Vehicle anti-skid control method and device

Abstract

The invention provides a vehicle anti-skid control method and device. The method comprises the following steps: perceiving and identifying the pavement type of a pavement in front of a vehicle, and determining the perceiving adhesion coefficient of each wheel; estimating based on the dynamic model, and determining the utilization adhesion coefficient of each wheel; according to the perception adhesion coefficient and the utilization adhesion coefficient of each wheel, determining an anti-skid control use adhesion coefficient of each wheel; under the condition that the anti-skid flag bit is activated, according to the anti-skid control use adhesion coefficient of each wheel, a first-time torque reduction target torque value of the vehicle is determined; and based on the first-time torque reduction target torque value, anti-skid control is conducted on the vehicle.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a vehicle anti-skid control method and device. Background Art

[0002] Vehicle anti-skid control technology is a key technology for improving vehicle stability and safety. In electric vehicles, it is particularly important for controlling power output during starting and acceleration. By monitoring and controlling wheel slip, this technology prevents loss of control and power waste caused by wheel slip, thereby improving vehicle handling and the driving experience.

[0003] Related technologies typically employ anti-skid control strategies based on the overall wheel state. These strategies detect wheel speed differences to determine whether skid has occurred and, upon detection, reduce drive torque to suppress it. However, these methods suffer from response delays during initial start-up or acceleration, leading to significant slip during initial intervention and potentially causing vehicle wobbling, impacting driving comfort and safety. Summary of the Invention

[0004] This application mainly provides a vehicle anti-skid control method and device. The technical solution of this application is implemented as follows:

[0005] In a first aspect, a vehicle anti-skid control method is provided, the method comprising: perceiving and identifying a road surface type in front of the vehicle to determine a perceived adhesion coefficient of each wheel; estimating based on a dynamic model to determine a utilized adhesion coefficient of each wheel; determining an anti-skid control used adhesion coefficient of each wheel based on the perceived adhesion coefficient and the utilized adhesion coefficient of each wheel; determining a first torque reduction target torque value of the vehicle based on the anti-skid control used adhesion coefficient of each wheel when an anti-skid flag is activated; and performing anti-skid control on the vehicle based on the first torque reduction target torque value.

[0006] According to the above technical approach, intelligent sensing technology is used to identify road surface type and calculate the perceived adhesion coefficient. This is then combined with a dynamic model to estimate the utilized adhesion coefficient, and the two are then integrated to determine the adhesion coefficient used for anti-skid control. When the anti-skid flag is activated, the initial target torque value for torque reduction is calculated based on the adhesion coefficient, and anti-skid control is implemented. This method utilizes multi-source data fusion to avoid the limitations of a single data source, improving the accuracy and robustness of adhesion coefficient identification. The initial target torque value for torque reduction is determined based on the fused adhesion coefficient used for anti-skid control. This process is decoupled from driver demand, and the torque reduction target is calculated based on the actual vehicle dynamic requirements. This ensures that the torque reduction strategy accurately adapts to road conditions, avoids insufficient or excessive torque reduction caused by over-reliance on driver input or empirical control, and improves the effectiveness and efficiency of anti-skid control.

[0007] In some embodiments, before determining the first torque reduction target torque value of the vehicle using the adhesion coefficient according to the anti-skid control, the method further includes: determining the accelerator pedal opening of the vehicle, the reference speed of the vehicle, the wheel speed of each wheel, and the required torque of each wheel; when the accelerator pedal opening is greater than a first preset opening threshold and the difference between the wheel speed of each wheel and the reference speed is greater than a first speed threshold, determining that the anti-skid flag is activated.

[0008] The aforementioned technical approach, when the anti-skid flag is activated, determines whether the vehicle is slipping based on a comprehensive assessment of accelerator pedal position, reference vehicle speed, wheel speed, and required torque, and activates the anti-skid control logic. This improves the response speed and accuracy of anti-skid control, enabling more timely adjustments to drive torque to prevent wheel slip, thereby enhancing vehicle stability and safety.

[0009] In some embodiments, determining the anti-skid control adhesion coefficient of each wheel includes: when the estimation based on the dynamic model is not activated and the credibility of the perception recognition is greater than a first credibility threshold, determining that the anti-skid control adhesion coefficient of the wheel is the perceived adhesion coefficient of the wheel; when the estimation based on the dynamic model is not activated and the credibility of the perception recognition is not greater than the first credibility threshold, determining that the anti-skid control adhesion coefficient of the wheel is 1; when the estimation based on the dynamic model is activated and a first difference between the utilized adhesion coefficient and the perceived adhesion coefficient of the wheel is greater than a first difference threshold, determining that the anti-skid control adhesion coefficient of the wheel is the utilized adhesion coefficient of the wheel; when the estimation based on the dynamic model is activated and the first difference is not greater than the first difference threshold, performing a linear difference between the perceived adhesion coefficient and the utilized adhesion coefficient according to the credibility of the perception recognition to determine the anti-skid control adhesion coefficient.

[0010] Based on the above technical means, the adhesion coefficient is dynamically selected and used through multi-level judgment logic, which improves the adaptability of anti-skid control under different perception accuracy and dynamic conditions, thereby enhancing the robustness of the overall system.

[0011] In some embodiments, when the estimation based on the dynamic model is activated, the first torque reduction target torque value of the vehicle is determined based on the adhesion coefficient used for anti-skid control, including: determining the average adhesion coefficient used for each wheel of the vehicle, the average adhesion coefficient used being the average value of the adhesion coefficient used for anti-skid control of the wheel in at least two cycles; when the driving type of the vehicle is distributed, determining the first torque reduction target torque value of each wheel based on the average adhesion coefficient of each wheel and the vertical load of each wheel; when the driving type of the vehicle is centralized, determining the first torque reduction target torque value corresponding to the first wheel and the second torque reduction target torque value corresponding to the second wheel on the target drive shaft based on the average adhesion coefficient and vertical load corresponding to the first wheel and the second wheel respectively; and taking the larger value of the first torque reduction target torque value and the second torque reduction target torque value multiplied by the first coefficient as the first torque reduction target torque value of the drive shaft.

[0012] Based on the above technical means, differentiated first-time torque reduction target torque value calculation methods are designed for vehicles with different drive types, making anti-skid control more precise and applicable to multiple drive configurations, thereby improving the overall control effect.

[0013] In some embodiments, when the estimation based on the dynamic model is not activated, the first torque reduction target torque value of the vehicle is determined according to the anti-skid control using the adhesion coefficient, including: when the driving type of the vehicle is distributed, the first torque reduction target torque value of each wheel is determined according to the anti-skid control using the adhesion coefficient of each wheel and the vertical load of each wheel; when the driving type of the vehicle is centralized, the first torque reduction target torque value corresponding to the first wheel and the second torque reduction target torque value corresponding to the second wheel on the target drive shaft are determined according to the anti-skid control using the adhesion coefficient and the vertical load corresponding to the first wheel and the second wheel respectively; and the larger value of the first torque reduction target torque value and the second torque reduction target torque value multiplied by the first coefficient is used as the first torque reduction target torque value of the drive shaft.

[0014] In some embodiments, the anti-skid control of the vehicle includes: performing a first stage of anti-skid control on the vehicle before the vehicle enters a low-adhesion road surface based on the first torque reduction target torque value, so as to maintain the stability of the vehicle when entering the low-adhesion road surface; and performing a second stage of anti-skid control on the vehicle when a preset switching condition is met, so that the vehicle has acceleration on the low-adhesion road surface; the preset switching condition is: the difference between the wheel speed of the vehicle and the reference vehicle speed is less than a first threshold value and the rate of change of the difference is greater than a second threshold value.

[0015] The aforementioned technical approach divides anti-skid control into a first and second phase, corresponding to stability and acceleration, respectively. This maintains vehicle stability on low-adhesion surfaces, thereby avoiding the risk of loss of control due to skidding and improving overall driving performance and safety on low-adhesion surfaces.

[0016] In some embodiments, the first stage anti-skid control of the vehicle includes: in a first time period before the vehicle enters a low-adjustment road, determining a first stage control torque target value based on the first torque reduction target torque value, the vehicle's wheel speed, the vehicle's reference speed, and the vehicle's motor speed limit; wherein the first stage control torque target is the sum of the first torque reduction target torque value, a first torque adjustment amount corresponding to the first speed limit of the motor, and a first dynamic compensation torque adjustment amount; wherein the first dynamic compensation torque adjustment amount is related to the difference between the vehicle's wheel speed and the vehicle speed and the change in the difference, and the first speed limit of the motor is related to the vehicle's reference speed and a first preset offset; according to the first stage control torque target, the first stage anti-skid control of the vehicle is performed so that the torque of the vehicle's wheels and / or drive shaft matches the first stage control torque target.

[0017] Based on the above technical means, the anti-skid control effect of the first stage is optimized by introducing motor speed limitation and dynamic compensation mechanism, so that the vehicle can start to adjust before entering the low-adhesion road, effectively reducing the occurrence of skidding while ensuring the stability of the vehicle.

[0018] In some embodiments, when the drive type of the vehicle is distributed and there is a difference in the usage adhesion coefficients of the left and right wheels, the first stage anti-skid control of the vehicle also includes: determining a first difference between the initial torque reduction target torque values of the left and right wheels; determining a first incremental torque reduction value of the wheel on the high adhesion side based on the first difference and a preset first proportional coefficient; in the first stage anti-skid control of the vehicle, compensating the first stage control torque target based on the first incremental torque reduction value to adjust the torque output of the wheel on the high adhesion side; determining a first braking target torque value of the wheel on the low adhesion side based on the first incremental torque value of the wheel on the high adhesion side; and performing braking control on the wheel on the low adhesion side based on the first braking target torque value.

