CN117325837A

CN117325837A - Vehicle brake control method and device, readable storage medium, chip and vehicle

Info

Publication number: CN117325837A
Application number: CN202210745462.0A
Authority: CN
Inventors: 谷文豪
Original assignee: Xiaomi Automobile Technology Co Ltd
Current assignee: Xiaomi Automobile Technology Co Ltd
Priority date: 2022-06-27
Filing date: 2022-06-27
Publication date: 2024-01-02

Abstract

The present disclosure relates to a vehicle brake control method, device, readable storage medium, chip, and vehicle. The method comprises the following steps: under the condition that an automatic bus parking AVP is started, if an ESP of a vehicle body electronic stability system fails, acquiring the shaft speed of a power motor; determining whether a vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold according to a shaft speed of the power motor; when the speed of the vehicle is greater than the first vehicle speed threshold, the backup brake controller controls hydraulic braking to apply regular braking force to the vehicle; in the process of applying the regular braking force to the vehicle, parking braking is performed according to the shaft speed of the power motor and the longitudinal acceleration control of the vehicle. Therefore, under the condition that the ESP fails, the backup brake controller is utilized, an additional wheel speed sensor is not added, the brake control of the vehicle can be realized, parts and wiring harnesses are reduced, and the mounting difficulty and cost of the vehicle are reduced.

Description

Vehicle brake control method and device, readable storage medium, chip and vehicle

Technical Field

The disclosure relates to the technical field of automatic driving, and in particular relates to a vehicle braking control method and device, a readable storage medium, a chip and a vehicle.

Background

Currently, more and more vehicles start to be equipped with an automatic driving system of L3 level or more and an automatic driving system of L3 level or more, and the braking systems of L3 and L3 level or more are provided with a brake redundancy backup system, and when the braking of the main braking unit fails, the redundancy braking unit is required to replace the main braking unit to perform braking. The automatic bus parking (Automated Valet Parking, AVP) function is a function with higher utilization rate in an automatic driving system, and a brake redundancy backup system is also required to ensure the running safety of the vehicle in an AVP scene. In the related art, when the main braking unit fails, the backup braking control unit is connected with the wheel speed sensor to realize the braking redundancy requirement in an AVP scene, so that parts and wire harnesses are correspondingly increased, and the assembly difficulty of the vehicle and the cost of the vehicle are increased.

Disclosure of Invention

To overcome the problems in the related art, the present disclosure provides a vehicle brake control method, apparatus, readable storage medium, chip, and vehicle.

According to a first aspect of an embodiment of the present disclosure, there is provided a vehicle brake control method including:

under the condition that an automatic bus parking AVP is started, if an ESP of a vehicle body electronic stability system fails, acquiring the shaft speed of a power motor;

Determining whether a vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold according to a shaft speed of the power motor;

when the speed of the vehicle is greater than the first vehicle speed threshold, the backup brake controller controls hydraulic braking to apply regular braking force to the vehicle;

in the process of applying the regular braking force to the vehicle, parking braking is performed according to the shaft speed of the power motor and the longitudinal acceleration control of the vehicle.

Optionally, the parking brake is controlled according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle, and the method comprises the following steps:

starting timing while applying a regular braking force to the vehicle;

determining whether a body of the vehicle is in a stable state according to a shaft speed of the power motor and a longitudinal acceleration of the vehicle;

when the vehicle body of the vehicle is in a stable state and the braking time period is longer than a preset first braking time period, controlling to release the regular braking force and controlling an electronic parking brake system EPB to brake;

when the vehicle body of the vehicle is not in a stable state and the braking time period is longer than a preset second braking time period, the regular braking force is controlled to be released, and the EPB is controlled to brake, wherein the first braking time period is shorter than the second braking time period.

Optionally, the determining whether the body of the vehicle is in a stable state according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle includes:

and if the longitudinal acceleration of the vehicle is judged to generate corresponding regular change and the shaft speed of the power motor is judged to steadily decrease under the condition that the wheels of the vehicle are not locked, determining that the body of the vehicle is in a steady state.

under the condition that wheels of the vehicle are locked, if the longitudinal acceleration of the vehicle is judged to not generate corresponding regular change and the shaft speed of the power motor is judged to be rapidly reduced, the regular braking force is controlled to be released within a preset third braking duration, and after the regular braking force is recovered, the recovery rate and the recovery amplitude of the shaft speed of the power motor are determined;

and if the recovery rate and the recovery amplitude meet the preset stable conditions, determining that the vehicle body of the vehicle is in a stable state.

Optionally, the determining whether the vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold according to the shaft speed of the power motor includes:

Under the condition that regular braking force is applied to the vehicle, if the longitudinal acceleration of the vehicle generates corresponding regular change and the wheels of the vehicle are not locked, taking the shaft speed of the power motor as the speed of the vehicle, and determining whether the speed of the vehicle is greater than a preset first vehicle speed threshold value;

under the condition that regular braking force is applied to the vehicle, if the longitudinal acceleration of the vehicle does not generate corresponding regular change and the shaft speed of the power motor is smaller than a preset shaft speed threshold value, controlling to release the regular braking force in a preset fourth braking duration, and after the regular braking force is recovered, determining the recovery rate and the recovery amplitude of the shaft speed of the power motor;

if the recovery rate and the recovery amplitude are within a predetermined interval, determining that the vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold;

and if the recovery rate and the recovery amplitude are not in the preset interval, determining that the speed of the vehicle is not greater than the first vehicle speed threshold value.

Optionally, the method further comprises:

when the speed of the vehicle is not greater than the first speed threshold, the backup brake controller controls hydraulic braking to generate allowable maximum braking force and starts timing;

Determining, during braking at the allowable maximum braking force, whether a vehicle speed of the vehicle is less than a predetermined second vehicle speed threshold according to a shaft speed of the power motor;

if the speed of the vehicle is smaller than the second vehicle speed threshold value, controlling the EPB to brake and controlling the allowable maximum braking force to be released;

and if the speed of the vehicle is not less than the second vehicle speed threshold value and the timing duration is greater than a preset third braking duration, controlling the EPB to brake and releasing the allowed maximum braking force.

