Pure electric four-wheel drive torque anti-slip method and system

Abstract

The application discloses a pure electric four-wheel drive torque anti-skid method and system, and relates to the technical field of torque control, comprising the following steps: collecting and calculating front axle speed, rear axle speed and whole vehicle reference speed; obtaining maximum and minimum values of whole vehicle longitudinal safety speed in real time; controlling damping torque adjustment PID to output damping torque value, and performing four-wheel drive torque distribution. The pure electric four-wheel drive torque anti-skid method provided by the application is obtained through the accumulation of three kinds of torque calculation sources, namely, acceleration feedforward, slip feedback and damping torque protection, and the torque algorithm of the rear axle is compatible with PHEV EV and more suitable for electric vehicles. Through PID feedback, the fixed torque distribution strategy is avoided, the response is more rapid, the demand of the driver is added when torque distribution is performed, and the driving personality of the driver is more in line with the driving personality of the driver. The application achieves better effects in terms of applicability, response delay and user demand.

Description

Technical Field

[0001] This invention relates to the field of torque control technology, specifically to a pure electric four-wheel drive torque anti-slip method and system. Background Technology

[0002] The four-wheel drive system of electric vehicles features a dual-power source architecture on both the front and rear axles, offering better stability and power, and enabling it to handle more extreme operating conditions. In full-time four-wheel drive mode, due to power and stability requirements, the vehicle needs to adjust the torque distribution between the front and rear axles in real time based on vehicle slippage.

[0003] Currently, many companies have proposed their own patented solutions for four-wheel drive anti-slip torque. Traditional torque anti-slip methods mainly rely on simple vehicle speed feedback and fixed torque distribution strategies. However, these methods have the following obvious drawbacks:

[0004] Traditional methods typically employ a fixed torque distribution strategy, meaning the same strategy is used under all driving conditions. This may not be optimal under varying road and driving conditions.

[0005] Because it relies on simple vehicle speed feedback, there may be a response delay at the start of a slip, which could lead to reduced vehicle stability.

[0006] Vehicle dynamics can change under different road conditions and driving scenarios. Traditional methods lack the ability to adapt to these changes, which may lead to unstable driving behavior.

[0007] Furthermore, it has absolutely no connection to the driver's driving needs and is entirely controlled by a preset program.

[0008] The simple algorithm for obtaining rear axle torque based on vehicle speed feedback and a fixed torque distribution strategy is incompatible with PHEVs and EVs. The calculation is more complex and it is not the optimal choice for electric vehicles.

[0009] Therefore, there is an urgent need for a pure electric four-wheel drive torque anti-slip method and system. Summary of the Invention

[0010] In view of the above-mentioned problems, the present invention is proposed.

[0011] Therefore, the technical problem solved by this invention is that existing four-wheel drive torque anti-slip methods have response delays and limitations, and how to optimize them to meet the driver's needs within a safe range.

[0012] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a pure electric four-wheel drive torque anti-slip method, comprising: collecting and calculating the front axle speed, the rear axle speed and the reference speed of the whole vehicle; calculating and obtaining the maximum and minimum longitudinal safe speed of the whole vehicle in real time; controlling the damping torque adjustment PID output damping torque value to perform four-wheel drive torque distribution.

[0013] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip method described in this invention, the step of collecting and calculating the front axle speed, rear axle speed, and overall vehicle reference speed includes collecting the speed V of the left front wheel. lb Right front wheel speed V rb Left rear wheel speed V la and the speed V of the right rear wheel ra The front axle speed and rear axle speed are expressed as:

[0014]

[0015]

[0016] Among them, V b轴 V represents the speed of the front axle. a轴 This indicates the speed of the rear axle.

[0017] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip method described in this invention, the reference vehicle speed includes calculating the difference between the front axle speed and the rear axle speed. When the difference between the front axle speed and the rear axle speed is less than or equal to a preset threshold, the overall vehicle reference speed is expressed as:

[0018]

[0019] When the speed difference between the front axle and the rear axle exceeds a preset threshold, the reference speed for the entire vehicle is the minimum of the front axle speed and the rear axle speed.

[0020] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip method of the present invention, the real-time calculation of the maximum and minimum longitudinal safe vehicle speed includes obtaining the minimum longitudinal safe vehicle speed by adding the preset calibration threshold and the real-time reference vehicle speed, and obtaining the maximum real-time longitudinal safe vehicle speed by looking up a table and weighting the reference vehicle speed according to the preset vehicle acceleration slip ratio formula and the maximum acceleration slip ratio.

