Brake energy recovery safety control method and system based on vehicle body dynamics

Abstract

The application provides a brake energy recovery safety control method and system based on vehicle body dynamics, and relates to the brake energy recovery field.The application comprises the following steps: calculating a road adhesion coefficient and a peak road adhesion coefficient;calculating a rear axle load, calculating a rear axle road limit adhesion force based on the peak road adhesion coefficient and the rear axle load;calculating a motor target recovery torque, judging whether to increase an upper limit constraint of the motor target recovery torque based on the road adhesion coefficient; and controlling a brake energy recovery torque exit opportunity based on the road adhesion coefficient.The application can identify the road adhesion coefficient, obtain the maximum brake energy recovery torque upper limit based on the vehicle body dynamics, guarantee the maximum brake energy recovery torque upper limit on the low adhesion road, optimize the brake energy recovery torque exit control strategy, avoid the rear axle lock and side slip accidents caused by the brake energy recovery, and solve the side slip and tail swing problems caused by the brake energy recovery on the low adhesion road.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of brake energy recovery, and particularly relates to a brake energy recovery safety control method and system based on vehicle body dynamics. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] At present, ABS systems are generally used for brake safety control in pure electric commercial vehicles on the market. The ABS system can effectively utilize the adhesion between the tire and the road surface, shorten the braking distance, and especially can shorten 10%-15% on icy road surfaces. In addition, during braking, the wheels can still roll, the steerability of the front wheels is maintained, the sideslip of the rear wheels is prevented, and the stability of the driving direction is maintained.

[0004] The inventor found that in the prior art, when the ABS system is matched with a pure electric commercial vehicle, there are certain limitations. When the vehicle is lightly braked on a low adhesion road surface, the brake pedal opening is small, the basic brake is not involved, at this time the vehicle is only braked by the rear axle driving motor, when the electric brake torque grows to a certain value, the ground braking force reaches the peak adhesion of the road surface, the rear wheel starts to lock and appears to slide. At the same time, since the electric brake torque needs a certain time to exit when the ABS is activated, the rear wheel slip rate cannot be effectively controlled in time. According to the braking force coefficient curve, as the slip rate continuously increases, the lateral force coefficient gradually decreases, at this time the vehicle is caused to slide and spin by a small lateral force.

[0005] Therefore, the slide and spin caused by the brake energy recovery of the pure electric commercial vehicle on the low adhesion road surface is a problem that needs to be solved urgently. SUMMARY

[0006] In order to overcome the shortcomings of the prior art, the present application provides a brake energy recovery safety control method and system based on vehicle body dynamics, which identifies the road adhesion coefficient, further obtains the maximum brake energy recovery torque upper limit of the low adhesion road surface based on the vehicle body dynamics to ensure the handling and stability performance, optimizes the brake energy recovery torque exit control strategy, thereby avoiding the occurrence of rear axle lock and sideslip accidents caused by brake energy recovery, and solving the problem of slide and spin caused by brake energy recovery of pure electric commercial vehicles on low adhesion road surfaces.

[0007] To achieve the above purpose, one or more embodiments of the present application provide the following technical solutions:

[0008] The present application provides a brake energy recovery safety control method based on vehicle body dynamics in the first aspect.

[0009] The brake energy recovery safety control method based on vehicle body dynamics comprises the following steps:

[0010] Calculate the road adhesion coefficient and peak road adhesion coefficient;

[0011] Calculate rear axle load, and calculate rear axle road limit adhesion based on peak road adhesion coefficient and rear axle load;

[0012] Calculate the motor's target regenerative torque and, based on the road adhesion coefficient, determine whether to add a rear axle road adhesion limit constraint to the motor's target regenerative torque.

[0013] The timing of exiting the braking energy recovery torque is controlled based on the road adhesion coefficient, and the exit of the braking energy recovery torque is optimized and managed.

[0014] A second aspect of the present invention provides a braking energy recovery safety control system based on vehicle body dynamics.

