CN-121989877-A - Electric automobile braking method, system and equipment and electric automobile

CN121989877ACN 121989877 ACN121989877 ACN 121989877ACN-121989877-A

Abstract

The application discloses an electric vehicle braking method, an electric vehicle braking system, electric vehicle braking equipment and an electric vehicle, and relates to the technical field of electric vehicles; the method comprises the steps of determining an adjustment driving torque by performing closed-loop adjustment on the current longitudinal acceleration, wherein the direction of the adjustment driving torque is opposite to that of the current braking torque, and braking based on the current braking torque and the adjustment driving torque. According to the application, the adjusting driving torque with the opposite direction to the current braking torque is output in the braking process, so that the forward movement of the center of gravity of the vehicle can be reduced, the phenomenon of braking nodding is restrained, the comfort in the braking process is improved, and the user experience is effectively improved.

Inventors

Lei Lingding
LIU LIBO
XUE HUI
YAN LEYANG
JIN XIAOLONG

Assignees

苏州汇川联合动力系统股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (10)

1. An electric vehicle braking method, characterized in that the method comprises: Determining a current longitudinal acceleration while braking based on the current braking torque; Determining an adjustment driving torque by performing closed-loop adjustment on the current longitudinal acceleration, wherein the direction of the adjustment driving torque is opposite to the direction of the current braking torque; braking is performed based on the current braking torque and the adjustment driving torque.
2. The electric vehicle braking method according to claim 1, wherein the step of determining the current longitudinal acceleration when braking based on the current braking torque includes: judging whether the current vehicle speed is lower than a preset vehicle speed, whether the current braking pressure is higher than a preset pressure and whether the current gradient is lower than a preset gradient when braking is performed based on the current braking torque; When the current vehicle speed is lower than the preset vehicle speed, the current braking pressure is higher than the preset pressure, and the current gradient is lower than the preset gradient, a comfortable braking function is started; When the comfort braking function is on, a current longitudinal acceleration is determined.
3. The electric vehicle braking method of claim 2, wherein the step of determining an adjusted drive torque by closed loop adjustment of the current longitudinal acceleration comprises: acquiring a preset starting vehicle speed and a preset starting longitudinal acceleration which are configured when the comfortable braking function is started; acquiring a preset closing vehicle speed and a preset closing longitudinal acceleration which are configured when the comfortable braking function is closed; Determining a target longitudinal acceleration according to the current vehicle speed, the preset opening longitudinal acceleration, the preset closing vehicle speed and the preset closing longitudinal acceleration, wherein the target longitudinal acceleration is an ideal longitudinal acceleration which enables the impact degree in the braking process to be lower than a preset impact degree; an adjustment drive torque is determined by closed loop adjustment of the current longitudinal acceleration and the target longitudinal acceleration.
4. The electric vehicle braking method according to claim 3, characterized in that the step of determining an adjustment drive torque by closed-loop adjustment of the current longitudinal acceleration and the target longitudinal acceleration includes: Calculating a difference value between the target longitudinal acceleration and the current longitudinal acceleration to obtain a first difference value; determining a proportional gain and an integration time constant; And performing proportional integral operation on the first difference value through the proportional gain and the integral time constant to obtain the regulated driving torque.
5. The method for braking an electric vehicle according to claim 4, wherein the step of performing a proportional-integral operation on the first difference value by the proportional gain and the integral time constant to obtain the adjusted driving torque includes: Performing proportional integral operation on the first difference value through the proportional gain and the integral time constant to obtain initial compensation torque; calculating a difference value between the target longitudinal acceleration and the preset opening longitudinal acceleration to obtain a second difference value; determining a feedforward compensation torque according to the second difference value and the current driving force; And compensating the initial compensation torque through the feedforward compensation torque to obtain the adjustment driving torque.
6. The method of braking an electric vehicle according to claim 2, wherein the step of determining the current longitudinal acceleration when the comfort braking function is on includes: When the comfortable braking function is started, acquiring the current motor measurement angular acceleration; Inputting the current motor measured angular acceleration to a first preset linear observer to obtain the current motor observed angular acceleration; And determining the current longitudinal acceleration according to the current motor observation angular acceleration.
7. The electric vehicle braking method according to any one of claims 2 to 6, characterized in that the step of determining whether the current vehicle speed is lower than a preset vehicle speed, whether the current braking pressure is higher than a preset pressure, and whether the current gradient is lower than a preset gradient, when braking based on the current braking torque, further comprises: Acquiring a current measured vehicle speed; Inputting the current measured vehicle speed into a second preset linear observer to obtain a current observed vehicle speed and a current observed gradient parameter; And taking the current observed vehicle speed as a current vehicle speed, and determining a current gradient according to the current observed gradient parameter.
8. An electric vehicle braking system, the system comprising: The acceleration acquisition module is used for determining the current longitudinal acceleration when braking is performed based on the current braking torque; The driving torque output module is used for determining an adjusting driving torque by performing closed-loop adjustment on the current longitudinal acceleration, and the direction of the adjusting driving torque is opposite to that of the current braking torque; and the vehicle braking module is used for braking based on the current braking torque and the adjusting driving torque.
9. An electric vehicle brake apparatus, characterized in that the apparatus comprises a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the electric vehicle brake method according to any one of claims 1 to 7.
10. An electric vehicle characterized in that it comprises the electric vehicle brake apparatus according to claim 9.

