WO2023098257A1

WO2023098257A1 - Vehicle anti-skid control method, motor controller, system, and storage medium

Info

Publication number: WO2023098257A1
Application number: PCT/CN2022/121438
Authority: WO
Inventors: 吴蒙; 彭耀润; 林浩强; 王金航; 陈立华; 李欢
Original assignee: 广州汽车集团股份有限公司
Priority date: 2021-12-03
Filing date: 2022-09-26
Publication date: 2023-06-08
Also published as: MX2024006781A; CN116215497A

Abstract

Disclosed in the present invention are a vehicle anti-skid control method, a motor controller, a system, and a storage medium. The method comprises: a motor controller determining whether an anti-skid rotating speed limiting request sent by a vehicle control unit is received; if the anti-skid rotating speed limiting request is received, starting an anti-skid driving mode to determine, according to a highest limited rotating speed and an actual rotating speed of a driving motor, whether torque reduction control is required to be performed on the driving motor; and if yes, performing closed-loop control on the torque of the driving motor according to the highest limited rotating speed and limited motor torque. According to the present invention, in the anti-skid driving mode, the motor controller determines, by itself according to the highest limited rotating speed and the actual rotating speed, whether to execute torque reduction control, and performs, during a torque reduction control process, closed-loop control on the torque of the driving motor according to the highest limited rotating speed and the limited motor torque so as to timely and accurately adjust the torque of the driving motor, so that the timeliness and effectiveness of vehicle anti-skid control are improved, and the anti-skid effect is further improved.

Description

Vehicle anti-skid control method, motor controller, system and storage medium

This application claims the priority of the Chinese patent application with the application number 202111469291.5 submitted to the China Patent Office on December 03, 2021, and the invention title is "vehicle anti-skid control method, motor controller, system and storage medium", the entire content of which is passed References are incorporated in this application.

technical field

The invention relates to the technical field of vehicle control, in particular to a vehicle anti-skid control method, a motor controller, a system and a storage medium.

Background technique

The dynamic characteristics of the driving system of hybrid vehicles and fuel vehicles are quite different. Compared with internal combustion engines, the driving motors of hybrid vehicles have the characteristics of small response time, small moment of inertia, and large speed range. higher real-time requirements.

In the vehicle anti-skid control strategy of the prior art, after determining that the vehicle is in a slipping state, the vehicle controller usually collects vehicle data, then calculates the motor torque based on the vehicle data, and sends the calculated motor torque to the motor controller , the motor controller receives the motor torque to execute the torque, and feeds back the execution result to continue slip judgment. However, the controllers communicate through the network, and there is a communication delay in data transmission. After the vehicle skids, the motor torque cannot be limited in time, which affects the real-time performance of the anti-skid control, thereby reducing the anti-skid effect.

Contents of the invention

The invention provides a vehicle anti-skid control method, a motor controller, a system and a storage medium to solve the problem in the prior art that the torque of the motor cannot be limited in time after the vehicle skids, which affects the real-time performance of the anti-skid control, thereby reducing the anti-skid effect .

A vehicle anti-skid control method is provided, comprising:

The motor controller confirms to receive the anti-slip speed limit request, and the anti-slip speed limit request includes the highest limit speed;

According to the maximum limit speed and the actual speed of the drive motor, determine whether to perform torque reduction control on the drive motor;

If it is necessary to perform torque reduction control on the drive motor, the motor controller performs closed-loop control on the torque of the drive motor according to the maximum speed limit.

A motor controller is provided, including:

The first determination module is configured to receive an anti-slip speed limit request, where the anti-slip speed limit request includes a maximum limit speed and a motor limit torque;

The second determination module is used to determine whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor;

The control module is used to perform closed-loop control on the torque of the driving motor according to the maximum speed limit of the motor controller if it is necessary to perform torque reduction control on the driving motor.

A vehicle antiskid control system is provided, comprising:

The vehicle body electronic stability system is used to send the traction function activation signal and the anti-skidding torque request to the vehicle controller after the traction function is activated;

Vehicle controller for:

Determine whether anti-slip speed limitation of the drive motor is required, and determine whether torque limitation of the drive motor is required;

If anti-slip speed limitation and torque limitation are required, then determine the maximum limit speed of the drive motor and determine the limit torque of the motor;

Generate an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and send the anti-slip speed limit request to the motor controller;

Receive the traction function activation signal and the anti-skid torque reduction request sent by the electronic stability system of the vehicle body, so as to generate the speed limit cancellation instruction according to the traction function activation signal, and send the speed limit cancellation instruction and the anti-skid torque reduction request to the motor controller;

Motor controllers for:

Receive the anti-skid speed limit request, and determine whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor;

If it is necessary to perform torque reduction control on the drive motor, perform closed-loop control on the torque of the drive motor according to the maximum limit speed and the limit torque of the motor;

After receiving the rotation speed limit cancellation instruction and the anti-slip torque reduction request, exit the anti-skid driving mode according to the rotation speed limit cancellation instruction, and respond to the anti-slip torque reduction request.

A motor controller or a vehicle controller is provided, comprising a memory, a processor, and a computer program stored in the memory and operable on the processor. When the processor executes the computer program, the steps of the vehicle anti-slip control method are realized.

A computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above vehicle anti-slip control method are implemented.

In a solution provided by the above-mentioned vehicle anti-skid control method, motor controller, system and storage medium, the motor controller receives the anti-skid speed limit request, and the anti-skid speed limit request includes the maximum limit speed; then according to the maximum limit speed and the actual driving motor Rotating speed, determine whether need to carry out torsion reduction control to drive motor; If need to carry out torsion control to drive motor, then motor controller carries out closed-loop control to the torque of drive motor according to the highest limit speed; In the present invention, through vehicle controller Request to the motor controller for anti-slip speed limit, so that the drive motor starts the anti-slip drive mode. In the anti-slip drive mode, the motor controller determines whether to execute the torque reduction control according to the maximum limit speed and the actual speed, and during the torque reduction control process, according to The highest limit speed performs closed-loop control on the torque of the drive motor, which can timely and accurately adjust the torque of the drive motor, thereby improving the real-time performance and effectiveness of vehicle anti-skid control, thereby improving the anti-skid effect.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments of the present invention. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention , for those skilled in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 is a schematic structural view of a vehicle anti-skid control system in an embodiment of the present invention;

Fig. 2 is a schematic flow chart of a vehicle anti-skid control method in an embodiment of the present invention;

Fig. 3 is a signaling interaction diagram of a vehicle anti-skid control method in an embodiment of the present invention;

Fig. 4 is a schematic diagram of changes in operating parameters after the traction function of a traditional vehicle is activated;

Fig. 5 is a schematic diagram of changes in operating parameters after adopting the vehicle anti-skid control method of the present invention;

Fig. 6 is a schematic structural diagram of a motor controller in an embodiment of the present invention;

Fig. 7 is a schematic structural diagram of a motor controller or a vehicle controller in an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The vehicle anti-skid control method provided by the embodiment of the present invention is applied to a two-drive hybrid vehicle or a two-drive pure electric vehicle (the power system operating mode of a pure electric vehicle is a pure electric mode), and can be applied to a vehicle as shown in FIG. 1 In the anti-skid control system, the vehicle anti-skid control system includes a vehicle controller, a motor controller, a drive motor, and an electronic stability system for a vehicle body. Among them, the motor controller and the vehicle body electronic stability system communicate with the vehicle controller through the CAN network, and the motor controller is electrically connected with the drive motor.

Among them, the body electronic stability system (Electronic Stability Program, ESP for short) includes the traction control system (Traction Control System, TCS for short). Send traction function activation signal and anti-skid torque down request.

The vehicle control unit (VCU for short) is used to determine whether it is necessary to limit the anti-slip speed of the drive motor, and determine whether it is necessary to limit the torque of the drive motor; if it is necessary to limit the anti-slip speed and torque limit, then Determine the maximum limit speed of the driving motor, and determine the limit torque of the motor; generate an anti-slip speed limit request according to the maximum limit speed, and send the anti-slip speed limit request to the motor controller, so that the motor controller determines whether to start according to the anti-slip speed limit request Anti-skid driving mode; it also receives the traction function activation signal and anti-skid torque reduction request sent by the electronic stability system of the vehicle body, so as to generate the speed limit cancellation command according to the traction force function activation signal, and send the speed limit cancellation command and anti-skid torque reduction request to the motor controller .

The motor controller (Intergrated Power Unit, referred to as IPU), is used to determine and receive the anti-skid speed limit request sent by the vehicle controller, and after receiving the anti-skid speed limit request, enable the anti-skid drive mode to drive the motor according to the maximum speed limit and The actual speed of the driving motor is determined to determine whether it is necessary to perform torque reduction control on the driving motor; if it is necessary to perform torque reduction control on the driving motor, perform closed-loop control on the torque of the driving motor according to the maximum speed limit; Finally, exit the anti-skid driving mode according to the speed limit cancellation command, and respond to the anti-skid torque reduction request.