[0015] The braking energy recovery safety control system based on vehicle body dynamics includes an ABS controller, wheel speed sensor, axle load sensor, brake pressure sensor, brake pedal opening sensor, vehicle controller, motor controller, and motor, including:

[0016] Wheel speed sensor, which is used to collect wheel speed data and send the wheel speed data to the ABS controller;

[0017] Axle load sensor, which is used to collect axle load data and send the axle load data to the vehicle controller;

[0018] Brake pressure sensor, which is used to collect brake pressure data and send the brake pressure data to the vehicle controller;

[0019] A brake pedal opening sensor is used to collect brake pedal opening data and send the brake pedal opening data to the vehicle controller;

[0020] ABS controller, which is used to receive wheel speed data and send the wheel speed data to the vehicle controller;

[0021] The motor controller is used to collect motor speed data and motor real-time torque, and send the motor speed data and motor real-time torque to the vehicle controller;

[0022] The vehicle controller is used to receive wheel speed data, axle load data, brake pressure data, brake pedal opening data, motor speed data and motor real-time torque, calculate the road adhesion coefficient and peak road adhesion coefficient based on the wheel speed data and the motor real-time torque, determine whether to add a rear axle road surface limit adhesion upper limit constraint to the motor target recovery torque based on the road adhesion coefficient, obtain the rear axle load based on the axle load data or brake pressure data, determine whether the air brake is turned on based on the brake pedal opening data, and control the exit timing of the brake energy recovery torque based on the road adhesion coefficient and motor speed data.

[0023] A third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the braking energy recovery safety control method based on vehicle body dynamics as described in the first aspect of the present invention.

[0024] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the braking energy recovery safety control method based on vehicle body dynamics as described in the first aspect of the present invention are implemented.

[0025] One or more of the above technical solutions have the following beneficial effects:

[0026] The vehicle body dynamics-based braking energy recovery safety control method and system provided by the present invention can achieve effective control of the motor braking energy recovery torque and the timing of braking energy recovery exit, solving the problem of skidding and tail-swinging caused by braking energy recovery on low-adhesion roads of pure electric commercial vehicles, improving the vehicle's braking safety, and thus reducing the loss of life and property caused by automobile traffic safety accidents.

[0027] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0029] Figure 1 This is a flow chart of the method of the first embodiment.

[0030] Figure 2 This is a flow chart of road adhesion coefficient identification in the first embodiment.

[0031] Figure 3 This is a flowchart of calculating the target recovery torque for braking energy recovery to ensure handling stability in the first embodiment.

[0032] Figure 4 This is a flow chart of the braking torque distribution and braking energy recovery torque exit control management in the first embodiment.

[0033] Figure 5 This is a system structure diagram of the second embodiment. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0035] It should be noted that the terms used herein are for describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present invention.

[0036] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0037] Example 1

[0038] This embodiment discloses a braking energy recovery safety control method based on vehicle body dynamics.

[0039] like Figure 1 As shown, the braking energy recovery safety control method based on vehicle body dynamics includes the following steps:

[0040] Calculate the road adhesion coefficient and peak road adhesion coefficient;

[0041] Calculate rear axle load, and calculate rear axle road limit adhesion based on peak road adhesion coefficient and rear axle load;

[0042] Calculate the motor's target regenerative torque and, based on the road adhesion coefficient, determine whether to add a rear axle road adhesion limit constraint to the motor's target regenerative torque.

[0043] The timing of exiting the braking energy recovery torque is controlled based on the road adhesion coefficient, and the exit of the braking energy recovery torque is optimized and managed.

[0044] (1) Road adhesion coefficient identification

[0045] like Figure 2 As shown, the road adhesion coefficient and peak road adhesion coefficient are calculated, specifically including:

[0046] Collect wheel speed and calculate reference vehicle speed, then perform time derivative of reference vehicle speed to get vehicle acceleration;

[0047] Obtain the real-time torque of the motor and estimate the real-time vehicle mass based on the vehicle acceleration and the real-time torque of the motor;

[0048] Calculate ground braking force based on vehicle acceleration and real-time vehicle mass;

[0049] Calculate the road adhesion coefficient from the ground braking force and the vertical load of the vehicle;

[0050] The point where the slope of the road adhesion coefficient is 0 is the peak road adhesion coefficient.

