Vehicle slip control method, motor controller, system, and storage medium

Abstract

The application discloses a vehicle anti-skid control method, a motor controller, a system and a storage medium, and the method comprises the following steps: the motor controller determines whether an anti-skid speed limit request sent by a vehicle controller is received; if the anti-skid speed limit request is received, an anti-skid driving mode is enabled, and whether the driving motor needs to be controlled in the torque reduction mode is determined according to the highest limit speed and the actual speed of the driving motor; if the driving motor needs to be controlled in the torque reduction mode, the torque of the driving motor is controlled in the closed loop according to the highest limit speed and the motor limit torque; in the anti-skid driving mode, the motor controller determines whether to execute the torque reduction control according to the highest limit speed and the actual speed, and the torque of the driving motor is controlled in the closed loop according to the highest limit speed and the motor limit torque in the torque reduction control process, so that the torque of the driving motor can be adjusted in time and accurately, and the real-time performance and effectiveness of the vehicle anti-skid control are improved, and the anti-skid effect is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a vehicle anti-skid control method, motor controller, system, and storage medium. Background Technology

[0002] Hybrid vehicles and gasoline vehicles have significantly different drive system dynamic characteristics. Compared to internal combustion engines, hybrid vehicles' drive motors have characteristics such as short response time, low moment of inertia, and wide speed range. This places higher real-time requirements on the anti-skid control of hybrid vehicles.

[0003] In existing vehicle anti-skid control strategies, after determining that the vehicle is in a skidding state, the vehicle controller typically collects vehicle data, calculates the motor torque based on this data, and sends the calculated motor torque to the motor controller. The motor controller receives the motor torque, executes the torque, and feeds back the execution result to continue judging skidding. However, since controllers communicate via network, data transmission has communication delays. This means that the motor torque cannot be limited in a timely manner after the vehicle skids, affecting the real-time performance of anti-skid control and thus reducing its effectiveness. Summary of the Invention

[0004] This 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 motor torque cannot be limited in time after the vehicle skids, affecting the real-time performance of anti-skid control and thus reducing the anti-skid effect.

[0005] A vehicle anti-skid control method is provided, comprising:

[0006] The motor controller does receive anti-slip speed limit requests, which include the maximum speed limit.

[0007] Determine whether torque reduction control of the drive motor is needed based on the maximum speed limit and the actual speed of the drive motor.

[0008] If torque reduction control of the drive motor is required, the motor controller will perform closed-loop control of the drive motor torque based on the maximum speed limit.

[0009] A motor controller is provided, comprising:

[0010] The first determining module is used to receive the anti-slip speed limit request, which includes the maximum limit speed and the motor limit torque.

[0011] The second determining module is used to determine whether torque reduction control of the drive motor is needed based on the maximum speed limit and the actual speed of the drive motor.

[0012] The control module is used to perform closed-loop control of the torque of the drive motor based on the maximum speed limit if torque reduction control of the drive motor is required.

[0013] A vehicle anti-skid control system is provided, comprising:

[0014] The electronic stability control system is used to send a traction function activation signal and an anti-slip torque reduction request to the vehicle controller after the traction function is activated.

[0015] The vehicle controller is used for:

[0016] Determine whether anti-slip speed limiting is required for the drive motor, and determine whether torque limiting is required for the drive motor;

[0017] If anti-slip speed limiting and torque limiting are required, then determine the maximum limiting speed of the drive motor and the limiting torque of the motor.

[0018] Based on the motor's limited torque and maximum limited speed, an anti-slip speed limit request is generated and sent to the motor controller;

[0019] It receives the traction function activation signal and anti-slip torque reduction request sent by the vehicle electronic stability system, generates a speed limit cancellation command based on the traction function activation signal, and sends the speed limit cancellation command and anti-slip torque reduction request to the motor controller.

[0020] Motor controller, used for:

[0021] Receive the anti-slip speed limit request and determine whether torque reduction control of the drive motor is needed based on the maximum limit speed and the actual speed of the drive motor;

[0022] If torque reduction control of the drive motor is required, the torque of the drive motor is controlled in a closed loop based on the maximum speed limit and the motor torque limit.

[0023] After receiving the speed limit cancellation command and the anti-slip torque reduction request, it exits the anti-slip drive mode according to the speed limit cancellation command and responds to the anti-slip torque reduction request.

[0024] A motor controller or vehicle controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the above-described vehicle anti-skid control method.

[0025] A computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described vehicle anti-skid control method.

[0026] In one solution provided by the aforementioned vehicle anti-slip control method, motor controller, system, and storage medium, the motor controller receives an anti-slip speed limit request, which includes a maximum speed limit. Then, based on the maximum speed limit and the actual speed of the drive motor, it determines whether torque reduction control of the drive motor is required. If torque reduction control is required, the motor controller performs closed-loop control of the drive motor's torque based on the maximum speed limit. In this invention, the vehicle controller sends an anti-slip speed limit request to the motor controller, causing the drive motor to activate an anti-slip drive mode. In this mode, the motor controller automatically determines whether to perform torque reduction control based on the maximum speed limit and the actual speed. During the torque reduction control process, it performs closed-loop control of the drive motor's torque based on the maximum speed limit, enabling timely and precise adjustment of the drive motor's torque. This improves the real-time performance and effectiveness of vehicle anti-slip control, thereby enhancing the anti-slip effect. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of a vehicle anti-skid control system according to an embodiment of the present invention;

[0029] Figure 2 This is a flowchart illustrating a vehicle anti-skid control method according to an embodiment of the present invention;

[0030] Figure 3 This is a signaling interaction diagram of a vehicle anti-skid control method in one embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram showing the changes in operating parameters after the traction function of a traditional vehicle is activated.

[0032] Figure 5 This is a schematic diagram showing the changes in operating parameters after adopting the vehicle anti-skid control method of the present invention;

[0033] Figure 6 This is a schematic diagram of a motor controller in one embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of a motor controller or a vehicle controller in one embodiment of the present invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] The vehicle anti-skid control method provided in this invention is applicable to two-wheel drive hybrid vehicles or two-wheel drive pure electric vehicles (the power system of the pure electric vehicle operates in pure electric mode), and can be applied to, for example... Figure 1 The vehicle anti-skid control system shown includes a vehicle controller, a motor controller, a drive motor, and an electronic stability control system. The motor controller and the electronic stability control system communicate with the vehicle controller via a CAN network, and the motor controller is electrically connected to the drive motor.

[0037] The Electronic Stability Program (ESP) includes the Traction Control System (TCS). After determining that the traction function is activated (i.e., TCS is activated), the ESP sends a traction function activation signal and an anti-slip torque reduction request to the vehicle controller.

[0038] The Vehicle Control Unit (VCU) determines whether anti-slip speed limiting and torque limiting of the drive motor are required. If both are required, it determines the maximum speed limit and torque limit of the drive motor. Based on the maximum speed limit, it generates an anti-slip speed limiting request and sends it to the motor controller, which then determines whether to activate the anti-slip drive mode. The VCU also receives traction control activation signals and anti-slip torque reduction requests from the Electronic Stability Program (ESP) system. Based on the traction control activation signal, it generates a speed limit cancellation command and sends both the command and the torque reduction request to the motor controller.

[0039] The Integrated Power Unit (IPU) is used to receive anti-slip speed limit requests from the vehicle controller. Upon receiving such a request, it activates the anti-slip drive mode to determine whether torque reduction control of the drive motor is required based on the maximum speed limit and the actual speed of the drive motor. If torque reduction control is required, it performs closed-loop control of the drive motor's torque based on the maximum speed limit. Upon receiving both the speed limit cancellation command and the anti-slip torque reduction request, it exits the anti-slip drive mode based on the speed limit cancellation command and responds to the anti-slip torque reduction request.

[0040] In this embodiment, the motor controller receives an anti-slip speed limit request from the vehicle controller and, upon receiving the request, activates the anti-slip drive mode. Based on the maximum speed limit and the actual speed of the drive motor, it determines whether torque reduction control of the drive motor is required. If torque reduction control is required, the motor controller performs closed-loop control of the drive motor's torque based on the maximum speed limit. In this embodiment, the vehicle controller sends an anti-slip speed limit request to the motor controller, initiating the anti-slip drive mode. In this mode, the motor controller automatically determines whether to perform torque reduction control based on the maximum speed limit and the actual speed. During torque reduction control, it performs closed-loop control of the drive motor's torque based on the maximum speed limit, enabling timely and precise adjustment of the drive motor's torque. This improves the real-time performance and effectiveness of the vehicle's anti-slip control, thereby enhancing the anti-slip effect.

