Vehicle wheel anti-skid control method, device, vehicle and storage medium

Abstract

The present application relates to the field of vehicle technology, and in particular to a wheel anti-skid control method, device, vehicle and storage medium of a vehicle, wherein the method comprises: detecting whether a plurality of wheels are in a slipping state, and determining the current anti-skid control stage of the slipping wheel in the slipping state among the plurality of wheels; when the current anti-skid control stage is the first stage of anti-skid control, calculating the target speed of the slipping wheel according to a preset first target speed calculation formula; when the current anti-skid control stage is the second stage of anti-skid control, calculating the target speed of the slipping wheel according to a preset second target speed calculation formula; calculating the anti-skid control torque of the slipping wheel according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and controlling the slipping wheel according to the anti-skid control torque. Thus, the adaptability of the anti-skid control algorithm is improved.

Description

Technical Field

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

[0002] The distributed drive wheels are driven by hub motors or wheel-side motors. They have a simple structure, independently controllable speed and torque, and fast response. The economy and safety of the entire vehicle can be improved through the torque vector combination of multiple wheels. Distributed drive wheel torque vector control is a key component of autonomous driving chassis domain control technology.

[0003] In the distributed drive control process of autonomous driving, when the wheel driving torque is greater than the maximum adhesion that the ground adhesion can provide, the wheel speed increases rapidly. When the slip rate exceeds a certain limit, the wheel enters an unstable area, which may cause dangerous situations such as vehicle skidding, affecting the safety of autonomous driving. Therefore, it is necessary to timely perform anti-skid control on the wheels to avoid further increase in wheel speed and control the wheel speed within a set reasonable range.

[0004] The wheel adhesion coefficient is affected by the conditions of the driving road and the vertical load of the wheel. The size of the adhesion coefficient directly affects the longitudinal force that the ground can provide, and affects the size and effect of the anti-skid control torque. The dynamically changing adhesion coefficient increases the difficulty of anti-skid control.

[0005] In order to adapt to the changes of different adhesion coefficients and obtain better anti-skid control effects, most current studies estimate the adhesion coefficient and use the relationship between the adhesion coefficient and the slip rate to perform anti-skid control.

[0006] In the related art, a distributed drive electric vehicle road adaptive anti-skid control system and method are proposed, which estimates the peak adhesion coefficient using the wheel vertical force and adhesion coefficient. Another distributed drive electric vehicle driving anti-skid control method estimates the optimal adhesion coefficient based on the actual adhesion coefficient and slip rate.

[0007] However, the calculation of vertical force depends on the position of the vehicle's center of mass, which changes during actual driving, and the influence of slope is not considered. It is difficult to accurately obtain the vertical force in practical applications, which directly affects the subsequent adhesion coefficient identification accuracy and the anti-skid control effect. The other method also has the problem of vertical force calculation. At the same time, the optimal adhesion coefficient under different slip rates is related to the wheel type and road conditions. The approximate fitting method has certain errors, which affects the final optimal slip rate identification effect. Summary of the invention

[0008] The present application provides a vehicle wheel anti-skid control method, device, vehicle and storage medium to solve the problem that the algorithm in the related art is always affected by the parameters that dynamically change during driving, thereby affecting the anti-skid control effect. There is no need to rely on the estimation of other dynamically changing parameters, thereby improving the adaptability of the anti-skid control algorithm.

[0009] A first aspect of the present application provides a method for controlling the wheels of a vehicle in an anti-skid state, wherein the vehicle comprises a plurality of symmetrically arranged wheels, each wheel being provided with a corresponding drive motor, and comprising the following steps: detecting whether the plurality of wheels are in a slipping state, and determining the anti-skid control stage currently located at a slipping wheel in the slipping state among the plurality of wheels; when the current anti-skid control stage is the first anti-skid control stage, calculating the target speed of the slipping wheel according to a preset first target speed calculation formula; when the current anti-skid control stage is the second anti-skid control stage, calculating the target speed of the slipping wheel according to a preset second target speed calculation formula; and calculating the anti-skid control torque of the slipping wheel according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and controlling the slipping wheel according to the anti-skid control torque.

[0010] According to the above technical means, the present application can solve the problem in the related art that the algorithm is always affected by the parameters that change dynamically during driving, thereby affecting the anti-skid control effect, without relying on the estimation of other dynamically changing parameters, thereby improving the adaptability of the anti-skid control algorithm.

[0011] Optionally, in some embodiments, detecting whether the multiple wheels are in a slipping state includes: obtaining the current wheel speed of each wheel; determining whether the current wheel speed is greater than a preset slipping speed, wherein the preset slipping speed is the product of a preset anti-slip coefficient and an axle equivalent speed; if the current wheel speed is greater than the preset slipping speed, then the wheel whose current wheel speed is greater than the preset slipping speed is determined to be in a slipping state.

[0012] According to the above technical means, the present application can determine whether the wheel is in a slipping state by the wheel speed.

[0013] Optionally, in some embodiments, determining the current anti-skid control stage of the slipping wheel in the slipping state among the multiple wheels includes: obtaining the direction of the wheel angular acceleration and the direction of the wheel center speed of the slipping wheel; if the direction of the wheel angular acceleration and the direction of the wheel center speed are opposite, then the current anti-skid control stage is the second anti-skid control stage; otherwise, the current anti-skid control stage is the first anti-skid control stage, wherein the anti-skid control strength of the second anti-skid control stage is less than the anti-skid control strength of the first anti-skid control stage.

[0014] According to the above technical means, the present application adopts a wheel speed proportional control method. When the speed rises rapidly, the torque automatically decreases, which can avoid the wheel speed from spinning rapidly and achieve stable control of the speed.