[0021] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip method described in this invention, the control damping torque adjustment PID output damping torque value includes real-time acquisition of the vehicle reference speed and the speed difference between the front and rear axles, using a sampling period T to perform a first-order derivative on the difference to obtain the speed difference change rate, limiting the speed difference change rate, obtaining the coefficient from a table based on the vehicle reference speed, and outputting the real-time damping torque value, expressed as:

[0022] e(t) = V 实 -V 整

[0023]

[0024]

[0025] τ d (t)=k d ×Δv(t)×u(t)

[0026] Among them, V 实 To obtain the vehicle's reference speed in real time, Δv(t) is the rate of change of speed difference, v(t) is the current vehicle speed, v(tT) is the vehicle speed in the previous sampling period, and K... p K i and K d These are the proportional, integral, and differential gains, respectively, τ d (t) represents the real-time damping control torque value, k d The damping torque coefficient is obtained from the vehicle speed reference table. The output value is then determined to be within the preset damping range. If it is within the damping range, torque is distributed.

[0027] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip method of the present invention, the four-wheel drive torque distribution includes real-time acquisition of the difference between the front axle speed, the rear axle speed and the maximum longitudinal safe speed of the whole vehicle. When the difference is determined to be greater than the slip threshold, the slip torque control flag is activated, and the speed difference input is obtained from the front axle speed, the rear axle speed and the maximum longitudinal safe speed of the whole vehicle as the speed error of PID control for torque feedback control.

[0028] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip method described in this invention, the four-wheel drive torque distribution further includes replacing the vehicle reference speed with the front axle speed and rear axle speed, replacing the real-time obtained vehicle reference speed with the maximum longitudinal safe speed of the vehicle, performing PID feedback damping torque, and outputting the front axle PID feedback torque value τ respectively. b (t) and rear axle PID feedback torque value τ a (t), the rear axle feedforward torque coefficient k is obtained by looking up the table based on the vehicle reference speed. ad Collect the control torque of the front and rear axles. The torque request for the rear axle is expressed as:

[0029] τ ka (t)=k ad ×τ na (t)+τ a (t)+τ ta (t)-τ b (t)-τ tb (t)-k×τna (t)

[0030] Where, τ na (t) represents the torque required by the driver, τ ta (t) represents the control torque of the rear axle, τ tb (t) represents the control torque of the front axle, k is the calibration coefficient, and τ is the torque distribution coefficient of the rear axle. ka The ratio of (t) to the driver's required torque limit, the sum of the rear axle torque distribution coefficient and the front axle distribution coefficient is 1.

[0031] Another objective of this invention is to provide a pure electric four-wheel drive torque anti-slip system, which can achieve the cumulative calculation of three types of torque sources: acceleration feedforward, slip feedback, and damping torque protection through longitudinal feedback of the vehicle using PID feedback damping torque, thus solving the problem of incompatibility between traditional distribution processes and PHEVs / EVs.

[0032] As a preferred embodiment of the pure electric four-wheel drive torque anti-slip system of the present invention, it includes: a speed integration module, a limit calculation module, and a torque distribution module; the speed integration module is used to collect the speeds of the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, and integrate and calculate the front axle speed, rear axle speed, and overall vehicle reference speed; the limit calculation module is used to calculate the maximum and minimum longitudinal safe speeds; the torque distribution module calculates the torque distribution coefficient through PID feedback control.

[0033] A computer device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement a pure electric four-wheel drive torque anti-slip method.

[0034] A computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of a pure electric four-wheel drive torque anti-slip method.

[0035] The beneficial effects of this invention are as follows: The pure electric four-wheel drive torque anti-slip method provided by this invention obtains the rear axle torque algorithm by accumulating torque from three calculation sources: acceleration feedforward, slip feedback, and damping torque protection. This algorithm is compatible with PHEVs and EVs, and is more suitable for electric vehicles. PID feedback avoids a fixed torque distribution strategy, resulting in a faster response. Furthermore, driver needs are incorporated into torque distribution, making it more aligned with the driver's driving style. This invention achieves better results in terms of applicability, response latency, and user needs. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0037] Figure 1 The above is an overall flowchart of a pure electric four-wheel drive torque anti-slip method provided in the first embodiment of the present invention.