Optionally, the method further comprises:

when the AVP is on, controlling the vehicle speed to be less than the first vehicle speed threshold when it is determined that the vehicle arrives at the parking lot entrance or the ambient temperature is determined to be lower than a predetermined ambient temperature threshold.

According to a second aspect of the embodiments of the present disclosure, there is provided a vehicle brake control device including:

the acquisition module is configured to acquire the shaft speed of the power motor if the ESP of the electronic stability system of the vehicle body fails under the condition that the automatic bus parking AVP is started;

a determination module configured to determine whether a vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold based on a shaft speed of the power motor;

A first control module configured to control hydraulic braking by a backup brake controller to apply a regular braking force to the vehicle when a vehicle speed of the vehicle is greater than the first vehicle speed threshold;

and a second control module configured to control parking brake according to a shaft speed of the power motor and a longitudinal acceleration of the vehicle during application of the regular braking force to the vehicle.

According to a third aspect of embodiments of the present disclosure, there is provided a computer-readable storage medium having stored thereon computer program instructions which, when executed by a first processor, implement the steps of the vehicle brake control method provided by the first aspect of the present disclosure.

According to a fourth aspect of embodiments of the present disclosure, there is provided a vehicle comprising:

a second processor;

a second memory for storing the second processor-executable instructions;

wherein the second processor is configured to:

According to a fifth aspect of embodiments of the present disclosure, there is provided a chip comprising a third processor and an interface; the third processor is configured to read instructions to perform the vehicle brake control method provided in the first aspect of the present disclosure.

The technical scheme provided by the embodiment of the disclosure can comprise the following beneficial effects:

when the ESP is invalid and the vehicle speed is larger than a first vehicle speed threshold value under the condition that the AVP is opened, the backup brake controller performs parking brake according to the shaft speed of the power motor and the longitudinal acceleration control of the vehicle in the process of applying regular braking force to the vehicle. Therefore, under the condition of ESP failure, the backup brake controller does not increase an additional wheel speed sensor, can also realize the brake control requirement, reduces parts and wiring harnesses, and reduces the mounting difficulty and cost of the vehicle.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.

Fig. 1 is a flowchart illustrating a vehicle brake control method according to an exemplary embodiment.

Fig. 2 is a flowchart showing a vehicle brake control method according to another exemplary embodiment.

Fig. 3 is a block diagram illustrating a vehicle brake control apparatus according to an exemplary embodiment.

Fig. 4 is a block diagram illustrating an apparatus for vehicle brake control according to an exemplary embodiment.

FIG. 5 is a functional block diagram of a vehicle, according to an exemplary embodiment.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.

It should be noted that, all actions for acquiring signals, information or data in the present application are performed under the condition of conforming to the corresponding data protection rule policy of the country of the location and obtaining the authorization given by the owner of the corresponding device.

The vehicle in this aspect may include a primary brake controller and a backup brake controller, the present aspect being applied to the backup brake controller.

Fig. 1 is a flowchart illustrating a vehicle brake control method according to an exemplary embodiment, including the following steps, as shown in fig. 1.

In step S101, if the vehicle body electronic stability system (Electronic Stability Program, ESP) fails when the AVP is on, the shaft speed of the power motor is acquired.

ESP may be considered a main brake controller of the vehicle and a backup brake controller may employ a decoupled service brake (Decoupled Power Brake, DPB) or an electronically controlled brake service system (iBooster). When the ESP fails, the backup brake controller obtains the shaft speed of the power unit motor (referred to herein as the power motor). The shaft speed of the power motor can be obtained through a shaft speed sensor arranged in the power motor.

In step S102, it is determined whether the vehicle speed is greater than a predetermined first vehicle speed threshold value based on the shaft speed of the power motor.

The first vehicle speed threshold may be preset by the designer and may be, for example, 15kph.

When the ESP fails, the wheel speed sensor inside the ESP may be considered to be in a failure state, and the vehicle speed of the vehicle cannot be acquired through the wheel speed sensor in the ESP, and it may be determined whether the vehicle speed is greater than 15kph at this time according to the shaft speed of the power motor.

In step S103, when the vehicle speed of the vehicle is greater than the first vehicle speed threshold, the backup brake controller controls to perform hydraulic braking to apply a regular braking force to the vehicle.

When the speed of the vehicle is greater than the first speed threshold, it may be considered that the speed of the vehicle is faster at this time, and anti-lock braking control of the wheels of the vehicle is required, the backup driving motor in the DPB may control the hydraulic braking mechanism to generate a regular braking force, which may be a periodic braking force, for example, a sinusoidal braking force, a sawtooth braking force, or a square wave braking force.

In step S104, in the course of applying a regular braking force to the vehicle, the parking brake is controlled according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle.

The longitudinal acceleration of the vehicle may be acquired by a longitudinal acceleration sensor provided on the vehicle body. Whether the vehicle is in a stable state or not can be accurately judged according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle, so that the parking brake can be safely performed accordingly.

According to the technical scheme, under the condition that the AVP is started, when the ESP fails and the vehicle speed is larger than the first vehicle speed threshold value, the backup brake controller performs parking brake according to the shaft speed of the power motor and the longitudinal acceleration control of the vehicle in the process of applying the regular braking force to the vehicle. Therefore, under the condition of ESP failure, the backup brake controller does not increase an additional wheel speed sensor, can also realize the brake control requirement, reduces parts and wiring harnesses, and reduces the mounting difficulty and cost of the vehicle.

In still another embodiment, the parking brake according to the shaft speed of the power motor and the longitudinal acceleration control of the vehicle in step S104 may include:

starting timing while applying a regular braking force to the vehicle;

when the body of the vehicle is in a stable state and the braking time period is longer than a preset first braking time period, controlling to release the regular braking force and controlling the electronic parking brake system EPB to brake;

When regular braking force is applied to the front and rear axles of the vehicle, unsprung vibration excitation drives the body of the vehicle to generate regular pitching motion, so that the vehicle is caused to shake. When the regular braking force is released, if the adhesive force on the ground is enough, the wheels are driven to rotate due to the inertia of the forward motion of the vehicle, so that the motor shaft speed of the front and rear shaft power motor is restored, and the sliding condition of the current wheels can be obtained according to the restoring speed and amplitude of the shaft speed. The magnitude of the longitudinal acceleration may characterize the intensity of the vehicle's body shaking when the vehicle is braked by the regular braking force, and thus it may be determined whether the vehicle's body is in a stable state or not based on the shaft speed and the longitudinal acceleration.