[0041] Meanwhile, when the TCS function of the vehicle electronic stability system fails or does not function (is not activated), the motor controller automatically performs torque reduction control based on its actual speed, which improves the real-time performance of the vehicle's anti-skid control, ensures vehicle stability, and can solve or improve the low-friction driving performance problem of electric vehicles. This also improves the driving performance problem of traditional TCS function applied to electric vehicles on low-friction roads.

[0042] Furthermore, during vehicle operation, if the vehicle is in series drive mode, the vehicle controller will determine the motor limiting torque based on the actual battery charging power, the actual engine generating power, and the actual drive motor discharging power. This allows the motor controller to perform torque reduction control when it determines that the drive motor needs to be controlled for torque reduction. This torque reduction control takes into account the state of the battery and engine, solving the problem in traditional anti-slip control methods that do not consider the limitation of motor anti-slip control capability by battery capacity. This ensures the adaptability of this method to hybrid vehicles. Under the condition of ensuring that the battery is not overcharged, the torque of the drive motor is adjusted in a timely and accurate manner, thereby improving the real-time performance and effectiveness of vehicle anti-slip control, and thus improving the anti-slip effect. Moreover, after the anti-slip drive mode is activated, when the TCS function is confirmed to be activated, the anti-slip drive mode is exited without controlling the speed of the drive motor. Instead, the drive motor responds to the anti-slip torque reduction request of the ESP, completely handing over the anti-slip control state of the entire vehicle to the ESP, ensuring the robustness of vehicle anti-slip control.

[0043] The vehicle anti-skid control method in this embodiment is a distributed control strategy coordinated by controllers such as the Electronic Stability Program (ESP), Vehicle Control Unit (VCU), and Motor Control Unit (IPU). The VCU determines the maximum speed limit of the drive motor and sends it to the IPU. Simultaneously, it calculates the motor torque limit based on the current battery and engine power generation status, enabling the IPU to accurately and promptly control the drive motor torque based on the maximum speed limit and the motor torque limit, improving the real-time performance of the vehicle anti-skid control. When the TCS function is activated, the maximum speed limit of the drive motor is removed, and the system responds to the ESP's anti-skid torque reduction request. The VCU, as the coordination center of the entire anti-skid control strategy, coordinates the work of each controller. This distributed implementation of the anti-skid control strategy allows each controller to perform its specific function, leveraging its advantages while minimizing development difficulty. This approach ensures both real-time control and the robustness of the entire control strategy.

[0044] In this embodiment, the vehicle anti-skid control system includes a vehicle controller, a motor controller, an electronic stability system, and a drive motor, which are only illustrative examples. In other embodiments, the vehicle anti-skid control system also includes other devices, such as an engine control system (EMS) and an engine assembly, which will not be described in detail here.

[0045] In one embodiment, such as Figure 2 As shown, a vehicle anti-skid control method is provided, which is applied to... Figure 1 Taking the vehicle anti-skid control system in the example, the explanation includes the following steps:

[0046] S10: The motor controller receives a request for anti-slip speed limit.

[0047] During vehicle operation, the motor controller needs to determine in real time whether it has received an anti-slip speed limit request from the vehicle controller, and determine whether to execute the anti-slip control strategy based on the receipt of the anti-slip speed limit request.

[0048] The anti-slip speed limit request includes a maximum speed limit. In this embodiment, the maximum speed limit is the maximum speed of the drive motor determined by the vehicle controller based on vehicle data.

[0049] In other embodiments, if the vehicle's power operating mode is a series drive mode, the anti-slip speed limit request further includes a motor limit torque to perform closed-loop control of the drive motor torque based on the maximum limit speed and the motor limit torque when it is determined that torque reduction control of the drive motor is required. The motor limit torque is the minimum torque of the drive motor determined by the vehicle controller based on the power generation status of the vehicle's battery, engine, and other devices.

[0050] The anti-slip speed limit request is generated by the vehicle controller based on vehicle data, after determining that the vehicle may be at risk of slippage under the current operating conditions. For example, if the vehicle controller detects that the vehicle speed is too high, the ground adhesion is low, or there is no ESP intervention, which may indicate a risk of vehicle slippage, it will calculate the maximum limit speed based on the vehicle data to limit the speed and torque of the drive motor, and then generate an anti-slip speed limit request based on the maximum limit speed.

[0051] S20: Determine whether torque reduction control of the drive motor is required based on the maximum speed limit and the actual speed of the drive motor.

[0052] If an anti-slip speed limit request is received, it indicates that the vehicle controller believes there is a risk of vehicle slippage under the current operating conditions. To reduce this risk, the motor controller needs to activate the anti-slip drive mode. In anti-slip drive mode, the motor controller will determine in real time whether to implement torque reduction control on the drive motor based on the maximum speed limit and the actual speed of the drive motor.

[0053] The motor controller determines whether torque reduction control of the drive motor is needed based on the maximum speed limit and the actual speed of the drive motor. This includes: the motor controller determining whether the actual speed of the drive motor is greater than the maximum speed limit; if the actual speed of the drive motor is greater than the maximum speed limit, it means that the actual speed of the drive motor exceeds the speed limit calculated by the vehicle controller, and the risk of vehicle slippage is high, so the speed of the drive motor needs to be reduced. In this case, the motor controller determines that torque reduction control of the drive motor is needed, and the motor controller performs closed-loop control of the torque of the drive motor based on the maximum speed limit; if the actual speed of the drive motor is less than or equal to the maximum speed limit, 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 is low, so there is no need to perform torque reduction control of the drive motor for the time being. In this case, 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 torque requirement in the vehicle torque request.

[0054] S20: If torque reduction control of the drive motor is required, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit and the motor torque limit.

[0055] After determining whether torque reduction control of the drive motor is needed based on the maximum speed limit and the actual speed of the drive motor, if torque reduction control of the drive motor is needed, the risk of vehicle slippage is high and the speed of the drive motor needs to be reduced. Then the motor controller performs closed-loop control of the torque of the drive motor based on the maximum speed limit.

[0056] Specifically, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit. This includes: when the vehicle's powertrain operates in series drive mode, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit and the motor's torque limit to adjust the drive motor torque in a timely and precise manner, improving the real-time performance and effectiveness of the vehicle's anti-skid control, thereby enhancing the anti-skid effect; when the vehicle's powertrain operates in pure electric drive mode, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit and the motor's torque limit to adjust the drive motor torque in a timely and precise manner while ensuring the battery is not overcharged, thus improving the anti-skid effect.

[0057] If torque reduction control of the drive motor is required, in order to prevent vehicle slippage and reduce vehicle speed to reduce the risk of loss of control, it is necessary to reduce the torque of the drive motor (torque reduction) by limiting the speed of the drive motor according to the maximum speed limit, ensuring that the actual speed of the drive motor is less than the maximum speed limit. At the same time, when the vehicle's power system is operating in series drive mode, in the process of limiting the speed of the drive motor according to the maximum speed limit, in order to prevent battery overcharging, it is also necessary to limit the torque of the drive motor. This is to prevent the motor torque from being too low, so that the engine's power generation has not had time to reduce before the engine generates too much electricity, exceeding the battery's charging capacity and causing battery overcharging.

[0058] In this embodiment, the motor controller receives an anti-slip speed limit request and determines whether torque reduction control of the drive motor is required based on the maximum limit speed and the actual speed of the drive motor. If torque reduction control is required, the motor controller performs closed-loop control of the drive motor torque based on the maximum limit speed. The vehicle controller sends an anti-slip speed limit request to the motor controller, causing the drive motor to start the anti-slip drive mode. In the anti-slip drive mode, the motor controller automatically determines whether to perform torque reduction control based on the maximum limit speed and the actual speed. During the torque reduction control process, it performs closed-loop control of the drive motor torque based on the maximum limit speed, which can adjust the drive motor torque in a timely and accurate manner, thereby improving the real-time performance and effectiveness of vehicle anti-slip control and thus improving the anti-slip effect.

[0059] In one embodiment, after step S30, that is, after the motor controller receives the anti-slip speed limit request, the method further includes the following steps:

[0060] S41: After activating the traction function, the electronic stability system sends a traction function activation signal and an anti-slip torque reduction request to the vehicle controller.