[0019] According to the above technical means, by introducing left and right wheel difference compensation and braking control under distributed drive, the deviation problem caused by asymmetric adhesion coefficient can be effectively prevented, and the stability and safety of anti-skid control can be further improved.

[0020] In some embodiments, the second-stage anti-skid control of the vehicle includes: performing the second-stage anti-skid control on the vehicle according to the second-stage control torque target, so that the torque of the vehicle's wheels and / or drive shaft matches the second-stage control torque target; when the accelerator pedal opening is less than a first preset opening threshold, and / or the difference between the wheel speed of each wheel and the reference vehicle speed is less than a first speed threshold, and the difference between the actual torque of each wheel and the target torque of each wheel is greater than a first torque difference, determining that the anti-skid flag is exited; when the anti-skid flag is exited, ending the second-stage anti-skid control; wherein the second-stage control torque target is the sum of a second torque adjustment amount corresponding to the second speed limit of the motor and a second dynamic compensation torque adjustment amount, the second dynamic compensation torque adjustment amount is related to the difference between the wheel speed of the vehicle and the vehicle speed and the change in the difference, and the second speed limit of the motor is related to the reference vehicle speed and a second preset offset.

[0021] By incorporating a second-stage control torque target into the second-stage anti-slip control, the aforementioned technical approach effectively controls wheel or driveshaft torque, thereby preventing slip while maintaining vehicle acceleration as much as possible. This improves vehicle stability in complex road conditions, enhancing the driving experience and ultimately enhancing vehicle safety and controllability.

[0022] In some embodiments, determining the utilization adhesion coefficient of each wheel includes: determining the vertical load of each wheel based on the vehicle's driving data and the vehicle's structural data; and processing the vertical load of each wheel through an extended state observer to obtain the utilization adhesion coefficient of each wheel.

[0023] According to the above technical means, the vertical load is processed by extending the state observer, which improves the estimation accuracy of the adhesion coefficient, thereby improving the reliability and adaptability of the anti-skid control.

[0024] In a second aspect, an anti-skid control device for a vehicle is provided, the anti-skid control device comprising: a perception and identification unit for perceiving and identifying the road surface type in front of the vehicle, and determining the perceived adhesion coefficient of each wheel; a dynamics estimation unit for estimating based on a dynamics model, and determining the utilized adhesion coefficient of each wheel; a first determination unit for determining the anti-skid control adhesion coefficient of each wheel based on the perceived adhesion coefficient and the utilized adhesion coefficient of each wheel; a second determination unit for determining a first torque reduction target torque value of the vehicle based on the anti-skid control adhesion coefficient when an anti-skid flag is activated; and an anti-skid control unit for performing staged anti-skid control on the vehicle based on the first torque reduction target torque value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic flow chart of a vehicle anti-skid control method provided in an embodiment of the present application;

[0026] Figure 2 A schematic flow chart of a vehicle anti-skid control method provided in another embodiment of the present application;

[0027] Figure 3 for Figure 1 A further technical solution flow diagram of step S140 in FIG.

[0028] Figure 4 for Figure 1 A further technical solution flow diagram of step S150 in FIG.

[0029] Figure 5 for Figure 4 A further technical solution flow diagram of step S152 in FIG.

[0030] Figure 6 A schematic flow chart of a second-stage anti-skid control method in the vehicle anti-skid control method provided in an embodiment of the present application;

[0031] Figure 7 for Figure 1 A further technical solution flow diagram of step S120 in FIG.

[0032] Figure 8 A schematic structural diagram of an anti-skid control device provided in an embodiment of the present application;

[0033] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the specific technical solutions of the application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application but are not intended to limit the scope of the present application.

[0035] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0036] In the following description, the terms "first, second, and third" are used merely as examples to distinguish between different objects and do not represent a specific order or precedence for the objects. It is understood that the specific order or precedence of "first, second, and third" can be interchanged where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0038] With the growing demand for intelligent and electrified vehicles, smart electric vehicles (EVs) in my country have already captured a significant market share. Compared to traditional vehicles, these vehicles offer advantages such as zero emissions, low noise, and reduced pollution, while also boasting significantly higher levels of intelligence. Due to the rapid torque response offered by electric drives and the development of technologies like distributed drives, some mature technologies used in traditional vehicles need to be redeveloped. Anti-skid control, an active safety system, effectively leverages ground adhesion to prevent skidding and ensure safe driving.

[0039] One anti-skid control solution in the related technology is to passively identify the slip state through chassis sensors, and achieve anti-skid control by simultaneously controlling the driving torque and braking torque through torque. This solution is widely used in traditional fuel vehicles. Since the electric drive torque response is much faster than that of fuel vehicles, the main problem of this solution is the response delay, which leads to a higher slip amount when the anti-skid control is first intervened, and the whole vehicle swings more obviously when starting.

[0040] Another solution in the related art achieves anti-skid control by simultaneously controlling the target speed of the electric drive and the braking torque. Compared with the previous solution, this solution optimizes the response delay, but cannot take into account the advantages of torque control and speed control at the same time. The vehicle's acceleration cannot be fully utilized in the continuous control after the first intervention.

[0041] In the above two related technical solutions, the initial torque reduction target is determined by the driver's required torque and the PID controller, and no segmented independent control strategy is implemented during the control process. In addition, the above two methods do not take into account the different road types, and the control process is passive control, which cannot achieve non-slip.

[0042] Embodiments of the present application provide a vehicle braking control method and device to solve at least one of the above problems.

[0043] Figure 1 1 is a schematic flow chart of a vehicle braking control method provided by an embodiment of the present application. The control method can be executed by a control system in a vehicle, which can be an electronic control unit (ECU) of the vehicle. Figure 1 The method includes steps S110-S150.

[0044] In step S110 , the road surface type in front of the vehicle is perceived and identified, and the perceived adhesion coefficient of each wheel is determined.

[0045] In the embodiments of the present application, intelligent sensing technology can be used to identify the road surface type in front of the vehicle through onboard sensors (such as lidar, millimeter-wave radar, visual recognition system, etc.). Road surface types may include, for example, new snow, compacted snow, dry asphalt, wet asphalt, ice, and abutting roads.

[0046] By identifying the road surface type and combining it with vehicle speed information, the system calculates the adhesion coefficient of each wheel at a fixed distance from the road surface. This coefficient reflects the friction characteristics between the wheel and the ground. For example, if the road surface is identified as icy or snowy, the adhesion coefficient is low, while if it is identified as dry asphalt, the adhesion coefficient is high.

[0047] As a possible implementation method, intelligent perception can also be carried out by combining multiple sensor data, such as camera images, radar point clouds, inertial navigation systems (INS), etc., through machine learning algorithms to classify road types and calculate the perceived adhesion coefficient of each wheel.

[0048] In step S120 , an estimation is performed based on the dynamics model to determine the utilized adhesion coefficient of each wheel.

[0049] The utilized adhesion coefficient is the actual adhesion coefficient for each wheel in its current state, estimated based on the vehicle's dynamics model. This model typically considers parameters such as the vehicle's vertical load, longitudinal force, wheel speed, and reference speed. By analyzing the relationships between these parameters, it estimates the actual adhesion between the tire and the road. For example, when a vehicle is rapidly accelerating, the vertical load on the wheel may change, affecting its adhesion. The dynamics model monitors these changes in real time and dynamically adjusts the calculated utilized adhesion coefficient to better reflect actual operating conditions.

[0050] Exemplary methods for determining the utilized adhesion coefficient can be to perform wheel-by-wheel estimation for each wheel based on a single-wheel dynamics model. The single-wheel dynamics model is a mathematical model based on vehicle dynamics theory that is used to estimate the utilized adhesion coefficient between each wheel and the ground in real time. This model takes into account factors such as wheel speed, acceleration, driving torque, and ground reaction force, and is capable of independently calculating the utilized adhesion coefficient for each wheel. For example, in a distributed drive system, the drive motor for each wheel is independently controlled, so independent dynamic modeling of each wheel is required to improve the accuracy of anti-skid control. The method for determining the utilized adhesion coefficient based on single-wheel dynamics will be described in more detail later and will not be described in detail here.

[0051] In step S130 , the anti-skid control use adhesion coefficient of the vehicle is determined based on the sensed adhesion coefficient and the utilized adhesion coefficient of each wheel.

[0052] The adhesion coefficient used in anti-skid control is calculated by merging the perceived and utilized adhesion coefficients. This fusion calculation can be achieved, for example, through weighted averaging, minimum value selection, or maximum value selection. Furthermore, as a possible implementation, dynamic adjustments can be made based on different road types and driving conditions to accommodate various driving scenarios.

[0053] As a possible implementation method, anti-skid control uses the adhesion coefficient as the smaller value of the perceived adhesion coefficient and the utilized adhesion coefficient. This fusion method can improve the robustness of adhesion coefficient identification and avoid control deviations caused by single sensor or model errors.

[0054] For example, if the adhesion coefficient identified by the intelligent perception system is high but estimated by the dynamics model is low, the anti-skid control will use the value estimated by the dynamics model, ensuring conservative and safe anti-skid control. Conversely, if the dynamics model estimates a high adhesion coefficient but the one identified by the intelligent perception system is low, the anti-skid control will use the value from the intelligent perception system, avoiding an overly conservative control strategy.