Description

Electric automobile braking method, system and equipment and electric automobile Technical Field The application relates to the technical field of electric automobiles, in particular to an electric automobile braking method, an electric automobile braking system, electric automobile braking equipment and an electric automobile. Background With the recent rapid development of electric vehicles, users pay more and more attention to the comfort of driving the electric vehicles, such as smoothness during braking and parking. Frequent use of the braking system in driving, especially in urban environments, has a great impact on the user experience. At present, in the braking process, a brake system of a traditional electric automobile moves forward near the center of gravity of the vehicle when the vehicle is parked, and a brake nodding phenomenon of trembling or sudden stopping of the vehicle can occur, and the brake nodding phenomenon can bring uncomfortable feeling to a driver and passengers. Therefore, the traditional electric automobile has poor comfort in the braking process, and influences the user experience. The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present application and is not intended to represent an admission that the foregoing is prior art. Disclosure of Invention The application mainly aims to provide a streaming data writing method, a streaming data writing device, streaming data writing equipment and a storage medium, and aims to solve the technical problems that in the prior art, comfort is poor in a braking process and user experience is affected. In order to achieve the above object, the present application provides a braking method for an electric vehicle, the method comprising: Determining a current longitudinal acceleration while braking based on the current braking torque; Determining an adjustment driving torque by performing closed-loop adjustment on the current longitudinal acceleration, wherein the direction of the adjustment driving torque is opposite to the direction of the current braking torque; braking is performed based on the current braking torque and the adjustment driving torque. In one embodiment, the step of determining the current longitudinal acceleration when braking based on the current braking torque includes: judging whether the current vehicle speed is lower than a preset vehicle speed, whether the current braking pressure is higher than a preset pressure and whether the current gradient is lower than a preset gradient when braking is performed based on the current braking torque; When the current vehicle speed is lower than the preset vehicle speed, the current braking pressure is higher than the preset pressure, and the current gradient is lower than the preset gradient, a comfortable braking function is started; When the comfort braking function is on, a current longitudinal acceleration is determined. In an embodiment, the step of determining the adjusted driving torque by closed loop adjustment of the current longitudinal acceleration comprises: acquiring a preset starting vehicle speed and a preset starting longitudinal acceleration which are configured when the comfortable braking function is started; acquiring a preset closing vehicle speed and a preset closing longitudinal acceleration which are configured when the comfortable braking function is closed; Determining a target longitudinal acceleration according to the current vehicle speed, the preset opening longitudinal acceleration, the preset closing vehicle speed and the preset closing longitudinal acceleration, wherein the target longitudinal acceleration is an ideal longitudinal acceleration which enables the impact degree in the braking process to be lower than a preset impact degree; an adjustment drive torque is determined by closed loop adjustment of the current longitudinal acceleration and the target longitudinal acceleration. In an embodiment, the step of determining the adjusted drive torque by closed loop adjustment of the current longitudinal acceleration and the target longitudinal acceleration comprises: Calculating a difference value between the target longitudinal acceleration and the current longitudinal acceleration to obtain a first difference value; determining a proportional gain and an integration time constant; And performing proportional integral operation on the first difference value through the proportional gain and the integral time constant to obtain the regulated driving torque. In an embodiment, the step of performing a proportional-integral operation on the first difference through the proportional gain and the integral time constant to obtain the adjusted driving torque includes: Performing proportional integral operation on the first difference value through the proportional gain and the integral time constant to obtain initial compensation torque; calculating a difference value between the target lo