the motor and a dragging coefficient under the condition that the torque dragging function is activated; A counterdrag torque request module configured to request the target counterdrag torque from a motor controller; The whole vehicle controller is configured to determine the magnitude of a torque increasing gradient according to the range of the target anti-tugging torque under the condition that an energy recovery starting signal is detected, and increase the target anti-tugging torque according to the magnitude of the torque increasing gradient; The whole vehicle controller is used for determining the magnitude of a torque increasing gradient according to the range of the target anti-tugging torque, and is configured to determine that the magnitude of the torque increasing gradient is a first torque increasing gradient and increase the target anti-tugging torque by adopting the first torque increasing gradient under the condition that the target anti-tugging torque is increased from 0 to a first preset torque according to the magnitude of the torque increasing gradient, wherein the first torque increasing gradient is smaller than the preset torque increasing gradient.
13. A vehicle control unit comprising: A memory for storing instructions; The processor is configured to execute the instruction, so that the whole vehicle controller implements the wheel speed difference control method according to any one of claims 1 to 11.
14. A wheel speed difference control system comprising the vehicle controller according to claim 12 or 13.
15. An electric vehicle comprising the wheel speed difference control system according to claim 14.
16. A computer-readable storage medium storing computer instructions that, when executed by a processor, implement the wheel speed difference control method of any one of claims 1-11.
17. A computer program product comprising a computer program, wherein the computer program, when executed by a processor, implements the wheel speed difference control method of any one of claims 1-11.

Description

Wheel speed difference control method and system, whole vehicle controller, electric vehicle and medium Technical Field The disclosure relates to the technical field of electric automobile control, in particular to a wheel speed difference control method and system, a whole vehicle controller, an electric automobile and a medium. Background With the popularization of electric automobiles, energy recovery technology has become a key means for improving the endurance mileage of vehicles. When the vehicle slides or brakes, the driving motor is converted from an electric state to a power generation state, and a reverse dragging torque opposite to the rotation direction of the wheels is generated, so that the kinetic energy of the vehicle is converted into electric energy and stored in a battery. Disclosure of Invention The inventor found through research that the related art wheel speed difference control strategy has a significant problem in that unexpected wheel speed differences may be generated between a driving wheel (typically rear wheel) and a follow-up steering wheel (typically front wheel) due to load transfer of the entire vehicle, road adhesion coefficient variation, or too fast torque request, etc. during application or increase of the anti-drag torque. When the wheel speed difference exceeds a threshold value preset by an anti-lock brake system (ABS) controller, the ABS can misjudge that locking slip occurs on the driving wheel and then is activated. After the ABS is activated, an activation signal is sent to a Vehicle Control Unit (VCU) through a CAN network. To ensure safety, the VCU immediately instructs the drive motor to clear or greatly reduce the anti-drag torque. The above-mentioned process of the related art causes a technical problem in that the energy recovery process is suddenly interrupted, remarkably reducing the energy recovery efficiency of the whole vehicle and shortening the endurance mileage. In view of at least one of the above technical problems, the present disclosure provides a wheel speed difference control method and system, a vehicle control unit, an electric vehicle, and a medium, capable of monitoring a wheel speed difference trend in real time, and smoothly reducing a wheel speed difference before an ABS false trigger by intelligently adjusting a request strategy of a reverse drag torque. According to one aspect of the present disclosure, there is provided a wheel speed difference control method including: Acquiring a current vehicle speed, a current wheel speed and a current actual output torque of a motor; Calculating the wheel speed difference between the driving wheel and the follower wheel according to the current wheel speed; Judging whether a torque pull-back function is activated or not according to the current vehicle speed and the wheel speed difference; under the condition that the torque pull-back function is activated, determining a target anti-drag torque according to the current actual output torque and a pull-back coefficient of the motor; requesting the target counter-drag torque from the motor controller. In some embodiments of the present disclosure, the wheel speed difference control method further includes: Under the condition that an energy recovery starting signal is detected, determining the magnitude of a torque increasing gradient according to the range of the target anti-dragging torque, wherein the torque increasing gradient is the magnitude of the target anti-dragging torque increased in a preset time, and increasing the target anti-dragging torque according to the magnitude of the torque increasing gradient. In some embodiments of the present disclosure, the determining the magnitude of the torque multiplication gradient according to the range of the target anti-tug torque includes determining the magnitude of the torque multiplication gradient as a first torque multiplication gradient if the target anti-tug torque increases from 0 to a first predetermined torque, wherein the first torque multiplication gradient is less than the predetermined torque multiplication gradient. In some embodiments of the present disclosure, the increasing the target counter-drag torque according to the magnitude of the torque up gradient includes increasing the target counter-drag torque with the first torque up gradient if the target counter-drag torque increases from 0 to the first predetermined torque. In some embodiments of the present disclosure, the determining the magnitude of the torque multiplication gradient according to the range of the target counter-drag torque includes determining the magnitude of the torque multiplication gradient to be a second torque multiplication gradient if the target counter-drag torque increases from the first predetermined torque to a second predetermined torque, wherein the second predetermined torque is greater than the first predetermined torque and the second torque multiplication gradient is greater than the first to