[0015] Optionally, in some embodiments, the preset first target speed calculation formula is:

[0016] Preset first target speed = n isd0 +k Fe0 (k iF n ie -n i )(i=1,2,…,N);

[0017] Among them, n isd0 is the first stage reference target speed, k Fe0 is the steady-state control coefficient of the first stage, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel;

[0018] The preset second target speed calculation formula is:

[0019] Preset second target speed = n isd1 +k Fe1 (k iF n ie -n i )(i=1,2,…,N);

[0020] Among them, n isd1 is the second stage reference target speed, k Fe1 is the second stage steady-state control coefficient, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel.

[0021] According to the above technical means, the present application can use the result of speed proportional control to estimate the adhesion coefficient of the wheel, correct the target speed of the wheel, obtain stable anti-skid control, and achieve adaptation to different adhesion coefficients.

[0022] Optionally, in some embodiments, the target speed change rate limit value determined by the target speed includes: a target speed change rate limit value determined by the target speed based on a preset target speed change rate formula, wherein the preset target speed change rate formula is:

[0023] n isdL =n isdLf +sign(n isd -n isdLf )min(Δn L ,|n isd -n isdLf |);

[0024] Among them, n isdL The target speed limit for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, n isd The target speed for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, Δn L It is the change limit of the target speed of wheel anti-skid control within a unit control cycle.

[0025] According to the above technical means, the present application can adapt to the steady-state time of different speed controls and adapt to different needs by changing the steady-state control coefficients of the second stage and the first stage.

[0026] Optionally, in some embodiments, the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, including: based on a preset torque calculation formula, the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, wherein the preset torque calculation formula is:

[0027] T in =k n (n isdL -n i )(i=1,2,…,6);

[0028] Among them, T in is the anti-slip control torque of the i-th distributed wheel, n isdL The target speed limit for wheel anti-slip control, ni is the speed of the i-th wheel.

[0029] According to the above technical means, when there is an error in the expected slip rate, the wheel speed will not increase rapidly and will be stably maintained at a certain value, thereby fully utilizing the adhesion and enhancing the applicability of the algorithm.

[0030] A second aspect of the present application provides a wheel anti-skid control device for a vehicle, comprising: the vehicle comprises a plurality of symmetrically arranged wheels, each wheel being provided with a corresponding drive motor, comprising: a detection module, for detecting whether the plurality of wheels are in a slipping state, and determining the anti-skid control stage currently located in the slipping wheel in the slipping state among the plurality of wheels; a calculation module, for calculating the target speed of the slipping wheel according to a preset first target speed calculation formula when the current anti-skid control stage is the first anti-skid control stage; and for calculating the target speed of the slipping wheel according to a preset second target speed calculation formula when the current anti-skid control stage is the second anti-skid control stage; and a control module, for calculating the anti-skid control torque of the slipping wheel according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and controlling the slipping wheel according to the anti-skid control torque.

[0031] Optionally, in some embodiments, the detection module is further used to: obtain the current wheel speed of each wheel; determine whether the current wheel speed is greater than a preset slip speed, wherein the preset slip speed is the product of a preset anti-slip coefficient and an axle equivalent speed; if the current wheel speed is greater than the preset slip speed, then the wheel whose current wheel speed is greater than the preset slip speed is determined to be in a slipping state.

[0032] Optionally, in some embodiments, the detection module is further used to: obtain the direction of the wheel angular acceleration and the direction of the wheel center speed of the slipping wheel; if the direction of the wheel angular acceleration and the direction of the wheel center speed are opposite, then the current anti-skid control stage is the second stage of anti-skid control; otherwise, the current anti-skid control stage is the first stage of anti-skid control, wherein the anti-skid control force of the second stage of anti-skid control is greater than the anti-skid control force of the first stage of anti-skid control.

[0033] Optionally, in some embodiments, the preset first target speed calculation formula is:

[0034] Preset first target speed = n isd0 +k Fe0 (k iF n ie -n i)(i=1,2,…,N);

[0035] Among them, n isd0 is the first stage reference target speed, k Fe0 is the steady-state control coefficient of the first stage, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel;

[0036] The preset second target speed calculation formula is:

[0037] Preset second target speed = n isd1 +k Fe1 (k iF n ie -n i )(i=1,2,…,N);

[0038] Among them, n isd1 is the second stage reference target speed, k Fe1 is the second stage steady-state control coefficient, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel.

[0039] Optionally, in some embodiments, the calculation module is further used to: determine the target speed change rate limit value based on a preset target speed change rate formula, wherein the preset target speed change rate formula is:

[0040] n isdL =n isdLf +sign(n isd -n isdLf )min(Δn L ,|n isd -n isdLf |);

[0041] Among them, n isdL The target speed limit for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, n isd The target speed for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, Δn L It is the change limit of the target speed of wheel anti-skid control within a unit control cycle.

[0042] Optionally, in some embodiments, the control module is further used to: calculate the anti-skid control torque of the slipping wheel based on a preset torque calculation formula according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, wherein the preset torque calculation formula is:

[0043] T in =k n (n isdL -n i )(i=1,2,…,6);

[0044] Among them, T in is the anti-slip control torque of the i-th distributed wheel, n isdL The target speed limit for wheel anti-slip control, n i is the speed of the i-th wheel.

[0045] A third aspect of the present application provides a vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the vehicle wheel anti-skid control method as described in the above embodiment.

[0046] A fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the vehicle wheel anti-skid control method as described in the above embodiment.