[0051] The braking force coefficient curve shows that as the slip rate increases, the road adhesion coefficient (longitudinal braking force coefficient) first increases and then decreases. Therefore, the peak road adhesion coefficient corresponds to the point where the slope of the adhesion coefficient is zero. Road adhesion coefficient identification begins by collecting wheel speeds through the ABS controller and calculating the reference vehicle speed. The vehicle controller then derivates the reference speed with time to obtain the vehicle acceleration. When the vehicle is in the driving state, the vehicle controller estimates the real-time vehicle mass based on the vehicle acceleration and the real-time torque of the generator outside the motor controller MCU. When the vehicle is braking, the vehicle controller calculates the ground braking force based on the vehicle deceleration and real-time mass. The road adhesion coefficient is then calculated from the ground braking force and the vehicle's vertical load. Finally, the vehicle controller derivates the road adhesion coefficient with respect to the slip rate. The point where the slope is zero is the peak road adhesion coefficient. The slip rate can then be calculated using the reference vehicle speed and wheel speed.

[0052] (2) Calculation of target torque for braking energy recovery to ensure stable handling performance

[0053] Furthermore, the rear axle load is calculated, including:

[0054] For vehicles with air suspension, an axle load sensor is installed at the air inlet of the rear axle air suspension airbag to collect rear axle load information in real time;

[0055] For vehicles equipped with leaf springs, a brake pressure sensor is installed between the outlet of the rear axle relay valve and the air inlet of the brake chamber. The brake force is calculated in real time based on the brake pressure value. During the braking process, before the wheel reaches the slip rate corresponding to the peak adhesion coefficient, the ground braking force is equal to the brake force. The left and right wheel loads on the rear axle are calculated using the ground braking force and the wheel deceleration, and the rear axle load is calculated based on the left and right wheel loads on the rear axle.

[0056] Furthermore, the motor target recovery torque is calculated to determine whether the road adhesion coefficient is less than a first set value. If not, the motor target recovery torque is not subject to an upper limit constraint; if so, the rear axle road adhesion limit upper limit constraint is added to the motor target recovery torque.

[0057] First, the rear axle's ultimate road adhesion is calculated, derived from the peak road adhesion coefficient and the rear axle load. There are two main methods for estimating rear axle load. One, applicable to vehicles with air suspension, involves installing an axle load sensor at the rear axle air suspension airbag inlet to collect axle load information in real time. The other, applicable to vehicles with leaf springs, involves installing a brake pressure sensor between the rear axle relay valve outlet and the brake chamber inlet. The brake pressure value allows for real-time calculation of the brake force. During braking, before the wheel reaches the slip ratio corresponding to the peak road adhesion coefficient, the ground braking force equals the brake force. The wheel load can then be calculated from the ground braking force and wheel deceleration, and the rear axle load is then calculated based on the left and right wheel loads.

[0058] Secondly, the peak power of the motor feed, the battery's allowable charging power, and the power calculated based on the rear axle's allowable reverse torque are compared. The minimum value is the peak reverse power of the electric brake. Combined with the real-time speed of the motor, the real-time maximum available recovery torque of the motor can be calculated.

[0059] The real-time motor recovery torque can be further obtained by a table lookup method, where the input of the table lookup is the opening of the brake pedal and the real-time motor speed, and the output is the real-time motor recovery torque T2.

[0060] The motor target recovery torque T is further calculated by comparing the motor's real-time maximum available recovery torque T1 and the motor's real-time recovery torque T2. The smaller value is the motor's target recovery torque, that is, T = min{T1, T2}.

[0061] When the road adhesion coefficient <k值时,电机目标回收扭矩需要增加后轴路面极限附着力进行约束,并乘上一定的安全系数,安全系数可通过标定效果进行设置,由此可以解决纯电动商用车低附路面轻踩制动时电机制动能量回收扭矩过大导致的后轴抱死侧滑问题。当路面附着系数≥k值时,,考虑到电制动回收扭矩达不到路面极限附着力以及制动能量回收效率最大化的因素,故电机目标回收扭矩不再额外进行约束。(k值大小可通过实车标定效果进行取值)

[0062] The motor's real-time maximum available regenerative torque constrains the motor's target regenerative torque (reflected in three aspects: the motor's peak power feed, the battery's allowable charging power, and the power calculated based on the rear axle's allowable reverse torque).

[0063] (3) Braking torque distribution management

[0064] Before determining the electric brake energy recovery torque exit time based on the road adhesion coefficient and optimizing the electric brake energy recovery torque exit management, the following steps are also included:

[0065] Get the brake pedal opening, and increase the air brake when the brake pedal opening is greater than the set value.