In this embodiment, the motor controller receives the anti-slip speed limit request sent by the vehicle controller, and after receiving the anti-slip speed limit request, enables the anti-slip drive mode to determine whether to It is necessary to perform torque reduction control on the driving motor; if it is necessary to perform torque reduction control on the driving motor, the motor controller performs closed-loop control on the torque of the driving motor according to the maximum speed limit; in this embodiment, the motor is controlled by the vehicle controller In the anti-skid driving mode, the motor controller determines whether to execute the torque reduction control according to the maximum speed limit and the actual speed, and in the process of torque reduction control, according to the maximum speed limit The closed-loop control of the torque of the drive motor can timely and accurately adjust the torque of the drive motor, thereby improving the real-time performance and effectiveness of the anti-skid control of the vehicle, thereby improving the anti-skid effect.

At the same time, when the TCS function of the body electronic stability system fails or does not work (not activated), the motor controller automatically performs torque reduction control according to its own actual speed, which improves the real-time performance of the vehicle anti-skid control and ensures the stability of the vehicle. It can solve or improve the drivability problem of electric drive vehicles on low-attachment roads, and improve the drivability problems of traditional TCS functions applied to electric drive vehicles on low-attachment roads.

In addition, when the vehicle is running, if the vehicle is in the series drive mode, the vehicle controller will also determine the motor limit torque according to the actual charging power of the battery, the actual power generation of the engine, and the actual discharge power of the driving motor, so that the motor controller can determine When it is necessary to control the drive motor for torque reduction control, combined with the maximum limit speed and motor limit torque for torque reduction control, the state of the battery and the engine is considered during the torque reduction control, which solves the problem that the motor anti-skid control ability is not considered in the traditional anti-skid control method Due to the limitation of battery capacity, the adaptability of this method to hybrid vehicles is guaranteed, and the torque of the drive motor is adjusted in a timely and precise manner under the condition that the battery is not fully charged, thereby improving the real-time and effectiveness of vehicle anti-skid control. Then the anti-skid effect is improved; and after the anti-skid driving mode is enabled, when the TCS function is determined to be activated, exiting the anti-skid driving mode does not control the speed of the drive motor, but allows the drive motor to respond to the anti-skid torque reduction request of the ESP, and the vehicle's anti-skid The control state is completely handed over to ESP to ensure the robustness of vehicle anti-skid control.

The vehicle anti-skid control method in this embodiment is a distributed control strategy coordinated and controlled by controllers such as the vehicle body electronic stability system ESP, the vehicle controller VCU, and the motor controller IPU. The VCU determines the maximum limit speed of the driving motor and sends it to the IPU, and at the same time calculates the motor limit torque for the drive motor based on the current battery state and engine power generation state, so that the IPU can accurately and accurately determine the torque of the drive motor according to the maximum limit speed and motor limit torque. Timely control improves the real-time performance of vehicle anti-skid control; when the TCS function is activated, it exits the maximum speed limit of the drive motor and responds to the request of ESP for anti-skid and torque reduction; VCU, as the coordination center of the entire anti-skid control strategy, coordinates the control of each controller Work, the anti-skid control strategy distributed implementation method, each controller performs its own duties, can give full play to its advantages, and the development difficulty is relatively small, which not only ensures the real-time performance of the control, but also ensures the robustness of the entire control strategy .

In this embodiment, the vehicle anti-skid control system includes a vehicle controller, a motor controller, a body electronic stability system, and a drive motor for illustrative purposes only. In other embodiments, the vehicle anti-skid control system also includes other devices, such as an engine control system EMS and engine assembly, etc., will not be repeated here.

In one embodiment, as shown in FIG. 2 , a vehicle anti-skid control method is provided, which is described by taking the method applied to the vehicle anti-skid control system in FIG. 1 as an example, including the following steps:

S10: The motor controller receives an anti-slip speed limit request.

During the running of the vehicle, the motor controller needs to determine in real time whether it has received the anti-skid speed limit request sent by the vehicle controller, and determines whether it needs to execute the anti-skid control strategy based on the reception of the anti-skid speed limit request.

Wherein, the anti-slip rotational speed limit request includes the maximum limited rotational speed. In this embodiment, the maximum speed limit is the maximum speed of the driving motor determined by the vehicle controller according to the vehicle data.

In other embodiments, if the power running mode of the vehicle is the series drive mode, the anti-slip speed limit request also includes the motor limit torque, so that when it is determined that the drive motor needs to be controlled for torque reduction, the maximum speed limit and the motor limit torque The torque of the drive motor is closed-loop controlled. Among them, the motor limit torque is the minimum torque of the drive motor determined by the vehicle controller according to the power generation status of the vehicle's battery and engine and other devices.

Wherein, the anti-skid speed limit request is a drive motor speed limit request generated by the vehicle controller after determining that the vehicle may have a slip risk under the current working condition according to the vehicle data. For example, when the vehicle controller detects that the vehicle speed is too high, the ground adhesion is low, and there is no ESP intervention, there may be a risk of vehicle skidding. and torque are limited, and then an anti-slip speed limit request is generated according to the highest limit speed.

S20: According to the maximum speed limit and the actual speed of the driving motor, determine whether to perform torque reduction control on the driving motor.

If it is determined that the anti-skid speed limit request is received, it means that the vehicle controller believes that the vehicle may have a slip risk under the current working conditions. In order to reduce the risk of vehicle slip, the motor controller needs to enable the anti-skid drive mode. In the anti-skid driving mode, the motor controller will determine in real time whether it is necessary to perform torque reduction control on the driving motor according to the maximum limit speed and the actual speed of the driving motor.

Wherein, the motor controller determines whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor, including: the motor controller determines whether the actual speed of the drive motor is greater than the maximum limit speed; if the actual speed of the drive motor If it is greater than the maximum speed limit, it means that the actual speed of the driving motor exceeds the speed limit calculated by the vehicle controller, and the risk of vehicle slippage is high, so the speed of the driving motor needs to be reduced. At this time, the motor controller determines that the torque reduction control of the driving motor is required. The motor controller performs closed-loop control on the torque of the drive motor according to the maximum limit speed; if the actual speed of the drive motor is less than or equal to the maximum limit speed, it means that the actual speed of the drive motor does not exceed the speed limit calculated by the vehicle controller, and the risk of vehicle slippage Smaller, there is no need to perform torque reduction control on the driving motor for the time being. At this time, the motor controller obtains the vehicle torque request sent by the vehicle controller, and responds normally to the vehicle torque request to output the vehicle demand in the vehicle torque request torque.

S30: If it is necessary to perform torque reduction control on the drive motor, the motor controller performs closed-loop control on the torque of the drive motor according to the maximum limit speed and the limit torque of the motor.

After determining whether the torque reduction control of the driving motor is required according to the maximum speed limit and the actual speed of the driving motor, if the torque reduction control of the driving motor is required, the risk of vehicle slippage is high, and the speed of the driving motor needs to be reduced, then the motor control The controller performs closed-loop control on the torque of the driving motor according to the maximum speed limit.

Among them, the motor controller performs closed-loop control on the torque of the drive motor according to the maximum limit speed, which specifically includes: when the power system operation mode of the vehicle is the series drive mode, the motor controller controls the torque of the drive motor according to the maximum limit speed and the motor limit torque. Closed-loop control of the torque of the vehicle, in order to timely and accurately adjust the torque of the drive motor, improve the real-time and effectiveness of vehicle anti-skid control, and then improve the anti-skid effect; According to the maximum limit speed and the limit torque of the motor, the torque of the drive motor is closed-loop controlled, so as to ensure that the battery is not fully charged, the torque of the drive motor can be adjusted in time and accurately, thereby improving the anti-skid effect.

If it is necessary to reduce the torque of the drive motor, in order to prevent the vehicle from slipping and reduce the speed of the vehicle to reduce the risk of vehicle loss of control, it is necessary to reduce the torque of the drive motor (torque reduction) and limit the speed of the drive motor according to the maximum limit speed to ensure The actual speed of the driving motor is lower than the maximum speed limit; at the same time, when the power system operation mode of the vehicle is the series drive mode, in the process of limiting the speed of the driving motor according to the maximum speed limit, in order to prevent the battery from being overcharged, it is also necessary to control the speed of the driving motor. The torque is limited to prevent the motor torque from being too low. When the power generated by the engine is not reduced in time, the engine generates too much power, which exceeds the charging capacity of the battery and causes the battery to overcharge.

In this embodiment, the motor controller determines whether to perform torque reduction control on the drive motor according to the maximum limit speed limit and the actual speed of the drive motor by receiving the anti-slip speed limit request; if it is necessary to perform torque reduction control on the drive motor, the motor The controller performs closed-loop control on the torque of the drive motor according to the maximum speed limit; through the vehicle controller, it requests the motor controller for anti-slip speed limit, so that the drive motor starts the anti-slip drive mode. In the anti-slip drive mode, the motor controller automatically The limit speed and the actual speed determine whether to perform torque reduction control, and in the process of torque reduction control, the torque of the drive motor is closed-loop controlled according to the highest limit speed, and the torque of the drive motor can be adjusted in time and accurately, thereby improving the performance of vehicle anti-slip control Immediate and effective, thereby improving the anti-slip effect.