[0047] Therefore, the embodiment of the present application calculates the wheel torque by speed proportional control to control the wheel speed to decrease. The difference between the speed proportional control target and the actual speed can reflect the change of the adhesion coefficient. The anti-skid control target speed is corrected according to the speed difference, and the change of the adhesion coefficient can be adaptively controlled to control the wheel speed within the set range to achieve the purpose of anti-skid control. The wheel anti-skid control method proposed in the embodiment of the present application improves the adaptability to the adhesion coefficient and the stability when the parameters are inaccurate, which is specifically reflected in:

[0048] 1. The embodiment of the present application adopts a wheel speed proportional control method. When the speed increases rapidly, the torque automatically decreases, which can avoid the wheel speed from spinning rapidly and achieve stable control of the speed.

[0049] 2. The embodiment of the present application uses the result of the speed proportional control to estimate the adhesion coefficient of the wheel, corrects the target speed of the wheel, obtains stable anti-skid control, and realizes self-adaptation to different adhesion coefficients;

[0050] 3. When there is an error in the expected slip rate used in the embodiment of the present application, the wheel speed will not increase rapidly but remain stably at a certain value, thereby making full use of the adhesion and enhancing the applicability of the algorithm;

[0051] 4. The embodiment of the present application can adapt to the steady-state time of different speed controls and different needs by changing the steady-state control coefficients of the second stage and the first stage;

[0052] 5. The anti-skid control method proposed in the embodiment of the present application can be used for the anti-skid control of vehicles with similar mechanical structures and has a wide range of applications.

[0053] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0055] Figure 1 A flowchart of a vehicle wheel anti-skid control method provided according to an embodiment of the present application;

[0056] Figure 2 A schematic diagram of the relationship between torque and rotation speed under a vehicle wheel anti-skid control method provided according to a specific embodiment of the present application;

[0057] Figure 3 A schematic diagram of longitudinal force on a wheel provided according to a specific embodiment of the present application;

[0058] Figure 4 A flowchart of a vehicle wheel anti-skid control method provided according to a specific embodiment of the present application;

[0059] Figure 5 It is a block diagram of a wheel anti-skid control device for a vehicle provided according to an embodiment of the present application;

[0060] Figure 6 A vehicle is provided according to an embodiment of the present application.

[0061] Explanation of reference numerals: 10 - vehicle wheel anti-skid control device, 100 - detection module, 200 - calculation module and 300 - control module. DETAILED DESCRIPTION

[0062] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0063] The following describes the wheel anti-skid control method, device, vehicle and storage medium of the vehicle in the embodiment of the present application with reference to the accompanying drawings. In view of the problem that the algorithm in the related art mentioned in the above background technology is always affected by the parameters that change dynamically during driving, thereby affecting the anti-skid control effect, the present application provides a wheel anti-skid control method for a vehicle, in which the method detects whether multiple wheels are in a slipping state, and determines the anti-skid control stage currently in which the slipping wheels in the slipping state among the multiple wheels are, and when the current anti-skid control stage is the first stage of anti-skid control, the target speed of the slipping wheel is calculated according to the preset first target speed calculation formula, and when the current anti-skid control stage is the second stage of anti-skid control, the target speed of the slipping wheel is calculated according to the preset second target speed calculation formula, and the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and the slipping wheel is controlled according to the anti-skid control torque. Thus, the problem in the related art that the algorithm is always affected by the parameters that change dynamically during driving, thereby affecting the anti-skid control effect is solved, without relying on the estimation of other dynamically changing parameters, thereby improving the adaptability of the anti-skid control algorithm.

[0064] Specifically, Figure 1 A schematic flow chart of a method for controlling wheel anti-skid of a vehicle provided in an embodiment of the present application.

[0065] like Figure 1 As shown, the wheel anti-skid control method of the vehicle, the vehicle includes a plurality of wheels arranged symmetrically, each wheel is correspondingly provided with a driving motor, and includes the following steps:

[0066] In step S101, it is detected whether a plurality of wheels are in a slipping state, and it is determined which anti-skid control stage a slipping wheel in a slipping state among the plurality of wheels is currently in.

[0067] It should be noted that in the embodiment of the present application, a distributed vehicle with multiple wheels, for example, a distributed vehicle driven by 6 hub motors, each wheel is driven by a corresponding motor, each motor is controlled by a motor controller, and the hub motors of the left and right wheels of the vehicle are arranged from front to back. In this embodiment, the left wheels of the vehicle are arranged from front to back as (1, 2, 3), and the right wheels are arranged from front to back as (4, 5, 6); the feedback information of the motor controller is matched one by one with the arrangement of each hub motor.

[0068] The embodiments of the present application are described under the conditions of a uniform vehicle speed and a constant adhesion coefficient. The effects of changes in vehicle speed and adhesion coefficient on the control effect will be discussed later. The method proposed in the embodiments of the present application can adapt to changes in vehicle speed and adhesion coefficient to prevent the wheels from continuing to slip.

[0069] Optionally, in some embodiments, detecting whether multiple wheels are in a slipping state includes: obtaining the current wheel speed of each wheel; determining whether the current wheel speed is greater than a preset slipping speed, wherein the preset slipping speed is the product of a preset anti-slip coefficient and an axle equivalent speed; if the current wheel speed is greater than the preset slipping speed, then the wheel whose current wheel speed is greater than the preset slipping speed is determined to be in a slipping state.