[0066] When the brake pedal opening is less than 25%, the target electric brake regenerative torque is determined by a table lookup. The table inputs are the brake pedal opening and the real-time motor speed. A 25% brake pedal opening corresponds to the maximum electric brake regenerative torque. Determined by the master cylinder's characteristic curve, the base air brake begins to intervene at a brake pedal opening of approximately 25-30%. Prior to this, only the rear axle drive motor provides anti-drag braking. After the air brake intervenes, the electric and air brakes work together, distributing braking force between the front and rear axles according to the ideal braking force I curve.

[0067] (4) Braking energy recovery torque exit control management

[0068] Furthermore, the electric brake energy recovery torque exit time is determined based on the road adhesion coefficient, specifically including:

[0069] If the road adhesion coefficient is less than the second set value, the rear wheel slip rate is greater than 10%, and the brake pedal opening rate is greater than the set threshold, the motor brake energy recovery begins to exit, and the proportion of air brake gradually increases. When the motor speed reaches 500 rpm, the motor brake energy recovery is completely exited.

[0070] If the road adhesion coefficient is less than the second set value, but at least one of the following conditions is not met: the rear wheel slip rate is greater than 10% and the brake pedal opening rate change rate is greater than the set threshold value, it is further determined whether the motor speed is less than 800r / min. If it is less than 800r / min, the brake energy recovery begins to exit, and the motor brake energy recovery is completely exited when the motor speed is 500r / min.

[0071] Furthermore, if the road adhesion coefficient is greater than or equal to a second set value, it is determined whether the ABS function is activated. If the ABS function is activated, the motor braking energy recovery starts to exit.

[0072] If the ABS function is not activated, it will further determine whether the motor speed is lower than 500r / min. If it is lower than 500r / min, the motor braking energy recovery will start to exit and will completely exit when the motor speed is 200r / min.

[0073] Usually, it takes a certain amount of time for the brake energy recovery torque to be released. Most rear axle locking and skidding accidents are often caused by the late or untimely release of brake energy recovery. Therefore, the electric brake torque release should be optimized according to the different road adhesion coefficients. <k值时,监测后轮滑移率大于10%并且制动踏板开度变化率大于一定门限值(识别为紧急制动工况),电机制动能量回收开始退出,基础气压制动的比重逐渐增大。此种情况下将制动能量回收退出时机提前,可以有效避免当ABS功能激活时制动能量回收不能及时快速退出,同时提高ABS激活时基础气压制动的占比,使得后轮滑移率能得到更有效的控制。另外制动末端电机转速小于800r / mi n时制动能量回收开始退出,500r / mi n完全退出,避免低附路面电机制动扭矩退出不及时导致的后轴抱死侧滑现象,更严重的会出现电机负转速。同样,制动末端电机目标回收扭矩也可通过查表的方式进行得到,查表的输入为制动踏板的开度和电机实时转速。

[0074] When the road adhesion coefficient is ≥ k, the electric brake regeneration torque cannot reach the road's ultimate adhesion and the braking energy recovery efficiency cannot be maximized. When the ABS function is activated, the electric brake energy recovery begins to exit. In addition, when the motor speed at the end of the brake is less than 500r / min, the braking energy recovery begins to exit, and at 200r / min, it is completely exited. The motor exit speed at the end of the brake needs to be calibrated on the actual vehicle to ensure braking safety while maximizing the braking energy recovery efficiency. (The k value can be determined based on the actual vehicle calibration effect)

[0075] Example 2

[0076] This embodiment discloses a braking energy recovery safety control system based on vehicle body dynamics.

[0077] like Figure 5 As shown in FIG, the braking energy recovery safety control system based on vehicle body dynamics includes an ABS controller, a wheel speed sensor, an axle load sensor, a brake air pressure sensor, a brake pedal opening sensor, a vehicle controller, a motor controller, and a motor, among which:

[0078] Wheel speed sensor, which is used to collect wheel speed data and send the wheel speed data to the ABS controller;

[0079] Axle load sensor, which is used to collect axle load data and send the axle load data to the vehicle controller;

[0080] Brake pressure sensor, which is used to collect brake pressure data and send the brake pressure data to the vehicle controller;

[0081] A brake pedal opening sensor is used to collect brake pedal opening data and send the brake pedal opening data to the vehicle controller;

