An Electric Vehicle Differential Torque Control Method, Device, Terminal and Storage Medium

Abstract

The present invention discloses an electric vehicle differential torque control method, device, terminal and storage medium in the technical field of distributed drive of electric vehicles, aiming to solve the problem that in the prior art, when controlling the rotational speeds of the inner and outer wheels during vehicle steering, there is usually a lack of slip control for the wheels, resulting in poor maneuverability of the whole vehicle, easy to cause overall torque imbalance, and affecting the stability during vehicle steering. It includes obtaining the torque distribution coefficient under preset working conditions; calculating the torque correction proportionality factor; calculating the torque of the inner wheel and the torque of the outer wheel; the present invention distributes torque proportionally with the equal slip ratio as the control target, and utilizes the characteristics of independent control of the torques of the two wheels to achieve the rotational speed difference between the inner and outer wheels during steering, while ensuring the slip control of the wheels and the maneuverability of the whole vehicle, thereby realizing the electronic differential control of the distributed drive electric vehicle, avoiding causing overall torque imbalance, and ensuring the stability during vehicle steering.

Description

Technical Field

[0001] The invention relates to a method, a device, a terminal and a storage medium for controlling differential torque of an electric vehicle, and belongs to the technical field of distributed drive of electric vehicles. Background Art

[0002] The traditional "oil-to-electric" central transmission electric vehicle has more transmission system components, more mechanical losses, and higher energy consumption of the whole vehicle; the layout space of the whole vehicle is relatively tight, and it is impossible to arrange more power batteries, and the vehicle's cruising range is short. Since the power batteries are mostly rear-mounted, the center of gravity of the whole vehicle is high and the handling stability is also poor. With the continuous maturity and application of distributed electric drive axle technology, it not only saves chassis space, but also improves transmission efficiency, improves vehicle power and stability, and solves various problems caused by transmission layout. The commonly used speed control method is to use the Ackermann steering model to determine the target speed of each drive wheel according to the steering angle, and then use PID to achieve speed closed-loop control of each drive wheel. The torque fluctuation caused by the speed fluctuation of a single drive wheel will directly lead to the output torque fluctuation of the whole vehicle, that is, the overall torque imbalance caused by the drive wheel when the unexpected disturbance decreases.

[0003] In the prior art, when controlling the speed of the inner and outer wheels when the vehicle is turning, there is usually a lack of wheel slip control, which leads to poor controllability of the entire vehicle, easily causes overall torque imbalance, and affects the stability of the vehicle when turning. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method, device, terminal and storage medium for differential torque control of an electric vehicle, which takes equal slip rate as the control target and calculates the torque correction proportional factor to obtain the inner wheel torque and the outer wheel torque, thereby ensuring the slip control of the wheels and the maneuverability of the entire vehicle while achieving the speed difference between the inner and outer wheels during steering.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a method for controlling differential torque of an electric vehicle, comprising the following steps:

[0007] Obtaining an inner wheel adhesion coefficient and an outer wheel adhesion coefficient, and obtaining a torque distribution coefficient under a preset working condition according to the inner wheel adhesion coefficient and the outer wheel adhesion coefficient; wherein the torque distribution coefficient under the preset working condition is represented by a vehicle speed;

[0008] Obtaining the vehicle speed, the inner wheel speed, and the outer wheel speed, calculating a first estimated vehicle speed according to the vehicle speed and the inner wheel speed, and calculating a second estimated vehicle speed according to the vehicle speed and the outer wheel speed;

[0009] Calculate a torque correction proportionality factor according to the first estimated vehicle speed and the second estimated vehicle speed;

[0010] Obtain the actual torque, calculate a torque difference according to the torque distribution coefficient and the torque correction proportionality factor, and calculate an inner wheel torque and an outer wheel torque according to the torque difference and the actual torque, thereby completing torque distribution.

[0011] Further, the obtaining of the inner wheel adhesion coefficient and the outer wheel adhesion coefficient specifically includes:

[0012] When the whole vehicle steers, the wheel on the side close to the steering center is the inner wheel, and the other wheel is the outer wheel;

[0013] The expression of the inner wheel adhesion coefficient is as follows:

[0014] ;

[0015] In the formula: is the inner wheel adhesion coefficient; is the inner wheel adhesion force; is the inner wheel vertical load;

[0016] The expression of the outer wheel adhesion coefficient is as follows:

[0017] ;

[0018] In the formula: is the outer wheel adhesion coefficient; is the outer wheel adhesion force; is the outer wheel vertical load.