[0070] Optionally, in some embodiments, determining the anti-skid control stage currently in which a slipping wheel among multiple wheels is in a slipping state includes: obtaining the direction of the wheel angular acceleration and the direction of the wheel center velocity of the slipping wheel; if the direction of the wheel angular acceleration and the direction of the wheel center velocity are opposite, then the current anti-skid control stage is the second anti-skid control stage; otherwise, the current anti-skid control stage is the first anti-skid control stage, wherein the anti-skid control strength of the second anti-skid control stage is less than the anti-skid control strength of the first anti-skid control stage.

[0071] It should be noted that when the wheel slip judgment method determines that the wheel is in a slipping state at time k, the wheel anti-skid control starts, wherein the specific anti-skid judgment method is not the focus of the embodiment of the present application and will not be described in detail here. Figure 2 It can be seen that at time k, the wheel speed n i Exceeds the set wheel anti-slip control coefficient k iF Equivalent speed of the shaft n ie When the product of , it is determined that the wheel is slipping.

[0072] Those skilled in the art should understand that wheel slip means that the wheel speed exceeds the wheel axle speed. The essence of anti-skid control is to first quickly reduce the torque to prevent the wheel speed from increasing further, and then control the wheel speed within the set speed limit. Therefore, in order to adapt to the control objectives of different stages, the reference target speeds at different stages are different. It is necessary to determine the anti-skid control stage according to the direction of the wheel angular acceleration and the wheel axle speed in the anti-skid control, as shown in formula (1):

[0073]

[0074] Among them, S iF is the anti-skid control stage number of the ith wheel. A value of 1 indicates that it is in the second stage of anti-skid control. The wheel angular acceleration is in a different direction from the wheel axis speed, indicating that the wheel speed has not continued to increase and has changed direction and started to decrease. A value of 0 indicates that it is in the first stage of anti-skid control. The wheel speed is still increasing and the wheel torque needs to be further reduced.

[0075] n i is the speed of the i-th wheel, obtained by feedback from the motor controller, nie is the equivalent speed of the wheel center of the i-th wheel, which is calculated from the wheel center speed, as shown in formula (2):

[0076]

[0077] Where r is the rolling radius of the wheel, π and 60 are used for unit conversion, and v ie is the wheel center speed of the i-th wheel, which is obtained by the vehicle state and the speed relationship between different positions of the rigid bodies. In the embodiment of the present application, the left front wheel is taken as an example, as shown in formula (3):

[0078] v 1e =v x +aω z ; (3)

[0079] Among them, v x is the longitudinal velocity of the measurement point obtained by state estimation, obtained by the vehicle velocity estimator, a is the lateral distance from the measurement point to the left wheel axle, ω z is the yaw angular velocity of the vehicle around the z-axis, measured by a yaw angular velocity sensor.

[0080] In step S102, when the current anti-skid control stage is the first anti-skid control stage, the target speed of the slipping wheel is calculated according to the preset first target speed calculation formula; when the current anti-skid control stage is the second anti-skid control stage, the target speed of the slipping wheel is calculated according to the preset second target speed calculation formula.

[0081] Specifically, the present application calculates the target speed of wheel anti-skid control after obtaining the wheel anti-skid control state.

[0082] The wheel anti-skid control in the embodiment of the present application adopts a speed control method, so it is necessary to obtain the wheel anti-skid control target speed at different stages, as shown in formula (4):

[0083]

[0084] Among them, n isd is the anti-skid control target speed of the i-th wheel, k Fe1 is the steady-state control coefficient of the second stage, which is set according to the desired control effect and the speed unit. The larger the value, the greater the change of the anti-skid control target speed with the speed. For proportional control, the stability is poor and may cause control oscillation. The main purpose of the second stage is to obtain a stable speed control effect. In the embodiment of the present application, it is 50, which has good stability. Fe0It is the steady-state control coefficient of the first stage, which is set according to the desired control effect and the speed unit. The main purpose in the first stage is to quickly reduce the wheel torque to avoid the continued increase in the wheel speed. Therefore, the steady-state control coefficient is relatively large and responds quickly to the increase in the wheel speed. In the embodiment of the present application, it is 100, which quickly reduces the torque and reduces the speed increase.

[0085] k iF is the wheel anti-slip control coefficient, corresponding to the expected wheel slip rate, as shown in formula (5):

[0086]

[0087] Among them, s id is the expected slip rate of the ith wheel, which can be determined according to the actual situation. In the embodiment of the present application, it is 0.15. From the relationship between the slip rate and the adhesion coefficient of the wheel, it can be seen that near the optimal adhesion coefficient, there is still a large adhesion ability. Therefore, it is only necessary to ensure that the rotation speed of the wheel does not diverge and is stable near a certain value to obtain a better anti-skid effect.

[0088] n isd0 is the reference target speed in the first stage, as shown in formula (6):

[0089]

[0090] Among them, n i0 is the wheel speed of the i-th wheel at time k-1, that is Figure 2 The wheel speed in the previous control cycle before the wheel slips is obtained by feedback from the motor controller; T io is the wheel torque command of the i-th wheel at time k-1, that is, Figure 2 The wheel torque command of the control cycle before the wheel slips is obtained by feedback from the vehicle controller. The purpose of choosing this as the benchmark here is to reduce the large changes in wheel torque in anti-skid control, which exceeds the response range of the motor and may cause sudden and large changes in vehicle acceleration.

[0091] It is understandable that the main purpose of the first stage of anti-skid control is to reduce torque and reduce the continued increase in wheel speed. The advantage of adopting speed proportional control here is that the torque can be adjusted according to the actual speed and it is convenient to calculate the benchmark target speed in the subsequent second stage.

[0092] n isd1 is the second stage reference target speed.

[0093] n isd1 =n isds +k iF n ies -n is (i=1,2,…,N); (7)

[0094] Among them, n isds The target speed of the wheel anti-skid control entering the second stage of anti-skid control is Figure 2 Medium k s The wheel anti-slip control target speed at all times.