[0082] ABS controller, which is used to receive wheel speed data and send the wheel speed data to the vehicle controller;

[0083] The motor controller is used to collect motor speed data and motor real-time torque, and send the motor speed data and motor real-time torque to the vehicle controller;

[0084] The vehicle controller is used to receive wheel speed data, axle load data, brake pressure data, brake pedal opening data, motor speed data and motor real-time torque, calculate the road adhesion coefficient and peak road adhesion coefficient based on the wheel speed data and the motor real-time torque, determine whether to add a rear axle road surface limit adhesion upper limit constraint to the motor target recovery torque based on the road adhesion coefficient, obtain the rear axle load based on the axle load data or brake pressure data, determine whether the air brake is turned on based on the brake pedal opening data, and control the exit timing of the brake energy recovery torque based on the road adhesion coefficient and motor speed data.

[0085] Furthermore, a battery management controller BMS is included, and the battery management controller BMS is used to manage battery power supply.

[0086] It can be understood that in this embodiment, the vehicle controller and the motor controller, the battery management controller BMS, and the ABS controller communicate through the vehicle CAN network.

[0087] Example 3

[0088] The purpose of this embodiment is to provide a computer-readable storage medium.

[0089] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the braking energy recovery safety control method based on vehicle body dynamics as described in Example 1 of the present disclosure.

[0090] Example 4

[0091] The purpose of this embodiment is to provide an electronic device.

[0092] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the braking energy recovery safety control method based on vehicle body dynamics as described in Example 1 of the present disclosure are implemented.

[0093] The steps involved in the apparatuses of Examples 2, 3, and 4 above correspond to those of Method Example 1. For detailed implementations, please refer to the relevant description of Example 1. The term "computer-readable storage medium" should be understood to mean a single medium or multiple media containing one or more instruction sets; it should also be understood to include any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and causing the processor to perform any method of the present invention.

[0094] Those skilled in the art will appreciate that the modules or steps of the present invention described above can be implemented using a general-purpose computer device. Alternatively, they can be implemented using program code executable by a computing device, which can then be stored in a storage device and executed by the computing device. Alternatively, they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0095] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A braking energy recovery safety control method based on vehicle body dynamics, characterized in that: The following steps are involved: Calculate the road adhesion coefficient and peak road adhesion coefficient; Calculate rear axle load, and calculate rear axle road limit adhesion based on peak road adhesion coefficient and rear axle load; Calculate the motor's target regenerative torque and, based on the road adhesion coefficient, determine whether to add a rear axle road adhesion limit constraint to the motor's target regenerative torque. Control the timing of braking energy regeneration torque exit based on the road adhesion coefficient, and optimize the management of braking energy regeneration torque exit; Calculating the target regenerative torque of the motor and further determining whether the road adhesion coefficient is less than a first set value; if not, no upper limit constraint is imposed on the target regenerative torque of the motor; If so, the upper limit constraint of the rear axle road surface adhesion is added to the motor target recovery torque; The electric brake energy recovery torque exit time is determined based on the road adhesion coefficient, specifically including: If the road adhesion coefficient is less than the second set value, the rear wheel slip rate is greater than 10%, and the brake pedal opening rate is greater than the set threshold, the electric motor brake energy recovery begins to exit, and the proportion of air braking gradually increases. When the motor speed reaches 500r / min, the electric motor brake energy recovery is completely exited; If the road adhesion coefficient is less than the second set value, but at least one of the following conditions is not met: the rear wheel slip rate is greater than 10% and the brake pedal opening change rate is greater than the set threshold value, it is further determined whether the motor speed is less than 800r / min. If it is less than 800r / min, the brake energy recovery begins to exit, and the motor brake energy recovery is completely exited when the motor speed is 500r / min.

2. The braking energy recovery safety control method based on vehicle body dynamics according to claim 1, characterized in that: Calculate the road adhesion coefficient and peak road adhesion coefficient, including: Collect wheel speed and calculate reference vehicle speed, then perform time derivative of reference vehicle speed to get vehicle acceleration; Obtain the real-time torque of the motor and estimate the real-time vehicle mass based on the vehicle acceleration and the real-time torque of the motor; Calculate ground braking force based on vehicle acceleration and real-time vehicle mass; Calculate the road adhesion coefficient from the ground braking force and the vertical load of the vehicle; The point where the slope of the road adhesion coefficient is 0 is the peak road adhesion coefficient.