In one embodiment, after step S30, that is, after the motor controller receives the anti-slip speed limit request, the method further specifically includes the following steps:

S41: After activating the traction force function, the body electronic stability system sends a traction force function activation signal and an anti-skid torque reduction request to the vehicle controller.

During the running of the vehicle, especially after the motor controller receives the anti-skid speed limit request to enable the anti-skid driving mode, the vehicle electronic stability system will determine the state of the driving wheels of the vehicle according to the vehicle data, so as to determine whether to activate the traction function according to the state of the driving wheels. Among them, the vehicle data includes information such as wheel speed information, driving torque request, and accelerator pedal opening. The vehicle body electronic stability system determines whether the state of the driving wheel is slipping according to the information such as wheel speed information, driving torque request, and accelerator pedal opening. If the state of the driving wheel is slipping, it is necessary to activate the traction function (TCS function) so that the function intervenes in the vehicle control to prevent the vehicle from slipping.

After activating the traction function, the vehicle body electronic stability system will send a traction function activation signal to the vehicle controller. In addition, the vehicle body electronic stability system will determine and generate an anti-skid torque reduction request according to actual needs, and send an anti-skid torque reduction request to the vehicle controller .

S42: After receiving the traction force function activation signal and the anti-skid torque reduction request, the vehicle controller generates a speed limit cancellation command according to the traction force function activation signal, and sends the speed limit cancellation command and the anti-skid torque reduction request to the motor controller.

After receiving the traction force function activation signal and the anti-skid torque reduction request, the vehicle controller generates a speed limit cancellation command according to the traction force function activation signal, and sends the speed limit cancellation command and the anti-skid torque down request to the motor controller.

S43: After the motor controller receives the rotation speed limit cancellation instruction and the anti-slip torque reduction request, cancels the instruction according to the rotation speed limit, and responds to the anti-slip torque reduction request.

After the motor controller receives the speed limit cancellation command and the anti-slip torque reduction request, it disables the anti-skid drive mode according to the speed limit cancellation command, that is, it exits the maximum speed limit of the drive motor by the vehicle controller, and it does not need to be based on the maximum speed limit and the drive motor. The actual speed determines whether the drive motor needs to be controlled for torque reduction. It only responds to the anti-skid torque reduction request sent by the vehicle body electronic stability system through the vehicle controller and the vehicle torque request sent by the vehicle controller. Instead, it responds to the anti-skid torque reduction request. Request, on the basis of ensuring that the battery is not fully charged, the anti-skid control state of the vehicle is completely handed over to the body electronic stability system to ensure the robustness of the anti-skid control.

In this embodiment, after the vehicle body electronic stability system activates the traction force function, it sends the traction force function activation signal and the anti-skid torque reduction request to the vehicle controller, and the vehicle controller receives the traction force function activation signal and the anti-skid torque reduction request, Generate a speed limit cancellation command according to the traction function activation signal, and send a speed limit cancellation command and an anti-skid torque reduction request to the motor controller; after receiving the speed limit cancellation command and anti-skid torque reduction request, the motor controller disables anti-skid according to the speed limit cancellation command drive mode, and respond to torque down request anti-skid down torque please. After the motor controller enables the anti-skid driving mode, if the vehicle controller finds that the electronic stability system of the body activates the traction function, it will send the speed limit cancellation command and the anti-skid torque reduction request to the motor controller to make the motor controller exit the anti-skid driving mode , and in response to the anti-skid and torque reduction request of the vehicle body electronic stability system, the anti-skid control of the vehicle is handed over to the vehicle body electronic stability system to ensure the robustness of the anti-skid control and avoid control conflicts caused by the adjustment of the anti-skid strategy, so that each system in this embodiment Performing its duties, it not only ensures the real-time performance of the control, but also ensures the robustness of the anti-skid control.

In one embodiment, after activating the traction force function, the vehicle body electronic stability system determines to generate an anti-skid torque request according to actual needs, and at the same time applies a hydraulic braking force to the driving wheels of the vehicle, and at the same time, sends an anti-skid request to the vehicle controller. Torque reduction request. After the body electronic stability system activates the TCS function, Stepper determines and generates an anti-skid and torque reduction request according to actual needs, so as to realize the control of vehicle driving anti-skid through the drive motor, and also participate in the execution of hydraulic braking of anti-skid control to ensure the anti-skid effect of the vehicle.

In one embodiment, after the vehicle controller receives the traction function activation signal and the request for anti-skid torque reduction, the vehicle controller will generate a power reduction request and send the power reduction request to the engine controller, so that the engine controller can receive power After the reduction request, the engine power generation is reduced to prevent overcharging of the vehicle's battery.

In one embodiment, before step S10, that is, before the motor controller determines whether the anti-slip speed limit request sent by the vehicle controller is received, the method further specifically includes the following steps:

S01: The vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor, and determines whether it is necessary to limit the torque of the drive motor.

After the vehicle controller is started, the vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor according to the gear information of the vehicle and the operation mode of the power system. Among them, the power system operation mode includes a pure electric drive mode, a series drive mode, and a parallel drive mode.

Wherein, the vehicle controller determines whether to limit the anti-slip speed of the drive motor according to the gear information of the vehicle and the power system operation mode, which may include: determining whether the vehicle is in a preset gear according to the gear information of the vehicle, the preset gear The position can be other gears except the park gear and neutral gear, and determine whether the power system operation mode is the preset mode, and the preset mode can be the parallel drive mode; if the vehicle is in the preset gear position, and the power system operation mode If the vehicle is in the preset mode, it means that the vehicle is in the driving state and there may be a risk of slipping, so it is determined that the anti-slip speed limit of the drive motor is required; state or the engine is directly connected to the wheel end, and there is no need to limit the drive motor, it is determined that no anti-skid speed limit is required for the drive motor.

When the vehicle is in certain gears (such as parking gear P, neutral gear N), the wheel ends of the vehicle have no power, and the vehicle is not in a driving state. At this time, there is no need to prevent slipping, and there is no need to limit the anti-skid speed of the drive motor. When the power system operation mode of the vehicle is certain mode (such as parallel driving mode), the engine of the vehicle is directly connected to the wheel end, and at this time, there is no need to limit the anti-slip speed of the drive motor.

In other embodiments, after the vehicle controller is started, the vehicle controller will determine in real time whether it is necessary to perform an anti-slip rotation speed on the drive motor according to the gear information of the vehicle, the operation mode of the power system, and the function activation of the electronic stability system of the vehicle body. Restriction, if the traction force function in the electronic stability system of the vehicle body is not activated, there may be a risk of slipping when the vehicle is in a driving state, and the anti-slip speed limit of the drive motor is required.

Among them, the vehicle controller determines whether to limit the torque of the drive motor according to the operation mode of the power system. If the operation mode of the power system is the series drive mode, the engine may fail to reduce the torque in time during the torque reduction process of the drive motor. , so that the engine generates too much power, which exceeds the charging capacity of the battery, resulting in overcharging of the battery. Therefore, in order to avoid overcharging of the battery, it is necessary to limit the torque of the driving motor during the process of reducing the torque of the driving motor; if the operating mode of the power system is pure electric drive mode , the engine does not work, and there is no situation where the engine generates too much power and the battery is overcharged, then there is no need to limit the torque of the drive motor during the process of reducing the torque of the drive motor.

S02: If anti-slip speed limitation and torque limitation are required, the vehicle controller determines the maximum limited rotational speed of the drive motor, and determines the limited torque of the motor.

After the vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor according to the gear information of the vehicle and the operation mode of the power system, if it is necessary to limit the anti-slip speed of the drive motor, it means that the vehicle is in a driving state and there is a risk of vehicle skidding. Then the vehicle controller determines the maximum limit speed of the drive motor according to the wheel speed information and the steering wheel angle, and if it is necessary to limit the torque of the drive motor, then determine the limit torque of the motor.

After determining whether it is necessary to limit the anti-slip speed of the drive motor, and determine whether it is necessary to limit the torque of the drive motor, if it is necessary to limit the anti-slip speed of the drive motor, but does not need to limit the torque of the drive motor, the vehicle controller determines the drive The maximum limit speed of the motor, and then generate an anti-slip speed limit request according to the maximum limit speed, and send the anti-slip speed limit request to the motor controller.

Among them, the maximum speed limit of the drive motor is determined according to the wheel speed information and the steering wheel angle. The radius calculation obtains the highest limit speed.

Among them, the maximum speed limit is calculated by the following formula:

Among them, V _max is the maximum limit speed of the drive motor, V _tar is the target speed of the drive shaft, M is the reduction ratio from the drive motor to the wheel end, and R is the radius of the wheel tire.