[0095] n isds =n isd0 +k Fe0 (k iF n ies -n is )(i=1,2,…,N); (8)

[0096] n ies When entering the second stage of anti-skid control, Figure 2 Medium k s The equivalent speed of the wheel center at the moment is obtained by feedback from the anti-skid controller, n is When entering the second stage of anti-skid control, Figure 2 Medium k s The wheel speed at the moment is obtained by feedback from the motor controller.

[0097] Furthermore, in order to avoid large changes in the calculated anti-skid target speed when the wheel slips severely, and large changes in the wheel target speed caused by switching the anti-skid control stage, the embodiment of the present application needs to limit the change rate of the wheel anti-skid target speed.

[0098] n isdL =n isdLf +sign(n isd -n isdLf )min(Δn L ,|n isd -n isdLf |); (9)

[0099] Among them, n isdL The target speed limit for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, Δn L is the target speed change limit of the wheel anti-skid control within a unit control period, which is calculated based on the actual motor characteristics and is 1000 in this embodiment of the application.

[0100] In general, when the wheel anti-skid control target speed change rate is within the set limit, the wheel anti-skid control target limit speed n isdL and wheel slip control target speed n isd equal,

[0101] n isdL =n isd ; (10)

[0102] In order to facilitate the subsequent derivation of the principle, Figure 2 The target speed of wheel anti-slip control in n isd Draw.

[0103] In step S103, the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and the slipping wheel is controlled according to the anti-skid control torque.

[0104] Specifically, according to the wheel anti-skid control target speed and the wheel speed, the wheel anti-skid control torque is calculated using a proportional control method:

[0105] T in =k n (n isdL -n i )(i=1,2,…,6); (11)

[0106] Among them, T in is the anti-slip control torque of the i-th distributed wheel, k n is the wheel anti-skid control proportional coefficient, which is set according to the anti-skid control requirements and is 0.5 in the embodiment of the present application.

[0107] In order to enable those skilled in the art to further understand the wheel anti-skid control method of the vehicle in the embodiment of the present application, the principle of the wheel anti-skid control method of the vehicle in the embodiment of the present application is discussed below in conjunction with specific embodiments, thereby discussing the impact of vehicle speed and adhesion coefficient changes on wheel anti-skid control.

[0108] In fact, the longitudinal force diagram of the wheel is Figure 3 It can be seen that, among them, o i is the wheel axle, x i Parallel to the longitudinal axis of the vehicle, z i The axis is perpendicular to the ground and points upward. Taking the moment about the wheel axis, we can get:

[0109]

[0110] Among them, J w is the moment of inertia of the wheel, F ix is the longitudinal force of the ground on the wheel, which is determined by the ground adhesion coefficient and the wheel vertical force F iz Decision, M. if is the wheel rolling resistance torque, which can be ignored during the wheel slip stage.

[0111] Therefore, the relationship between wheel torque and longitudinal force can be obtained when the wheel speed is controlled in a steady state, that is, when the wheel angular acceleration is 0:

[0112] T i =F ix r; (13)

[0113] Substituting the torque calculation method of wheel speed proportional control into equation (13), and considering the relationship (10) when the wheel anti-slip control target speed change rate is small, we can get:

[0114] k n (n isd -n ip )=F ixp r; (14)

[0115] Among them, n ip is the wheel speed at equilibrium, F ixp is the longitudinal force of the wheel when it is balanced.

[0116] By adjusting equation (14), the relationship between the anti-skid control target speed and the wheel speed can be obtained, as shown in equation (15).

[0117]

[0118] It can be seen from formula (15) that the difference between the anti-skid control target of the wheel speed proportional control and the steady-state speed is equivalent to the longitudinal force exerted by the ground on the wheel. The longitudinal force of the ground is directly related to the adhesion coefficient, vertical load, etc., thus achieving adaptation to the adhesion coefficient.

[0119] Therefore, if the equivalent longitudinal force of the wheel in the wheel balance control state under the current adhesion condition can be obtained, the target wheel speed can be designed so that the actual wheel speed is near the desired speed limit. That is, if the desired wheel speed steady-state value is k iF n ie , then the target wheel speed is as shown in formula (16).

[0120]

[0121] However, in actual control, it is difficult to obtain a stable equilibrium state, and it is further hoped that the actual wheel speed is within the set speed limit. Therefore, the wheel equivalent longitudinal force identified when the wheel speed decreases is considered as the steady-state equivalent longitudinal force, that is, the second stage in the embodiment of the present application. Figure 2 k s At this moment, the relationship between the target wheel speed, actual wheel speed and equivalent longitudinal force is as shown in formula (17).

[0122]

[0123] Among them, F ixs is the longitudinal force of the wheel at the beginning of the second stage.

[0124] From formula (17), we can see that in the second stage of switching, that is, k s The difference between the target speed and the actual speed at the moment is less than the actual equivalent longitudinal force. If the wheel anti-skid control target speed is designed based on the difference between the target wheel speed and the actual speed at this moment, the actual speed should be within the set limit.

[0125] Furthermore, in order to avoid the wheel target speed changing too abruptly and causing a sudden change in wheel torque, the wheel target speed is calculated as shown in formula (4). In steady state, if the wheel speed is equal to the set ratio of the axle equivalent speed, the reference target speed is the steady-state target speed.

[0126] According to the calculation method of the second-stage reference target speed (Equation (7)) and the relationship between the wheel target speed, actual speed and equivalent longitudinal force at the beginning of the second stage (Equation (17), Equation (18) can be obtained.