The first braking duration may be preset by the designer and may be, for example, 6s. When it is determined that the body of the vehicle is in a stable state and the braking time period is longer than the first braking time period, the vehicle may be considered to be stationary, the backup drive motor may be controlled to release the regular braking force, and the electronic parking brake system (Electrical Park Brake, EPB) may be controlled to clamp the parking caliper.

The second braking duration may be preset by the designer and may be, for example, 10s. When the vehicle body of the vehicle is not in a stable state, whether the vehicle is close to a standstill or not cannot be judged, and meanwhile, dangerous situations such as rollover and the like of the vehicle can be possibly caused, but when the braking time is longer than the second braking time, the vehicle can be considered to be stationary at the moment, the backup driving motor can be controlled to release the regular braking force, and the EPB is controlled to clamp the parking calipers.

In this embodiment, when the ESP fails and the vehicle speed is large, the DPB can perform anti-lock brake control of the vehicle according to the motor shaft speed and the vehicle longitudinal acceleration without adding an additional wheel speed sensor.

In still another embodiment, the determining whether the body of the vehicle is in a stable state according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle may include:

when the wheels of the vehicle are not locked, if it is determined that the longitudinal acceleration of the vehicle generates corresponding regular change and the shaft speed of the power motor is stably reduced, the body of the vehicle is determined to be in a stable state.

Whether or not the wheel is locked may be judged according to a method in the related art. The corresponding regular change is a regular change corresponding to the regular braking force, and can be obtained in advance through a test method.

There are various methods for determining whether the shaft speed of the power motor steadily decreases. For example, when the falling speed of the shaft speed is smaller than a predetermined falling threshold value for a predetermined period of time, it is determined that the shaft speed thereof steadily falls.

When it is determined that the longitudinal acceleration of the vehicle generates a regular change corresponding to a regular braking force applied to the vehicle and it is determined that the shaft speed of the power motor steadily decreases, it is considered that irregular sloshing of the vehicle body does not occur at this time, and that the vehicle body is in a steady state.

In this embodiment, in the case where locking of the wheels of the vehicle does not occur, it is determined whether the body of the vehicle is in a stable state or not according to the longitudinal acceleration of the vehicle and the shaft speed of the power motor, with high accuracy.

under the condition that wheels of a vehicle are locked, if it is judged that the longitudinal acceleration of the vehicle does not generate corresponding regular change and the shaft speed of the power motor is judged to be fast reduced, the regular braking force is controlled to be released within a preset third braking duration, and after the regular braking force is restored, the restoration rate and the restoration amplitude of the shaft speed of the power motor are determined;

and if the recovery rate and the recovery amplitude meet the preset stable conditions, determining that the body of the vehicle is in a stable state.

The third braking duration may be preset by the designer and may be, for example, 200ms. There are various methods for determining whether the shaft speed of the power motor is rapidly lowered. For example, when the falling speed of the shaft speed is greater than a predetermined falling threshold value for a predetermined period of time, it is determined that the shaft speed thereof falls rapidly.

Whether or not the wheel is locked may be judged according to a method in the related art. When it is determined that the longitudinal acceleration of the vehicle does not generate a regular change corresponding to the regular braking force and it is determined that the shaft speed of the power motor is rapidly lowered under the condition that the wheels of the vehicle are locked, it can be considered that the vehicle body of the vehicle is severely rocked at this time and dangerous situations such as sideslip and the like may occur, and therefore, the backup drive motor is controlled to release the regular braking force for the third braking duration. The recovery rate and recovery amplitude of the motor shaft speed of the power motor are the rate and amplitude between the moment when the regular braking force is released and the moment when the corresponding regular change is recovered, respectively.

The predetermined steady condition may be that the recovery rate is greater than the rate threshold and the recovery amplitude is greater than the amplitude threshold. The rate threshold and the amplitude threshold may be preset by a designer. If the predetermined stability condition is determined to be satisfied, it is considered that the motor shaft speed of the power motor can quickly recover the corresponding regular change, and thus it is determined that the body of the vehicle is in a stable state.

In this embodiment, the stable state of the vehicle body can be determined with high accuracy in the event of wheel locking.

In still another embodiment, determining whether the vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold based on the shaft speed of the power motor in step S102 may include:

under the condition that regular braking force is applied to the vehicle, if the longitudinal acceleration of the vehicle does not generate corresponding regular change and the shaft speed of the power motor is smaller than a preset shaft speed threshold value, controlling to release the regular braking force within a preset fourth braking duration, and determining the recovery rate and the recovery amplitude of the shaft speed of the power motor after recovering the regular braking force;

If the recovery rate and the recovery amplitude are within the preset interval, determining that the speed of the vehicle is greater than a preset first vehicle speed threshold;

if the recovery rate and the recovery amplitude are not within the predetermined interval, it is determined that the vehicle speed is not greater than the first vehicle speed threshold.

When the longitudinal acceleration of the vehicle generates corresponding regular changes and the wheels of the vehicle are not locked under the condition that the regular braking force is applied to the vehicle, the shaft speed of the power motor is considered to be the same as the speed of the current vehicle, and whether the speed of the current vehicle is greater than the first speed threshold value can be determined by judging whether the shaft speed is greater than the first speed threshold value.

The axle speed threshold may be preset by the designer and may be, for example, 15kph. When the longitudinal acceleration of the vehicle does not generate corresponding regular change and the shaft speed of the power motor is smaller than the shaft speed threshold, the dangerous situations such as sideslip, tail flick and the like of the vehicle can be considered to happen, the regular braking force can be controlled to be released within a preset fourth braking duration, and then whether the speed of the vehicle is larger than the first vehicle speed threshold is judged according to the recovery speed and the recovery amplitude of the shaft speed of the power motor. The fourth braking duration may be preset by the designer and may be, for example, 200ms.