[0061] During vehicle operation, especially after the motor controller receives a request to limit the anti-slip speed to activate the anti-slip drive mode, the Electronic Stability Control (ESC) system determines the status of the drive wheels based on vehicle data. This data, including wheel speed, drive torque request, and accelerator pedal opening, determines whether the drive wheels are slipping. If slipping is detected, the ESC system activates the traction control function (TCS) to intervene in vehicle control and prevent slippage.

[0062] After activating the traction function, the electronic stability system sends a traction function activation signal to the vehicle controller. In addition, the electronic stability system generates an anti-slip torque reduction request based on actual needs and sends the anti-slip torque reduction request to the vehicle controller.

[0063] S42: After receiving the traction function activation signal and the anti-slip torque reduction request, the vehicle controller generates a speed limit cancellation command based on the traction function activation signal and sends the speed limit cancellation command and the anti-slip torque reduction request to the motor controller.

[0064] After receiving the traction function activation signal and the anti-slip torque reduction request, the vehicle controller generates a speed limit cancellation command based on the traction function activation signal and sends the speed limit cancellation command and the anti-slip torque reduction request to the motor controller.

[0065] S43: After receiving the speed limit cancellation command and the anti-slip torque reduction request, the motor controller responds to the speed limit cancellation command and the anti-slip torque reduction request.

[0066] After receiving the speed limit cancellation command and the anti-slip torque reduction request, the motor controller disables the anti-slip drive mode according to the speed limit cancellation command. That is, it exits the vehicle controller's maximum speed limit on the drive motor. It does not need to determine whether to reduce the torque of the drive motor based on the maximum speed limit and the actual speed of the drive motor. It only responds to the anti-slip torque reduction request sent by the electronic stability system through the vehicle controller and the vehicle torque request sent by the vehicle controller. Instead, it responds to the anti-slip torque reduction request and, on the premise of ensuring that the battery is not overcharged, completely hands over the anti-slip control state of the vehicle to the electronic stability system, thus ensuring the robustness of the anti-slip control.

[0067] In this embodiment, after the electronic stability system activates the traction function, it sends a traction function activation signal and an anti-slip torque reduction request to the vehicle controller. Upon receiving the traction function activation signal and the anti-slip torque reduction request, the vehicle controller generates a speed limit cancellation command based on the traction function activation signal and sends the speed limit cancellation command and the anti-slip torque reduction request to the motor controller. Upon receiving the speed limit cancellation command and the anti-slip torque reduction request, the motor controller disables the anti-slip drive mode based on the speed limit cancellation command and responds to the torque reduction request. After the motor controller enables the anti-slip drive mode, if the vehicle controller detects that the electronic stability system has activated the traction function, it will send a speed limit cancellation command and an anti-slip torque reduction request to the motor controller, causing the motor controller to exit the anti-slip drive mode and respond to the anti-slip torque reduction request from the electronic stability system. This transfers the vehicle's anti-slip control to the electronic stability system, ensuring the robustness of the anti-slip control and avoiding control conflicts caused by adjustments to the anti-slip strategy. In this embodiment, each system performs its own function, ensuring both real-time control and robustness of the anti-slip control.

[0068] In one embodiment, after activating the traction control function, the electronic stability system (TCS) generates an anti-slip torque reduction request based on actual needs, applies hydraulic braking force to the vehicle's drive wheels, and simultaneously sends the anti-slip torque reduction request to the vehicle controller. After activating the TCS function, the system generates the anti-slip torque reduction request based on actual needs to control vehicle traction and anti-slip through the drive motor. It also participates in the execution of hydraulic braking for anti-slip control, ensuring the vehicle's anti-slip effect.

[0069] In one embodiment, after receiving the traction function activation signal and the anti-slip torque reduction request, the vehicle controller generates a power reduction request and sends the power reduction request to the engine controller, so that after receiving the power reduction request, the engine controller reduces the engine's power generation to prevent the vehicle's battery from overcharging.

[0070] In one embodiment, before step S10, that is, before the motor controller determines whether it has received an anti-slip speed limit request from the vehicle controller, the method further includes the following steps:

[0071] S01: The vehicle controller determines whether anti-slip speed limiting of the drive motor is required and whether torque limiting of the drive motor is required.

[0072] After the vehicle controller is activated, it determines whether to apply anti-slip speed limiting to the drive motor based on the vehicle's gear information and the powertrain operating mode. The powertrain operating modes include pure electric drive mode, series drive mode, and parallel drive mode.

[0073] The vehicle controller determines whether anti-slip speed limiting of the drive motor is required based on the vehicle's gear information and powertrain operating mode. This can include: determining whether the vehicle is in a preset gear (other than parking and neutral) and whether the powertrain operating mode is a preset mode (parallel drive mode). If the vehicle is in a preset gear and the powertrain operating mode is a preset mode, it indicates that the vehicle is in motion and there is a risk of slippage, so anti-slip speed limiting of the drive motor is required. If the vehicle is in a preset gear or the powertrain operating mode is not a preset mode, it indicates that the vehicle is not in motion or the engine is directly connected to the wheels, and no limitation on the drive motor is required, so anti-slip speed limiting of the drive motor is not required.

[0074] When a vehicle is in certain gears (such as Park (P) and Neutral (N), the wheels are not powered and the vehicle is not in motion. In this case, there is no need to prevent slippage or limit the drive motor's anti-slip speed. Similarly, when the vehicle's powertrain operates in certain modes (such as parallel drive mode), the engine is directly connected to the wheels, and in this case, there is no need to limit the drive motor's anti-slip speed.

[0075] In other embodiments, after the vehicle controller is started, the vehicle controller will determine in real time whether it is necessary to limit the anti-slip speed of the drive motor based on the vehicle's gear information, power system operating mode and the activation status of the electronic stability system. If the traction function of the electronic stability system is not activated, there may be a risk of slippage when the vehicle is in motion, and therefore it is necessary to limit the anti-slip speed of the drive motor.

[0076] The vehicle controller determines whether torque limiting of the drive motor is required based on the powertrain operating mode. If the powertrain is in series drive mode, the engine may not reduce torque in time during the drive motor torque reduction process, causing the engine to generate too much electricity, exceeding the battery's charging capacity and leading to battery overcharging. Therefore, to avoid battery overcharging, torque limiting of the drive motor is required during the drive motor torque reduction process. If the powertrain is in pure electric drive mode, the engine does not work, and there is no situation where the engine generates too much electricity leading to battery overcharging. Therefore, torque limiting of the drive motor is not required during the drive motor torque reduction process.

[0077] S02: If anti-slip speed limitation and torque limitation are required, the vehicle controller determines the maximum speed limit of the drive motor and the motor limit torque.

[0078] After determining whether anti-slip speed limiting of the drive motor is required based on the vehicle's gear information and power system operating mode, if anti-slip speed limiting of the drive motor is required, it indicates that the vehicle is in motion and there is a risk of vehicle slippage. In this case, the vehicle controller determines the maximum speed limit of the drive motor based on wheel speed information and steering wheel angle. If torque limiting of the drive motor is required, the controller determines the motor limit torque.

[0079] After determining whether anti-slip speed limiting and torque limiting of the drive motor are required, if anti-slip speed limiting is required but torque limiting is not required, the vehicle controller determines the maximum speed limit of the drive motor, generates an anti-slip speed limiting request based on the maximum speed limit, and sends the anti-slip speed limiting request to the motor controller.

[0080] The process of determining the maximum speed limit of the drive motor based on wheel speed information and steering wheel angle includes: determining the target vehicle speed of the drive shaft based on wheel speed information and steering wheel angle, and then calculating the maximum speed limit based on the target vehicle speed of the drive shaft, the reduction ratio from the drive motor to the wheel end, and the wheel tire radius.

[0081] The maximum speed limit is calculated using the following formula:

[0082]

[0083] Among them, V max V is the maximum speed limit for the drive motor. tar M represents the target vehicle speed of the drive axle, M represents the reduction ratio from the drive motor to the wheel end, and R represents the wheel tire radius.

[0084] In one embodiment, the vehicle controller determines the motor limiting torque based on the actual battery charging power, the actual engine generating power, and the actual drive motor discharging power. This takes into account the impact of engine power generation and drive motor discharge on battery capacity. When implementing torque reduction control for the drive motor, the torque reduction torque is limited to prevent battery overcharging. In other embodiments, the motor limiting torque can be the calibrated torque or a torque calculated using other methods, which will not be elaborated further here.