[0055] In step S140 , when the anti-skid flag is activated, the first torque reduction target torque value of the vehicle is determined according to the anti-skid control using the adhesion coefficient.

[0056] The anti-skid flag indicates whether the anti-skid control system is active. When a potential skid risk is detected, the anti-skid flag is activated, initiating the anti-skid control process. For example, when the accelerator pedal opening exceeds a certain threshold and the difference between each wheel speed and the reference vehicle speed exceeds a certain value, the anti-skid flag is activated. When the anti-skid flag is activated, the system uses the adhesion coefficient to calculate the initial torque reduction target value based on the anti-skid control.

[0057] As an implementation method, the first torque reduction target torque can be determined based on a vehicle dynamics equation according to the driving force of the wheel, the vertical load, and the adhesion coefficient.

[0058] In step S150 , anti-skid control is performed on the vehicle based on the first torque reduction target torque value.

[0059] In some embodiments, anti-skid control can be divided into a first stage and a second stage. In the first stage, the slip can be quickly suppressed by limiting the speed of the drive motor and the PI controller, while the acceleration performance is optimized in the second stage through an independently designed I-PD controller. For example, in the first stage, the system will start to reduce the torque 0.5 seconds after the wheel reaches the corresponding road surface based on the original torque target value calculated by the identified adhesion coefficient, and complete the torque reduction when the wheel arrives, so as to achieve no slip on low-adhesion roads. At the same time, the system will avoid obvious slip by sending a maximum speed limit to the drive motor. In the second stage, the system will independently design the maximum target speed limit of the electric drive and design an independent I-PD controller to solve the dynamic torque error of each wheel. For example, when the first stage ends but the anti-skid is not over, the system will enter the second stage and optimize the acceleration performance through an independently designed I-PD controller while maintaining driving stability.

[0060] In actual implementation, the two stages of anti-skid control can be set with different control parameters and logic to adapt to different driving scenarios and road conditions. For example, on icy and snowy roads, the control parameters of the first stage can be more conservative, while on dry roads, the control parameters of the second stage can be more aggressive to improve acceleration performance.

[0061] According to the above technical approach, intelligent sensing technology is used to identify road surface type and calculate the perceived adhesion coefficient. This is then combined with a dynamic model to estimate the utilized adhesion coefficient, and the two are then integrated to determine the adhesion coefficient used for anti-skid control. When the anti-skid flag is activated, the initial target torque value for torque reduction is calculated based on the adhesion coefficient, and anti-skid control is implemented. This method utilizes multi-source data fusion to avoid the limitations of a single data source, improving the accuracy and robustness of adhesion coefficient identification. The initial target torque value for torque reduction is determined based on the fused adhesion coefficient used for anti-skid control. This process is decoupled from driver demand, and the torque reduction target is calculated based on the actual vehicle dynamic requirements. This ensures that the torque reduction strategy accurately adapts to road conditions, avoids insufficient or excessive torque reduction caused by over-reliance on driver input or empirical control, and improves the effectiveness and efficiency of anti-skid control.

[0062] In some embodiments, see Figure 2 Before the aforementioned step S140, in which the first torque reduction target torque value of the vehicle is determined according to the anti-slip control using the adhesion coefficient, the method further includes steps S210-S220.

[0063] In step S210 , the accelerator pedal opening of the vehicle, the reference vehicle speed, the wheel speed of each wheel, and the required torque of each wheel are determined.

[0064] Accelerator pedal position refers to the degree to which the driver depresses the accelerator pedal, typically expressed as a percentage, and reflects the driver's desire for vehicle acceleration. The reference speed is a baseline speed calculated by the system based on the vehicle's current driving state. It is used to compare wheel speeds to determine whether slippage is occurring. The wheel speed of each wheel is collected in real time by a wheel speed sensor and reflects the actual rotational speed of the wheel. The required torque for each wheel is the theoretical driving torque calculated based on factors such as the driver's accelerator pedal position, vehicle load, and road conditions. It is used to determine whether a wheel is slipping.

[0065] By collecting information about accelerator pedal position, reference vehicle speed, wheel speed, and required torque, the system can comprehensively determine whether the vehicle is slipping, providing a basis for subsequent activation of the anti-skid flag. This improves the response speed and accuracy of anti-skid control, allowing for more timely adjustment of drive torque to prevent wheel slip, thereby enhancing vehicle stability and safety.

[0066] In step S220 , when the accelerator pedal opening is greater than a first preset opening threshold, and the difference between the wheel speed of each wheel and the reference vehicle speed is greater than a first speed threshold, it is determined that the anti-skid flag is activated.

[0067] The first preset opening threshold is a system-defined critical value for accelerator pedal opening, used to determine whether the driver is in a high acceleration demand state. The first speed threshold is a system-defined critical value for the difference between wheel speed and a reference vehicle speed, used to determine whether the wheels are slipping. When the accelerator pedal opening exceeds this threshold, and the difference between the wheel speed and the reference vehicle speed exceeds this speed threshold, the system determines that the vehicle is slipping and activates the anti-skid flag.

[0068] By setting appropriate opening and speed thresholds, the system can accurately determine whether the vehicle is slipping and activate the anti-skid control logic in a timely manner. This can avoid unnecessary anti-skid control, thereby improving vehicle acceleration performance, while ensuring timely response when anti-skid control is truly needed, thereby improving vehicle driving safety and the driving experience.

[0069] The aforementioned technical approach, when the anti-skid flag is activated, determines whether the vehicle is slipping based on a comprehensive assessment of accelerator pedal position, reference vehicle speed, wheel speed, and required torque, and activates the anti-skid control logic. This improves the response speed and accuracy of anti-skid control, enabling more timely adjustments to drive torque to prevent wheel slip, thereby enhancing vehicle stability and safety.

[0070] In some embodiments, the aforementioned step S130 of determining the vehicle's anti-skid control adhesion coefficient based on the perceived adhesion coefficient and the utilized adhesion coefficient of each wheel further includes:

[0071] When the estimation based on the dynamic model is not activated and the credibility of the perception recognition is greater than a first credibility threshold, the anti-skid control adhesion coefficient of the wheel is determined to be the perceived adhesion coefficient of the wheel.

[0072] When the estimation based on the dynamics model is not activated and the credibility of the perception recognition is less than a first credibility threshold, it is determined that the adhesion coefficient used for the anti-skid control of the wheel is 1.

[0073] When the estimation based on the dynamics model is activated and a first difference between the utilized adhesion coefficient and the perceived adhesion coefficient of the wheel is greater than a first difference threshold, the anti-skid control adhesion coefficient of the wheel is determined to be the utilized adhesion coefficient of the wheel.

[0074] When the estimation based on the dynamic model is activated and the first difference is not greater than the first difference threshold, a linear difference is performed on the perceived adhesion coefficient and the utilized adhesion coefficient according to the credibility of the perception recognition to determine the adhesion coefficient used for anti-skid control.

[0075] In various situations described above, when the dynamics model is inactive, the system relies on the results of sensory recognition. If the confidence level of sensory recognition exceeds a predefined first confidence threshold, the recognition result is deemed sufficiently reliable, and the sensory adhesion coefficient is directly used as the adhesion coefficient for anti-skid control. This approach ensures that even when the dynamics model is unavailable, the system can still perform anti-skid control based on reliable sensory data, avoiding control failures due to model failures.

[0076] The first credibility threshold may be, for example, 0.8, that is, when the dynamic model is not activated and the credibility of the perception recognition α>0.8, the anti-skid control of the wheel is determined to use the adhesion coefficient u 总 =u 感知 .

[0077] When the dynamics model is not activated and the perception recognition confidence level is below the first confidence threshold, the current perception data is unreliable and cannot provide valid adhesion coefficient information. In this case, the system will default to setting the adhesion coefficient used for anti-skid control to 1, assuming maximum adhesion between the wheels and the ground.

[0078] Still taking the first credibility pre-threshold value of 0.8 as an example, when the dynamic model is not activated and the credibility of perception recognition α≤0.8, the anti-skid control of the wheel is determined to use the adhesion coefficient u 总 =1.

[0079] When the dynamics model is activated, the system uses both the dynamically estimated and perceived adhesion coefficients. The utilized adhesion coefficient refers to the adhesion coefficient calculated by the dynamics model, while the perceived adhesion coefficient is the adhesion coefficient identified by the intelligent sensing system. The first difference value is the absolute difference between the two adhesion coefficients, and the first difference threshold is a preset value used to determine whether the difference between the two is within an acceptable range.

[0080] If the first difference is greater than the first difference threshold, it indicates a significant discrepancy between the dynamically estimated adhesion coefficient and the perceived adhesion coefficient, possibly indicating a deviation in one of the estimated results. In this case, the system prioritizes the dynamically estimated adhesion coefficient as the adhesion coefficient for anti-skid control.

[0081] The first difference threshold may be, for example, 0.2. When the dynamic model is activated, if |u 动力学 -u 感知 |>0.2, then the anti-skid control of the wheel is determined using the adhesion coefficient u 总 =u 动力学 .

[0082] When the dynamics model is activated and the first difference is no greater than the first difference threshold, the discrepancy between the dynamics estimation and the perceived adhesion coefficient is small, indicating that both are reliable. At this point, the system linearly interpolates the two adhesion coefficients based on the perceived reliability to generate a combined adhesion coefficient for anti-skid control.