3. The braking energy recovery safety control method based on vehicle body dynamics according to claim 1, characterized in that: Calculate the rear axle load, including: For vehicles with air suspension, an axle load sensor is installed at the air inlet of the rear axle air suspension airbag to collect rear axle load information in real time; For vehicles equipped with leaf springs, a brake pressure sensor is installed between the outlet of the rear axle relay valve and the air inlet of the brake chamber. The brake force is calculated in real time based on the brake pressure value. During the braking process, before the wheel reaches the slip rate corresponding to the peak adhesion coefficient, the ground braking force is equal to the brake force. The left and right wheel loads on the rear axle are calculated using the ground braking force and the wheel deceleration, and the rear axle load is calculated based on the left and right wheel loads on the rear axle.

4. The braking energy recovery safety control method based on vehicle body dynamics according to claim 1, characterized in that: Before optimizing the management of the electric brake energy recovery torque exit by controlling the electric brake energy recovery torque exit timing based on the road adhesion coefficient, the following steps are also included: Get the brake pedal opening, and increase the air brake when the brake pedal opening is greater than the set value.

5. The braking energy recovery safety control method based on vehicle body dynamics according to claim 1, characterized in that: If the road adhesion coefficient is greater than or equal to the second set value, it is determined whether the ABS function is activated. If the ABS function is activated, the motor braking energy recovery starts to exit; If the ABS function is not activated, it will further determine whether the motor speed is lower than 500r / min. If it is lower than 500r / min, the motor braking energy recovery will start to exit and will completely exit when the motor speed is 200r / min.

6. A braking energy recovery safety control system based on vehicle body dynamics, characterized by: It includes ABS controller, wheel speed sensor, axle load sensor, brake pressure sensor, brake pedal opening sensor, vehicle controller, motor controller and motor, including: Wheel speed sensor, which is used to collect wheel speed data and send the wheel speed data to the ABS controller; Axle load sensor, which is used to collect axle load data and send the axle load data to the vehicle controller; Brake pressure sensor, which is used to collect brake pressure data and send the brake pressure data to the vehicle controller; A brake pedal opening sensor is used to collect brake pedal opening data and send the brake pedal opening data to the vehicle controller; ABS controller, which is used to receive wheel speed data and send the wheel speed data to the vehicle controller; The motor controller is used to collect motor speed data and motor real-time torque, and send the motor speed data and motor real-time torque to the vehicle controller; A vehicle controller is configured to receive wheel speed data, axle load data, brake pressure data, brake pedal opening data, motor speed data, and real-time motor torque; calculate a road adhesion coefficient and a peak road adhesion coefficient based on the wheel speed data and real-time motor torque; determine whether to add a rear axle road adhesion upper limit constraint to the motor target regenerative torque based on the road adhesion coefficient; obtain rear axle load based on axle load data or brake pressure data; determine whether the air brake is engaged based on brake pedal opening data; and control the timing of exiting the regenerative braking torque based on the road adhesion coefficient and motor speed data; Calculating the target regenerative torque of the motor and further determining whether the road adhesion coefficient is less than a first set value; if not, then adding an upper limit constraint of the rear axle road adhesion limit to the target regenerative torque of the motor; The electric brake energy recovery torque exit time is determined based on the road adhesion coefficient, specifically including: If the road adhesion coefficient is less than the second set value, the rear wheel slip rate is greater than 10%, and the brake pedal opening rate is greater than the set threshold, the electric motor brake energy recovery begins to exit, and the proportion of air braking gradually increases. When the motor speed reaches 500r / min, the electric motor brake energy recovery is completely exited; If the road adhesion coefficient is less than the second set value, but at least one of the following conditions is not met: the rear wheel slip rate is greater than 10% and the brake pedal opening change rate is greater than the set threshold value, it is further determined whether the motor speed is less than 800r / min. If it is less than 800r / min, the brake energy recovery begins to exit, and the motor brake energy recovery is completely exited when the motor speed is 500r / min.

7. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps of the braking energy recovery safety control method based on vehicle body dynamics as described in any one of claims 1 to 5 are implemented.

8. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the braking energy recovery safety control method based on vehicle body dynamics as described in any one of claims 1 to 5 are implemented.

Images