[0085] Specifically, the motor limiting torque is determined based on the actual charging power of the battery, the actual generating power of the engine, and the actual discharging power of the drive motor. This includes: the vehicle controller determining the available power for torque reduction of the drive motor based on the actual charging power of the battery, the actual generating power of the engine, and the actual discharging power of the drive motor; and then the vehicle controller determining the motor limiting torque based on the actual speed of the drive motor and the available power for torque reduction.

[0086] The motor limiting torque is calculated using the following formula:

[0087] T min =W m *9550 / V r ;

[0088] Among them, T min To limit the torque of the motor, W m V is the available power for reducing the torque of the drive motor. r This represents the actual speed of the drive motor.

[0089] The available power for reducing the torque of the drive motor is calculated using the following formula:

[0090] W m =W c +W d -W e

[0091] Among them, W c The actual charging power of the battery, W d W represents the actual discharge power of the drive motor. e This represents the actual power output of the engine.

[0092] Therefore, we can obtain:

[0093]

[0094] Among them, T min To limit the torque of the motor, W c The actual charging power of the battery, W d W represents the actual discharge power of the drive motor. e V represents the actual power output of the engine. r This represents the actual speed of the drive motor.

[0095] S03: The vehicle controller generates an anti-slip speed limit request based on the motor's limited torque and maximum limited speed, and sends the anti-slip speed limit request to the motor controller.

[0096] After determining the motor limit torque and maximum speed limit of the drive motor, the vehicle controller generates an anti-slip speed limit request based on the motor limit torque and maximum speed limit, and sends the anti-slip speed limit request to the motor controller. Upon receiving the anti-slip speed limit request, the motor controller activates the anti-slip drive mode to determine whether torque reduction control of the drive motor is required based on the actual speed of the drive motor.

[0097] In this embodiment, before the motor controller determines whether it has received the anti-slip speed limit request from the vehicle controller, the vehicle controller determines whether anti-slip speed limit is required for the drive motor and whether torque limit is required for the drive motor. If both anti-slip speed limit and torque limit are required, the vehicle controller determines the maximum speed limit of the drive motor and the motor torque limit. Based on the motor torque limit and the maximum speed limit, the vehicle controller generates an anti-slip speed limit request and sends it to the motor controller. This clarifies the process of determining the motor torque limit and the maximum speed limit. By having the vehicle controller calculate the motor torque limit and the maximum speed limit, the amount of information processing by the motor controller can be reduced, thereby reducing the load on the motor controller, improving the response speed of the motor controller, and thus improving the real-time performance of the drive motor control.

[0098] In one embodiment, such as Figure 3 As shown, a vehicle anti-skid control method is provided, which is applied to... Figure 1 Taking the vehicle anti-skid control system in the example, the explanation includes the following steps:

[0099] S1: The vehicle controller determines whether anti-slip speed limiting of the drive motor is required and whether torque limiting of the drive motor is required.

[0100] After the vehicle controller starts, it determines whether to apply anti-slip speed limiting to the drive motor based on the vehicle's gear information and the powertrain operating mode, and further determines whether to apply torque limiting to the drive motor based on the powertrain operating mode. The specific determination process is as described above and will not be repeated here.

[0101] S2: If anti-slip speed limitation and torque limitation are required, the vehicle controller determines the maximum speed limit of the drive motor and the motor limit torque.

[0102] After determining whether anti-slip speed limiting of the drive motor is required based on the vehicle's gear information and power system operating mode, if anti-slip speed limiting is required, it indicates that the vehicle is in motion and there is a risk of vehicle slippage. The vehicle controller then determines the maximum speed limit of the drive motor based on wheel speed information and steering wheel angle, and determines the motor limit torque based on the actual battery charging power, the actual engine generating power, and the actual drive motor discharging power.

[0103] The process for determining the maximum speed limit and torque limit of the drive motor has been described above and will not be repeated here.

[0104] S3: The vehicle controller generates an anti-slip speed limit request based on the motor's limited torque and maximum limited speed, and sends the anti-slip speed limit request to the motor controller.

[0105] After determining the motor limit torque and maximum speed limit of the drive motor, the vehicle controller generates an anti-slip speed limit request based on the motor limit torque and maximum speed limit, and sends the anti-slip speed limit request to the motor controller.

[0106] S4: After receiving the anti-slip speed limit request, the motor controller enables the anti-slip drive mode to determine whether torque reduction control of the drive motor is required based on the maximum limit speed and the actual speed of the drive motor.

[0107] After receiving the anti-slip speed limit request, the motor controller activates the anti-slip drive mode to determine whether torque reduction control of the drive motor is needed based on the maximum limit speed and the actual speed of the drive motor.

[0108] Specifically, the motor controller determines whether torque reduction control of the drive motor is needed based on the maximum speed limit and the actual speed of the drive motor. This includes: the motor controller determining whether the actual speed of the drive motor is greater than the maximum speed limit; if the actual speed of the drive motor is greater than the maximum speed limit, it means that the actual speed of the drive motor exceeds the speed limit calculated by the vehicle controller, and the risk of vehicle slippage is relatively high, so the speed of the drive motor needs to be reduced, and the motor controller determines that torque reduction control of the drive motor is needed; if the actual speed of the drive motor is less than or equal to the maximum speed limit, 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 relatively low, and torque reduction control of the drive motor is not needed for the time being.

[0109] S5: If torque reduction control of the drive motor is required, the motor controller will perform closed-loop control of the drive motor torque based on the maximum speed limit and the motor torque limit.

[0110] If the motor controller determines that torque reduction control of the drive motor is required, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit and the motor torque limit. If torque reduction control of the drive motor is not required, 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 torque requirement in the vehicle torque request.

[0111] S6: The electronic stability control system determines in real time whether the traction function needs to be activated.

[0112] During vehicle operation, especially after the motor controller activates the anti-slip drive mode, the electronic stability control system (ESC) determines the status of the drive wheels in real time based on vehicle data to determine whether traction control needs to be activated. If the drive wheels are slipping, the traction control system needs to intervene to determine if traction control is required; conversely, if the drive wheels are not slipping, the traction control system does not need to intervene and traction control does not need to be activated.

[0113] S7: If the traction function needs to be activated, the electronic stability system activates the traction function to generate an anti-skid torque reduction request according to actual needs, and sends the traction function activation signal and the anti-skid torque reduction request to the vehicle controller.

[0114] After the electronic stability system determines in real time whether the traction function needs to be activated, if the traction function needs to be activated, the electronic stability system activates the traction function to generate an anti-skid and torque reduction request according to actual needs and applies hydraulic braking force to the drive wheels. At the same time as activating the traction function, the traction function activation signal is sent to the vehicle controller in a timely manner. After generating the anti-skid and torque reduction request according to actual needs, the anti-skid and torque reduction request is also sent to the vehicle controller in real time.

[0115] S8: After receiving the traction function activation signal and the anti-slip torque reduction request, the vehicle controller generates a speed limit cancellation command based on the traction function activation signal and sends the speed limit cancellation command and the anti-slip torque reduction request to the motor controller.

[0116] After receiving the traction function activation signal, the vehicle controller generates a speed limit cancellation command based on the traction function activation signal. After receiving the anti-slip torque reduction request, it sends the speed limit cancellation command and the anti-slip torque reduction request to the motor controller.

[0117] S9: After receiving the speed limit cancellation command and the anti-slip torque reduction request, the motor controller disables the anti-slip drive mode according to the speed limit cancellation command and responds to the anti-slip torque reduction request.

[0118] After receiving the speed limit cancellation command and the anti-slip torque reduction request, the motor controller disables the anti-slip drive mode according to the 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. It does not need to determine whether to reduce the torque of the drive motor based on the maximum speed limit and the actual speed of the drive motor. It only responds to the anti-slip torque reduction request sent by the electronic stability system through the vehicle controller and the vehicle torque request sent by the vehicle controller. On the premise of ensuring that the battery is not overcharged, the anti-slip control state of the whole vehicle is completely handed over to the electronic stability system, ensuring the robustness of the anti-slip control.

[0119] The vehicle anti-skid control method in this embodiment is a distributed control strategy coordinated by controllers such as the Electronic Stability Program (ESP), Vehicle Control Unit (VCU), and Individual Power Controller (IPU). The VCU determines the maximum speed limit of the drive motor and sends it to the IPU. Simultaneously, it calculates the motor torque limit based on the current battery and engine power generation status. This allows the IPU to accurately and promptly control the drive motor torque based on the maximum speed limit and the motor torque limit, improving the real-time performance of the anti-skid control and thus enhancing its effectiveness and anti-skid performance. When the TCS (Traction Control System) function is activated, the maximum speed limit of the drive motor is deactivated, and the system responds to the ESP's anti-skid torque reduction request, completely handing over the vehicle's anti-skid control state to the ESP to ensure robustness. The VCU, as the coordination center of the entire anti-skid control strategy, coordinates the work of each controller. The distributed implementation of the anti-skid control strategy allows each controller to perform its specific function, leveraging its advantages while minimizing development difficulty. This approach ensures both real-time control and the robustness of the entire control strategy.