[0038] Figure 2 The flowchart shows a data acquisition and speed measurement process for a pure electric four-wheel drive torque anti-slip method provided in the first embodiment of the present invention.

[0039] Figure 3 The first embodiment of the present invention provides a PID feedback torque flowchart for a pure electric four-wheel drive torque anti-slip method.

[0040] Figure 4 The flowchart illustrates the torque distribution process of a pure electric four-wheel drive torque anti-slip method provided in the first embodiment of the present invention.

[0041] Figure 5 The following is an overall flowchart of a pure electric four-wheel drive torque anti-slip system provided for the third embodiment of the present invention. Detailed Implementation

[0042] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0044] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0045] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0046] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] Example 1

[0049] Reference Figures 1-3 As an embodiment of the present invention, a pure electric four-wheel drive torque anti-slip method is provided, comprising:

[0050] S1: Collect and calculate the front axle speed, rear axle speed, and overall vehicle reference speed.

[0051] Furthermore, the system collects and calculates the front axle speed, rear axle speed, and overall vehicle reference speed, including the speed of the left front wheel, V. lb Right front wheel speed V rb Left rear wheel speed V la and the speed V of the right rear wheel ra The front axle speed and rear axle speed are expressed as:

[0052]

[0053]

[0054] Among them, V b轴 V represents the speed of the front axle. a轴 This indicates the speed of the rear axle.

[0055] It should be noted that the reference vehicle speed includes the difference between the front axle speed and the rear axle speed. When the difference between the front axle speed and the rear axle speed is less than or equal to a preset threshold, the overall vehicle reference speed is expressed as:

[0056]

[0057] When the speed difference between the front axle and the rear axle exceeds a preset threshold, the reference speed for the entire vehicle is the minimum of the front axle speed and the rear axle speed.

[0058] It should also be noted that by collecting the speeds of all four wheels, a more comprehensive understanding of the vehicle's motion can be obtained. This method can more accurately detect slippage and unstable driving behavior. The speed data from all four wheels provides more information, helping to more accurately calculate the speeds of the front and rear axles and the overall vehicle reference speed.

[0059] S2: Real-time calculation to obtain the maximum and minimum longitudinal safe vehicle speeds.

[0060] Furthermore, the real-time calculation of the maximum and minimum longitudinal safe vehicle speeds includes obtaining the minimum longitudinal safe vehicle speed by adding a preset calibration threshold to the real-time reference speed, and obtaining the maximum real-time longitudinal safe vehicle speed by weighting the reference speed according to a preset vehicle acceleration slip ratio formula and maximum acceleration slip ratio. By comparing the speed difference between the front and rear axles, signs of slippage can be detected earlier. In addition, when the speed difference is within a preset threshold, using the average vehicle speed as the reference speed provides more stable data. This method ensures accurate reference speeds in most situations. Under different driving conditions, the speeds of the front and rear axles may vary, and the calculation of the front and rear differential speeds addresses various complex environments.

[0061] It should be noted that the PID control for damping torque adjustment outputs the damping torque value by acquiring the real-time vehicle reference speed and the speed difference between the front and rear axles. The first derivative of the difference is performed using a sampling period T to obtain the rate of change of the speed difference. The rate of change of the speed difference is then limited, and a coefficient is obtained from a table based on the vehicle reference speed. The resulting real-time damping torque value is expressed as:

[0062] e(t) = V 实 -V 整

[0063]

[0064]

[0065] τ d (t)=k d ×Δv(t)×u(t)

[0066] Among them, V 实To obtain the vehicle reference speed in real time, Δv(t) is the rate of change of speed difference, v(t) is the current vehicle speed, v(tT) is the vehicle speed in the previous sampling period, and K... p K i and K d These are the proportional, integral, and differential gains, respectively, τ d (t) represents the real-time damping control torque value, k d The damping torque coefficient, obtained from a table based on the vehicle's reference speed, is used to determine if the output value falls within a preset damping range. If it does, torque is distributed accordingly. Through PID control, the damping torque can be adjusted in real time, thus improving vehicle stability. Furthermore, the damping torque coefficient obtained from the table ensures appropriate damping torque is achieved under various driving conditions.

[0067] S3: Controls the damping torque by adjusting the PID output damping torque value to distribute torque across four-wheel drive systems.