The recovery rate and recovery amplitude at a predetermined interval rate may be, for example: the recovery rate is greater than the rate threshold and the recovery amplitude is greater than the amplitude threshold. The rate threshold and the amplitude threshold may be preset by a designer. If the recovery rate is determined to be greater than the rate threshold and the recovery amplitude is greater than the amplitude threshold, the vehicle speed of the vehicle may be considered to be greater than the first vehicle speed threshold. When the recovery rate is less than the rate threshold or the recovery amplitude is less than the amplitude threshold, the recovery rate and the recovery amplitude may be considered not to be within a predetermined interval, thereby determining that the vehicle speed of the vehicle is not greater than the first vehicle speed threshold.

In this embodiment, in the case of applying a regular braking force to the vehicle, it is determined whether the vehicle speed of the vehicle is greater than the first vehicle speed threshold value according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle, and there is no need to additionally provide a wheel speed sensor, so that parts and wiring harnesses are reduced, and the difficulty and cost of mounting the vehicle are reduced.

In yet another embodiment, the method further comprises:

when the speed of the vehicle is not greater than the first speed threshold, the backup brake controller controls the hydraulic brake to generate the allowable maximum braking force and starts timing;

determining, during braking with the allowable maximum braking force, whether a vehicle speed of the vehicle is less than a predetermined second vehicle speed threshold according to a shaft speed of the power motor;

If the speed of the vehicle is smaller than a second vehicle speed threshold value, the EPB is controlled to brake and release the allowed maximum braking force;

and if the speed of the vehicle is not less than the second vehicle speed threshold value and the timing duration is greater than the preset third braking duration, controlling the EPB to brake and controlling the EPB to release the allowed maximum braking force.

When the vehicle speed is smaller than a certain value, the vehicle can be braked regardless of whether the wheel locking condition of the vehicle occurs, and the backup driving motor can control the service braking mechanism to generate the allowed maximum braking force to brake. The second vehicle speed threshold may be preset by the designer and may be, for example, 3kph. When the vehicle speed is smaller than the second vehicle speed threshold value, the vehicle speed can be considered to be small, the EPB can be directly used for braking, and the backup driving motor can be controlled to release the allowed maximum braking force and control the EPB to clamp the parking calipers.

The third braking duration may be a duration generally required from the start of generation of the allowable maximum braking force to the substantially zero vehicle speed in the case where the vehicle speed is not greater than the first vehicle speed threshold. The third braking duration may be preset by the designer and may be, for example, 3s. When the vehicle speed is not less than the second vehicle speed threshold value, but the time duration has been greater than the third brake duration, it is considered that the result of the determination that the vehicle speed is greater than the second vehicle speed threshold value based on the shaft speed of the power motor may not be accurate, and the determination result may be ignored, and the vehicle speed is directly considered to have been reduced to such an extent that the vehicle can be braked directly by the EPB, at which time the DPB may control the release of the allowable maximum braking force and control the EPB to clamp the parking caliper.

In this embodiment, when the vehicle speed is not greater than the first vehicle speed threshold, the DPB control generates the allowable maximum braking force, and the EPB and the hydraulic mechanism are controlled to brake according to the axle speed, shortening the braking distance and the braking duration in the AVP scene.

In yet another embodiment, the method further comprises:

when the AVP is on, controlling the vehicle speed to be less than a first vehicle speed threshold when it is determined that the vehicle has arrived at the parking lot garage entrance or when it is determined that the ambient temperature is below a predetermined ambient temperature threshold.

The arrival of the vehicle at the parking lot library entrance may be determined by positioning in an electronic map, or may be determined by identifying a mark of the parking lot library entrance in an environment image acquired by the vehicle, and the environment temperature is acquired by an on-vehicle temperature sensor. The ambient temperature threshold may be preset by the designer and may be, for example, 5 ℃.

When the ambient temperature is lower than the ambient temperature threshold, the ground of the parking lot where the vehicle is located can be considered to be relatively moist, and the situation that the wheels slip and are unstable when the vehicle is braked can occur. The situation that vehicles are unstable is easily caused because a downhill road is usually arranged after the vehicles enter the ground garage from the ground garage entrance of the parking lot. In both cases, the vehicle speed of the vehicle is controlled to be smaller than the first vehicle speed threshold value, so that the maximum allowable braking force can be controlled to be generated under the condition that the ESP fails, thereby shortening the braking distance and the braking duration and improving the driving safety.

Fig. 2 is a flowchart showing a vehicle brake control method according to another exemplary embodiment. The steps in the embodiment of fig. 2 are a combination of the steps in the embodiments described above, and specifically include the following steps.

1. Under the condition that the AVP is started, if the ESP fails, the shaft speed of the power motor is obtained, and whether the vehicle speed is greater than 15kph is determined according to the shaft speed;

2. if the vehicle speed is greater than 15kph, the backup brake controller controls to carry out hydraulic braking, applies regular braking force to the vehicle and starts timing;

3. determining whether a body of the vehicle is in a stable state according to a shaft speed of the power motor and a longitudinal acceleration of the vehicle;

4. when the body of the vehicle is in a stable state and the braking time is longer than 6s, controlling to release the regular braking force and controlling the EPB to brake;

5. when the body of the vehicle is in a stable state and the braking duration is not more than 6s, continuously determining whether the body of the vehicle is in a stable state according to the shaft speed and the longitudinal acceleration of the power motor;

6. when the body of the vehicle is not in a stable state and the braking time is longer than 10s, controlling to release the regular braking force and controlling the EPB to brake;

7. when the body of the vehicle is not in a stable state and the braking duration is not more than 10s, continuously determining whether the body of the vehicle is in a stable state according to the shaft speed and the longitudinal acceleration of the power motor;

8. If the vehicle speed is not greater than 15kph, controlling to perform hydraulic braking, applying the allowable maximum braking force to the vehicle and starting timing;

9. determining whether the speed of the vehicle is less than 3kph according to the shaft speed of the power motor;

10. if the speed of the vehicle is less than 3kph, the EPB is controlled to brake and the allowable maximum braking force is controlled to be released;

11. if the speed of the vehicle is not less than 3kph and the timing duration is greater than 3s, the EPB is controlled to brake and release the allowed maximum braking force.