[0120] When the vehicle anti-skid control method provided in this embodiment is not used, the changes in vehicle operating parameters after the TCS function is activated and controlled separately in traditional vehicle anti-skid systems are as follows: Figure 4 As shown. Using the vehicle anti-skid control method provided in this embodiment, after the controller performs coordinated control, the vehicle operating parameters change as follows: Figure 5 As shown. Figure 4 and Figure 5 The horizontal axis represents time (m is minutes, s is seconds). Figure 4 and Figure 5 The vertical axis represents rotational speed or acceleration. Figure 4 and Figure 5 The graph shows the changes in vehicle longitudinal acceleration, drive motor speed (motor speed), and rear wheel speed over time. By comparison... Figure 4 and Figure 5 As can be seen, by adopting the vehicle anti-skid control method provided in this embodiment, the wheel speed of the vehicle is significantly suppressed after the controller performs coordinated control, which can effectively improve the anti-skid effect and improve the driving performance on low-friction surfaces.

[0121] In one embodiment, step S1 or step S01, which determines whether anti-slip speed limiting of the drive motor is required, specifically includes the following steps:

[0122] S11: The vehicle controller determines whether the powertrain operating mode is the preset mode.

[0123] During vehicle operation, the vehicle controller acquires vehicle data such as the powertrain operating mode, gear position information, and the activation status of the electronic stability control system. After acquiring the powertrain operating mode, the vehicle controller determines whether the powertrain operating mode is a preset mode. The preset mode is either pure electric drive mode or series drive mode.

[0124] S12: If the power system is in the preset mode, the vehicle controller determines whether the vehicle is in the preset gear based on the gear information.

[0125] After determining whether the powertrain operating mode is the preset mode, if the vehicle controller determines that the powertrain operating mode is the preset mode, it means that the engine is not directly connected to the wheel ends. Then, the vehicle controller determines whether the vehicle is in the preset gear based on the gear information. The preset gear can be any gear other than Park (P) and Neutral (N).

[0126] S13: If the vehicle is in a preset gear, the vehicle controller determines whether the traction function is activated based on the activation status of the electronic stability system.

[0127] After determining whether the vehicle is in the preset gear based on the gear information, if the vehicle controller determines that the vehicle is in the preset gear, it means that the vehicle is in a driving state. Then, the vehicle controller determines whether the traction function is activated based on the activation status of the electronic stability system.

[0128] S14: If the traction function is not activated, the vehicle controller determines that the drive motor needs to be limited to anti-slip speed.

[0129] After determining whether the traction function is activated based on the activation status of the vehicle's electronic stability system, if the vehicle controller determines that the traction function is not activated, it means that the engine is not directly connected to the wheel ends, the vehicle is in motion, and the traction control body has not intervened. At this time, the vehicle is at risk of slipping, and it is necessary to limit the torque and speed of the drive motor. Therefore, the vehicle controller determines that it is necessary to limit the anti-slip speed of the drive motor in order to perform precise anti-slip control on the vehicle and prevent the vehicle from slipping.

[0130] In this embodiment, the vehicle controller determines whether the powertrain operating mode is a preset mode. If the powertrain operating mode is a preset mode, the vehicle controller determines whether the vehicle is in a preset gear based on the gear information. If the vehicle is in a preset gear, the vehicle controller determines whether the traction function is activated based on the activation status of the electronic stability control system. If the traction function is not activated, the vehicle controller determines that the drive motor needs to be anti-slip speed limited. This clarifies the specific steps for determining whether the drive motor needs to be anti-slip speed limited, ensuring the accuracy of the anti-slip speed limiting structure and reducing the possibility of poor system load and power performance caused by frequent anti-slip speed limiting of the drive motor.

[0131] In one embodiment, step S2 or step S02, where the vehicle controller determines the maximum speed limit of the drive motor, specifically includes the following steps:

[0132] S21: The vehicle controller determines the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value based on the vehicle's wheel speed information and steering wheel angle.

[0133] During vehicle operation, the vehicle controller acquires vehicle data in real time, including wheel speed information and steering wheel angle. After determining the need for anti-slip speed limiting of the drive motor based on the vehicle's gear information and powertrain operating mode, the vehicle controller determines the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value based on the wheel speed information and steering wheel angle. The reference speed is based on the average wheel speed of the rear wheels when the front wheels are not slipping, with the addition of a wheel steering correction function. Specifically, the average wheel speed of the rear wheels is corrected using the relationship between the steering wheel angle and the front wheel steering angle to calculate the reference speed of the front axle. Compared to traditional vehicle slip control methods that acquire wheel speed information to calculate the target speed of the drive motor when the vehicle is slipping, this embodiment calculates the reference speed based on the average wheel speed of the rear wheels when the front wheels are not slipping. This eliminates wheel speed differences generated during normal vehicle steering, improving the accuracy of the reference speed calculation.

[0134] In this embodiment, the safe speed offset value is the safe boundary speed corresponding to the current reference speed. Since the calculated reference speed is a theoretical point value, while the actual speed often deviates from the reference speed and fluctuates, a safe boundary needs to be set for the reference speed to prevent the anti-slip driving mode from being frequently turned on and off. That is, a safe speed offset value is set to correct the reference speed.

[0135] During vehicle operation, if the vehicle slips on a split-plane surface (where the left and right wheels have different coefficients of friction), the drive axle cannot effectively utilize the traction on the higher-friction side to output driving force for vehicle movement. ESP will then apply mechanical braking to the lower-friction side to provide sufficient driving force to the drive axle. However, when ESP is not activated, or when the initial drive motor speed calculated by the VCU on a split-plane surface limits the wheel speed difference to a small range, ESP may fail to apply mechanical braking and thus fail to provide sufficient driving force to the drive axle. Therefore, to effectively utilize the longitudinal traction on the higher-friction side, the wheel speed difference generated by drive wheel slippage needs to be added to the reference vehicle speed to correct the reference speed; this corrected wheel speed difference is called the wheel speed difference correction value.

[0136] S22: The vehicle controller will use the sum of the reference vehicle speed, wheel speed difference correction value and safe vehicle speed offset value as the target vehicle speed for the drive shaft.

[0137] After determining the reference vehicle speed, wheel speed difference correction value, and safe vehicle speed offset value, the vehicle controller directly uses the sum of the reference vehicle speed, wheel speed difference correction value, and safe vehicle speed offset value as the target vehicle speed of the drive axle.

[0138] S23: The vehicle controller performs speed ratio conversion on the target vehicle speed of the drive shaft to calculate the maximum speed limit.

[0139] After determining the target speed of the drive shaft, the vehicle controller performs a speed ratio conversion on the target speed of the drive shaft to calculate the maximum speed limit. That is, the maximum speed limit is calculated based on the target speed of the drive shaft, the reduction ratio from the drive motor to the wheel end, and the wheel tire radius.

[0140] The maximum speed limit is calculated using the following formula:

[0141]

[0142] Among them, V max V is the maximum speed limit for the drive motor. tar M represents the target vehicle speed of the drive axle, M represents the reduction ratio from the drive motor to the wheel end, and R represents the wheel tire radius.

[0143] In other embodiments, the reference vehicle speed can be directly used as the target vehicle speed of the drive axle, or the sum of the reference vehicle speed and the wheel speed difference correction value can be used as the target vehicle speed of the drive axle, or the sum of the reference vehicle speed and the safe vehicle speed offset value can be used as the target vehicle speed of the drive axle.

[0144] The maximum speed limit is then calculated based on the target speed of the drive axle, the reduction ratio from the drive motor to the wheel end, and the wheel tire radius. In this embodiment, the reference speed is corrected by a wheel speed difference correction value, which solves the problem of single-sided slippage of two-wheel drive vehicles on opposing roads, thus improving the accuracy of the calculated target speed of the drive axle. Furthermore, the reference speed is corrected by a safe speed offset value, taking into account the deviation between the calculated reference speed and the actual speed, further improving the accuracy of the calculated target speed of the drive axle.