[0083] Still taking the first interpolation threshold as 0.2 as an example, if |u 动力学 -u 感知 |≤0.2, then the anti-skid control adhesion coefficient of the wheel is determined as:

[0084] u 总 =f Liner (α*u 感知 , (1-α)*u 动力学 ) (1)

[0085] Among them, f Liner Represents a linear interpolation function, which is used to calculate the value of the middle point through two known points and their weights. Combined with the above formula, the adhesion coefficient is used by u 感知 and u 动力学 Linear interpolation is performed, and the weight of the linear interpolation is determined by the credibility of the perception recognition. The higher the credibility, the greater the weight of the perception adhesion coefficient in the interpolation.

[0086] Based on the above technical means, the adhesion coefficient is dynamically selected and used through multi-level judgment logic, which improves the adaptability of anti-skid control under different perception accuracy and dynamic conditions, thereby enhancing the robustness of the overall system.

[0087] As a possible implementation manner, the anti-skid control adhesion coefficient corresponding to each wheel may also be determined by the following method.

[0088] When the driving type of the vehicle is distributed, the smaller value of the utilized adhesion coefficient of each wheel and the perceived adhesion coefficient of each wheel is used as the anti-skid control adhesion coefficient corresponding to each wheel.

[0089] In a distributed drive system, each wheel is independently controlled, so the anti-skid control adhesion coefficient must be calculated for each wheel individually. In this step, the system obtains the utilized adhesion coefficient and the perceived adhesion coefficient for each wheel and uses the smaller value as the anti-skid control adhesion coefficient for that wheel. This ensures that on low-grip surfaces, the system does not overly rely on a higher estimated adhesion coefficient, thereby reducing the risk of skidding.

[0090] The above process can be expressed as: 总 =min(u 感知 ,u 动力学 ); where u总 Use the adhesion coefficient for wheel anti-slip control, u 感知 is the wheel’s perceived adhesion coefficient determined by perception and recognition, u 动力学 The applied adhesion coefficient of the wheel is determined based on dynamic estimation. For example, on icy or snowy roads, if the perceived adhesion coefficient of a wheel is 0.2 and the applied adhesion coefficient is 0.3, 0.2 is used as the applied adhesion coefficient for anti-skid control of that wheel to ensure conservative and safe anti-skid control.

[0091] When the vehicle's drive type is centralized, the first working adhesion coefficient and the second working adhesion coefficient of the first wheel and the second wheel in the drive shaft are respectively determined; the product of the larger value of the first working adhesion coefficient and the second working adhesion coefficient and the first coefficient is used as the anti-skid control working adhesion coefficient of the drive shaft; wherein the first working adhesion coefficient is the smaller value of the perceived adhesion coefficient of the first wheel and the utilized adhesion coefficient of the wheel, and the second working adhesion coefficient is the smaller value of the perceived adhesion coefficient of the second wheel and the utilized adhesion coefficient of the wheel.

[0092] In a centralized drive system, typically front-wheel drive or rear-wheel drive, both wheels on the drive shaft share the same power output. Therefore, the system needs to calculate the operating adhesion coefficients of the first and second wheels separately and multiply the larger of the two by a first coefficient (usually an empirical coefficient, such as 0.8) to determine the operating adhesion coefficient for anti-slip control of the drive shaft:

[0093] u AxleRaw =max(min le (u 感知 ,u 动力学 ), min ri (u 感知 ,u 动力学 ))*fac; (2)

[0094] In the above formula, u AxleRaw Adhesion coefficient used for anti-slip control of the drive shaft, min le (u 感知 ,u 动力学 ) is the first use adhesion coefficient of the left wheel in the drive shaft, which is the smaller value of the perceived adhesion coefficient of the left wheel determined based on the identification and the utilization adhesion coefficient of the left wheel determined based on the dynamic model, min ri (u 感知 ,u 动力学 ) is the second service adhesion coefficient of the right wheel in the drive shaft, and fac is the first coefficient (for example, 0.8).

[0095] For example, if the service adhesion coefficient of the first wheel is 0.3 and the service adhesion coefficient of the second wheel is 0.4, the larger value 0.4 is multiplied by the first coefficient 0.8 to obtain 0.32 as the anti-skid control service adhesion coefficient of the drive shaft.

[0096] In some embodiments, see Figure 3 In the case where the estimation based on the dynamic model is activated, the aforementioned step S140 of determining the first torque reduction target torque value of the vehicle according to the anti-slip control using the adhesion coefficient further includes steps S141-S144.

[0097] In step S141, the average service adhesion coefficient of each wheel of the vehicle is determined.

[0098] The average working adhesion coefficient refers to the average value of the wheel's anti-skid control working adhesion coefficient calculated over multiple cycles. As previously described, when dynamic model-based estimation is activated, the working adhesion coefficient for each wheel's anti-skid control is derived by arbitrating the perceived and utilized adhesion coefficients, a result that is subject to measurement error. Therefore, in the technical solution of the embodiments of this application, setting the working adhesion coefficient to the average value over multiple cycles can prioritize avoiding control deviations caused by single measurement errors.

[0099] In actual application, the system will record the anti-skid control adhesion coefficient of each wheel in two or more consecutive cycles and calculate the average value through arithmetic averaging or other statistical methods. For example, on icy and snowy roads, since the adhesion coefficient is low and changes rapidly, the use of multi-cycle averaging can effectively suppress instantaneous fluctuations and ensure the accuracy of the subsequent torque reduction target value.

[0100] In step S142 , when the driving type of the vehicle is distributed, the first torque reduction target torque value of each wheel is determined according to the average adhesion coefficient of each wheel and the vertical load of each wheel.

[0101] In distributed drive, the average adhesion coefficient and vertical load of each wheel jointly determine its first torque reduction target torque value. Vertical load refers to the vertical force acting on the wheel, which is usually determined by the vehicle's weight distribution. The first torque reduction target torque value of the wheel is the product of the average adhesion coefficient and the vertical load. That is:

[0102]

[0103] In formula (3), is the average adhesion coefficient of each wheel, F zi is the vertical force of each wheel, F i is the first torque reduction target torque value of each wheel.

[0104] By combining these two parameters, the torque reduction requirement for each wheel can be more accurately calculated. For example, in a front-wheel drive electric vehicle, if the vertical load on the left front wheel is high and the adhesion coefficient is low, the system will reduce the output torque of this wheel to prevent slip and maintain vehicle stability.

[0105] In step S143, when the vehicle's driving type is centralized, a first torque reduction target torque value corresponding to the first wheel and a second torque reduction target torque value corresponding to the second wheel are determined based on the average adhesion coefficient and vertical load of the first wheel and the second wheel on the drive shaft respectively.

[0106] According to a method similar to that in the aforementioned step S142 , the torque reduction target value of each wheel on the drive shaft can be determined separately.

[0107] In step S144, the first torque reduction target value and the second torque reduction target value are multiplied by the first coefficient as the first torque reduction target torque value of the drive shaft.

[0108] F AxleRaw =max(F1, F2)*fac (4)

[0109] In formula (3), F1 and F2 are the first torque reduction target torque value and the second torque reduction target torque value, respectively, and fac is the first coefficient.

[0110] It can be understood that in the centralized drive type, the two wheels on the same drive shaft have the same power source. In order to ensure the stability of the entire drive shaft, the system will compare the torque reduction target values of the two wheels and take the larger value multiplied by a preset first coefficient as the first torque reduction target torque value of the drive shaft.

[0111] The first parameter is an empirical value, usually less than 1, and is used to balance the difference between the two wheels on the same drive shaft to ensure that the torque reduction operation does not excessively affect the acceleration performance of the vehicle.

[0112] For example, in a rear-wheel drive electric vehicle, if the target torque reduction for the left rear wheel is 50 N·m and the target torque reduction for the right rear wheel is 60 N·m, and the first coefficient is 0.8, the initial target torque reduction for the drive shaft is 60 × 0.8 = 48 N·m. This approach minimizes the impact on acceleration while ensuring vehicle stability, resulting in a smoother driving experience.

[0113] Based on the above technical means, differentiated first-time torque reduction target torque value calculation methods are designed for vehicles with different drive types, making anti-skid control more precise and applicable to multiple drive configurations, thereby improving the overall control effect.

[0114] In some embodiments, when the estimation based on the dynamic model is not activated, the step S140 of determining the first torque reduction target torque value of the vehicle according to the anti-slip control using the adhesion coefficient further includes:

[0115] When the vehicle's drive type is distributed, the first torque reduction target value of each wheel is determined based on the anti-slip control using the adhesion coefficient of each wheel and the vertical load of each wheel.

[0116] Unlike the aforementioned case where dynamics model-based estimation is activated, when dynamics estimation is inactive, the value of the anti-skid control's adhesion coefficient is solely dependent on the reliability of the sensory recognition and is not affected by measurement errors. In this case, the initial torque reduction target value can be determined directly based on the anti-skid control's adhesion coefficient.

[0117] When the vehicle is of a centralized drive type, a first torque reduction target torque value for the first wheel and a second torque reduction target torque value for the second wheel are determined based on the anti-slip control adhesion coefficient and vertical load for the first and second wheels on the target drive shaft. The product of the larger of the first and second torque reduction target torque values and the first coefficient is used as the initial torque reduction target torque value for the drive shaft.