In one embodiment, the vehicle controller determines the limit torque of the motor according to the actual charging power of the battery, the actual power generated by the engine, and the actual discharge power of the driving motor, so as to consider the impact of the power generation of the engine and the discharge of the driving motor on the battery capacity. When the drive motor performs torque reduction control, the torque reduction torque is limited to prevent battery overcharging. In other embodiments, the limited torque of the electric motor may be a nominal torque, or a torque obtained through calculation in other ways, which will not be repeated here.

Among them, according to the actual charging power of the battery, the actual generating power of the engine, and the actual discharging power of the driving motor, the motor limit torque is determined, including: the vehicle controller determines the driving motor according to the actual charging power of the battery, the actual generating power of the engine, and the actual discharging power of the driving motor. The available torque reduction power, and then the vehicle controller determines the motor limit torque according to the actual speed of the drive motor and the torque reduction available power.

Among them, the motor limit torque is calculated by the following formula:

T _min =W _m *9550/V _r ;

Among them, T _min is the limited torque of the motor, W _m is the torque-reducing available power of the driving motor, and V _r is the actual speed of the driving motor.

Because, the torque-reducing available power of the driving motor is calculated by the following formula:

W _m =W _c +W _d -W _e

Among them, W _c is the actual charging power of the battery, W _d is the actual discharging power of the drive motor, and W _e is the actual power generated by the engine.

Then, you can get:

Among them, T _min is the limited torque of the motor, W _c is the actual charging power of the battery, W _d is the actual discharge power of the driving motor, W _e is the actual power generation of the engine, and V _r is the actual speed of the driving motor.

S03: The vehicle controller generates an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and sends the anti-slip speed limit request to the motor controller.

After determining the motor limit torque and the maximum limit speed of the driving motor, the vehicle controller generates an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and sends the anti-slip speed limit request to the motor controller, so that the motor controller After receiving the anti-slip speed limit request, start the anti-slip driving mode to determine whether to perform torque reduction control on the drive motor according to the actual speed of the drive motor.

In this embodiment, before the motor controller determines whether to receive the anti-slip speed limit request sent by the vehicle controller, the vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor, and determines whether it is necessary to limit the torque of the drive motor ; If anti-skid speed limitation and torque limitation are required, the vehicle controller determines the maximum speed limit of the driving motor, and then determines the motor limit torque; the vehicle controller generates an anti-skid speed limit according to the motor limit torque and maximum speed limit Request, and send the anti-slip speed limit request to the motor controller, which clarifies the determination process of the motor limit torque and the maximum limit speed, and calculates the motor limit torque and maximum limit speed through the vehicle controller, which can reduce the information processing amount of the motor controller , thereby reducing the load of the motor controller, improving the response speed of the motor controller, thereby improving the real-time performance of the drive motor control.

In one embodiment, as shown in FIG. 3 , a vehicle anti-skid control method is provided, which is described by taking the method applied to the vehicle anti-skid control system in FIG. 1 as an example, including the following steps:

S1: The vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor, and determines whether it is necessary to limit the torque of the drive motor.

After the vehicle controller is started, the vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor according to the gear information of the vehicle and the power system operation mode, and determines whether it is necessary to limit the torque of the drive motor according to the power system operation mode . The specific determination process is as described above, and will not be repeated here.

S2: If anti-slip speed limitation and torque limitation are required, the vehicle controller determines the maximum limited rotational speed of the drive motor, and determines the motor limited torque.

After the vehicle controller determines whether it is necessary to limit the anti-skid speed of the drive motor according to the gear information of the vehicle and the operation mode of the power system, if the anti-skid speed limit is required, it means that the vehicle is in a driving state and there is a risk of vehicle skidding, then the vehicle The controller determines the maximum limit speed of the drive motor according to the wheel speed information and the steering wheel angle, and determines the limit torque of the motor according to the actual charging power of the battery, the actual power generated by the engine, and the actual discharge power of the drive motor.

The process of determining the maximum speed limit of the drive motor and the limit torque of the motor is as described above, and will not be repeated here.

S3: The vehicle controller generates an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and sends the anti-slip speed limit request to the motor controller.

After determining the motor limit torque and the maximum limit speed of the driving motor, the vehicle controller generates an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and sends the anti-slip speed limit request to the motor controller.

S4: The motor controller enables the anti-slip drive mode after receiving the anti-slip speed limit request, so as to determine whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor.

The motor controller enables the anti-slip drive mode after receiving the anti-slip speed limit request, so as to determine whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor.

Wherein, the motor controller determines whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor, including: the motor controller determines whether the actual speed of the drive motor is greater than the maximum limit speed; if the actual speed of the drive motor If it is greater than the maximum speed limit, it means that the actual speed of the driving motor exceeds the speed limit calculated by the vehicle controller, and the risk of vehicle slippage is high, so the speed of the driving motor needs to be reduced. At this time, the motor controller determines that the torque reduction control of the driving motor is required; If the actual speed of the drive motor is less than or equal to the maximum limit speed, it means that the actual speed of the drive motor does not exceed the speed limit calculated by the vehicle controller, the risk of vehicle slippage is small, and there is no need to perform torque reduction control on the drive motor for the time being.

S5: If it is necessary to perform torque reduction control on the drive motor, the motor controller performs closed-loop control on the torque of the drive motor according to the maximum limit speed and the limit torque of the motor.

If the motor controller determines that it is necessary to perform torque reduction control on the drive motor, the motor controller performs closed-loop control on the torque of the drive motor according to the maximum limit speed and the motor limit torque; if it is not necessary to perform torque reduction control on the drive motor, then the motor The controller obtains the vehicle torque request sent by the vehicle controller, and normally responds to the vehicle torque request, so as to output the vehicle required torque in the vehicle torque request.

S6: The vehicle body electronic stability system determines whether the traction function needs to be activated in real time.

When the vehicle is running, especially after the motor controller activates the anti-skid driving mode, the body electronic stability system determines the state of the driving wheels of the vehicle in real time according to the vehicle data, so as to determine whether the traction function needs to be activated according to the state of the driving wheels. If the state of the driving wheel is slipping, the traction control system needs to intervene, and it is determined that the traction function needs to be activated. On the contrary, if the state of the driving wheel is not slipping, the traction control system does not need to intervene, and the traction function does not need to be activated.

S7: If the traction force function needs to be activated, the vehicle body electronic stability system activates the traction force function to generate an anti-skid torque request according to actual needs, and sends the traction force function activation signal and the anti-skid torque request to the vehicle controller.

After the vehicle body electronic stability system determines in real time whether the traction force function needs to be activated, if the traction force function needs to be activated, the body electronic stability system activates the traction force function to generate anti-skidding torque requests according to actual needs, and apply hydraulic braking force to the driving wheels; wherein, in While activating the traction force function, the traction force function activation signal is sent to the vehicle controller in time, and after the anti-skid torque reduction request is generated according to actual needs, the anti-skid torque reduction request is also sent to the vehicle controller in real time.

S8: After receiving the traction function activation signal and the anti-skid torque reduction request, the vehicle controller generates a speed limit cancellation command according to the traction function activation signal, and sends the speed limit cancellation command and the anti-skid torque reduction request to the motor controller.

After receiving the traction function activation signal, the vehicle controller generates a speed limit cancellation command according to the traction function activation signal, and sends the speed limit cancellation command and the anti-skid torque reduction request to the motor controller after receiving the anti-skid torque reduction request.

S9: After the motor controller receives the rotation speed limit cancellation instruction and the anti-slip torque reduction request, it disables the anti-slip driving mode according to the rotation speed limit cancellation instruction, and responds to the anti-slip torque reduction request.

After the motor controller receives the rotation speed limit cancellation command and the anti-slip torque reduction request, it disables the anti-slip drive mode according to the rotation speed limit cancellation command and responds to the anti-slip torque reduction request, that is, it exits the maximum speed limit of the drive motor by the vehicle controller. Limit the rotational speed and the actual rotational speed of the drive motor, and determine whether the torque reduction control of the drive motor is required, and only respond to the anti-slip torque reduction request sent by the vehicle body electronic stability system through the vehicle controller, and the vehicle torque request sent by the vehicle controller. On the basis of ensuring that the battery is not fully charged, the anti-skid control state of the vehicle is completely handed over to the body electronic stability system to ensure the robustness of the anti-skid control.

The vehicle anti-skid control method in this embodiment is a distributed control strategy coordinated and controlled by controllers such as the vehicle body electronic stability system ESP, the vehicle controller VCU, and the motor controller IPU. The VCU determines the maximum limit speed of the driving motor and sends it to the IPU, and at the same time calculates the motor limit torque for the drive motor based on the current battery state and engine power generation state, so that the IPU can accurately and accurately determine the torque of the drive motor according to the maximum limit speed and motor limit torque. Timely control improves the real-time performance of vehicle anti-skid control, thereby improving the real-time performance and effectiveness of vehicle anti-skid control, thereby improving the anti-skid effect; when the TCS function is activated, it exits the maximum speed limit of the drive motor and responds to ESP anti-skid To reduce the torque request, the anti-skid control state of the whole vehicle is completely handed over to the ESP to ensure the robustness of the vehicle anti-skid control. As the coordinating center of the entire anti-skid control strategy, the VCU coordinates the work of each controller. The distributed implementation of the anti-skid control strategy allows each controller to perform its own duties, which can give full play to its advantages, and the development is less difficult, which ensures The real-time nature of control ensures the robustness of the entire control strategy.