[0145] The vehicle controller will use the vehicle speed as a reference for the safe vehicle speed offset value, which will be used as the target vehicle speed for the drive shaft.

[0146] Further, the maximum speed limit of the drive motor is determined, including:

[0147] In this embodiment, the vehicle controller determines the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value based on the vehicle's wheel speed information and steering wheel angle. The sum of these three values ​​is then used as the target speed for the drive axle. Finally, a speed ratio conversion is performed on the target speed to calculate the maximum speed limit. Calculating the maximum speed limit by referencing actual wheel speed information allows for a more accurate assessment of the vehicle's state. Furthermore, correcting the reference speed based on the wheel speed difference correction value and the safe speed offset value yields a more accurate target speed for the drive axle, thus enabling the accurate maximum speed limit and providing a foundation for subsequent precise anti-slip control of the drive motor.

[0148] In one embodiment, step S21, where the vehicle controller determines the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value based on the vehicle's wheel speed information and steering wheel angle, specifically includes the following steps:

[0149] S211: The vehicle controller determines the front wheel steering angle of the vehicle based on the steering wheel angle and preset wheel-end steering angle data.

[0150] After obtaining the steering wheel angle, the vehicle controller determines the front wheel steering angle based on the steering wheel angle and preset wheel steering angle data. The preset wheel steering angle data includes the wheel steering angles corresponding to different steering wheel angles.

[0151] It is important to understand that there is a corresponding relationship between the steering wheel angle of a vehicle and the wheel-end steering angle of each wheel. In this embodiment, by conducting whole-vehicle tests on different vehicle models, the wheel-end steering angle of each wheel of each vehicle model at different steering wheel angles is obtained. This data is then summarized into preset wheel-end steering angle data for that vehicle model and stored in the vehicle memory of the corresponding vehicle model for direct use later.

[0152] During vehicle operation, after the vehicle controller obtains the steering wheel angle, it directly looks up the corresponding front wheel steering angle in the preset wheel steering angle data. The front wheel steering angle includes the left front wheel steering angle and the right front wheel steering angle.

[0153] S212: The vehicle controller determines the reference speed based on the steering angle of the front wheel ends and the wheel speed of the rear wheels.

[0154] After determining the front wheel steering angles based on the steering wheel angle and preset wheel steering angle data, the vehicle controller extracts the rear wheel speeds from the vehicle's wheel speed information, including the left and right rear wheel speeds. Then, the vehicle controller determines a reference vehicle speed based on the front wheel steering angles and the rear wheel speeds.

[0155] The vehicle controller determines a reference speed based on the steering angles of the front wheels and the rear wheel speeds. This process includes: correcting the left rear wheel speed using the steering angle of the left front wheel to obtain a corrected left rear wheel speed value; correcting the right rear wheel speed using the steering angle of the right front wheel to obtain a corrected right rear wheel speed value; and using the average of the corrected left and right rear wheel speed values ​​as the reference speed. Correcting the rear wheel speeds using the front wheel steering angle and using the average corrected rear wheel speed as the reference speed improves the accuracy of the reference speed, avoids erroneous slip judgments due to inaccurate reference speeds, and thus ensures the vehicle's dynamic performance during steering.

[0156] The reference speed can be calculated using the following formula:

[0157]

[0158] Among them, V ref For reference vehicle speed; V RL V is the wheel speed of the left rear wheel. RR V is the wheel speed of the right rear wheel; a and b are the steering angles of the left and right front wheels, respectively; cos a is the cosine of the steering angle of the left front wheel, and cos b is the cosine of the steering angle of the right front wheel; RL / cos a is the left rear wheel speed correction value, V RR / cos b is the right rear wheel speed correction value.

[0159] S213: The vehicle controller determines the safe speed offset value based on the reference vehicle speed and the preset safe speed offset data.

[0160] After calculating and obtaining the reference vehicle speed, the vehicle controller determines the safe vehicle speed offset value based on the reference vehicle speed and the preset safe vehicle speed offset data.

[0161] The preset safe speed offset data includes the safe boundary speeds corresponding to different reference speeds. These preset safe speed offset data are the required safe boundary speeds at different speeds, calibrated based on test data obtained after conducting full-vehicle tests at various speeds. After obtaining the preset safe speed offset data, this data is pre-stored in the vehicle's memory for the corresponding model for later direct use.

[0162] After calculating and obtaining the reference vehicle speed, the vehicle controller searches for the safe boundary speed corresponding to the current reference vehicle speed in the preset safe vehicle speed offset data based on the reference vehicle speed, and uses it as the safe vehicle speed offset value.

[0163] For example, the correspondence between reference speed and safe boundary speed can be shown in Table 1 below:

[0164] Table 1

[0165] Reference speed 0 2 4 6 8 10 20 30 40 60 80 100 Safe boundary speed 0 0 2 3 4 5 6 7 8 8 8 8

[0166] S214: The vehicle controller determines the wheel speed difference correction value based on the reference vehicle speed, wheel speed information and preset corrected vehicle speed data.

[0167] After calculating and obtaining the reference vehicle speed, the vehicle controller determines the wheel speed difference correction value based on the reference vehicle speed, wheel speed information, and preset corrected vehicle speed data.

[0168] The preset corrected speed data includes corrected speed values ​​corresponding to different reference speeds. This data is generated by conducting a full-vehicle test on a split-road surface, determining the wheel speed difference caused by drive wheel slippage on top of the reference speed, and using this wheel speed difference as the corrected speed value for that reference speed. This process is repeated to obtain the corrected speed values ​​for different reference speeds, which are then compiled into the preset corrected speed data. After obtaining this data, it is pre-stored in the vehicle's memory for the corresponding vehicle model for later direct use.

[0169] The vehicle controller determines the wheel speed difference correction value based on the reference vehicle speed, wheel speed information, and preset correction speed data. This includes: after calculating the reference vehicle speed, finding the correction speed value corresponding to the current reference vehicle speed in the preset correction speed data, and using it as the correction speed corresponding to the reference vehicle speed; extracting the front wheel speeds of the vehicle from the wheel speed information, including the left front wheel speed and the right front wheel speed, and determining the front wheel speed difference between the left and right front wheel speeds; calculating the reference wheel speed difference between the left and right front wheels based on the left and right front wheel speeds, and subtracting the correction speed from the absolute value of the difference between the front wheel speed difference and the reference wheel speed difference to obtain the target vehicle speed; determining whether the target vehicle speed is greater than 0. If the target correction speed is less than or equal to 0, half of the target correction speed is used as the wheel speed difference correction value; if the target correction speed is less than or equal to 0, 0 is used as the wheel speed difference correction value. By comparing the target corrected vehicle speed with the value 0, half of the target corrected vehicle speed greater than 0 is used as the wheel speed difference correction value, ensuring that the wheel speed difference correction value is a positive value. This increases the target speed of the drive shaft, and while ensuring the accuracy of the target speed of the drive shaft, it also increases the upper limit of the maximum speed limit, reducing the possibility of insufficient vehicle power caused by the maximum speed limit being too low when the subsequent drive motor reduces torque.

[0170] The wheel speed difference correction value can be determined by the following formula:

[0171]

[0172] The reference wheel speed difference is calculated using the following formula:

[0173] V corr =(V FL -V FR ) / 2;

[0174] Among them, V diff V is the wheel speed difference correction value. FL V is the wheel speed of the left front wheel. FR V is the wheel speed of the right front wheel. FL -V FR V represents the front wheel speed difference. corr For reference wheel speed difference, V offset The corrected speed is the speed corresponding to the reference speed.

[0175] For example, the correspondence between the reference vehicle speed and the corrected vehicle speed can be shown in Table 2 below:

[0176] Table 2

[0177] Reference speed 0 1.5 10 20 30 40 50 60 70 80 90 100 Correct speed 4 5 3 3 3 3 3 10 15 15 15 15

[0178] In this embodiment, the vehicle controller determines the front wheel steering angle based on the steering wheel angle and preset wheel steering angle data. The preset wheel steering angle data includes wheel steering angles corresponding to different steering wheel angles. Then, based on the front wheel steering angles and the rear wheel speeds, a reference vehicle speed is determined. Subsequently, based on the reference vehicle speed and preset safe vehicle speed offset data, a safe vehicle speed offset value is determined. The preset safe vehicle speed offset data includes safe boundary speeds corresponding to different reference vehicle speeds. Finally, based on the reference vehicle speed, wheel speed information, and preset corrected vehicle speed data, a wheel speed difference correction value is determined. The preset corrected vehicle speed data includes corrected vehicle speed values ​​corresponding to different reference vehicle speeds. This clarifies the specific process by which the vehicle controller determines the reference vehicle speed, wheel speed difference correction value, and safe vehicle speed offset value based on the vehicle's wheel speed information and steering wheel angle, providing an accurate data foundation for subsequent operations.