[0118] For a front-wheel drive or rear-wheel drive vehicle, the target drive shaft is the front drive shaft or rear drive shaft of the vehicle; for a vehicle with multiple drive shafts (e.g., a four-wheel drive vehicle), the target drive shaft can be any one of the multiple drive shafts. In some embodiments, the aforementioned anti-skid control of the vehicle based on the first torque reduction target value includes: performing a first stage of anti-skid control on the vehicle based on the first torque reduction target torque value before the vehicle enters a low-adhesion road surface to maintain vehicle stability when entering the low-adhesion road surface; and, if a preset switching condition is met, performing a second stage of anti-skid control on the vehicle to ensure acceleration of the vehicle on the low-adhesion road surface.

[0119] In the technical solution of the embodiments of this application, the first stage of anti-skid control involves reducing the drive motor's output torque before the vehicle enters a low-adhesion road surface (such as snow or ice) to prevent wheel slip and thus ensure vehicle stability. This process utilizes an intelligent sensing system to identify the road surface type and, in conjunction with a dynamic model, calculates an appropriate torque reduction target. This allows the vehicle to adjust drive output immediately before entering the low-adhesion road surface, preventing sudden slip and resulting in vehicle instability or loss of control. The specific control methods for this first stage of control will be described in more detail later.

[0120] The second stage of anti-skid control, after the first stage, occurs and the vehicle has stabilized on a low-adhesion road and remains largely stable, further optimizing the driving strategy to enhance acceleration. The primary goal of this stage is to dynamically adjust the drive motor's speed limit and braking strategy to maximize acceleration without sacrificing stability, thereby improving the driving experience.

[0121] In practice, after the first phase, the system reassesses the current road conditions and vehicle status and initiates the second phase of control based on pre-set switching conditions: the difference between the vehicle's wheel speed and the reference speed is less than a first threshold, and the rate of change of the difference is greater than a second threshold.

[0122] The aforementioned technical approach divides anti-skid control into a first and second phase, corresponding to stability and acceleration, respectively. This maintains vehicle stability on low-adhesion surfaces, thereby avoiding the risk of loss of control due to skidding and improving overall driving performance and safety on low-adhesion surfaces.

[0123] In some embodiments, see Figure 4 The anti-skid control of the vehicle in the aforementioned step S150 further includes steps S151-S152.

[0124] In step S151, in the first time period before the vehicle enters a low-adjustment road, the first stage control torque target value is determined based on the first torque reduction target torque value, the vehicle's wheel speed, the vehicle's reference speed, and the vehicle's motor speed limit.

[0125] The initial torque reduction target is calculated based on the vehicle's current driving state and road adhesion conditions. It is used to make preliminary torque adjustments before the vehicle enters a low-adhesion road. Wheel speed is the actual rotational speed of the vehicle's wheels. Reference speed is a reference value for the vehicle's current speed, typically provided by a speed sensor or navigation system. The motor speed limit is the maximum speed limit for the drive motor, set based on the vehicle's current driving state and road conditions, to prevent wheel slip.

[0126] In practice, when a vehicle is about to enter a low-adhesion road, the system calculates the first-stage control torque target value based on the current wheel speed, reference vehicle speed, and motor speed limit, combined with the initial torque reduction target value. This target value is used to make preliminary torque adjustments before the vehicle enters the low-adhesion road to prevent slippage.

[0127] The calculation formula for the first stage control torque target value is:

[0128] F tarmot =F Raw F AxleRaw +FPid +F motspdlim (5)

[0129] Among them, F Raw or F AxleRaw is the original torque reduction target value calculated based on the road adhesion coefficient, F Pid is the adjustment value output by the PID controller, F motspdlim It is the adjustment value calculated based on the motor speed limit.

[0130] The first-stage control torque target is the sum of the first torque reduction target torque value, the first torque adjustment amount corresponding to the first speed limit of the motor, and the first dynamic compensation torque adjustment amount; wherein the first dynamic compensation torque adjustment amount is related to the difference between the vehicle's wheel speed and the vehicle speed and the change in the difference, and the first speed limit of the motor is related to the vehicle's reference speed and the first preset offset.

[0131] In the embodiment of the present application, the first torque reduction target torque value is an initial torque reduction target calculated based on the current driving state of the vehicle and the road adhesion conditions, and is used to quickly reduce the driving torque when the vehicle tends to slip to prevent the slip from worsening.

[0132] The first speed limit is an upper limit of the motor speed calculated based on the vehicle reference speed and a first preset offset, and is used to limit the motor output speed, thereby indirectly controlling the driving torque to avoid slipping due to excessive speed.

[0133] The first dynamic compensating torque adjustment is a torque compensation value dynamically adjusted based on the difference between wheel speed and vehicle speed and its rate of change. It is used to correct the torque reduction target in real time to account for rapidly changing road adhesion conditions. The introduction of this adjustment improves the response speed and accuracy of anti-slip control, ensuring the vehicle maintains excellent driving stability even in complex road conditions. In practice, this process can be implemented using a PI controller, where the P control is determined by the difference between wheel speed and reference speed and the rate of change of this difference, while the I control is determined by the difference between wheel speed and reference speed. The P term primarily addresses rapid adjustment when there is an error in sensing and the maximum speed limit of the drive motor, while the I term addresses slip caused by errors in estimating the torque reduction target value for each wheel.

[0134] By adding the above-mentioned first torque reduction target torque value, the first torque adjustment amount corresponding to the first speed limit, and the first dynamic compensation torque adjustment amount, the first stage control torque target can be obtained. This target comprehensively considers the current state of the vehicle, road conditions and dynamic changes, thereby achieving more precise anti-skid control.

[0135] In step S152 , the first stage anti-slip control is performed on the vehicle according to the first stage control torque target, so that the torque of the vehicle wheels and / or drive shaft matches the first stage control torque target.

[0136] This control process typically includes two parts: drive motor control and brake control. In the drive motor control part, the system adjusts the drive motor's output torque based on the first-stage control torque target value to ensure that the wheel torque matches the target value. The brake control part will be described in detail later.

[0137] Alternatively, as a possible implementation, the system can dynamically adjust the output torque of the drive motor based on the difference between the current wheel speed and the reference vehicle speed. For example, if a slight slip of the front wheel is detected, the system will immediately reduce the drive torque of the front wheel and may increase the drive torque of the rear wheel to maintain vehicle balance and traction.

[0138] See Figure 5 When the driving type of the vehicle is distributed and there is a difference in the adhesion coefficients of the left and right wheels, the aforementioned step S152 performs the first stage of anti-skid control on the vehicle, and also includes steps S1521-1525.

[0139] In step S1521, a first difference between the initial torque reduction target values of the left and right wheels is determined.

[0140] In a distributed drive vehicle, the left and right wheels may experience differences in road adhesion conditions, which can cause the vehicle to veer during anti-skid control. The initial torque reduction target value for a wheel is closely related to its adhesion coefficient. A larger initial difference indicates a more pronounced difference in adhesion conditions between the two wheels.

[0141] In step S1522, a first incremental torque reduction value of the wheel on the high adhesion side is determined according to the first difference and a preset first proportional coefficient.

[0142] The first incremental torque value is:

[0143] F u1 =(F umax -F umin )*k1 (6)

[0144] Among them, F u1 is the first incremental torque value, F umax is the first torque reduction target value on the high adhesion side, F umin is the first torque reduction target torque value on the low adhesion side, k1 is the first proportional coefficient, and the first proportional coefficient may be 0.7, for example.

[0145] In step S1523 , during the first stage of anti-slip control of the vehicle, the first stage control torque target is compensated according to the first incremental torque reduction value to adjust the torque output of the wheel on the high adhesion side.

[0146] When the vehicle is performing the first stage of anti-skid control, the first stage control torque target is compensated according to the calculated first incremental torque reduction value, which can achieve dynamic adjustment of the torque output of the high-adhesion side wheel, thereby ensuring that the vehicle maintains good driving stability and controllability during the anti-skid control process.

[0147] In step S1524, a first braking target torque value of the wheel on the low adhesion side is determined according to the first incremental torque value of the wheel on the high adhesion side.

[0148] In step S1525 , braking control is performed on the wheels on the low adhesion side according to the first braking target torque value.

[0149] As described above, in a distributed drive system, the left and right wheels of a vehicle may have different adhesion coefficients due to varying road adhesion conditions. For example, when turning, the inside wheel may be on a wet surface, while the outside wheel may be on a dry surface, resulting in different adhesion coefficients on both sides. This difference affects the vehicle's driving force distribution and driving stability. The wheel with higher adhesion typically has higher driving force output, while the wheel with lower adhesion is more prone to slipping.

[0150] To balance the driving force on both wheels and prevent slippage, in this embodiment of the present application, the first incremental torque value of the high-adhesion wheel can be used as the first braking target torque value of the low-adhesion wheel. This means that a corresponding braking force is applied to the low-adhesion wheel to offset its potential slippage. This control method effectively balances the driving force on both wheels and prevents significant vehicle deviation or slippage during driving.

[0151] According to the above technical means, by introducing the first torque reduction target torque value, the first torque adjustment amount corresponding to the first speed limit, and the first dynamic compensation torque adjustment amount into the first-stage control torque target, and performing torque compensation and braking control according to the difference in adhesion coefficients of the left and right wheels in a distributed drive vehicle, the deviation problem caused by asymmetric adhesion coefficient can be effectively prevented, and more precise anti-skid control can be achieved, thereby improving driving stability and further enhancing the vehicle's handling performance and safety under different road conditions.

