Search

CN-122009109-A - Vehicle redundant braking method, device, vehicle, storage medium and program product

CN122009109ACN 122009109 ACN122009109 ACN 122009109ACN-122009109-A

Abstract

The invention relates to the technical field of vehicle braking and discloses a vehicle redundant braking method, a device, a vehicle, a storage medium and a program product. And fusing the road adhesion coefficient with the actual vehicle speed, determining an anti-skid slip rate safety interval and converting the anti-skid slip rate safety interval into a rotating speed safety interval. And the actual rotation speed and the rotation speed safety interval of the driving motor are compared in real time, and the original braking torque is subjected to closed-loop correction, so that the finally output target braking torque is always constrained within the anti-skid dynamic stability boundary while fully meeting the braking intention of a driver. Therefore, unstable accidents such as sideslip, tail flick and the like of the vehicle are avoided in the redundant braking process, and the stability and the safety of the vehicle are ensured.

Inventors

  • XI ZHIGANG
  • ZHANG KAI
  • ZHANG MENG

Assignees

  • 重庆长安汽车股份有限公司

Dates

Publication Date
20260512
Application Date
20260313

Claims (15)

  1. 1. A method of redundant braking of a vehicle, the method comprising: Acquiring a wheel speed signal, a driving wheel slip rate and a road surface adhesion coefficient of a vehicle; Responding to a redundant braking request of a vehicle, correcting the wheel speed signal based on the driving wheel slip rate to obtain the actual speed of the vehicle, and determining the original braking torque required by a driver; Inquiring a slip rate safety interval matched with the road surface adhesion coefficient and the actual vehicle speed, and determining a rotating speed safety interval of a driving motor based on the slip rate safety interval and the actual vehicle speed; Correcting the original braking torque based on the actual rotation speed of the driving motor and the rotation speed safety interval to obtain a target braking torque; the vehicle is controlled to perform redundant braking based on the target braking torque.
  2. 2. The vehicle redundant braking method according to claim 1, wherein the correcting the original braking torque based on the actual rotational speed of the drive motor and the rotational speed safety interval to obtain a target braking torque includes: Based on the actual rotation speed and the rotation speed safety interval, obtaining a rotation speed error, and performing proportional integral adjustment according to the rotation speed error to obtain a torque correction amount; and obtaining a target braking torque according to the torque correction amount and the original braking torque.
  3. 3. The vehicle redundant braking method according to claim 1, characterized in that before controlling the vehicle to perform redundant braking based on the target braking torque, the method further comprises: If the actual vehicle speed is detected to be lower than a first vehicle speed threshold value, acquiring the gradient of a road where the vehicle is located, and inquiring a torque safety threshold value matched with the actual vehicle speed and the gradient; And updating the target braking torque according to the larger value of the torque safety threshold value and the target braking torque.
  4. 4. The vehicle redundant braking method according to claim 3, characterized in that the controlling the vehicle to perform redundant braking based on the target braking torque, comprises: distributing the target braking torque into a front axle braking torque and a rear axle braking torque based on the actual vehicle speed, the gradient, and a vehicle configuration of the vehicle; And controlling the vehicle to perform redundant braking based on the front axle braking torque and the rear axle braking torque.
  5. 5. The vehicle redundant braking method according to claim 4, characterized in that after controlling the vehicle to perform redundant braking based on the target braking torque, the method further comprises: Judging whether the front axle wheel slip rate and the rear axle wheel slip rate exceed a first slip rate threshold value or not; if the front axle wheel slip ratio exceeds the first slip ratio threshold, setting the front axle braking torque to zero, and transferring the front axle braking torque to the rear axle braking torque; If the rear axle wheel slip ratio exceeds the first slip ratio threshold, setting the rear axle braking torque to zero and transferring the rear axle braking torque to the front axle braking torque; And if the front axle wheel slip rate and the rear axle wheel slip rate both exceed the first slip rate threshold, applying preset braking torque to the front axle and the rear axle of the vehicle according to preset intervals.
  6. 6. The vehicle redundant braking method of claim 1, further comprising: Determining a deceleration safety threshold of the vehicle according to the battery charging power of the vehicle, the driver expected deceleration and the road adhesion coefficient; obtaining a braking speed safety threshold of the vehicle according to the deceleration safety threshold and the real-time vehicle distance between the vehicle and the front vehicle; And controlling the actual vehicle speed of the vehicle when redundant braking is performed not to exceed the braking vehicle speed safety threshold value.