[0127]

[0128] Therefore, from equation (15) and the actual second-stage reference target speed calculation method equation (7), the wheel speed in the steady state calculated in the second stage can be obtained, as shown in equation (19).

[0129]

[0130] Further simplification can be obtained, and the wheel speed in the steady state calculated in the second stage is shown in formula (20).

[0131]

[0132] Substituting into equation (18), we can obtain equation (21).

[0133]

[0134] Under the assumption that the speed and adhesion coefficient remain unchanged, equation (21) can be transformed into equation (22).

[0135] n ip <k iF n ies ; (twenty two)

[0136] Therefore, it can be theoretically proved that the method proposed in the embodiment of the present application can control the actual rotation speed within the set limit range.

[0137] The following discusses the impact of anti-skid control when the vehicle speed changes during operation. If the vehicle speed increases, it will be as shown in formula (23).

[0138] n iep >n ies ; (twenty three)

[0139] Then equation (21) becomes equation (24).

[0140] It can be seen from formula (24) that when the vehicle speed increases, it is easier to reach the set limit.

[0141]

[0142] When the vehicle speed decreases, it is as shown in formula (25).

[0143] n iep <n ies ; (25)

[0144] Then equation (21) becomes equation (26).

[0145]

[0146] From formula (26), it can be obtained that the steady-state speed is not within the set limit, but can be stabilized near a value. At this time, there is still a large adhesion capacity available, and the wheel steady-state slip speed difference can be reduced by selecting a larger steady-state control coefficient. If the wheel speed changes direction during control, the wheel slip coefficient can be controlled within the limit based on the wheel rotation resistance identified when the speed changes. Therefore, the proposed method is still effective.

[0147] Similarly, when the ground adhesion coefficient increases, the steady-state wheel longitudinal force is greater than the equivalent longitudinal force in the second stage, as shown in formula (27).

[0148] F ixp >F ixs ; (27)

[0149] From the previous analysis, it can be seen that it is easier to make the wheel speed reach the set limit at this time.

[0150] If the ground adhesion coefficient becomes smaller, the steady-state wheel longitudinal force is smaller than the equivalent longitudinal force in the second stage, as shown in formula (28).

[0151] F ixp <F ixs ; (28)

[0152] At this time, equation (21) becomes equation (29).

[0153]

[0154] Likewise, further increase in wheel speed can be avoided and the wheel speed can be stabilized near a value, at which point there is still a large amount of adhesion available. The wheel steady-state slip speed difference can also be reduced by selecting a larger steady-state control coefficient.

[0155] From the above analysis, it can be seen that the basic idea of ​​the anti-skid control proposed in the embodiment of the present application is to estimate the equivalent longitudinal force of the wheel according to the wheel speed proportional control, and correct the wheel target speed so that the wheel speed reaches the set speed limit. This method can be directly proved theoretically.

[0156] When the vehicle anti-skid control steady-state speed is greater than the speed at the start of the second stage of anti-skid control, the error between the target speed of speed proportional control and the actual speed makes it easier to control the actual speed within the set speed range. When the vehicle anti-skid control steady-state speed is less than the speed at the start of the second stage of anti-skid control, the characteristics of proportional control can also be used to prevent the wheel speed from spinning and keep it stable at a certain value, thus making full use of adhesion.

[0157] When the vehicle adhesion conditions change, if the wheel adhesion conditions gradually improve, the error between the target and actual speed of the speed proportional control can make it easier to control the actual speed within the set speed range; and when the wheel adhesion conditions deteriorate, the characteristics of proportional control can be used to prevent the wheel speed from spinning rapidly and to maintain it at a certain value, thereby making full use of the adhesion.

[0158] Therefore, if Figure 4 As shown, the present application calculates the wheel torque by means of speed proportional control to control the wheel speed reduction. The difference between the target speed of the speed proportional control and the actual speed can reflect the change of the adhesion coefficient. The anti-skid control target speed is corrected according to the speed difference. The change of the adhesion coefficient can be adaptively controlled to control the wheel speed within the set range, thereby achieving the purpose of anti-skid control.

[0159] According to the vehicle wheel anti-skid control method proposed in the embodiment of the present application, by detecting whether multiple wheels are in a slipping state, and judging the anti-skid control stage currently in which the slipping wheels in the slipping state are in the multiple wheels, and when the current anti-skid control stage is the first stage of anti-skid control, the target speed of the slipping wheel is calculated according to the preset first target speed calculation formula, and when the current anti-skid control stage is the second stage of anti-skid control, the target speed of the slipping wheel is calculated according to the preset second target speed calculation formula, and the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and the slipping wheel is controlled according to the anti-skid control torque. Thus, the problem that the algorithm in the related art is always affected by the parameters that change dynamically during driving, thereby affecting the anti-skid control effect, is solved, and there is no need to rely on the estimation of other dynamically changing parameters, thereby improving the adaptability of the anti-skid control algorithm.

[0160] Next, the vehicle wheel anti-skid control device proposed in accordance with the embodiment of the present application will be described with reference to the accompanying drawings.

[0161] Figure 5 It is a block diagram of a wheel anti-skid control device for a vehicle according to an embodiment of the present application.

[0162] like Figure 5 As shown, the vehicle wheel anti-skid control device 10 includes: a detection module 100, a calculation module 200 and a control module 300.