[0152] In some embodiments, see Figure 6 The aforementioned second stage anti-skid control of the vehicle further includes steps S610-630.

[0153] In step S610 , the vehicle is subjected to second-stage anti-slip control according to the second-stage control torque target, so that the torque of the vehicle's wheels and / or drive shaft matches the second-stage control torque target.

[0154] Among them, the second-stage control torque target is the sum of the second torque adjustment amount corresponding to the second speed limit of the motor and the second dynamic compensation torque adjustment amount. The second speed limit of the motor is related to the reference speed of the vehicle and the second preset offset. The second dynamic compensation torque adjustment amount is related to the difference between the wheel speed and the vehicle speed of the vehicle and the change in the difference.

[0155] The second-stage control torque target is a reference value used to adjust wheel or driveshaft torque during the second stage of anti-slip control. This target value takes into account the vehicle's current operating state, road adhesion conditions, and driver intent, thereby minimizing vehicle acceleration while preventing slip. By adjusting wheel or driveshaft torque to match this target value, wheel slip can be effectively controlled, preventing degradation of handling and energy waste caused by slip.

[0156] The second stage control torque target includes: a second torque adjustment amount and a second dynamic compensation torque adjustment amount.

[0157] The second torque adjustment amount is an adjustment amount calculated based on the second speed limit of the motor, and is used to further adjust the torque of the wheel in the second stage of control to ensure that the vehicle can still maintain good handling during acceleration.

[0158] The second motor speed limit is calculated based on the vehicle's reference speed and a second preset offset. It is used to limit the drive motor's speed to prevent slippage caused by excessive speed. This second preset offset can be the same as or different from the first preset offset, as is not limited in this embodiment of the present application. For example, the second preset offset can be set to be greater than the first offset to ensure that the vehicle does not slip on low-adhesion roads during the first control phase and to ensure that the vehicle has a certain degree of acceleration during the second control phase.

[0159] The second dynamic compensating torque adjustment is dynamically adjusted based on the difference between the vehicle's wheel speed and vehicle speed, as well as its rate of change. This adjustment is used to compensate for torque deviations caused by road surface or vehicle state changes in real time. This process can be implemented using a PI controller, where the P control is determined by the difference between the wheel speed and the reference speed, as well as the rate of change of that difference, while the I control is also determined by the difference between the wheel speed and the reference speed. The P term primarily addresses the need for rapid adjustment when there is an error in sensing and the maximum speed limit of the drive motor, while the I term addresses slip caused by errors in estimating the torque reduction target for each wheel.

[0160] In step S620, when the accelerator pedal opening is less than the first preset opening threshold, and / or the difference between the speed of each driven wheel and the reference vehicle speed is less than the first speed threshold, and the difference between the actual torque of each wheel and the target torque of each wheel is greater than the first torque difference, the anti-skid flag is determined to be exited.

[0161] When the above conditions are met, the system determines that the anti-skid flag should be disengaged, meaning that anti-skid control is no longer required. This judgment logic combines driver intent (accelerator pedal position), vehicle driving status (wheel speed difference from reference speed), and control effectiveness (actual torque difference from target torque) to ensure that anti-skid control is disengaged when necessary, avoiding unnecessary control intervention and improving system response efficiency and driving comfort.

[0162] Accelerator pedal opening refers to the degree to which the driver depresses the accelerator pedal, typically expressed as a percentage, reflecting the driver's desire for vehicle acceleration. The first preset opening threshold is a reference value set based on the vehicle's powertrain characteristics and is used to determine whether the driver is experiencing a low acceleration demand. When the accelerator pedal opening is below this threshold, the driver's acceleration demand is low, the vehicle is experiencing low power output, and the need for anti-skid control is reduced.

[0163] Wheel speed refers to the actual rotational speed of each wheel. The reference speed is a theoretical speed calculated based on the vehicle's overall motion (e.g., speed sensor, GPS, etc.). The first speed threshold is a reference value used to determine whether the difference between the wheel speed and the reference speed is within an acceptable range. When the difference between the wheel speed and the reference speed is less than this threshold, the vehicle's driving state is stable and there is no significant wheel slip.

[0164] The actual torque is the current torque output by the drive motor, and the target torque is the desired torque value calculated based on the anti-slip control strategy. The first torque difference is a reference value used to determine whether the difference between the actual torque and the target torque exceeds the allowable range.

[0165] In step S630, when the anti-skid flag is exited, the second stage of anti-skid control is ended.

[0166] When the anti-skid flag is released, the system determines that the current vehicle state no longer requires anti-skid control and therefore ends the second stage of anti-skid control. The second stage of anti-skid control is typically used to maintain anti-skid effectiveness after the first stage of control, while also taking into account acceleration performance. When the anti-skid flag is released, it indicates that the vehicle has returned to a stable driving state and anti-skid control is no longer required. The system can resume normal driving mode, improving vehicle responsiveness and driving experience.

[0167] In the technical solution of the embodiments of this application, by introducing a second-stage control torque target into the second-stage anti-slip control, the torque applied to the wheels or drive shaft can be effectively controlled, thereby preventing slip while maintaining the vehicle's acceleration performance as much as possible. This improves the vehicle's driving stability in complex road conditions, thereby enhancing the driving experience and, in turn, enhancing the vehicle's safety and controllability.

[0168] In this embodiment of the present application, the second phase of anti-skid control is terminated by exiting the anti-skid flag when the accelerator pedal opening is low and / or the difference between the wheel speed and the reference vehicle speed is small, and the difference between the actual torque and the target torque is greater than a certain range. This prevents continued anti-skid control when the vehicle is stable, thereby reducing unnecessary control interventions, improving system response efficiency, and ultimately enhancing driving comfort and vehicle performance.

[0169] This application addresses the issues of large response delays, significant starting slip, and insufficient acceleration performance in existing anti-skid control technologies by proposing a vehicle anti-skid control method based on the fusion of intelligent perception and dynamics models. This method uses intelligent perception technology to identify road surface types and calculate the perceived adhesion coefficient. This method then combines this with a single-wheel dynamics model to independently estimate the utilized adhesion coefficient, and then fuses these two factors to determine the adhesion coefficient used for anti-skid control.

[0170] With the anti-slip flag activated, the initial torque reduction target is calculated based on the adhesion coefficient. Anti-slip control is implemented in stages. In the first stage, the drive motor speed is limited and a PI controller is used for rapid suppression. In the second stage, an independently designed I-PD controller optimizes acceleration performance. This approach not only addresses the issue of excessive slippage caused by response lag in traditional solutions, but also balances driving stability and power output through a phased control strategy, achieving maximum synergy between anti-slip control and acceleration performance.

[0171] In some embodiments, see Figure 7 The aforementioned step S120, estimating based on the dynamic model to determine the utilized adhesion coefficient of each wheel, further includes steps S121-S122.

[0172] In step S121 , the vertical load of each wheel is determined based on the vehicle's driving data and the vehicle's structural data.

[0173] Vehicle driving data refers to various dynamic information collected during the actual operation of the vehicle, such as speed, acceleration, steering angle, braking status, etc. This data is usually collected in real time by on-board sensors (such as wheel speed sensors, accelerometers, gyroscopes, etc.) to reflect the current operating status of the vehicle.

[0174] The vehicle's structural data refers to the vehicle's static physical parameters, such as vehicle mass, axle mass distribution, tire radius, center of gravity position, wheelbase, etc.

[0175] Vertical load refers to the vertical force acting on each wheel, which depends on factors such as the total mass of the vehicle, the center of gravity, the vehicle posture (such as pitch, roll), and the road conditions.

[0176] In practice, the system uses real-time calculations based on vehicle driving and structural data, combined with a dynamic model, to determine the vertical load on each wheel. For example, during acceleration, the vertical load on the front wheels may increase while that on the rear wheels decreases due to the forward shift in the center of gravity. The opposite occurs during braking. The system dynamically adjusts the vertical load on each wheel based on these changes, improving the accuracy and responsiveness of anti-skid control.

[0177] Based on the vehicle's driving data and structural data, the method for determining the vertical load on the wheel can be referred to the following formula:

[0178]

[0179] In the above formula, F z1 、F z2 、F z3 、F z4 are the vertical loads on the left front, right front, left rear and right rear tires of the vehicle, respectively. x is the vehicle longitudinal acceleration uploaded by the vehicle chassis, a y represents the lateral acceleration, w v represents the yaw rate, m represents the vehicle mass, L f Indicates the vehicle's front wheelbase, L r Indicates the vehicle's rear wheelbase, h g represents the height of the vehicle's center of mass, g represents the acceleration due to gravity, and B represents the vehicle's wheelbase.

[0180] In step S122, the vertical load of each wheel is processed by the extended state observer to obtain the utilized adhesion coefficient of each wheel.

[0181] In this step, the vehicle single wheel dynamics equation is first constructed using the following formula (8).

[0182]

[0183] In formula (8), I z is the vehicle's Z-axis moment of inertia, is the angular acceleration of each wheel, T bi is the braking torque of each wheel, T di is the driving torque of each wheel, F i is the driving force of each wheel, R is the free rolling radius of the wheel, and K is the vehicle dynamic feature identification coefficient, which is mainly used to judge the vehicle's driving direction and working status. bi +T di >0, K=1; if T bi +T di <0, K=-1; otherwise K=0.

[0184] Among them, Fi It can be obtained based on the following formula (9).