When the vehicle anti-skid control method provided by this embodiment is not adopted, after the TCS function is activated in the traditional vehicle anti-skid mode and the independent control is performed, the changes of the vehicle operating parameters are shown in FIG. 4 . Using the vehicle anti-skid control method provided in this embodiment, after the controller performs coordinated control, changes in the vehicle operating parameters are shown in FIG. 5 . The horizontal axis in Fig. 4 and Fig. 5 is time (m is minute, s is second), and the vertical axis in Fig. 4 and Fig. 5 is rotational speed or acceleration, and Fig. 4 and Fig. 5 have shown that with time, vehicle Graph of longitudinal acceleration, rotational speed of the drive motor (motor speed) and rear wheel speed as a function of reality. By comparing Fig. 4 and Fig. 5, it can be known that the vehicle anti-skid control method provided by this embodiment, after the controller performs coordinated control, the soaring wheel speed of the vehicle wheels is significantly suppressed, the anti-skid effect can be effectively improved, and the low-adhesion road surface can be improved. drivability.

In one embodiment, in step S1 or step S01, it is determined whether it is necessary to limit the anti-slip speed of the drive motor, which specifically includes the following steps:

S11: The vehicle controller determines whether the power system operation mode is a preset mode.

During the driving process of the vehicle, the vehicle controller will obtain vehicle data such as power system operation mode, gear information, and function activation of the electronic stability system of the vehicle body. After acquiring the operating mode of the power system, the vehicle controller determines whether the operating mode of the power system is a preset mode. Wherein, the preset mode is a pure electric drive mode or a series drive mode.

S12: If the power system operation mode is the preset mode, the vehicle controller determines whether the vehicle is in the preset gear according to the gear information.

After determining whether the power system operation mode is the default mode, if the vehicle controller determines that the power system operation mode is the default mode, indicating that the engine is not directly connected to the wheel end, the vehicle controller determines whether the vehicle is In preset gear. Wherein, the preset gear can be other gears except the parking gear (P gear) and the neutral gear (N gear).

S13: If the vehicle is in the preset gear, the vehicle controller determines whether the traction force function is activated according to the activation of the electronic stability system of the vehicle body.

After determining whether the vehicle is in the preset gear according to the gear information, if the vehicle controller determines that the vehicle is in the preset gear, indicating that the vehicle is in a driving state, then the vehicle controller determines according to the activation of the vehicle body electronic stability system. Whether the traction force function is activated.

S14: If the traction force function is not activated, the vehicle controller determines that it is necessary to limit the anti-slip speed of the drive motor.

After determining whether the traction function is activated according to the function activation of the vehicle body electronic stability system, if the vehicle controller determines that the traction function is not Intervention. At this time, the vehicle has a risk of slipping. It is necessary to limit the torque and speed of the drive motor. The vehicle controller determines that the anti-skid speed limit of the drive motor is required to perform precise anti-skid control on the vehicle and prevent the vehicle from slipping.

In this embodiment, the vehicle controller determines whether the power system operation mode is a preset mode; if the power system operation mode is a preset mode, the vehicle controller determines whether the vehicle is in a preset gear according to the gear information; if When the vehicle is in a preset gear, the vehicle controller determines whether the traction function is activated according to the activation of the electronic stability system of the vehicle body; The specific steps for determining whether to limit the anti-slip speed of the drive motor are provided, which ensures the accuracy of the structure of the anti-slip speed limit and reduces the possibility of poor system load and dynamic performance caused by frequent anti-slip speed limits for the drive motor.

In one embodiment, in step S2 or step S02, that is, the vehicle controller determines the maximum speed limit of the drive motor, which specifically includes the following steps:

S21: The vehicle controller determines the reference vehicle speed, wheel speed difference correction value and safe vehicle speed bias value of the vehicle according to the wheel speed information of the vehicle and the steering wheel angle.

During the driving process of the vehicle, the vehicle controller will obtain vehicle data in real time, and the vehicle data also includes wheel speed information and steering wheel angle. After determining the anti-skid speed limit for the drive motor according to the gear information of the vehicle and the power system operation mode, the vehicle controller determines the reference vehicle speed, wheel speed difference correction value and Safe vehicle speed offset value. Among them, the reference vehicle speed is based on the average wheel speed of the rear wheels of the vehicle when the front wheels do not slip, adding the wheel steering correction function, that is, after correcting the average wheel speed of the rear wheels through the relationship between the steering wheel angle and the front wheel steering angle, the calculation is obtained Reference speed of the front axle. Compared with the traditional vehicle slip control method, in which the wheel speed information is obtained to calculate the target rotational speed of the drive motor when the vehicle is slipping, in this embodiment, the reference vehicle speed is calculated according to the average wheel speed of the rear wheels of the vehicle when the front wheels are not slipping, The wheel speed difference generated when the vehicle turns normally can be eliminated, and the accuracy of reference vehicle speed calculation can be improved.

The safe vehicle speed offset value in this embodiment is the safe boundary vehicle speed corresponding to the current reference vehicle speed. Since the calculated reference speed is a theoretical point value, the actual speed often has a certain deviation from the reference speed and fluctuates up and down; in order to prevent the frequent opening and closing of the anti-skid driving mode, it is necessary to set a safety boundary for the reference speed, that is, to set the safety The vehicle speed offset value corrects the reference vehicle speed.

When the vehicle is running, if the vehicle slips on the opposite road (the road adhesion coefficients of the left and right wheels of the vehicle are different), the drive shaft of the vehicle cannot effectively use the adhesion force on the high-attachment side to output driving force for the vehicle to drive, and ESP will operate at low-attachment The superimposed mechanical brake on the slip side provides sufficient driving force for the drive shaft. However, when the ESP function is activated, or the initial driving motor speed calculated by the VCU limits the wheel speed difference at the wheel end to a small range when the ESP function is off, it will cause the ESP to be unable to apply mechanical braking and cannot drive the shaft. provide sufficient driving force. Therefore, in order to effectively utilize the adhesion of the longitudinally high side, it is necessary to superimpose the wheel speed difference caused by the slipping of the driving wheel on the basis of the reference vehicle speed to correct the reference vehicle speed. The corrected wheel speed difference is the wheel speed difference correction value.

S22: The vehicle controller uses the sum of the reference vehicle speed, the wheel speed difference correction value and the safe vehicle speed bias value as the target vehicle speed of the drive shaft.

After determining the reference vehicle speed, the wheel speed difference correction value and the safe vehicle speed bias value, the vehicle controller directly uses the sum of the reference vehicle speed, the wheel speed difference correction value and the safe vehicle speed bias value as the target vehicle speed of the drive shaft.

S23: The vehicle controller performs speed ratio conversion on the target vehicle speed of the drive shaft to calculate the maximum speed limit.

After determining the target speed of the drive shaft, the vehicle controller converts the speed ratio of the target speed of the drive shaft to calculate the maximum limit speed, which is calculated according to the target speed of the drive shaft, the reduction ratio from the drive motor to the wheel end, and the radius of the wheel tire Maximum speed limit.

Among them, the maximum speed limit is calculated by the following formula:

In other embodiments, the reference vehicle speed can also be directly used as the drive shaft target vehicle speed, the sum of the reference vehicle speed and the wheel speed difference correction value can also be used as the drive shaft target vehicle speed, and the sum of the reference vehicle speed and the safe vehicle speed offset value can also be used as Drive shaft target vehicle speed.

Furthermore, the maximum speed limit is calculated according to the target vehicle speed of the drive shaft, the reduction ratio from the drive motor to the wheel end, and the radius of the wheel tire. In this embodiment, the reference vehicle speed is corrected by the wheel speed difference correction value, which solves the problem that the traditional vehicle anti-skid control method does not pay attention to the two-wheel drive vehicle slipping on one side of the opposite road, and improves the calculated target vehicle speed of the drive shaft. The accuracy of the reference vehicle speed is corrected by the safe vehicle speed offset value, which takes into account the problem of the deviation between the calculated reference vehicle speed and the actual vehicle speed, and improves the accuracy of the calculated target vehicle speed of the drive shaft.

And the safety vehicle speed offset value is used for the whole vehicle controller to refer to the vehicle speed as the target vehicle speed of the drive shaft.