12. If the speed of the vehicle is not less than 3kph and the timing duration is not more than 3s, continuously determining whether the speed of the vehicle is less than 3kph according to the shaft speed of the power motor;

13. if the ESP is valid under the condition that the AVP is opened, the ESP acquires a braking instruction sent by the automatic driving controller, and the ESP responds to the braking instruction to brake.

Based on the same inventive concept, the present disclosure also provides a vehicle brake control device. Fig. 3 is a block diagram illustrating a vehicle brake control apparatus according to an exemplary embodiment. Referring to fig. 3, the vehicle brake control apparatus 300 includes an acquisition module 301, a first determination module 302, a first control module 303, and a second control module 304.

The acquisition module 301 is configured to acquire the shaft speed of the power motor if the ESP fails in case of AVP on;

the first determination module 302 is configured to determine whether a vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold based on a shaft speed of the power motor;

the first control module 303 is configured to control the backup brake controller to perform hydraulic braking to apply a regular braking force to the vehicle when the speed of the vehicle is greater than a first vehicle speed threshold;

the second control module 304 is configured to perform a parking brake according to a shaft speed of the power motor and a longitudinal acceleration control of the vehicle during application of a regular braking force to the vehicle.

Optionally, the second control module 304 includes a timing sub-module, a first determination sub-module, a first braking sub-module, and a second braking sub-module.

The timing sub-module is configured to begin timing while applying a regular braking force to the vehicle.

The first determination sub-module is configured to determine whether a body of the vehicle is in a steady state based on a shaft speed of the power motor and a longitudinal acceleration of the vehicle.

The first braking submodule is configured to control release of the regular braking force and control the EPB to apply braking when the body of the vehicle is in a steady state and the braking time period is longer than a predetermined first braking time period.

The second braking submodule is configured to control release of the regular braking force and control the EPB to apply braking when the body of the vehicle is not in a steady state and the braking time period is longer than a predetermined second braking time period, wherein the first braking time period is less than the second braking time period.

Optionally, the first determining sub-module is further configured to determine that the body of the vehicle is in a stable state if it is determined that the longitudinal acceleration of the vehicle generates a corresponding regular change and it is determined that the shaft speed of the power motor steadily decreases, in a case where the wheels of the vehicle are not locked.

Optionally, the first determination submodule is further configured to: under the condition that wheels of a vehicle are locked, if it is judged that the longitudinal acceleration of the vehicle does not generate corresponding regular change and the shaft speed of the power motor is judged to be fast reduced, the regular braking force is controlled to be released within a preset third braking duration, and after the regular braking force is restored, the restoration rate and the restoration amplitude of the shaft speed of the power motor are determined; and if the recovery rate and the recovery amplitude meet the preset stable conditions, determining that the body of the vehicle is in a stable state.

Optionally, the first determination module 302 includes a second determination sub-module, a third determination sub-module, a fourth determination sub-module, and a fifth determination sub-module.

The second determining submodule is configured to take the shaft speed of the power motor as the speed of the vehicle and determine whether the speed of the vehicle is greater than a preset first speed threshold value if the longitudinal acceleration of the vehicle generates corresponding regular change and the wheels of the vehicle are not locked under the condition that regular braking force is applied to the vehicle;

the third determining submodule is configured to control the release of the regular braking force in a preset fourth braking duration and determine the recovery rate and the recovery amplitude of the motor shaft speed after the recovery of the regular braking force if the longitudinal acceleration of the vehicle does not generate corresponding regular change and the motor shaft speed of the motor is smaller than a preset shaft speed threshold under the condition that the regular braking force is applied to the vehicle;

the fourth determination submodule is configured to determine that the speed of the vehicle is greater than a predetermined first speed threshold if the recovery rate and the recovery amplitude are within a predetermined interval;

the fifth determination submodule is configured to determine that a vehicle speed of the vehicle is not greater than the first vehicle speed threshold if the recovery rate and the recovery magnitude are not within a predetermined interval.

Optionally, the vehicle brake control device 300 further includes a third control module, a second determination module, a fourth control module, and a fifth control module.

The third control module is configured to control the backup brake controller to perform hydraulic braking to generate an allowable maximum braking force and start timing when a vehicle speed of the vehicle is not greater than a first vehicle speed threshold;

the second determination module is configured to determine, during braking with the maximum allowable braking force, whether a vehicle speed of the vehicle is less than a predetermined second vehicle speed threshold according to a shaft speed of the power motor;

the fourth control module is configured to control the EPB to brake and control the EPB to release the allowed maximum braking force if the speed of the vehicle is less than the second vehicle speed threshold;

the fifth control module is configured to control the EPB to apply braking and control release of the allowable maximum braking force if the vehicle speed is not less than the second vehicle speed threshold and the timed duration is greater than the predetermined third braking duration.

Optionally, the vehicle brake control device 300 further includes a sixth control module.

The sixth control module is configured to control a vehicle speed of the vehicle to be less than a first vehicle speed threshold when it is determined that the vehicle arrives at the parking lot garage entrance or when it is determined that the ambient temperature is below a predetermined ambient temperature threshold with the AVP on.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

According to the technical scheme, when the ESP is invalid and the vehicle speed is larger than the first vehicle speed threshold value under the condition that the AVP is opened, the backup brake controller controls parking brake according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle in the process of applying the regular braking force to the vehicle. Therefore, under the condition of ESP failure, the backup brake controller does not increase an additional wheel speed sensor, can also realize the brake control requirement, reduces parts and wiring harnesses, and reduces the mounting difficulty and cost of the vehicle.

The present disclosure also provides a computer readable storage medium having stored thereon computer program instructions which, when executed by a first processor, implement the steps of the vehicle brake control method provided by the present disclosure.