[0185]

[0186] In formula (9), is the adhesion coefficient of each wheel, F zi is the vertical force of each wheel, F i For the driving force of each wheel.

[0187] Then, a typical first-order extended state observer is used to determine the utilization adhesion coefficient. For example, the utilization adhesion coefficient is determined according to the following formula (8).

[0188]

[0189] In formula (10), is the estimated utilization adhesion coefficient, F zi is the vertical force of each wheel, R is the free rolling radius of the wheel, I z is the vehicle's Z-axis moment of inertia, is the parameter value determined based on the extended state observer.

[0190] Combined with the above Figure 1-Figure 7 , describes the method embodiment of the present application in detail, and will be combined with Figure 8-Figure 9 Introducing the device embodiment of the present application, it should be understood that the description of the device embodiment corresponds to the method embodiment. Therefore, for parts that are not described in detail, reference can be made to the method embodiment above.

[0191] Figure 8 3 is a schematic structural diagram of an anti-skid control device provided in an embodiment of the present application. The anti-skid control device may be, for example, an electronic control unit ECU in a vehicle. Figure 8 The anti-skid control device 800 includes:

[0192] The perception and recognition unit 810 is used to perceive and recognize the road surface type in front of the vehicle and determine the perceived adhesion coefficient of each wheel.

[0193] The dynamics estimation unit 820 is configured to estimate based on the dynamics model and determine the utilization adhesion coefficient of each wheel.

[0194] The first determining unit 830 is configured to determine the anti-skid control use adhesion coefficient of each wheel according to the sensed adhesion coefficient and the utilized adhesion coefficient of each wheel.

[0195] The second determining unit 840 is configured to determine the first torque reduction target torque value of the vehicle according to the anti-skid control adhesion coefficient of each wheel when the anti-skid flag is activated.

[0196] The anti-skid control unit 850 is used to perform anti-skid control on the vehicle based on the first torque reduction target torque value.

[0197] In some embodiments, the anti-skid control device also includes a third determination unit for determining the accelerator pedal opening of the vehicle, the reference speed of the vehicle, the wheel speed of each wheel, and the required torque of each wheel; and, when the accelerator pedal opening is greater than a first preset opening threshold and the difference between the wheel speed of each wheel and the reference speed is greater than a first speed threshold, determining that the anti-skid flag is activated.

[0198] In some embodiments, the first determination unit 830 is further used to: when the estimation based on the dynamic model is not activated and the credibility of the perception recognition is greater than a first credibility threshold, determine that the adhesion coefficient used for anti-skid control of the wheel is the perceived adhesion coefficient of the wheel; when the estimation based on the dynamic model is not activated and the credibility of the perception recognition is not greater than the first credibility threshold, determine that the adhesion coefficient used for anti-skid control of the wheel is 1; when the estimation based on the dynamic model is activated and the first difference between the utilized adhesion coefficient and the perceived adhesion coefficient of the wheel is greater than a first difference threshold, determine that the adhesion coefficient used for anti-skid control of the wheel is the utilized adhesion coefficient of the wheel; when the estimation based on the dynamic model is activated and the first difference is not greater than the first difference threshold, perform a linear difference between the perceived adhesion coefficient and the utilized adhesion coefficient according to the credibility of the perception recognition to determine the adhesion coefficient used for anti-skid control.

[0199] In some embodiments, when the estimation based on the dynamic model is activated, the second determination unit 840 is also used to: determine the average usage adhesion coefficient of each wheel of the vehicle, the average usage adhesion coefficient being the average value of the anti-skid control usage adhesion coefficient of the wheel in at least two cycles; when the driving type of the vehicle is distributed, determine the first torque reduction target torque value of each wheel according to the average adhesion coefficient of each wheel and the vertical load of each wheel; when the driving type of the vehicle is centralized, determine the first torque reduction target torque value corresponding to the first wheel and the second torque reduction target torque value corresponding to the second wheel according to the average adhesion coefficient and the vertical load of the first wheel and the second wheel on the drive shaft respectively; and take the product of the larger value of the first torque reduction target torque value and the second torque reduction target torque value and the first coefficient as the first torque reduction target torque value of the drive shaft.

[0200] In some embodiments, when the estimation based on the dynamic model is not activated, the second determining unit 840 is further configured to: determine, when the drive type of the vehicle is distributed, a first torque reduction target torque value for each wheel based on the anti-slip control adhesion coefficient of each wheel and the vertical load of each wheel;

[0201] When the vehicle is of a centralized drive type, determining a first torque reduction target torque value corresponding to a first wheel and a second torque reduction target torque value corresponding to a second wheel on a target drive shaft according to an anti-slip control adhesion coefficient and a vertical load corresponding to the first wheel and the second wheel, respectively;

[0202] A product of a larger value of the first torque reduction target torque value and the second torque reduction target torque value and a first coefficient is used as a first torque reduction target torque value of the drive shaft.

[0203] In some embodiments, the anti-skid control unit 850 is further used to: perform a first stage of anti-skid control on the vehicle before the vehicle enters the low-adhesion road surface according to the first torque reduction target torque value, so as to maintain the stability of the vehicle when entering the low-adhesion road surface; and, when a preset switching condition is met, perform a second stage of anti-skid control on the vehicle, so as to accelerate the vehicle on the low-adhesion road surface; the preset switching condition is: the difference between the wheel speed of the vehicle and the reference vehicle speed is less than a first threshold value and the rate of change of the difference is greater than a second threshold value.

[0204] In some embodiments, the anti-skid control unit 850 is further used to: in a first time period before the vehicle enters a low-adjustment road, determine a first-stage control torque target value based on the first torque reduction target torque value, the wheel speed of the vehicle, the reference speed of the vehicle, and the motor speed limit of the vehicle; wherein the first-stage control torque target is the sum of the first torque reduction target torque value, the first torque adjustment amount corresponding to the first speed limit of the motor, and the first dynamic compensation torque adjustment amount; wherein the first dynamic compensation torque adjustment amount is related to the difference between the wheel speed of the vehicle and the vehicle speed and the change in the difference, and the first speed limit of the motor is related to the reference speed of the vehicle and a first preset offset; according to the first-stage control torque target, perform first-stage anti-skid control on the vehicle so that the torque of the wheels and / or drive shaft of the vehicle matches the first-stage control torque target.

[0205] In some embodiments, the anti-skid control device also includes a fourth determination unit, which is used to determine a first difference in the initial torque reduction target torque values of the left and right wheels when the drive type of the vehicle is distributed and there is a difference in the usage adhesion coefficients of the left and right wheels; and, based on the first difference and a preset first proportional coefficient, determine a first incremental torque reduction value of the wheel on the high adhesion side.

[0206] The anti-skid control unit 850 is also used to compensate the first-stage control torque target according to the first incremental torque reduction value during the first-stage anti-skid control of the vehicle, so as to adjust the torque output of the wheels on the high-adhesion side; determine the first braking target torque value of the wheels on the low-adhesion side according to the first incremental torque value of the wheels on the high-adhesion side; and perform braking control on the wheels on the low-adhesion side according to the first braking target torque value.

[0207] In some embodiments, the anti-skid control unit 850 is further used to: perform a second-stage anti-skid control on the vehicle according to a second-stage control torque target, so that the torque of the vehicle's wheels and / or drive shaft matches the second-stage control torque target; determine that the anti-skid flag is exited when the accelerator pedal opening is less than a first preset opening threshold, and / or the difference between the speed of each driven wheel and the reference vehicle speed is less than a first speed threshold, and the difference between the actual torque of each wheel and the target torque of each wheel is greater than a first torque difference; end the second-stage anti-skid control when the anti-skid flag is exited; wherein the second-stage control torque target is the sum of a second torque adjustment amount corresponding to the second speed limit of the motor and a second dynamic compensation torque adjustment amount, the second dynamic compensation torque adjustment amount is related to the difference between the wheel speed of the vehicle and the vehicle speed and the change in the difference, and the second speed limit of the motor is related to the reference vehicle speed and a second preset offset of the vehicle.

[0208] In some embodiments, the dynamic estimation unit 820 is further used to: determine the vertical load of each wheel based on the driving data of the vehicle and the structural data of the vehicle; and process the vertical load of each wheel through an extended state observer to obtain the utilization adhesion coefficient of each wheel.

[0209] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Figure 9 As shown, the hardware entity of the electronic device 900 includes: a processor 910 and a memory 920, wherein the memory 920 stores a computer program that can be run on the processor 910, and the processor 910 implements the steps in the method of any of the above embodiments when executing the program.

[0210] The vehicle 900 may further include a transceiver 930. The processor 910 may communicate with other devices or chips via the transceiver 930. For example, the processor 910 may transmit and receive data with other devices or chips via the transceiver 930.

[0211] The memory 920 stores computer programs that can be run on the processor. The memory 920 is configured to store instructions and applications executable by the processor 910. It can also cache data to be processed or processed by the processor 910 and various modules in the electronic device 900 (for example, image data, audio data, voice communication data, and video communication data). This can be implemented through flash memory (FLASH) or random access memory.

[0212] In one embodiment, the electronic device 900 may be a vehicle or a device deployed in a vehicle, such as an on-board controller.

[0213] An embodiment of the present application provides a computer storage medium, which stores one or more programs. The one or more programs can be executed by one or more processors to implement the steps of the control method of any of the above embodiments.

[0214] It should be noted that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0215] The processor may be at least one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a central processing unit (CPU), a controller, a microcontroller, and a microprocessor. It is understood that the electronic device that implements the functions of the processor may also be other electronic devices, which are not specifically limited in the embodiments of the present application.