[0068] Furthermore, the four-wheel drive torque distribution includes real-time acquisition of the differences between the front axle speed, rear axle speed, and the maximum longitudinal safe speed of the entire vehicle. When the difference exceeds a slip threshold, a slip torque control flag is activated. The speed difference input is then used as the speed error for PID control to provide torque feedback control. Real-time vehicle speed data allows for more precise torque distribution. Additionally, when slip is detected, torque control can be activated to better protect the vehicle.

[0069] It should be noted that the four-wheel drive torque distribution also includes replacing the vehicle reference speed with the front axle speed and rear axle speed, and replacing the real-time vehicle reference speed with the maximum longitudinal safe speed of the vehicle, and performing PID feedback damping torque, outputting the PID feedback torque value τ of the front axle respectively. b (t) and rear axle PID feedback torque value τ a (t), the rear axle feedforward torque coefficient k is obtained by looking up the table based on the vehicle reference speed. ad Collect the control torque of the front and rear axles. The rear axle torque request is expressed as:

[0070] τ ka (t)=k ad ×τ na (t)+τ a (t)+τ ta (t)-τ b (t)-τ tb (t)-k×τ na (t)

[0071] Where, τ na (t) represents the torque required by the driver, τ ta (t) represents the control torque of the rear axle, τtb (t) represents the control torque of the front axle, k is the calibration coefficient, and τ is the torque distribution coefficient of the rear axle. ka The ratio of (t) to the driver's required torque limit, the sum of the rear axle torque distribution coefficient and the front axle distribution coefficient is 1. By replacing the overall vehicle reference speed with the front and rear axle speeds, torque distribution can be performed more accurately.

[0072] Example 2

[0073] Reference Figure 2-5 As an embodiment of the present invention, a pure electric four-wheel drive torque anti-slip method is provided. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiment.

[0074] Two identical trams were selected, and our invented anti-slip method and existing technology were used respectively. Two roads were selected, one a relatively smooth wet road surface and the other a dry road surface. Five round trips were made on each road and the data was recorded.

[0075] As shown in Table 1, the average vehicle speed achieved by our invention on slippery road sections is 50 km / h, which is 10 km / h higher than the 40 km / h of the prior art. This demonstrates that our invention is better able to maintain a stable vehicle speed on slippery road sections, providing a better driving experience. Our invention features a 50 / 50 torque distribution, while the prior art uses a 60 / 40 distribution. This means that our invention can distribute torque more evenly between the front and rear axles, thus providing better vehicle stability. Our invention has a slip ratio of 10%, which is 5% lower than the 15% of the prior art. This further proves that our invention has better stability and grip on slippery road sections, and better anti-skid performance.

[0076] On uphill sections, our invention achieved an average vehicle speed of 35 km / h, 5 km / h higher than the existing technology's 30 km / h. This indicates that our invention can provide stronger power output when going uphill. Our invention has a torque distribution of 55 / 45, while the existing technology has 70 / 30. This shows that our invention can distribute torque more evenly between the front and rear axles when going uphill, ensuring vehicle stability. Our invention has a slip ratio of 15%, 5% lower than the existing technology's 20%. This further demonstrates that our invention has better stability on uphill sections.

[0077] On ordinary road sections, our invention achieves an average vehicle speed of 65 km / h, which is 5 km / h higher than the existing technology's 60 km / h. This demonstrates that our invention provides a better driving experience even on ordinary road sections. Our invention also exhibits a slip ratio of 3%, which is 2% lower than the existing technology's 5%. This indicates that our invention also demonstrates better stability on ordinary road sections.

[0078] In summary, our invention maintains good anti-slip performance even on various road surfaces.

[0079] Table 1 Data Comparison Table

[0080]

[0081] Example 3

[0082] Reference Figure 4 As an embodiment of the present invention, a pure electric four-wheel drive torque anti-slip system is provided, comprising: a speed integration module, a limit calculation module, and a torque distribution module.

[0083] The speed integration module is used to collect the speeds of the vehicle's left front wheel, right front wheel, left rear wheel, and right rear wheel, and integrates and calculates the front axle speed, rear axle speed, and overall vehicle reference speed; the limit calculation module is used to calculate the maximum and minimum longitudinal safe speeds; and the torque distribution module calculates the torque distribution coefficient through PID feedback control.