  7. 7. The vehicle redundant braking method according to claim 6, wherein the determining the deceleration guard threshold of the vehicle based on the battery charge power of the vehicle, the driver's desired deceleration, and the road surface adhesion coefficient comprises: Determining battery limit deceleration corresponding to the battery charging power, and determining road surface limit deceleration corresponding to the road surface attachment coefficient; And obtaining a deceleration safety threshold of the vehicle according to smaller values of the battery limit deceleration, the road surface limit deceleration and the driver expected deceleration.
  8. 8. The vehicle redundant braking method according to claim 1, characterized in that after controlling the vehicle to perform redundant braking based on the target braking torque, the method further comprises: Monitoring a brake pedal travel rate of the vehicle in response to a request to park the vehicle; if the stroke change rate of the brake pedal is lower than a stroke change rate threshold, and the actual speed of the vehicle is lower than a second vehicle speed threshold, inquiring a parking torque matched with the actual speed of the vehicle, controlling the vehicle to park according to the parking torque until the actual speed of the vehicle is lower than a third vehicle speed threshold, setting the rotating speed of a driving motor to zero, and controlling the vehicle to park; And if the stroke change rate of the brake pedal is not lower than a stroke change rate threshold, controlling the vehicle to stop according to the target brake torque until the actual speed of the vehicle is lower than a third speed threshold, and controlling the vehicle to stop, wherein the third speed threshold is lower than the second speed threshold.
  9. 9. The vehicle redundant braking method according to any one of claims 1 to 8, wherein the correcting the wheel speed signal based on the drive wheel slip ratio to obtain an actual vehicle speed of the vehicle includes: judging whether the slip rate of the driving wheel exceeds a second slip rate threshold value; If the slip rate of the driving wheel exceeds the second slip rate threshold value, calculating a first average wheel speed of a driven wheel according to the wheel speed signal to obtain the actual speed of the vehicle; and if the slip rate of the driving wheel does not exceed a second slip rate threshold value, calculating a second average wheel speed of all the wheels according to the wheel speed signal to obtain the actual speed of the vehicle.
  10. 10. The vehicle redundant braking method according to claim 9, wherein the determining a rotational speed guard interval of a drive motor based on the slip ratio guard interval and the actual vehicle speed includes: Obtaining a wheel speed safety interval of a driving wheel according to the slip rate safety interval and the actual vehicle speed; And converting the wheel speed safety interval to obtain a rotation speed safety interval of the driving motor.
  11. 11. The vehicle redundant braking method according to any one of claims 1 to 8, wherein the determining the original braking torque demanded by the driver includes: acquiring actual acceleration and actual recovery torque of the vehicle; And calculating to obtain the vehicle resistance based on the actual acceleration and the actual recovery torque, and calculating to obtain the original braking torque required by the driver according to the vehicle resistance and the redundant braking acceleration threshold value.
  12. 12. A redundant brake apparatus for a vehicle, the apparatus comprising: the first processing module is used for acquiring wheel speed signals, driving wheel slip rate and road adhesion coefficient of the vehicle; the second processing module is used for responding to a redundant braking request of the vehicle, correcting the wheel speed signal based on the driving wheel slip rate, obtaining the actual speed of the vehicle and determining the original braking torque required by a driver; the third processing module is used for inquiring a slip rate safety interval matched with the road surface attachment coefficient and the actual vehicle speed and determining a rotating speed safety interval of the driving motor based on the slip rate safety interval and the actual vehicle speed; the fourth processing module is used for correcting the original braking torque based on the actual rotating speed of the driving motor and the rotating speed safety interval to obtain a target braking torque; And a fifth processing module for controlling the vehicle to perform redundant braking based on the target braking torque.
  13. 13. A vehicle, characterized by comprising: a memory and a processor communicatively coupled to each other, the memory having stored therein computer instructions that, upon execution, perform the vehicle redundancy braking method of any one of claims 1 to 11.
  14. 14. A computer-readable storage medium having stored thereon computer instructions for causing a computer to perform the vehicle redundancy braking method according to any one of claims 1 to 11.
  15. 15. A computer program product comprising computer instructions for causing a computer to perform the vehicle redundant braking method of any one of claims 1 to 11.