[0163] Among them, the vehicle includes a plurality of symmetrically arranged wheels, each wheel is correspondingly provided with a driving motor, including: a detection module 100, used to detect whether the plurality of wheels are in a slipping state, and determine the anti-skid control stage currently located in the slipping wheel in the slipping state among the plurality of wheels; a calculation module 200, used to calculate the target speed of the slipping wheel according to a preset first target speed calculation formula when the current anti-skid control stage is the first anti-skid control stage; when the current anti-skid control stage is the second anti-skid control stage, calculate the target speed of the slipping wheel according to a preset second target speed calculation formula; and a control module 300, used to calculate the anti-skid control torque of the slipping wheel according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and control the slipping wheel according to the anti-skid control torque.

[0164] Optionally, in some embodiments, the detection module 100 is further used to: obtain the current wheel speed of each wheel; determine whether the current wheel speed is greater than a preset slip speed, wherein the preset slip speed is the product of a preset anti-slip coefficient and an axle equivalent speed; if the current wheel speed is greater than the preset slip speed, then the wheel whose current wheel speed is greater than the preset slip speed is determined to be in a slipping state.

[0165] Optionally, in some embodiments, the detection module 100 is further used to: obtain the direction of the wheel angular acceleration and the direction of the wheel center speed of the slipping wheel; if the direction of the wheel angular acceleration and the direction of the wheel center speed are opposite, the current anti-skid control stage is the second stage of anti-skid control; otherwise, the current anti-skid control stage is the first stage of anti-skid control, wherein the anti-skid control force of the second stage of anti-skid control is less than the anti-skid control force of the first stage of anti-skid control.

[0166] Optionally, in some embodiments, the preset first target speed calculation formula is:

[0167] Preset first target speed = n isd0 +k Fe0 (k iF n ie -n i )(i=1,2,…,N);

[0168] Among them, n isd0is the first stage reference target speed, k Fe0 is the steady-state control coefficient of the first stage, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel;

[0169] The preset second target speed calculation formula is:

[0170] Preset second target speed = n isd1 +k Fe1 (k iF n ie -n i )(i=1,2,…,N);

[0171] Among them, n isd1 is the second stage reference target speed, k Fe1 is the second stage steady-state control coefficient, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel.

[0172] Optionally, in some embodiments, the calculation module 200 is further used to: determine the target speed change rate limit value based on a preset target speed change rate formula, wherein the preset target speed change rate formula is:

[0173] n isdL =n isdLf +sign(n isd -n isdLf )min(Δn L ,|n isd -n isdLf |);

[0174] Among them, n isdL The target speed limit for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, n isd The target speed for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, Δn L It is the change limit of the target speed of wheel anti-skid control within a unit control cycle.

[0175] Optionally, in some embodiments, the control module 300 is further used to: calculate the anti-skid control torque of the slipping wheel based on a preset torque calculation formula according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, wherein the preset torque calculation formula is:

[0176] T in =k n (n isdL -n i )(i=1,2,…,6);

[0177] Among them, T in is the anti-slip control torque of the i-th distributed wheel, n isdL The target speed limit for wheel anti-slip control, n i is the speed of the i-th wheel.

[0178] It should be noted that the above explanation of the embodiment of the vehicle wheel anti-skid control method is also applicable to the vehicle wheel anti-skid control device of this embodiment, which will not be repeated here.

[0179] According to the vehicle wheel anti-skid control device proposed in the embodiment of the present application, by detecting whether multiple wheels are in a slipping state, and judging the anti-skid control stage currently in which the slipping wheels in the slipping state are in the multiple wheels, and when the current anti-skid control stage is the first stage of anti-skid control, the target speed of the slipping wheel is calculated according to the preset first target speed calculation formula, and when the current anti-skid control stage is the second stage of anti-skid control, the target speed of the slipping wheel is calculated according to the preset second target speed calculation formula, and the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and the slipping wheel is controlled according to the anti-skid control torque. Thus, the problem that the algorithm in the related art is always affected by the parameters that change dynamically during driving, thereby affecting the anti-skid control effect, is solved, and there is no need to rely on the estimation of other dynamically changing parameters, thereby improving the adaptability of the anti-skid control algorithm.

[0180] Figure 6 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0181] A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

[0182] When the processor 602 executes the program, the vehicle wheel anti-skid control method provided in the above embodiment is implemented.

[0183] Furthermore, the vehicle also includes:

[0184] The communication interface 603 is used for communication between the memory 601 and the processor 602 .

[0185] The memory 601 is used to store computer programs that can be executed on the processor 602 .

[0186] The memory 601 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0187] If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0188] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

[0189] The processor 602 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0190] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned vehicle wheel anti-skid control method.

[0191] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0192] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0193] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0194] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0195] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0196] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for controlling wheel slip of a vehicle, characterized in that: The vehicle comprises a plurality of wheels arranged symmetrically, each wheel being provided with a corresponding driving motor, and comprises the following steps: Detecting whether the multiple wheels are in a slipping state, and determining the anti-skid control stage currently in which the slipping wheels in the slipping state among the multiple wheels are; When the current anti-skid control stage is the first anti-skid control stage, the target speed of the slipping wheel is calculated according to a preset first target speed calculation formula; when the current anti-skid control stage is the second anti-skid control stage, the target speed of the slipping wheel is calculated according to a preset second target speed calculation formula; and The anti-slip control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and the slipping wheel is controlled according to the anti-slip control torque.

2. The method according to claim 1, characterized in that The detecting whether the plurality of wheels are in a slipping state comprises: Get the current wheel speed of each wheel; Determining whether the current wheel speed is greater than a preset slip speed, wherein the preset slip speed is the product of a preset anti-slip coefficient and an axle equivalent speed; If the current wheel speed is greater than the preset slip speed, the wheel whose current wheel speed is greater than the preset slip speed is determined to be in a slip state.