Further, determine the maximum limit speed of the drive motor, including:

In this embodiment, the vehicle controller determines the reference vehicle speed, wheel speed difference correction value and safety vehicle speed offset value of the vehicle according to the vehicle wheel speed information and steering wheel angle, and then calculates the reference vehicle speed, wheel speed difference correction value and safety The sum of vehicle speed offset values is used as the target vehicle speed of the drive shaft, and finally the speed ratio conversion is performed on the target speed of the drive shaft to calculate the maximum limit speed; when calculating the maximum limit speed, refer to the actual wheel speed information to judge the state of the vehicle more accurately. At the same time, the reference vehicle speed is corrected according to the wheel speed difference correction value and the safe vehicle speed offset value, so that a more accurate target vehicle speed of the drive shaft can be obtained, and thus an accurate maximum speed limit can be obtained, which provides a basis for subsequent precise anti-skid control of the drive motor .

In one embodiment, in step S21, the vehicle controller determines the reference vehicle speed, the wheel speed difference correction value and the safe vehicle speed bias value of the vehicle according to the wheel speed information and the steering wheel angle of the vehicle, specifically including the following steps:

S211: The vehicle controller determines the front wheel steering angle of the vehicle according to the steering wheel angle and the preset wheel steering angle data.

After obtaining the steering wheel angle, the vehicle controller will determine the front wheel steering angle of the vehicle according to the steering wheel angle and the preset wheel steering angle data. Wherein, the preset wheel-end steering angle data includes wheel-end steering angles corresponding to different steering wheel angles.

It should be understood that there is a corresponding relationship between the steering wheel angle of the vehicle and the wheel-end steering angle of each wheel of the vehicle. In this embodiment, by performing vehicle tests on vehicles of different models, it is obtained that when each model of vehicle is at different steering wheel angles, The wheel-end steering angle of each wheel is summarized as the preset wheel-end steering angle data of the vehicle type, and is pre-stored in the vehicle memory of the corresponding model for subsequent direct use.

During the running of the vehicle, after the vehicle controller obtains the steering wheel angle, it directly searches the preset wheel-end steering angle data for the front-wheel wheel-end steering angle corresponding to the steering wheel angle according to the steering wheel angle. Wherein, the front wheel steering angle includes the left front wheel steering angle and the right front wheel steering angle.

S212: The vehicle controller determines the reference vehicle speed according to the front wheel steering angle and the rear wheel speed of the vehicle.

After determining the front wheel steering angle of the vehicle according to the steering wheel angle and the preset wheel steering angle data, the vehicle controller will also extract the rear wheel speed from the vehicle wheel speed information, where the rear wheel speed Including left rear wheel speed and right rear wheel speed. Then, the vehicle controller will determine the reference vehicle speed according to the front wheel steering angle and the rear wheel speed of the vehicle.

Wherein, the vehicle controller determines the reference vehicle speed according to the steering angle of the front wheel and the rear wheel speed of the vehicle, including: correcting the wheel speed of the left rear wheel through the steering angle of the left front wheel to obtain the wheel speed of the left rear wheel The speed correction value of the right rear wheel is corrected by the wheel end steering angle of the right front wheel to obtain the wheel speed correction value of the right rear wheel; the average value of the wheel speed correction value of the left rear wheel and the wheel speed correction value of the right rear wheel , as the reference speed. The rear wheel speed of the vehicle is corrected through the steering angle of the front wheel, and the average value of the corrected rear wheel speed is used as the reference speed, which improves the accuracy of the reference speed and avoids the wrong skidding judgment due to inaccurate reference speed , so as to ensure the dynamic performance of the vehicle when turning.

Among them, the reference speed can be calculated by the following formula:

Among them, V _ref is the reference vehicle speed; V _RL is the wheel speed of the left rear wheel, and V _RR is the wheel speed of the right rear wheel; a and b are the wheel end steering angle of the left front wheel and the right front wheel respectively; The cosine value of the steering angle of the front wheel, cosb is the cosine value of the steering angle of the right front wheel; V _RL /cos a is the wheel speed correction value of the left rear wheel, and V _RR /cos b is the wheel speed correction value of the right rear wheel .

S213: The vehicle controller determines a safe vehicle speed bias value according to the reference vehicle speed and preset safe vehicle speed bias data.

After the reference vehicle speed is obtained through calculation, the vehicle controller determines a safe vehicle speed offset value according to the reference vehicle speed and preset safe vehicle speed offset data.

Wherein, the preset safe vehicle speed offset data includes safe boundary vehicle speeds corresponding to different reference vehicle speeds. The preset safe vehicle speed offset data is the required safe boundary vehicle speed at different vehicle speeds calibrated according to the test data after the vehicle is pre-tested at different vehicle speeds. After the preset safe vehicle speed bias data is obtained, the data is pre-stored in the vehicle memory of the corresponding model for subsequent direct use.

After calculating the reference vehicle speed, the vehicle controller searches the preset safe vehicle speed offset data for a safe boundary vehicle speed corresponding to the current reference vehicle speed as the safe vehicle speed offset value according to the reference vehicle speed.

For example, the corresponding relationship between the reference vehicle speed and the safety boundary vehicle speed can be shown in Table 1 below:

Table 1

S214: The vehicle controller determines a wheel speed difference correction value according to the reference vehicle speed, wheel speed information and preset corrected vehicle speed data.

After calculating the reference vehicle speed, the vehicle controller determines the wheel speed difference correction value according to the reference vehicle speed, wheel speed information and preset corrected vehicle speed data.

Wherein, the preset corrected vehicle speed data includes corrected vehicle speed values corresponding to different reference vehicle speeds. The preset corrected vehicle speed data is to test the vehicle on the open road in advance, determine the superimposition of the wheel speed difference caused by the driving wheel slipping on the basis of the reference vehicle speed, and use the wheel speed difference as the correction corresponding to the reference vehicle speed Vehicle speed values, so as to obtain corrected vehicle speed values corresponding to different reference vehicle speeds, which are summarized as preset corrected vehicle speed data. After the preset corrected vehicle speed data is obtained, the data is pre-stored in the vehicle memory of the corresponding model for subsequent direct use.

Wherein, the vehicle controller determines the correction value of the wheel speed difference according to the reference vehicle speed, wheel speed information and preset correction speed data, including: after calculating and obtaining the reference speed, it is necessary to search the current speed in the preset correction speed data according to the reference speed The corrected vehicle speed value corresponding to the reference vehicle speed is used as the corrected vehicle speed corresponding to the reference vehicle speed; the front wheel speed of the vehicle is extracted from the wheel speed information, and the front wheel speed includes the left front wheel speed and the right front wheel speed, and the left The front wheel speed difference between the front wheel speed and the right front wheel speed; calculate the reference wheel speed difference of the left and right front wheels according to the left front wheel speed and the right front wheel speed, and compare the front wheel speed difference with the reference The absolute value of the wheel speed difference is subtracted from the corrected vehicle speed to obtain the target vehicle speed; determine whether the target vehicle speed is greater than 0, if the target corrected vehicle speed is smaller than 0, then take half of the target corrected vehicle speed as the wheel speed difference correction value, If the target corrected vehicle speed is less than or equal to 0, then 0 is used as the wheel speed difference correction value. By comparing the target corrected vehicle speed with the value 0, one-half of the target corrected vehicle speed greater than 0 is used as the wheel speed difference correction value, which ensures that the wheel speed difference correction value is a positive value and increases the drive shaft target speed. On the basis of ensuring the target speed of the drive shaft is accurate, the upper limit of the maximum limit speed is increased, which reduces the possibility of insufficient power of the vehicle due to the low maximum limit speed when the subsequent drive motor reduces torque.

Among them, the wheel speed difference correction value can be determined by the following formula:

Among them, the reference wheel speed difference is calculated by the following formula:

V _corr = (V _FL -V _FR )/2;

Among them, V _diff is the wheel speed difference correction value, V _FL is the left front wheel speed, V _FR is the right front wheel speed, V _FL -V _FR is the front wheel speed difference, V _corr is the reference wheel speed difference, V _offset is the corrected vehicle speed corresponding to the reference vehicle speed.

For example, the corresponding relationship between the reference vehicle speed and the corrected vehicle speed can be shown in Table 2 below:

Table 2

参考车速 reference speed	00	1.51.5	1010	2020	3030	4040	5050	6060	7070	8080	9090	100100
修正车速corrected speed	44	55	33	33	33	33	33	1010	1515	1515	1515	1515

In this embodiment, the vehicle controller determines the front wheel steering angle of the vehicle according to the steering wheel angle and preset wheel steering angle data, and the preset wheel steering angle data includes wheel steering angles corresponding to different steering wheel angles, and then Determine the reference vehicle speed according to the steering angle of the front wheels and the rear wheel speed of the vehicle, and then determine the safe vehicle speed offset value according to the reference vehicle speed and the preset safe vehicle speed offset data. The preset safe vehicle speed offset data includes different reference vehicle speeds The corresponding safety boundary speed, and according to the reference speed, wheel speed information and preset correction speed data, determine the correction value of the wheel speed difference. The preset correction speed data includes correction speed values corresponding to different reference speeds. The vehicle's wheel speed information and steering wheel angle, and the specific process of determining the vehicle's reference speed, wheel speed difference correction value and safe speed bias value, provide an accurate data basis for the follow-up.