[0179] In one embodiment, if the anti-slip speed limit request also includes motor limit torque, then after the motor controller determines that torque reduction control of the drive motor is required, closed-loop control of the drive motor torque is performed based on the maximum limit speed and the motor limit torque. Step S5, namely, performing closed-loop control of the drive motor torque based on the maximum limit speed and the motor limit torque, specifically includes the following steps:

[0180] S51: The motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit.

[0181] After the motor controller determines that torque reduction control of the drive motor is required, it performs proportional-integral-derivative (PID) torque control on the drive motor torque, targeting the maximum speed limit. During PID torque control, to prevent battery overcharging, it is necessary to ensure that the drive motor torque is greater than the motor's torque limit.

[0182] When performing PID torque control, the motor controller needs to first determine the speed difference between the actual speed of the drive motor and the maximum speed limit.

[0183] S52: The motor controller inputs the speed difference into the PID controller to obtain the PID-regulated torque.

[0184] After the motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit, the motor controller inputs the speed difference into the PID controller to obtain the PID adjustment torque.

[0185] If the difference between the actual speed of the drive motor and the maximum speed limit is greater than 0, the proportional coefficient P of the PID controller is determined to be positive, and the integral coefficient I and the derivative coefficient D are calibrated according to the actual situation; the PID adjustment torque is determined based on the proportional coefficient P, integral coefficient I, derivative coefficient D and speed difference.

[0186] The PID control torque can be calculated using the following formula:

[0187] TqPID=P*delta+I*delta*D*delta;

[0188] Where TqPID is the PID control torque; delta is the speed difference between the actual speed of the drive motor and the maximum speed limit; P, I, and D are the proportional coefficient, integral coefficient, and derivative coefficient, respectively.

[0189] S53: The motor controller uses the sum of the PID-adjusted torque and the vehicle's required torque as the target torque.

[0190] After inputting the speed difference into the PID controller to obtain the PID-adjusted torque, the motor controller uses the sum of the PID-adjusted torque and the vehicle's required torque as the target torque. The vehicle's required torque is determined based on the vehicle torque request sent by the vehicle controller, and this request includes the vehicle's required torque. The vehicle controller calculates the vehicle's required torque based on the vehicle's power demand and then sends the vehicle torque request, which includes the required torque, to the motor controller, causing the drive motor to execute the required torque in response to the vehicle torque request.

[0191] S54: The motor controller outputs the larger of the absolute values ​​of the target torque and the motor limit torque as the control torque for driving the motor, until the actual speed of the drive motor is less than the maximum limit speed.

[0192] After using the sum of the PID-adjusted torque and the vehicle's required torque as the target torque, the motor controller outputs the larger absolute value of the target torque and the motor's limiting torque as the control torque for the drive motor. This is to prevent the absolute value of the drive motor's output torque from being lower than the motor's limiting torque. While ensuring that the battery is not overcharged, the controller reduces the torque and speed of the drive motor until the actual speed of the drive motor is lower than the maximum limiting speed to prevent the vehicle from slipping.

[0193] 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. The sum of the PID adjustment torque and the vehicle's required torque is then used as the target torque. The larger of the absolute values ​​of the target torque and the motor's limit torque is output as the control torque of the drive motor, until the actual speed of the drive motor is less than the maximum speed limit. Through PID control, the speed of the drive motor changes towards the maximum speed limit, ensuring the smoothness of the speed change. At the same time, the larger of the absolute values ​​of the target torque and the motor's limit torque is output as the control torque of the drive motor. This allows for precise torque reduction control of the drive motor while ensuring that the battery is not overcharged, thus preventing vehicle slippage.

[0194] If the anti-slip speed limit request only includes the maximum speed limit, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit. Specifically, this closed-loop control of the drive motor torque based on the maximum speed limit includes the following steps:

[0195] S31: The motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit.

[0196] In this embodiment, if the anti-slip speed limit request only includes the maximum limit speed, it means that the vehicle's power system drive mode is pure electric drive mode, and there is no need to consider the battery overcharging situation. Therefore, when it is necessary to control the torque reduction of the drive motor, the motor controller directly uses the maximum limit speed as the target and performs PID torque control on the torque of the drive motor.

[0197] S32: The motor controller inputs the speed difference into the PID controller to obtain the PID-regulated torque.

[0198] The motor controller inputs the speed difference into the PID controller to obtain the PID-regulated torque. The specific process is described above and will not be repeated here.

[0199] S33: The motor controller sums the PID-adjusted torque with the vehicle's required torque and outputs it as the control torque for the drive motor until the actual speed of the drive motor is less than the maximum speed limit.

[0200] After inputting the speed difference into the PID controller to obtain the PID adjustment torque, the motor controller sums the PID adjustment torque with the vehicle's required torque and outputs it as the control torque of the drive motor until the actual speed of the drive motor is less than the maximum speed limit to prevent the vehicle from slipping.

[0201] In this embodiment, when the anti-slip speed limit request only includes the maximum speed limit, 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. The sum of the PID adjustment torque and the required torque of the vehicle is then output as the control torque of the drive motor until the actual speed of the drive motor is less than the maximum speed limit. Through PID control, the speed of the drive motor changes towards the maximum speed limit, ensuring the smoothness of the speed change, and performing fast and precise torque reduction control on the drive motor to prevent vehicle slippage.

[0202] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0203] In one embodiment, a motor controller is provided, which corresponds one-to-one with the vehicle anti-skid control method described in the above embodiments. For example... Figure 6 As shown, the motor controller includes a first determining module 601, a second determining module 602, and a control module 603. Detailed descriptions of each functional module are as follows:

[0204] Receiver module 601 is used to receive anti-slip speed limit request, the anti-slip speed limit request including the maximum limit speed;

[0205] The determination module 602 is used to determine whether torque reduction control of the drive motor is needed based on the maximum speed limit and the actual speed of the drive motor.

[0206] The control module 603 is used to perform closed-loop control of the torque of the drive motor based on the maximum speed limit if torque reduction control of the drive motor is required.

[0207] Furthermore, if the anti-slip speed limiting request also includes motor torque limiting, the control module 603 is specifically used for:

[0208] Determine the speed difference between the actual speed of the drive motor and the maximum speed limit;

[0209] The speed difference is input into the PID controller to obtain the PID-regulated torque.

[0210] The sum of the PID-adjusted torque and the vehicle's required torque is used as the target torque;

[0211] The larger of the absolute values ​​of the target torque and the motor's limiting torque is output as the control torque for the drive motor, until the actual speed of the drive motor is less than the maximum limiting speed.

[0212] In one embodiment, a vehicle controller is provided, which corresponds one-to-one with the vehicle anti-skid control method described in the above embodiments. The vehicle controller includes a first determining module, a second determining module 602, and a sending module. Detailed descriptions of each functional module are as follows:

[0213] The first determining module is used to determine whether it is necessary to limit the anti-slip speed of the drive motor and whether it is necessary to limit the torque of the drive motor.

[0214] The second determining module is used to determine the maximum limiting speed of the drive motor and the limiting torque of the motor if anti-slip speed limitation and torque limitation are required.

[0215] The sending module is used by the vehicle controller to generate an anti-slip speed limit request based on the motor's limited torque and maximum limited speed, and send the anti-slip speed limit request to the motor controller. Upon receiving the anti-slip speed limit request, the anti-slip drive mode is activated. Based on the maximum limited speed and the actual speed of the drive motor, it is determined whether torque reduction control of the drive motor is required. If torque reduction control of the drive motor is required, closed-loop control of the drive motor's torque is performed based on the maximum limited speed and the motor's limited torque.

[0216] Furthermore, the second determining module is specifically used for:

[0217] Based on the vehicle's wheel speed information and steering wheel angle, determine the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value;

[0218] The sum of the reference vehicle speed, wheel speed difference correction value, and safe vehicle speed offset value is used as the target vehicle speed for the drive axle.

[0219] The target vehicle speed of the drive shaft is converted into a speed ratio to calculate the maximum speed limit.

[0220] Furthermore, the second determining module is specifically used for:

[0221] The front wheel steering angle of the vehicle is determined based on the steering wheel angle and preset wheel-end steering angle data. The preset wheel-end steering angle data includes the wheel-end steering angles corresponding to different steering wheel angles.