Fig. 4 is a block diagram illustrating an apparatus 400 for vehicle braking control, according to an exemplary embodiment. For example, apparatus 400 may be a mobile phone, computer, digital broadcast terminal, messaging device, game console, tablet device, medical device, exercise device, personal digital assistant, or the like.

Referring to fig. 4, apparatus 400 may include one or more of the following components: a processing component 402, a first memory 404, a power component 406, a multimedia component 408, an audio component 410, an input/output (I/O) interface 412, a sensor component 414, and a communication component 416.

The processing component 402 generally controls the overall operation of the apparatus 400, such as operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing assembly 402 may include one or more first processors 420 to execute instructions to perform all or part of the steps of the vehicle brake control method described above. Further, the processing component 402 can include one or more modules that facilitate interaction between the processing component 402 and other components. For example, the processing component 402 may include a multimedia module to facilitate interaction between the multimedia component 408 and the processing component 402.

The first memory 404 is configured to store various types of data to support operations at the apparatus 400. Examples of such data include instructions for any application or method operating on the apparatus 400, contact data, phonebook data, messages, pictures, videos, and the like. The first memory 404 may be implemented by any type or combination of volatile or nonvolatile memory devices such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

The power supply component 406 provides power to the various components of the apparatus 400. The power supply components 406 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the apparatus 400.

The multimedia component 408 includes a screen between the device 400 and the user that provides an output interface. In some embodiments, the screen may include a Liquid Crystal Display (LCD) and a Touch Panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensor may sense not only the boundary of a touch or sliding action, but also the duration and pressure associated with the touch or sliding operation. In some embodiments, the multimedia component 408 includes a front camera and/or a rear camera. The front camera and/or the rear camera may receive external multimedia data when the apparatus 400 is in an operation mode, such as a photographing mode or a video mode. Each front camera and rear camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

The audio component 410 is configured to output and/or input audio signals. For example, the audio component 410 includes a Microphone (MIC) configured to receive external audio signals when the apparatus 400 is in an operational mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals may be further stored in the first memory 404 or transmitted via the communication component 416. In some embodiments, audio component 410 further includes a speaker for outputting audio signals.

Input/output (I/O) interface 412 provides an interface between processing component 402 and peripheral interface modules, which may be keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to: homepage button, volume button, start button, and lock button.

The sensor assembly 414 includes one or more sensors for providing status assessment of various aspects of the apparatus 400. For example, the sensor assembly 414 may detect the on/off state of the device 400, the relative positioning of the components, such as the display and keypad of the device 400, the sensor assembly 414 may also detect the change in position of the device 400 or one of the components of the device 400, the presence or absence of user contact with the device 400, the orientation or acceleration/deceleration of the device 400, and the change in temperature of the device 400. The sensor assembly 414 may include a proximity sensor configured to detect the presence of nearby objects in the absence of any physical contact. The sensor assembly 414 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 414 may also include an acceleration sensor, a gyroscopic sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 416 is configured to facilitate communication between the apparatus 400 and other devices in a wired or wireless manner. The apparatus 400 may access a wireless network based on a communication standard, such as WiFi,2G or 3G, or a combination thereof. In one exemplary embodiment, the communication component 416 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component 416 further includes a Near Field Communication (NFC) module to facilitate short range communications. For example, the NFC module may be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra Wideband (UWB) technology, bluetooth (BT) technology, and other technologies.

In an exemplary embodiment, the apparatus 400 may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements for performing the above-described vehicle brake control method.

In an exemplary embodiment, a non-transitory computer readable storage medium is also provided, such as first memory 404, that includes instructions executable by first processor 420 of apparatus 400 to perform the vehicle brake control method described above. For example, the non-transitory computer readable storage medium may be ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

The apparatus may be a stand-alone electronic device or may be part of a stand-alone electronic device, for example, in one embodiment, the apparatus may be an integrated circuit (Integrated Circuit, IC) or a chip, where the integrated circuit may be an IC or may be a collection of ICs; the chip may include, but is not limited to, the following: GPU (Graphics Processing Unit, graphics processor), CPU (Central Processing Unit ), FPGA (Field Programmable Gate Array, programmable logic array), DSP (Digital Signal Processor ), ASIC (Application Specific Integrated Circuit, application specific integrated circuit), SOC (System on Chip, SOC, system on Chip or System on Chip), etc. The integrated circuit or chip may be configured to execute executable instructions (or code) to implement the vehicle brake control method described above. The executable instructions may be stored on the integrated circuit or chip or may be retrieved from another device or apparatus, such as the integrated circuit or chip including a third processor, a third memory, and an interface for communicating with the other device. The executable instructions may be stored in the third processor, which when executed by the third processor, implement the vehicle brake control method described above; or the integrated circuit or the chip can receive the executable instruction through the interface and transmit the executable instruction to the third processor for execution, so as to realize the vehicle brake control method.

Referring to fig. 5, fig. 5 is a functional block diagram of a vehicle 500 according to an exemplary embodiment. The vehicle 500 may be configured in a fully or partially autonomous mode. For example, the vehicle 500 may obtain environmental information of its surroundings through the perception system 520 and derive an automatic driving strategy based on analysis of the surrounding environmental information to achieve full automatic driving, or present the analysis results to the user to achieve partial automatic driving.

The vehicle 500 may include various subsystems, such as an infotainment system 510, a perception system 520, a decision control system 530, a drive system 540, and a computing platform 550. Alternatively, vehicle 500 may include more or fewer subsystems, and each subsystem may include multiple components. In addition, each of the subsystems and components of the vehicle 500 may be interconnected by wire or wirelessly.

In some embodiments, the infotainment system 510 may include a communication system 511, an entertainment system 512, and a navigation system 513.

The communication system 511 may include a wireless communication system that may communicate wirelessly with one or more devices directly or via a communication network. For example, the wireless communication system may use 3G cellular communication, such as CDMA, EVD0, GSM/GPRS, or 4G cellular communication, such as LTE. Or 5G cellular communication. The wireless communication system may communicate with a wireless local area network (wireless local area network, WLAN) using WiFi. In some embodiments, the wireless communication system may communicate directly with the device using an infrared link, bluetooth, or ZigBee. Other wireless protocols, such as various vehicle communication systems, for example, wireless communication systems may include one or more dedicated short-range communication (dedicated short range communications, DSRC) devices, which may include public and/or private data communications between vehicles and/or roadside stations.