[0216] The computer storage medium / memory may be a read-only memory, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface mount memory, an optical disc, or a compact disc read-only memory (CD ROM).

[0217] An embodiment of the present application provides a computer program, including computer-readable code. When the computer-readable code runs in an electronic device, a processor in the electronic device executes some or all of the steps for implementing the above method.

[0218] An embodiment of the present application provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and when the computer program is read and executed by a computer, implements some or all of the steps in the above method. The computer program product can be implemented specifically through hardware, software, or a combination thereof. In some embodiments, the computer program product is specifically embodied as a computer storage medium. In other embodiments, the computer program product is specifically embodied as a software product, such as a software development kit (SDK), etc.

[0219] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned steps / processes does not mean the order of execution, and the execution order of each step / 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 application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments.

[0220] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0221] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is merely a logical function division. In actual implementation, there may be other division methods, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0222] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed across multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the scheme of this embodiment.

[0223] In addition, all functional units in the embodiments of the present application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the above-mentioned integrated units can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0224] Those skilled in the art will understand that all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, and other media that can store program codes.

[0225] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling an on-board terminal (which can be a personal computer, server, or network device, etc.) to execute all or part of the methods of each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks or optical disks.

[0226] The above are only implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the present application.

Claims

1. A vehicle anti-skid control method, characterized in that: The method comprises: sensing and identifying a road surface type in front of the vehicle and determining a sensed adhesion coefficient of each wheel; Estimating based on a dynamic model to determine the utilization adhesion coefficient of each wheel; determining an anti-skid control use adhesion coefficient for each wheel according to the sensed adhesion coefficient and the utilized adhesion coefficient of each wheel; When the anti-skid flag is activated, determining a first torque reduction target torque value of the vehicle according to the anti-skid control adhesion coefficient of each wheel; Anti-skid control is performed on the vehicle based on the first torque reduction target torque value.

2. The method according to claim 1, characterized in that Before determining the first torque reduction target torque value of the vehicle according to the anti-slip control using the adhesion coefficient, the method further includes: determining an accelerator pedal opening of the vehicle, a reference speed of the vehicle, a wheel speed of each wheel, and a required torque of each wheel; When the accelerator pedal opening is greater than a first preset opening threshold, and the difference between the wheel speed of each wheel and the reference vehicle speed is greater than a first speed threshold, it is determined that the anti-skid flag is activated.

3. The method according to claim 2, characterized in that Determining the anti-skid control adhesion coefficient of each wheel includes: When the estimation based on the dynamic model is not activated and the credibility of the perception recognition is greater than a first credibility threshold, determining that the adhesion coefficient used for the anti-skid control of the wheel is the perceived adhesion coefficient of the wheel; When the estimation based on the dynamic model is not activated and the credibility of the perception recognition is not greater than the first credibility threshold, determining that the adhesion coefficient used for the anti-skid control of the wheel is 1; When the estimation based on the dynamic model is activated and a first difference between the utilized adhesion coefficient and the perceived adhesion coefficient of the wheel is greater than a first difference threshold, determining the anti-skid control adhesion coefficient of the wheel to be the utilized adhesion coefficient of the wheel; When the dynamic model-based estimation is activated and the first difference is not greater than the first difference threshold, a linear difference is performed on the perceived adhesion coefficient and the utilized adhesion coefficient according to the credibility of the perceived recognition to determine the adhesion coefficient used for anti-skid control.

4. The method according to claim 3, characterized in that When the estimation based on the dynamic model is activated, determining the first torque reduction target torque value of the vehicle according to the anti-slip control using the adhesion coefficient includes: Determining an average service adhesion coefficient of each wheel of the vehicle, where the average service adhesion coefficient is an average value of anti-skid control service adhesion coefficients of the wheel in at least two cycles; When the driving type of the vehicle is distributed, determining a first torque reduction target torque value of each wheel according to an average adhesion coefficient of each wheel and a vertical load of each wheel; In the case where the driving type of the vehicle is centralized, a first torque reduction target torque value corresponding to the first wheel and a second torque reduction target torque value corresponding to the second wheel are determined according to the average adhesion coefficients and vertical loads corresponding to the first wheel and the second wheel on the target drive shaft respectively; and the larger value of the first torque reduction target torque value and the second torque reduction target torque value multiplied by the first coefficient is used as the first torque reduction target torque value of the drive shaft.

5. The method according to claim 3, characterized in that When the estimation based on the dynamic model is not activated, determining the first torque reduction target torque value of the vehicle according to the anti-slip control using the adhesion coefficient includes: When the driving type of the vehicle is distributed, determining a first torque reduction target torque value for each wheel according to an adhesion coefficient used for anti-slip control of each wheel and a vertical load of each wheel; When the vehicle is of a centralized drive type, determining a first torque reduction target torque value corresponding to a first wheel and a second torque reduction target torque value corresponding to a second wheel on a target drive shaft according to an anti-slip control adhesion coefficient and a vertical load corresponding to the first wheel and the second wheel, respectively; A product of a larger value of the first torque reduction target torque value and the second torque reduction target torque value and a first coefficient is used as a first torque reduction target torque value of the drive shaft.

6. The method according to claim 4 or 5, characterized in that The anti-skid control of the vehicle includes: performing a first stage of anti-skid control on the vehicle before the vehicle enters a low-adhesion road surface according to the first torque reduction target torque value, so as to maintain vehicle stability when the vehicle enters the low-adhesion road surface; and When a preset switching condition is met, the vehicle is subjected to a second stage of anti-skid control so that the vehicle has acceleration on the low-adhesion road surface; The preset switching condition includes: a difference between the wheel speed of the vehicle and a reference vehicle speed is less than a first threshold and a rate of change of the difference is greater than a second threshold.

7. The method according to claim 6, characterized in that The first stage anti-skid control of the vehicle includes: In a first time period before the vehicle enters a low-adjustment road, determining a first-stage control torque target value based on the first torque reduction target torque value, the vehicle's wheel speed, the vehicle's reference speed, and the vehicle's motor speed limit; The first-stage control torque target is the sum of the first torque reduction target torque value, a first torque adjustment value corresponding to the first speed limit of the motor, and a first dynamic compensation torque adjustment value; wherein the first dynamic compensation torque adjustment value is related to the difference between the wheel speed of the vehicle and the vehicle speed and the change in the difference, and the first speed limit of the motor is related to the reference speed of the vehicle and a first preset offset; According to the first-stage control torque target, the vehicle is subjected to a first-stage anti-slip control so that the torque of the wheels and / or the drive shaft of the vehicle matches the first-stage control torque target.

8. The method according to claim 7, characterized in that When the drive type of the vehicle is distributed and there is a difference in the working adhesion coefficients of the left and right wheels, the first stage anti-skid control of the vehicle further includes: Determining a first difference between the first torque reduction target torque values of the left and right wheels; determining a first incremental torque reduction value of the wheel on the high adhesion side according to the first difference and a preset first proportional coefficient; During the first stage of anti-slip control of the vehicle, the first stage control torque target is compensated according to the first incremental torque reduction value to adjust the torque output of the wheel on the high adhesion side; and a first braking target torque value of the wheel on the low adhesion side is determined according to the first incremental torque value of the wheel on the high adhesion side. Braking control is performed on the wheel on the low-adhesion side according to the first braking target torque value.

9. The method according to claim 7 or 8, characterized in that The second stage anti-skid control of the vehicle includes: performing a second-stage anti-slip control on the vehicle according to the second-stage control torque target, so that the torque of the wheels and / or drive shaft of the vehicle matches the second-stage control torque target; When the accelerator pedal opening is less than a first preset opening threshold, and / or the difference between the wheel speed of each wheel and the reference vehicle speed is less than a first speed threshold, and the difference between the actual torque of each wheel and the target torque of each wheel is greater than a first torque difference, determining that the anti-skid flag position is exited; When the anti-skid flag is exited, ending the second stage of anti-skid control; Among them, the second-stage control torque target is the sum of the second torque adjustment amount corresponding to the second speed limit of the motor and the second dynamic compensation torque adjustment amount, the second dynamic compensation torque adjustment amount is related to the difference between the wheel speed of the vehicle and the vehicle speed and the change in the difference, and the second speed limit of the motor is related to the reference speed of the vehicle and a second preset offset.

10. The method according to any one of claims 1 to 5, 7 or 8, characterized in that Determining the utilization adhesion coefficient of each wheel includes: determining a vertical load of each wheel based on the driving data of the vehicle and the structural data of the vehicle; The vertical load of each wheel is processed by an extended state observer to obtain the utilization adhesion coefficient of each wheel.

11. A vehicle anti-skid control device, characterized in that: The anti-skid control device comprises: a sensing and identifying unit, configured to sense and identify a road surface type in front of the vehicle and determine a sensed adhesion coefficient of each wheel; a dynamics estimation unit, configured to estimate based on a dynamics model and determine a utilized adhesion coefficient of each wheel; a first determining unit, configured to determine an anti-skid control use adhesion coefficient for each wheel according to the sensed adhesion coefficient and the use adhesion coefficient of each wheel; a second determining unit, configured to determine a first torque reduction target torque value of the vehicle according to an adhesion coefficient used in the anti-skid control when an anti-skid flag is activated; An anti-skid control unit is used to perform anti-skid control on the vehicle in stages based on the first torque reduction target torque value.

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