In one embodiment, if the anti-slip speed limit request also includes the motor limit torque, then after the motor controller determines that the torque reduction control of the drive motor is required, the torque of the drive motor is closed-loop controlled according to the maximum limit speed and the motor limit torque . In step S5, according to the maximum speed limit and the motor limit torque, the torque of the drive motor is closed-loop controlled, specifically including the following steps:

S51: The motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit.

After the motor controller determines that it is necessary to perform torque reduction control on the drive motor, the motor controller takes the highest limit speed as the target, and performs proportional integral differential control on the torque of the drive motor, that is, performs PID torque control. Among them, when performing PID torque control, in order to avoid battery overcharging, it is necessary to ensure that the torque of the driving motor is greater than the motor limit torque.

When performing PID torque control, the motor controller needs to determine the speed difference between the actual speed of the drive motor and the maximum speed limit.

S52: The motor controller inputs the rotational speed difference into the PID controller to obtain the PID adjustment torque.

After the motor controller determines the speed difference between the actual speed of the driving motor and the maximum speed limit, the motor controller inputs the speed difference into the PID controller to obtain the PID adjustment torque.

Among them, if the difference between the actual speed of the driving motor and the maximum speed limit is greater than 0, then the proportional coefficient P of the PID controller is determined to be a positive value, and the integral coefficient I and differential coefficient D are calibrated according to the actual situation; according to the proportional coefficient P, integral Coefficient I, differential coefficient D and speed difference determine PID regulation torque.

Among them, the PID adjustment torque can be calculated by the following formula:

TqPID=P*delta+I*delta*D*delta;

Among them, TqPID is the PID adjustment torque; delta is the speed difference between the actual speed of the driving motor and the maximum speed limit; P, I, and D are proportional coefficients, integral coefficients, and differential coefficients, respectively.

S53: The motor controller uses the sum of the PID adjustment torque and the vehicle demand torque as the target torque.

After inputting the rotational speed difference into the PID controller to obtain the PID adjustment torque, the motor controller takes the sum of the PID adjustment torque and the vehicle demand torque as the target torque. Wherein, the vehicle demand torque is determined according to the vehicle torque request sent by the vehicle controller, and the vehicle torque request includes the vehicle demand torque. The vehicle controller calculates the vehicle demand torque according to the vehicle power demand, and then sends the vehicle torque request including the vehicle demand torque to the motor controller, so that the drive motor executes the vehicle demand torque in response to the vehicle torque request .

S54: The motor controller outputs the larger torque between the target torque and the motor limit torque as the control torque of the drive motor until the actual speed of the drive motor is lower than the maximum limit speed.

After taking the sum of the PID adjustment torque and the vehicle demand torque as the target torque, the motor controller outputs the larger torque between the target torque and the motor limit torque as the control torque of the drive motor to avoid the output torque of the drive motor The absolute value is not lower than the limit torque of the motor. On the basis of ensuring that the battery is not fully charged, the torque and speed of the drive motor are controlled to decrease until the actual speed of the drive motor is lower than the maximum limit speed to prevent the vehicle from slipping.

In this embodiment, the motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit, and then inputs the speed difference into the PID controller to obtain the PID adjustment torque, and then compares the PID adjustment torque with the vehicle demand torque The sum is used as the target torque, and the larger absolute value of the target torque and the motor limit torque is output as the control torque of the drive motor until the actual speed of the drive motor is lower than the maximum limit speed; through PID control, the speed of the drive motor is The maximum speed limit changes to ensure the stability of the speed change. At the same time, the target torque and the motor limit torque are output as the control torque of the drive motor. On the basis of ensuring that the battery is not fully charged, the drive motor Precise torque reduction control to prevent the vehicle from slipping.

If the anti-slip speed limit request only includes the maximum speed limit, the motor controller performs closed-loop control on the torque of the driving motor according to the maximum speed limit. Among them, the motor controller performs closed-loop control on the torque of the driving motor according to the maximum speed limit, which specifically includes the following steps:

S31: The motor controller determines the speed difference between the actual speed of the driving motor and the maximum speed limit.

In this embodiment, if the anti-skid speed limit request only includes the maximum speed limit, it means that the drive mode of the power system of the vehicle is a pure electric drive mode, and there is no need to consider the battery overcharge. The controller directly takes the highest limit speed as the target, and performs PID torque control on the torque of the driving motor.

S32: The motor controller inputs the rotational speed difference into the PID controller to obtain the PID adjustment torque.

The motor controller inputs the rotational speed difference into the PID controller to obtain the PID regulating torque. For the specific process, refer to the foregoing, and details will not be repeated here.

S33: The motor controller outputs the sum of the PID adjustment torque and the vehicle demand torque as the control torque of the drive motor until the actual speed of the drive motor is lower than the maximum limit speed.

After inputting the speed difference into the PID controller to obtain the PID adjustment torque, the motor controller outputs the sum of the PID adjustment torque and the vehicle demand torque as the control torque of the drive motor until the actual speed of the drive motor is lower than the maximum limit speed , to prevent the vehicle from skidding.

In this embodiment, when the anti-slip speed limit request only includes the maximum limit speed, the motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit, and then inputs the speed difference into the PID controller to obtain the PID regulation Torque, and then the sum of the PID adjustment torque and the vehicle demand torque is output as the control torque of the drive motor until the actual speed of the drive motor is less than the maximum limit speed; through PID control, the speed of the drive motor changes to the maximum limit speed to ensure the speed The smoothness of changes, fast and precise torque reduction control of the torque of the drive motor, prevents the vehicle from slipping.

It should be understood that the sequence numbers of the steps in the above embodiments do not mean the order of execution, and the execution order of each process should be determined by its functions and internal logic, and should not constitute any limitation to the implementation process of the embodiment of the present invention.

In an embodiment, a motor controller is provided, and the motor controller corresponds to the vehicle anti-slip control method in the above embodiments one by one. As shown in FIG. 6 , the motor controller includes a first determination module 601 , a second determination module 602 and a control module 603 . The detailed description of each functional module is as follows:

The receiving module 601 is configured to receive an anti-slip speed limit request, where the anti-slip speed limit request includes the highest limit speed;

A determination module 602, configured to determine whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor;

The control module 603 is used to perform closed-loop control on the torque of the driving motor according to the maximum speed limit of the motor controller if it is necessary to perform torque reduction control on the driving motor.

Further, if the anti-slip speed limit request also includes the motor limit torque, the control module 603 is specifically used to:

Determine the speed difference between the actual speed of the drive motor and the maximum speed limit;

Input the rotational speed difference into the PID controller to obtain the PID adjustment torque;

The sum of the PID adjustment torque and the vehicle demand torque is taken as the target torque;

The larger absolute value of the target torque and the motor limit torque is output as the control torque of the drive motor until the actual speed of the drive motor is lower than the maximum limit speed.

In one embodiment, a vehicle controller is provided, and the vehicle controller is in one-to-one correspondence with the vehicle anti-slip control method in the above embodiments. The vehicle controller includes a first determination module, a second determination module 602 and a sending module. The detailed description of each functional module is as follows:

The first determining module is used to determine whether it is necessary to limit the anti-slip speed of the drive motor, and determine whether it is necessary to limit the torque of the drive motor;

The second determination module is used to determine the maximum limit speed of the drive motor and determine the limit torque of the motor if anti-slip speed limit and torque limit are required;

The sending module is used for the vehicle controller to generate an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and send the anti-slip speed limit request to the motor controller, so that when the anti-slip speed limit request is received, the anti-skid drive mode is enabled , so as to determine whether the torque reduction control of the drive motor is required according to the maximum speed limit and the actual speed of the drive motor, and to determine whether the torque reduction control of the drive motor is required, according to the maximum speed limit and the limit torque of the motor, the torque of the drive motor Perform closed-loop control.

Further, the second determining module is specifically used for:

According to the vehicle's wheel speed information and steering wheel angle, determine the vehicle's reference speed, wheel speed difference correction value and safe vehicle speed offset value;

The sum of the reference vehicle speed, the wheel speed difference correction value and the safe vehicle speed offset value is used as the target vehicle speed of the drive shaft;

Perform speed ratio conversion on the target vehicle speed of the drive shaft to calculate the maximum speed limit.

Further, the second determination module is also specifically used for:

Determine the wheel-end steering angle of the vehicle according to the steering wheel angle and the preset wheel-end steering angle data, and the preset wheel-end steering angle data includes wheel-end steering angles corresponding to different steering wheel angles;

Determine the reference vehicle speed according to the steering angle of the front wheels and the rear wheel speed of the vehicle;

According to the reference vehicle speed and the preset safe vehicle speed offset data, a safe vehicle speed offset value is determined, and the preset safe vehicle speed offset data includes safe boundary vehicle speeds corresponding to different reference vehicle speeds;

The wheel speed difference correction value is determined according to the reference vehicle speed, the wheel speed information and the preset corrected vehicle speed data. The preset corrected vehicle speed data includes corrected vehicle speed values corresponding to different reference vehicle speeds.