3. The method according to claim 2, characterized in that The step of determining the anti-skid control stage currently in which the slipping wheel in the slipping state among the plurality of wheels is located comprises: Obtaining the direction of the wheel angular acceleration and the direction of the wheel center speed of the slipping wheel; If the direction of the wheel angular acceleration is opposite to the direction of the wheel center speed, the current anti-skid control stage is the second stage of anti-skid control; otherwise, the current anti-skid control stage is the first stage of anti-skid control, wherein the anti-skid control force of the second stage of anti-skid control is less than the anti-skid control force of the first stage of anti-skid control.

4. The method according to claim 3, characterized in that The preset first target speed calculation formula is: Preset first target speed = n isd0 +k Fe0 (k iF n ie -n i )(i=1,2,...,N); Among them, n isd0 is the first stage reference target speed, k Fe0 is the steady-state control coefficient of the first stage, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel; The preset second target speed calculation formula is: Preset second target speed = n isd1 +k Fe1 (k iF n ie -n i )(i=1,2,...,N); Among them, n isd1 is the second stage reference target speed, k Fe1 is the second stage steady-state control coefficient, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel.

5. The method according to claim 4, characterized in that The target speed change rate limit value determined by the target speed includes: Based on a preset target speed change rate formula, a target speed change rate limit value determined by the target speed, wherein the preset target speed change rate formula is: n isdL =n isdLf +sign(n isd -n isdLf )min(Δn L ,|n isd -n isdLf |); Among them, n isdL The target speed limit for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, n isd The target speed for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, Δn L It is the change limit of the target speed of wheel anti-skid control within a unit control cycle.

6. The method according to claim 5, characterized in that The calculating the anti-skid control torque of the slipping wheel according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed comprises: Based on a preset torque calculation formula, the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, wherein the preset torque calculation formula is: T in =k n (n isdL -n i )(i=1,2,...,6); Among them, T in is the anti-slip control torque of the i-th distributed wheel, n isdL The target speed limit for wheel anti-slip control, n i is the speed of the i-th wheel.

7. A wheel anti-skid control device for a vehicle, characterized in that: The vehicle comprises a plurality of wheels arranged symmetrically, each wheel being provided with a corresponding driving motor, including: a detection module, used for detecting whether the multiple wheels are in a slipping state, and determining the anti-skid control stage currently in which the slipping wheels in the slipping state among the multiple wheels are; a calculation module, configured to calculate the target speed of the slipping wheel according to a preset first target speed calculation formula when the current anti-skid control stage is the first anti-skid control stage; and to calculate the target speed of the slipping wheel according to a preset second target speed calculation formula when the current anti-skid control stage is the second anti-skid control stage; and A control module is used to calculate the anti-skid control torque of the slipping wheel according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, and control the slipping wheel according to the anti-skid control torque.

8. The device according to claim 7, characterized in that The detection module is further used for: Get the current wheel speed of each wheel; Determining whether the current wheel speed is greater than a preset slip speed, wherein the preset slip speed is the product of a preset anti-slip coefficient and an axle equivalent speed; If the current wheel speed is greater than the preset slip speed, the wheel whose current wheel speed is greater than the preset slip speed is determined to be in a slip state.

9. The device according to claim 8, characterized in that The detection module is further used for: Obtaining the direction of the wheel angular acceleration and the direction of the wheel center speed of the slipping wheel; If the direction of the wheel angular acceleration is opposite to the direction of the wheel center speed, the current anti-skid control stage is the second stage of anti-skid control; otherwise, the current anti-skid control stage is the first stage of anti-skid control, wherein the anti-skid control force of the second stage of anti-skid control is less than the anti-skid control force of the first stage of anti-skid control.

10. The device according to claim 9, characterized in that The preset first target speed calculation formula is: Preset first target speed = n isd0 +k Fe0 (k iF n ie -n i )(i=1,2,...,N); Among them, n isd0 is the first stage reference target speed, k Fe0 is the steady-state control coefficient of the first stage, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel; The preset second target speed calculation formula is: Preset second target speed = n isd1 +k Fe1 (k iF n ie -n i )(i=1,2,...,N); Among them, n isd1 is the second stage reference target speed, k Fe1 is the second stage steady-state control coefficient, k iF is the wheel anti-slip control coefficient, n ie is the equivalent speed of the wheel center of the i-th wheel, n i is the speed of the i-th wheel.

11. The device according to claim 10, characterized in that The computing module is further used for: Based on a preset target speed change rate formula, a target speed change rate limit value determined by the target speed, wherein the preset target speed change rate formula is: n isdL =n isdLf +sign(n isd -n isdLf )min(Δn L ,|n isd -n isdLf |); Among them, n isdL The target speed limit for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, n isd The target speed for wheel anti-slip control, n isdLf The wheel anti-slip control target speed limit of the previous control cycle, Δn L It is the change limit of the target speed of wheel anti-skid control within a unit control cycle.

12. The device according to claim 11, characterized in that The control module is also used for: Based on a preset torque calculation formula, the anti-skid control torque of the slipping wheel is calculated according to the target speed of the slipping wheel, the current wheel speed of the slipping wheel and the target speed change rate limit value determined by the target speed, wherein the preset torque calculation formula is: T in =k n (n isdL -n i )(i=1,2,...,6); Among them, T in is the anti-slip control torque of the i-th distributed wheel, n isdL The target speed limit for wheel anti-slip control, n i is the speed of the i-th wheel.

13. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the vehicle wheel anti-skid control method as described in any one of claims 1 to 6.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the vehicle wheel anti-skid control method as described in any one of claims 1 to 6.

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