Entertainment system 512 may include a display device, a microphone, and an audio, and a user may listen to the broadcast in the vehicle based on the entertainment system, playing music; or the mobile phone is communicated with the vehicle, the screen of the mobile phone is realized on the display equipment, the display equipment can be in a touch control type, and a user can operate through touching the screen.

In some cases, the user's voice signal may be acquired through a microphone and certain controls of the vehicle 500 by the user may be implemented based on analysis of the user's voice signal, such as adjusting the temperature within the vehicle, etc. In other cases, music may be played to the user through sound.

The navigation system 513 may include map services provided by map providers to provide navigation of travel routes for the vehicle 500, and the navigation system 513 may be used in conjunction with a global positioning system 521 and an inertial measurement unit 522 of the vehicle. The map service provided by the map provider may be a two-dimensional map or a high-precision map.

The sensing system 520 may include several sensors that sense information about the environment surrounding the vehicle 500. For example, sensing system 520 may include a global positioning system 521 (which may be a GPS system, or may be a beidou system or other positioning system), an inertial measurement unit (inertial measurement unit, IMU) 522, a lidar 523, a millimeter wave radar 524, an ultrasonic radar 525, and a camera 526. The sensing system 520 may also include sensors (e.g., in-vehicle air quality monitors, fuel gauges, oil temperature gauges, etc.) of the internal systems of the monitored vehicle 500. Sensor data from one or more of these sensors may be used to detect objects and their corresponding characteristics (location, shape, direction, speed, etc.). Such detection and identification is a critical function of the safe operation of the vehicle 500.

The global positioning system 521 is used to estimate the geographic location of the vehicle 500.

The inertial measurement unit 522 is used to sense the pose change of the vehicle 500 based on inertial acceleration. In some embodiments, inertial measurement unit 522 may be a combination of an accelerometer and a gyroscope.

The lidar 523 uses a laser to sense objects in the environment in which the vehicle 500 is located. In some embodiments, the lidar 523 may include one or more laser sources, a laser scanner, and one or more detectors, among other system components.

The millimeter wave radar 524 senses objects within the surrounding environment of the vehicle 500 using radio signals. In some embodiments, millimeter-wave radar 524 may be used to sense the speed and/or heading of an object in addition to sensing the object.

Ultrasonic radar 525 may utilize ultrasonic signals to sense objects around vehicle 500.

The image pickup device 526 is used to capture image information of the surrounding environment of the vehicle 500. The image capturing device 526 may include a monocular camera, a binocular camera, a structured light camera, a panoramic camera, and the like, and the image information acquired by the image capturing device 526 may include still images or video stream information.

The decision control system 530 includes a computing system 531 that makes an analytical decision based on information acquired by the perception system 520, and the decision control system 530 further includes a vehicle controller 532 that controls the power system of the vehicle 500, and a steering system 533, throttle 534, and braking system 535 for controlling the vehicle 500.

The computing system 531 may be operable to process and analyze various information acquired by the perception system 520 in order to identify targets, objects, and/or features in the environment surrounding the vehicle 500. The targets may include pedestrians or animals and the objects and/or features may include traffic signals, road boundaries, and obstacles. The computing system 531 may use object recognition algorithms, in-motion restoration structure (Structure from Motion, SFM) algorithms, video tracking, and the like. In some embodiments, computing system 531 may be used to map an environment, track objects, estimate the speed of objects, and so forth. The computing system 531 may analyze the acquired various information and derive a control strategy for the vehicle.

The vehicle controller 532 may be configured to coordinate control of the power battery and the engine 541 of the vehicle to enhance the power performance of the vehicle 500.

The steering system 533 is operable to adjust the forward direction of the vehicle 500. For example, in one embodiment may be a steering wheel system.

The throttle 534 is used to control the operating speed of the engine 541 and, in turn, the speed of the vehicle 500.

The braking system 535 is used to control the vehicle 500 to slow down. The braking system 535 may use friction to slow the wheels 544. In some embodiments, the braking system 535 may convert the kinetic energy of the wheels 544 into electrical current. The brake system 535 may take other forms to slow the rotational speed of the wheels 544 to control the speed of the vehicle 500.

The drive system 540 may include components that provide powered movement of the vehicle 500. In one embodiment, the drive system 540 may include an engine 541, an energy source 542, a transmission system 543, and wheels 544. The engine 541 may be an internal combustion engine, an electric motor, an air compression engine, or other type of engine combination, such as a hybrid engine of a gasoline engine and an electric motor, or a hybrid engine of an internal combustion engine and an air compression engine. The engine 541 converts the energy source 542 into mechanical energy.

Examples of energy sources 542 include gasoline, diesel, other petroleum-based fuels, propane, other compressed gas-based fuels, ethanol, solar panels, batteries, and other sources of electricity. The energy source 542 may also provide energy to other systems of the vehicle 500.

The transmission 543 may transmit mechanical power from the engine 541 to wheels 544. The transmission system 543 may include a gearbox, a differential, and a driveshaft. In one embodiment, the transmission system 543 may also include other devices, such as clutches. Wherein the drive shaft may include one or more axles that may be coupled to one or more wheels 544.

Some or all of the functions of the vehicle 500 are controlled by the computing platform 550. The computing platform 550 may include at least one second processor 551, and the second processor 551 may execute instructions 553 stored in a non-transitory computer readable medium, such as a second memory 552. In some embodiments, computing platform 550 may also be a plurality of computing devices that control individual components or subsystems of vehicle 500 in a distributed manner.