Further, the first determination module is specifically used for:

determining whether the operating mode of the power system is a preset mode;

If the power system operation mode is the preset mode, then determine whether the vehicle is in the preset gear according to the gear information;

If the vehicle is in a preset gear, it is determined whether the traction function is activated according to the activation of the electronic stability system of the vehicle body;

If the traction force function is not active, it is determined that a non-slip speed limitation of the drive motor is required.

As for the specific limitations of the motor controller and the vehicle controller, please refer to the above-mentioned limitations of the vehicle anti-skid control method, which will not be repeated here. Each module in the above-mentioned motor controller and vehicle controller can be realized in whole or in part by software, hardware and combinations thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, and can also be stored in the memory of the computer device in the form of software, so that the processor can invoke and execute the corresponding operations of the above-mentioned modules.

In one embodiment, a motor controller or vehicle controller is provided. The motor controller or vehicle controller includes a processor, a memory, a network interface, a display screen and an input device connected through a system bus. Wherein, the motor controller or the processor of the vehicle controller is used to provide calculation and control capabilities. The memory of the motor controller or the vehicle control device includes a storage medium and an internal memory. The storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the storage medium. The network interface of the motor controller or the vehicle controller is used to communicate with external devices through a network connection. When the computer program is executed by the processor, a vehicle anti-slip control method is realized.

In one embodiment, as shown in FIG. 7 , a motor controller or a vehicle controller is provided, including a memory, a processor, and a computer program stored on the memory and operable on the processor, and the processor executes the computer program. The program realizes the steps of the vehicle anti-skid control method described above.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned vehicle anti-slip control method are implemented.

Those of ordinary skill in the art can understand that realizing all or part of the processes in the methods of the above embodiments can be completed by instructing related hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed, it may include the processes of the embodiments of the above-mentioned methods. Wherein, any references to memory, storage, database or other media used in the various embodiments provided in the present application may include non-volatile and/or volatile memory.

Those skilled in the art can clearly understand that for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used for illustration. In practical applications, the above-mentioned functions can be assigned to different functional units, Completion of modules means that the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above.

The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still carry out the foregoing embodiments Modifications to the technical solutions recorded in the examples, or equivalent replacement of some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should be included in within the protection scope of the present invention.

Claims

A vehicle anti-skid control method, characterized in that, comprising:

The motor controller receives an anti-slip speed limit request, and the anti-slip speed limit request includes a maximum limit speed;

According to the maximum speed limit and the actual speed of the driving motor, determine whether to perform torque reduction control on the driving motor;

If it is necessary to perform torque reduction control on the drive motor, the motor controller performs closed-loop control on the torque of the drive motor according to the maximum speed limit.
The vehicle anti-skid control method according to claim 1, wherein after the motor controller receives the anti-skid speed limit request, the method further comprises:

After the vehicle body electronic stability system activates the traction force function, it sends the traction force function activation signal and the anti-skidding torque request to the vehicle controller;

After receiving the traction force function activation signal and the anti-skid torque reduction request, the vehicle controller generates a rotation speed limit cancel instruction according to the traction force function activation signal, and sends the rotation speed limit cancellation instruction and The anti-skid torque reduction request;

After the motor controller receives the rotation speed limit cancellation instruction and the anti-slip torque reduction request, it disables the anti-slip drive mode according to the rotation speed limit cancellation instruction, and responds to the anti-slip torque reduction request.
The vehicle anti-skid control method according to claim 1, wherein before the motor controller receives the anti-skid speed limit request, the method further comprises:

The vehicle controller determines whether it is necessary to limit the anti-slip speed of the drive motor, and determines whether it is necessary to limit the torque of the drive motor;

If anti-slip speed limitation and torque limitation are required, the vehicle controller determines the maximum limited rotational speed of the drive motor, and determines the motor limited torque;

The vehicle controller generates the anti-slip speed limit request according to the motor limited torque and the maximum speed limit, and sends the anti-slip speed limit request to the motor controller.
The vehicle anti-skid control method according to claim 3, wherein the determination of the maximum speed limit of the drive motor by the vehicle controller comprises:

The vehicle controller determines the reference vehicle speed, wheel speed difference correction value and safe vehicle speed bias value of the vehicle according to the wheel speed information and steering wheel angle of the vehicle;

The vehicle controller uses the sum of the reference vehicle speed, the wheel speed difference correction value and the safe vehicle speed bias value as the drive shaft target vehicle speed;

The vehicle controller performs speed ratio conversion on the target vehicle speed of the drive shaft to calculate and obtain the maximum speed limit.
The vehicle anti-skid control method according to claim 4, wherein the vehicle controller determines the reference vehicle speed, wheel speed difference correction value and safe vehicle speed of the vehicle according to the wheel speed information and steering wheel angle of the vehicle Offset values, including:

The vehicle controller determines the front wheel steering angle of the vehicle according to the steering wheel angle and preset wheel-end steering angle data, and the preset wheel-end steering angle data includes wheel-end steering angles corresponding to different steering wheel angles horn;

The vehicle controller determines the reference vehicle speed according to the front wheel steering angle and the rear wheel speed of the vehicle;

The vehicle controller determines the safe vehicle speed offset value according to the reference vehicle speed and preset safe vehicle speed offset data, and the preset safe vehicle speed offset data includes safe boundary vehicle speeds corresponding to different reference vehicle speeds;

The vehicle controller determines the wheel speed difference correction value according to the reference vehicle speed, the wheel speed information and preset corrected vehicle speed data, and the preset corrected vehicle speed data includes corrected vehicle speed values corresponding to different reference vehicle speeds.
The vehicle anti-skid control method according to claim 3, wherein the vehicle controller determines whether to limit the anti-skid speed of the drive motor according to the gear information of the vehicle and the power system operation mode, including:

The vehicle controller determines whether the operation mode of the power system is a preset mode;

If the operation mode of the power system is a preset mode, the vehicle controller determines whether the vehicle is in a preset gear according to the gear information;

If the vehicle is in a preset gear, the vehicle controller determines whether the traction function is activated according to the activation of the electronic stability system of the vehicle body;

If the traction force function is not activated, the vehicle controller determines that it is necessary to limit the anti-slip speed of the drive motor.
The vehicle anti-skid control method according to claim 3, wherein the vehicle controller determines the limit torque of the motor according to the actual charging power of the battery, the actual generating power of the engine, and the actual discharging power of the driving motor.
The vehicle anti-slip control method according to any one of claims 1-7, characterized in that, if the anti-slip speed limit request also includes a motor limit torque, the motor controller controls the drive according to the maximum limit speed The torque of the motor is closed-loop controlled, including:

The motor controller determines the speed difference between the actual speed of the driving motor and the maximum speed limit;

The motor controller inputs the rotational speed difference into a PID controller to obtain a PID adjustment torque;

The motor controller uses the sum of the PID adjustment torque and the vehicle demand torque as the target torque;

The motor controller outputs the larger torque between the target torque and the motor limit torque as the control torque of the drive motor until the actual speed of the drive motor is less than the maximum limit speed.
A motor controller, characterized in that, comprising:

A receiving module, configured to receive an anti-skid speed limit request, where the anti-skid speed limit request includes a maximum speed limit;

A determining module, configured to determine whether to perform torque reduction control on the drive motor according to the maximum speed limit and the actual speed of the drive motor;

The control module is configured to perform closed-loop control on the torque of the driving motor according to the maximum speed limit speed if it is necessary to perform torque reduction control on the driving motor.
A vehicle anti-skid control system, characterized in that it comprises:

The vehicle body electronic stability system is used to send the traction function activation signal and the anti-skidding torque request to the vehicle controller after the traction function is activated;

The vehicle controller is used for:

Determining whether anti-slip speed limitation of the drive motor is required, and determining whether torque limitation of said drive motor is required;

If anti-slip speed limitation and torque limitation are required, then determine the maximum limit speed of the drive motor and determine the limit torque of the motor;

generating an anti-slip speed limit request according to the motor limit torque and the maximum limit speed, and sending the anti-slip speed limit request to a motor controller;

receiving the traction function activation signal and the anti-skid torque reduction request sent by the vehicle body electronic stability system, to generate a speed limit cancel instruction according to the traction function activation signal, and send the speed limit cancel instruction and The anti-skid torque reduction request;

Motor controllers for:

receiving the anti-slip speed limit request, and determining whether to perform torque reduction control on the drive motor according to the maximum limit speed and the actual speed of the drive motor;

If it is necessary to perform torque reduction control on the drive motor, perform closed-loop control on the torque of the drive motor according to the maximum speed limit and the limit torque of the motor;

After receiving the rotation speed limit cancellation instruction and the anti-skid torque reduction request, exit the anti-skid driving mode according to the rotation speed limit cancellation instruction, and respond to the anti-skid torque reduction request.
A readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, the steps of the vehicle anti-slip control method according to any one of claims 1 to 8 are realized.