[0019] Further, the obtaining of the torque distribution coefficient under a preset working condition specifically includes:

[0020] Under the preset working condition, the expressions of the inner wheel adhesion coefficient and the outer wheel adhesion coefficient are as follows:

[0021] ;

[0022] Then the expression of the torque distribution coefficient is as follows:

[0023] ;

[0024] In the formula; is the torque distribution coefficient;

[0025] It is obtained that the expression of the torque distribution coefficient under the preset working condition is as follows, and its expression is as follows:

[0026] ;

[0027] Where: L is the wheelbase of the whole vehicle; W is the horizontal distance from the center of gravity of the whole vehicle to the rear axle; H is the height from the center of gravity of the whole vehicle to the ground; B is the track width of the whole vehicle; is the acceleration due to gravity; is the wheel rotation angle, and the wheel rotation angle is obtained through a steering wheel sensor; v is the vehicle speed of the whole vehicle.

[0028] Furthermore, the calculation of the first estimated vehicle speed and the calculation of the second estimated vehicle speed specifically include:

[0029] According to the instantaneous center theorem:

[0030] ;

[0031] Where: R is the turning radius of the whole vehicle; is the linear speed of the inner wheel; is the turning radius of the inner wheel; is the linear speed of the outer wheel; is the turning radius of the outer wheel;

[0032] Among them, the turning radius of the whole vehicle has the following expression:

[0033] ;

[0034] Calculate the first estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the inner wheel, and calculate the second estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the outer wheel. The expressions are as follows:

[0035] ;

[0036] Where: is the first estimated vehicle speed; is the second estimated vehicle speed; is the vehicle speed of the inner wheel; is the vehicle speed of the outer wheel.

[0037] Furthermore, the expression of the calculated torque correction proportionality factor is as follows:

[0038] ;

[0039] Where: is the torque correction proportionality factor, is the proportionality coefficient.

[0040] Furthermore, the obtaining of the actual torque specifically includes:

[0041] Obtain the total required power and the current throttle pedal opening. Based on the total required power and the current throttle pedal opening, obtain the actual torque. The expression is as follows:

[0042] ;

[0043] In the formula: is the total required power; is the maximum power of the motor; is the current throttle pedal opening; is the output voltage of the current throttle pedal; X is the maximum output voltage of the throttle pedal; is the actual torque.

[0044] Furthermore, calculate the torque difference. Based on the torque difference and the actual torque, calculate the inner wheel torque and the outer wheel torque. The specific expression is as follows:

[0045] ;

[0046] In the formula: is the torque difference; is the inner wheel torque; is the outer wheel torque.

[0047] In the second aspect, the present invention provides an electric vehicle differential torque control device. Based on the electric vehicle differential torque control method described in the first aspect, the device includes:

[0048] The first calculation module: used to obtain the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel, and obtain the torque distribution coefficient under the preset working condition according to the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel; wherein, the torque distribution coefficient under the preset working condition is represented by the vehicle speed of the whole vehicle;

[0049] The second calculation module: used to obtain the vehicle speed of the whole vehicle, the rotation speed of the inner wheel and the rotation speed of the outer wheel, calculate the first estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the inner wheel, and calculate the second estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the outer wheel;

[0050] The third calculation module: used to calculate the torque correction proportionality factor according to the first estimated vehicle speed and the second estimated vehicle speed;

[0051] The distribution module: used to obtain the actual torque, calculate the torque difference according to the torque distribution coefficient and the torque correction proportionality factor, and calculate the inner wheel torque and the outer wheel torque according to the torque difference and the actual torque to complete the torque distribution.

[0052] In the third aspect, the present invention provides a terminal, including a processor and a storage medium;

[0053] The storage medium is used to store instructions;

[0054] The processor is used to operate according to the instructions to execute the steps of the method according to the first aspect.

[0055] In a fourth aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method according to the first aspect are implemented.

[0056] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0057] In this electric vehicle differential torque control method, the equal slip ratio is used as the control target, and the torque correction proportionality factor is calculated to obtain the inner wheel torque and the outer wheel torque. While realizing the speed difference between the inner and outer wheels during steering, the slip control of the wheels and the maneuverability of the whole vehicle are ensured, so as to realize the electronic differential control of the distributed drive electric vehicle, avoid causing overall torque imbalance, and ensure the stability of the vehicle during steering. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is a schematic flow chart of an electric vehicle differential torque control method provided according to an embodiment of the present invention;

[0059] Figure 2 is a schematic diagram of the relationship between the adhesion coefficient and the slip ratio provided according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0060] The technical solution of the present invention will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present invention and the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. Without conflict, the technical features in the embodiments of the present invention and the embodiments can be combined with each other.