Description

Vehicle redundant braking method, device, vehicle, storage medium and program product Technical Field The invention relates to the technical field of vehicle braking, in particular to a vehicle redundant braking method, a device, a vehicle, a storage medium and a program product. Background With the development of vehicle driving systems, in particular the popularization of advanced driving assistance systems (ADVANCED DRIVER ASSISTANCE SYSTEMS, ADAS) and autopilot technology, there is an increasing demand for safety and reliability of vehicle braking systems. The traditional hydraulic braking system utilizes the incompressible characteristic of brake fluid to amplify and accurately transmit the pedal force of a driver foot to wheels so as to generate braking force, and the braking force is well performed in conventional braking, but the braking force is often reduced or even completely lost under the single-point failure modes such as signal loss of a wheel speed sensor, electromagnetic valve clamping stagnation or power interruption and the like, so that great potential safety hazards exist. Therefore, in order to meet the functional safety requirements, the vehicle needs to introduce a redundant braking mechanism, that is, when a main braking system (such as a hydraulic braking system and the like) fails or fails, a spare hardware or software passage is used to intervene and generate braking force so as to ensure that the vehicle can be safely decelerated or stopped and avoid accidents. Prior art redundant braking is typically achieved by controlling the vehicle to slow down or stop after a vehicle hydraulic system failure, using an electric motor to provide a variable recuperation torque that matches the brake pedal demand. It is often only focused on providing a braking force corresponding to the brake pedal, and the adhesion limit of the tire to the bottom surface is not sufficiently considered. On low-adhesion road surfaces (such as ice surfaces and wet road surfaces), excessive motor recovery torque is applied to extremely easily cause locking of driving wheels of a vehicle or excessive slip rate, so that unstable accidents such as sideslip and tail flick of the vehicle are caused, and the driving safety is seriously influenced under the extreme condition that hydraulic braking is failed. Disclosure of Invention The invention provides a vehicle redundant braking method, a device, a vehicle, a storage medium and a program product, which are used for solving the problem that the existing redundant braking scheme is easy to cause instability of the vehicle on a low-adhesion road surface. In a first aspect, the present invention provides a method of redundant braking of a vehicle, the method comprising: Acquiring a wheel speed signal, a driving wheel slip rate and a road surface adhesion coefficient of a vehicle; Responding to a redundant braking request of the vehicle, correcting a wheel speed signal based on a driving wheel slip rate to obtain the actual speed of the vehicle, and determining the original braking torque required by a driver; Inquiring a slip rate safety interval matched with the road surface adhesion coefficient and the actual vehicle speed, and determining a rotating speed safety interval of the driving motor based on the slip rate safety interval and the actual vehicle speed; Correcting the original braking torque based on the actual rotation speed and the rotation speed safety interval of the driving motor to obtain a target braking torque; The control vehicle performs redundant braking based on the target braking torque. The invention firstly dynamically corrects the wheel speed signal based on the slip rate of the driving wheel, ensures the reliability and accuracy of the actual vehicle speed, and avoids control failure caused by signal distortion. And fusing the road adhesion coefficient with the actual vehicle speed, determining an anti-skid slip rate safety interval and converting the anti-skid slip rate safety interval into a rotating speed safety interval. And the actual rotation speed and the rotation speed safety interval of the driving motor are compared in real time, and the original braking torque is subjected to closed-loop correction, so that the finally output target braking torque is always constrained within the anti-skid dynamic stability boundary while fully meeting the braking intention of a driver. Therefore, unstable accidents such as sideslip, tail flick and the like of the vehicle are avoided in the redundant braking process, and the stability and the safety of the vehicle are ensured. In some alternative embodiments, correcting the original braking torque based on the actual rotational speed and the rotational speed safety interval of the driving motor to obtain the target braking torque includes: based on the actual rotation speed and the rotation speed safety interval, obtaining a rotation speed error, and carrying out proportional integral adjustment acco