The second processor 551 may be any conventional processor, such as a commercially available CPU. Alternatively, the second processor 551 may also include, for example, an image processor (Graphic Process Unit, GPU), a field programmable gate array (FieldProgrammable Gate Array, FPGA), a System On Chip (SOC), an application specific integrated Chip (Application Specific Integrated Circuit, ASIC), or a combination thereof. Although FIG. 5 functionally illustrates a processor, memory, and other elements of a computer in the same block, it will be understood by those of ordinary skill in the art that the processor, computer, or memory may in fact comprise multiple processors, computers, or memories that may or may not be stored within the same physical housing. For example, the memory may be a hard disk drive or other storage medium located in a different housing than the computer. Thus, references to a processor or computer will be understood to include references to a collection of processors or computers or memories that may or may not operate in parallel. Rather than using a single processor to perform the steps described herein, some components, such as the steering component and the retarding component, may each have their own processor that performs only calculations related to the component-specific functions.

In the embodiment of the present disclosure, the second processor 551 may perform the vehicle brake control method described above.

In various aspects described herein, the second processor 551 may be located remotely from the vehicle and in wireless communication with the vehicle. In other aspects, some of the processes described herein are performed on a processor disposed within the vehicle and others are performed by a remote processor, including taking the necessary steps to perform a single maneuver.

In some embodiments, the second memory 552 may contain instructions 553 (e.g., program logic), the instructions 553 being executable by the second processor 551 to perform various functions of the vehicle 500. The second memory 552 may also contain additional instructions, including instructions to send data to, receive data from, interact with, and/or control one or more of the infotainment system 510, the perception system 520, the decision control system 530, the drive system 540.

In addition to instructions 553, the second memory 552 may also store data such as road maps, route information, vehicle position, direction, speed, and other such vehicle data, as well as other information. Such information may be used by the vehicle 500 and the computing platform 550 during operation of the vehicle 500 in autonomous, semi-autonomous, and/or manual modes.

The computing platform 550 may control the functions of the vehicle 500 based on inputs received from various subsystems (e.g., the drive system 540, the perception system 520, and the decision control system 530). For example, computing platform 550 may utilize input from decision control system 530 in order to control steering system 533 to avoid obstacles detected by perception system 520. In some embodiments, computing platform 550 is operable to provide control over many aspects of vehicle 500 and its subsystems.

Alternatively, one or more of these components may be mounted separately from or associated with vehicle 500. For example, the second memory 552 may exist partially or completely separate from the vehicle 500. The above components may be communicatively coupled together in a wired and/or wireless manner.

Alternatively, the above components are only an example, and in practical applications, components in the above modules may be added or deleted according to actual needs, and fig. 5 should not be construed as limiting the embodiments of the present disclosure.

An autonomous car traveling on a road, such as the vehicle 500 above, may identify objects within its surrounding environment to determine adjustments to the current speed. The object may be another vehicle, a traffic control device, or another type of object. In some examples, each identified object may be considered independently and based on its respective characteristics, such as its current speed, acceleration, spacing from the vehicle, etc., may be used to determine the speed at which the autonomous car is to adjust.

Alternatively, the vehicle 500 or a sensing and computing device associated with the vehicle 500 (e.g., computing system 531, computing platform 550) may predict the behavior of the identified object based on the characteristics of the identified object and the state of the surrounding environment (e.g., traffic, rain, ice on a road, etc.). Alternatively, each identified object depends on each other's behavior, so all of the identified objects can also be considered together to predict the behavior of a single identified object. The vehicle 500 is able to adjust its speed based on the predicted behavior of the identified object. In other words, the autonomous car is able to determine what steady state the vehicle will need to adjust to (e.g., accelerate, decelerate, or stop) based on the predicted behavior of the object. In this process, the speed of the vehicle 500 may also be determined in consideration of other factors, such as the lateral position of the vehicle 500 in the road on which it is traveling, the curvature of the road, the proximity of static and dynamic objects, and so forth.

In addition to providing instructions to adjust the speed of the autonomous vehicle, the computing device may also provide instructions to modify the steering angle of the vehicle 500 so that the autonomous vehicle follows a given trajectory and/or maintains safe lateral and longitudinal distances from objects in the vicinity of the autonomous vehicle (e.g., vehicles in adjacent lanes on a roadway).

The vehicle 500 may be various types of traveling tools, such as a car, a truck, a motorcycle, a bus, a ship, an airplane, a helicopter, a recreational vehicle, a train, etc., and the embodiments of the present disclosure are not particularly limited.

In another exemplary embodiment, a computer program product is also provided, which comprises a computer program executable by a programmable apparatus, the computer program having code portions for performing the above-mentioned vehicle brake control method when being executed by the programmable apparatus.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A vehicle brake control method, characterized by comprising:

2. The method according to claim 1, wherein the parking brake is controlled according to the shaft speed of the power motor and the longitudinal acceleration of the vehicle, comprising:

starting timing while applying a regular braking force to the vehicle;

3. The method of claim 2, wherein the determining whether the body of the vehicle is in a steady state based on the shaft speed of the power motor and the longitudinal acceleration of the vehicle comprises:

4. The method of claim 2, wherein the determining whether the body of the vehicle is in a steady state based on the shaft speed of the power motor and the longitudinal acceleration of the vehicle comprises:

5. The method of claim 1, wherein said determining whether the vehicle speed of the vehicle is greater than a predetermined first vehicle speed threshold based on the shaft speed of the power motor comprises:

6. The method according to claim 1, wherein the method further comprises:

when the speed of the vehicle is not greater than the first vehicle speed threshold, the backup brake controller controls hydraulic braking to generate an allowable maximum braking force and starts timing;

7. The method of claim 6, wherein the method further comprises:

8. A vehicle brake control apparatus, characterized by comprising:

the acquisition module is configured to acquire the shaft speed of the power motor if the ESP fails under the condition that the AVP is opened;

9. A computer readable storage medium having stored thereon computer program instructions, which when executed by a first processor, implement the steps of the method of any of claims 1 to 7.

10. A vehicle, characterized by comprising:

a second processor;

a second memory for storing the second processor-executable instructions;

wherein the second processor is configured to:

Under the condition that the AVP is opened, if the ESP fails, the shaft speed of the power motor is obtained;

11. A chip comprising a third processor and an interface, the third processor being configured to read instructions to perform the method of any one of claims 1 to 7.