[0061] Embodiment 1:

[0062] As Figure 1 shown, the present invention provides a differential torque control method for a distributed drive electric vehicle, including the following steps:

[0063] Obtain the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel, and obtain the torque distribution coefficient under a preset working condition according to the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel; wherein, the torque distribution coefficient under the preset working condition is represented by the vehicle speed of the whole vehicle;

[0064] Obtain the vehicle speed, the rotational speed of the inner wheel, and the rotational speed of the outer wheel. Calculate a first estimated vehicle speed based on the vehicle speed and the rotational speed of the inner wheel, and calculate a second estimated vehicle speed based on the vehicle speed and the rotational speed of the outer wheel;

[0065] Calculate a torque correction proportionality factor based on the first estimated vehicle speed and the second estimated vehicle speed;

[0066] Obtain the actual torque. Calculate a torque difference based on the torque distribution coefficient and the torque correction proportionality factor, and calculate the torque of the inner wheel and the torque of the outer wheel based on the torque difference and the actual torque to complete torque distribution.

[0067] In one embodiment, the obtaining of the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel specifically includes:

[0068] When the vehicle is turning, the wheel on the side closer to the center of the turn is the inner wheel, and the other wheel is the outer wheel;

[0069] The expression of the adhesion coefficient of the inner wheel is as follows:

[0070] ;

[0071] In the formula: is the adhesion coefficient of the inner wheel; is the adhesion force of the inner wheel; is the vertical load of the inner wheel;

[0072] The expression of the adhesion coefficient of the outer wheel is as follows:

[0073] ;

[0074] In the formula: is the adhesion coefficient of the outer wheel; is the adhesion force of the outer wheel; is the vertical load of the outer wheel.

[0075] In one embodiment, the obtaining of the torque distribution coefficient under a preset working condition specifically includes:

[0076] Under the preset working condition, the expressions of the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel are as follows:

[0077] ;

[0078] Then the expression of the torque distribution coefficient is as follows:

[0079] ;

[0080] In the formula; is the torque distribution coefficient;

[0081] It is obtained that the expression of the torque distribution coefficient under the preset working conditions is as follows:

[0082] ;

[0083] In the formula: L is the wheelbase of the whole vehicle; W is the horizontal distance from the center of gravity of the whole vehicle to the rear axle; H is the height from the center of gravity of the whole vehicle to the ground; B is the track width of the whole vehicle; is the acceleration due to gravity; is the wheel steering angle, and the wheel steering angle is obtained through a steering wheel sensor; v is the vehicle speed of the whole vehicle.

[0084] Specifically, the adhesion coefficient , which is an important index characterizing the steering stability of the vehicle, and the expression is as follows;

[0085] ;

[0086] In the formula: is the adhesion force, is the wheel vertical load;

[0087] As Figure 2 shown, the adhesion coefficient is directly related to the slip ratio, and through the torque regulation of the motor, a reasonable electronic differential control method can control the slip ratio of the driving wheels within the target range , thereby avoiding the phenomenon of dragging or slipping when the vehicle steers; among them, is the peak adhesion coefficient;

[0088] It can be seen from this that under the preset working conditions, the adhesion coefficients of the inner wheel and the outer wheel are the same:

[0089] ;

[0090] Based on this, the torque distribution is carried out, and the expression of the torque distribution coefficient is as follows:

[0091] ;

[0092] When the vehicle is turning, the action of the centrifugal force causes the load of the inner wheel to decrease and the load of the outer wheel to increase, that is, the wheel load is transferred, and as the vehicle speed increases and the steering wheel angle increases, the phenomenon of load transfer becomes more obvious; the motor target torque is distributed according to the load ratio of the two wheels, which can maximize the driving force. Then, the torque distribution coefficient under the preset working conditions has the following expression:

[0093] .

[0094] An embodiment, the calculation of the first estimated vehicle speed and the calculation of the second estimated vehicle speed specifically include:

[0095] According to the instantaneous center theorem:

[0096] ;

[0097] In the formula: R is the turning radius of the whole vehicle; is the linear velocity of the inner wheel; is the turning radius of the inner wheel; is the linear velocity of the outer wheel; is the turning radius of the outer wheel;

[0098] Among them, the turning radius of the whole vehicle The expression is as follows:

[0099] ;

[0100] Calculate the first estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the inner wheel, and calculate the second estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the outer wheel. The expression is as follows:

[0101] ;

[0102] In the formula: is the first estimated vehicle speed; is the second estimated vehicle speed; is the vehicle speed of the inner wheel; is the vehicle speed of the outer wheel.