[0084] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0085] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0086] More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0087] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc. It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A pure electric four-wheel drive torque anti-slip method, characterized in that, include: Collect and calculate the front axle speed, rear axle speed, and overall vehicle reference speed; Real-time calculation and acquisition of the maximum and minimum longitudinal safe vehicle speeds; The PID controller adjusts the output damping torque value to distribute torque across the four-wheel drive system. The real-time calculation to obtain the maximum and minimum longitudinal safe vehicle speeds includes obtaining the minimum longitudinal safe vehicle speed by adding a preset calibration threshold and the real-time reference vehicle speed, and obtaining the maximum real-time longitudinal safe vehicle speed by looking up a table and weighting the reference vehicle speed according to the preset vehicle acceleration slip ratio formula and the maximum acceleration slip ratio. The controlled damping torque adjustment PID output damping torque value includes real-time acquisition of the vehicle reference speed and the speed difference between the front and rear axles, using a sampling period T to perform a first-order derivative on the difference to obtain the speed difference change rate, limiting the speed difference change rate, obtaining a coefficient from a table based on the vehicle reference speed, and outputting the real-time damping torque value, expressed as: in, To obtain the vehicle's reference speed in real time, Indicates the reference speed of the entire vehicle. The rate of change of speed difference Current vehicle speed The vehicle speed in the previous sampling period. Indicates the PID output value. This is the difference between the real-time vehicle reference speed and the actual vehicle speed. , as well as These are the proportional, integral, and differential gains, respectively. This is the real-time damping control torque value. The damping torque coefficient is obtained from the reference speed table for the whole vehicle. It is then determined whether the output value is within the preset damping range. If it is within the damping range, torque distribution is performed. The four-wheel drive torque distribution includes real-time acquisition of the difference between the front axle speed, the rear axle speed, and the maximum longitudinal safe speed of the whole vehicle. When the difference is determined to be greater than the slip threshold, the slip torque control flag is activated, and the speed difference input is obtained from the front axle speed, the rear axle speed, and the maximum longitudinal safe speed of the whole vehicle as the speed error of the PID control for torque feedback control.

2. The pure electric four-wheel drive torque anti-slip method as described in claim 1, characterized in that: The process of collecting and calculating the front axle speed, rear axle speed, and overall vehicle reference speed includes collecting the speed of the left front wheel, V. lb Right front wheel speed V rb Left rear wheel speed V la and the speed V of the right rear wheel ra The front axle speed and rear axle speed are expressed as: in, Indicates the speed of the front axle. This indicates the speed of the rear axle.

3. The pure electric four-wheel drive torque anti-slip method as described in claim 1 or 2, characterized in that: The reference vehicle speed includes calculating the difference between the front axle speed and the rear axle speed. When the difference between the front axle speed and the rear axle speed is less than or equal to a preset threshold, the overall vehicle reference speed is expressed as: When the speed difference between the front axle and the rear axle exceeds a preset threshold, the reference speed for the entire vehicle is the minimum of the front axle speed and the rear axle speed.

4. The pure electric four-wheel drive torque anti-slip method as described in claim 3, characterized in that: The four-wheel drive torque distribution also includes replacing the vehicle reference speed with the front axle speed and rear axle speed, and replacing the real-time vehicle reference speed with the maximum longitudinal safe speed of the vehicle, performing PID feedback damping torque, and outputting the PID feedback torque value of the front axle respectively. and rear axle PID feedback torque value The coefficients of the rear axle feedforward torque are obtained by referring to a table based on the vehicle's reference speed. Collect the control torque of the front and rear axles. The rear axle torque request is expressed as: in, For the driver's required torque, For the control torque of the rear axle, For the control torque of the front axle, The calibration coefficient is: [Rear axle torque distribution coefficient] The ratio of the torque distribution factor to the driver's required torque limit, the sum of the rear axle torque distribution factor and the front axle torque distribution factor is 1.

5. A system employing the pure electric four-wheel drive torque anti-slip method as described in any one of claims 1 to 4, characterized in that: Includes a speed integration module, a limit calculation module, and a torque distribution module; The speed integration module is used to collect the speed of the vehicle's left front wheel, right front wheel, left rear wheel, and right rear wheel, and integrate and calculate the front axle speed, rear axle speed, and overall vehicle reference speed. The limit calculation module is used to calculate the maximum and minimum longitudinal safe vehicle speeds. The torque distribution module calculates the torque distribution coefficient through PID feedback control.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the pure electric four-wheel drive torque anti-slip method as described in any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the pure electric four-wheel drive torque anti-slip method as described in any one of claims 1 to 4.

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