[0222] Determine the reference speed based on the steering angle of the front wheel ends and the wheel speed of the rear wheels;

[0223] The safe speed offset value is determined based on the reference vehicle speed and the preset safe speed offset data. The preset safe speed offset data includes the safe boundary speeds corresponding to different reference vehicle speeds.

[0224] Based on the reference vehicle speed, wheel speed information, and preset corrected vehicle speed data, the wheel speed difference correction value is determined. The preset corrected vehicle speed data includes the corrected vehicle speed values ​​corresponding to different reference vehicle speeds.

[0225] Furthermore, the first determining module is specifically used for:

[0226] Determine whether the power system is operating in the preset mode;

[0227] If the powertrain operating mode is the preset mode, then determine whether the vehicle is in the preset gear based on the gear information;

[0228] If the vehicle is in a preset gear, the traction function is activated based on the activation status of the electronic stability control system.

[0229] If the traction function is not activated, it is determined that the drive motor needs to be subject to anti-slip speed limit.

[0230] For specific limitations regarding the motor controller and vehicle controller, please refer to the limitations on vehicle anti-skid control methods mentioned above, which will not be repeated here. The modules in the aforementioned motor controller and vehicle controller can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0231] In one embodiment, a motor controller or vehicle controller is provided. The motor controller or vehicle controller includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor of the motor controller or vehicle controller provides computing and control capabilities. The memory of the motor controller or vehicle controller includes a storage medium and 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 vehicle controller is used for communication with external devices via a network connection. When the computer program is executed by the processor, it implements a vehicle anti-skid control method.

[0232] In one embodiment, such as Figure 7 As shown, a motor controller or vehicle controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the above-described vehicle anti-skid control method.

[0233] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the vehicle anti-skid control method described above.

[0234] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Furthermore, any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory.

[0235] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0236] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A vehicle anti-skid control method, characterized in that, include: The motor controller receives an anti-slip speed limit request, which includes a maximum speed limit. Based on the maximum speed limit and the actual speed of the drive motor, determine whether it is necessary to perform torque reduction control on the drive motor; If torque reduction control is required for the drive motor, the motor controller performs closed-loop control of the torque of the drive motor based on the maximum speed limit. If the anti-slip speed limit request also includes a motor torque limit, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit, including: The motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit; The motor controller inputs the speed difference into the PID controller to obtain the PID adjustment torque. The motor controller uses the sum of the PID-adjusted torque and the vehicle's required torque as the target torque; The motor controller outputs the larger of 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.

2. The vehicle anti-skid control method as described in claim 1, characterized in that, After the motor controller receives the anti-slip speed limit request, the method further includes: After activating the traction function, the electronic stability system sends a traction function activation signal and an anti-slip torque reduction request to the vehicle controller. After receiving the traction function activation signal and the anti-skid torque reduction request, the vehicle controller generates a speed limit cancellation command based on 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 speed limit cancellation command and the anti-slip torque reduction request, the motor controller disables the anti-slip drive mode according to the speed limit cancellation command and responds to the anti-slip torque reduction request.

3. The vehicle anti-skid control method as described in claim 1, characterized in that, Before the motor controller receives the anti-slip speed limit request, the method further includes: The vehicle controller determines whether anti-slip speed limiting is required for the drive motor and whether torque limiting is required for the drive motor. If anti-slip speed limiting and torque limiting are required, the vehicle controller determines the maximum limiting speed of the drive motor and the limiting torque of the motor. The vehicle controller generates the anti-slip speed limit request based on the motor limit torque and the maximum limit speed, and sends the anti-slip speed limit request to the motor controller.

4. The vehicle anti-skid control method as described in claim 3, characterized in that, The vehicle controller determines the maximum speed limit of the drive motor, including: The vehicle controller determines the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value based on the vehicle's wheel speed information and steering wheel angle. The vehicle controller uses the sum of the reference vehicle speed, the wheel speed difference correction value, and the safe vehicle speed offset value as the target vehicle speed of the drive shaft. The vehicle controller performs a speed ratio conversion on the target vehicle speed of the drive shaft to calculate the maximum speed limit.

5. The vehicle anti-skid control method as described in claim 4, characterized in that, The vehicle controller determines the vehicle's reference speed, wheel speed difference correction value, and safe speed offset value based on the vehicle's wheel speed information and steering wheel angle, including: The vehicle controller determines the front wheel steering angle of the vehicle based on the steering wheel angle and the preset wheel steering angle data, wherein the preset wheel steering angle data includes wheel steering angles corresponding to different steering wheel angles; The vehicle controller determines the reference vehicle speed based on the steering angle of the front wheel ends and the wheel speed of the rear wheels of the vehicle; The vehicle controller determines the safe speed offset value based on the reference vehicle speed and the preset safe speed offset data, wherein the preset safe speed offset data includes the safe boundary speeds corresponding to different reference vehicle speeds. The vehicle controller determines the wheel speed difference correction value based on the reference vehicle speed, the wheel speed information, and the preset correction vehicle speed data. The preset correction vehicle speed data includes correction vehicle speed values ​​corresponding to different reference vehicle speeds.

6. The vehicle anti-skid control method as described in claim 3, characterized in that, The vehicle controller determines whether to apply anti-slip speed limiting to the drive motor based on the vehicle's gear information and powertrain operating mode, including: The vehicle controller determines whether the powertrain operating mode is a preset mode; If the power system operating mode is a preset mode, the vehicle controller determines whether the vehicle is in a preset gear based on the gear information; If the vehicle is in a preset gear, the vehicle controller determines whether the traction function is activated based on the activation status of the electronic stability control system. If the traction function is not activated, the vehicle controller determines that the drive motor needs to be subject to anti-slip speed limitation.

7. The vehicle anti-skid control method as described in claim 3, characterized in that, The vehicle controller determines the motor limiting torque based on the actual battery charging power, the actual engine generating power, and the actual drive motor discharging power.

8. A motor controller, characterized in that, include: A receiving module is configured to receive an anti-slip speed limit request, wherein the anti-slip speed limit request includes a maximum limit speed. The determining module is used to determine whether it is necessary to perform torque reduction control on the drive motor based on the maximum speed limit and the actual speed of the drive motor; The control module is used to perform closed-loop control of the torque of the drive motor based on the maximum speed limit if torque reduction control of the drive motor is required. If the anti-slip speed limit request also includes a motor torque limit, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit, including: The motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit; The motor controller inputs the speed difference into the PID controller to obtain the PID adjustment torque. The motor controller uses the sum of the PID-adjusted torque and the vehicle's required torque as the target torque; The motor controller outputs the larger of 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.

9. A vehicle anti-skid control system, characterized in that, include: The electronic stability control system is used to send a traction function activation signal and an anti-slip torque reduction request to the vehicle controller after the traction function is activated. The vehicle controller is used for: Determine whether anti-slip speed limiting is required for the drive motor, and determine whether torque limiting is required for the drive motor; If anti-slip speed limiting and torque limiting are required, then determine the maximum limiting speed of the drive motor and the limiting torque of the motor. Based on the motor's limited torque and the maximum limited speed, an anti-slip speed limit request is generated and sent to the motor controller; The system receives the traction function activation signal and anti-skid torque reduction request sent by the vehicle electronic stability system, generates a speed limit cancellation command based on the traction function activation signal, and sends the speed limit cancellation command and the anti-skid torque reduction request to the motor controller. Motor controller, used for: Receive the anti-slip speed limit request, and determine whether to perform torque reduction control on the drive motor based on the maximum limit speed and the actual speed of the drive motor; If torque reduction control is required for the drive motor, then the torque of the drive motor is controlled in a closed loop based on the maximum speed limit and the motor torque limit. Upon receiving the speed limit cancellation command and the anti-slip torque reduction request, the system exits the anti-slip drive mode according to the speed limit cancellation command and responds to the anti-slip torque reduction request. If the anti-slip speed limit request also includes a motor torque limit, the motor controller performs closed-loop control of the drive motor torque based on the maximum speed limit, including: The motor controller determines the speed difference between the actual speed of the drive motor and the maximum speed limit; The motor controller inputs the speed difference into the PID controller to obtain the PID adjustment torque. The motor controller uses the sum of the PID-adjusted torque and the vehicle's required torque as the target torque; The motor controller outputs the larger of 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.

10. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the vehicle anti-skid control method as described in any one of claims 1 to 7.

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