[0103] An embodiment, the calculation of the torque correction proportionality factor specifically includes:

[0104] The expression of the torque correction proportionality factor is as follows:

[0105] ;

[0106] In the formula: is the torque correction proportionality factor, is the proportionality coefficient.

[0107] Specifically, during driving, the wheels are prone to slip. It can be considered that the wheel with a relatively high estimated vehicle speed value slips. The torque of this side wheel can be partially transferred to the other side wheel to correct the wheel slip;

[0108] Taking the vehicle speed difference obtained from the rotational speeds of the motors on both sides of the wheels as the torque correction proportionality factor:

[0109] ;

[0110] In the formula, f is the public value;

[0111] The torque ratio correction method adopts a linear adjustment mechanism. Pure P-value control can retain a certain static error range and meet the requirements of the control model. Pure proportional control is used to achieve the slip control of interval self-adaptation, that is, is substituted into f, and the expression is as follows:

[0112] .

[0113] An embodiment, the obtaining of the actual torque specifically includes:

[0114] Obtain the total demand power and the current throttle pedal opening. According to the total demand power and the current throttle pedal opening, obtain the actual torque, and the expression is as follows:

[0115] ;

[0116] In the formula: is the total demand power; is the maximum power of the motor; is the current throttle pedal opening; is the output voltage of the current throttle pedal; X is the maximum output voltage of the throttle pedal; is the actual torque.

[0117] Specifically, the output voltage range of the throttle pedal is 0 to X volts. The voltage output signal is input to the vehicle controller, and the current throttle pedal opening is calculated. Through the preset maximum vehicle power, the current total demand power and actual torque can be calculated, and the calculated actual torque signal is used to allocate the motor target torque through the electronic differential control strategy.

[0118] An embodiment, the calculating of the torque difference, according to the torque difference and the actual torque, calculate the inner wheel torque and the outer wheel torque, and the specific expression is as follows:

[0119] ;

[0120] In the formula: is the torque difference; is the inner wheel torque; is the outer wheel torque.

[0121] The present invention utilizes the characteristics of independent control of the torques of two wheels, takes the equal slip ratio as the control target, and calculates the torque correction proportional factor to obtain the inner wheel torque and the outer wheel torque. While realizing the rotational speed difference between the inner and outer wheels during steering, it ensures the slip control of the wheels and the maneuverability of the whole vehicle, thereby realizing the electronic differential control of the distributed drive electric vehicle, avoiding causing overall torque imbalance, and ensuring the stability of the vehicle during steering.

[0122] The present invention adopts an algorithm combining offline calculation and online optimization. Compared with the method of solving by sequential quadratic programming, the complexity of the system is low and the real-time calculation efficiency is high. The objective function focusing on torque change in the present invention can better balance the problem of increased energy consumption caused by large instantaneous current fluctuations due to motor distribution changes, as well as the problems of reduced efficiency and poor subjective feeling of the driver caused by the increased time for the motor to transition from low efficiency to high efficiency. The slip ratio control method of the present invention establishes the torque relationship between the driving wheels by proportionally distributing torque with the equal slip ratio as the control target, and corrects the wheel slip through the torque correction factors of the inner and outer wheels, with relatively high stability, thereby improving the handling stability of the vehicle.

[0123] Embodiment 2:

[0124] Based on the same inventive concept as Embodiment 1, the present invention provides a differential torque control device for a distributed drive electric vehicle, and the device includes:

[0125] The first calculation module: used to obtain the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel, and obtain the torque distribution coefficient under a preset working condition according to the adhesion coefficient of the inner wheel and the adhesion coefficient of the outer wheel; wherein, the torque distribution coefficient under the preset working condition is represented by the vehicle speed of the whole vehicle.

[0126] The second calculation module: used to obtain the vehicle speed of the whole vehicle, the rotation speed of the inner wheel and the rotation speed of the outer wheel, calculate the first estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the inner wheel, and calculate the second estimated vehicle speed according to the vehicle speed of the whole vehicle and the rotation speed of the outer wheel.

[0127] The third calculation module: used to calculate the torque correction proportional factor according to the first estimated vehicle speed and the second estimated vehicle speed.

[0128] The distribution module: used to obtain the actual torque, calculate the torque difference according to the torque distribution coefficient and the torque correction proportional factor, and calculate the torque of the inner wheel and the torque of the outer wheel according to the torque difference and the actual torque to complete the torque distribution.

[0129] Embodiment 3:

[0130] The embodiment of the present invention also provides a terminal, including a processor and a storage medium;

[0131] The storage medium is used to store instructions;

[0132] The processor is used to operate according to the instructions to execute the steps of the method described in Embodiment 1.

[0133] Embodiment 4:

[0134] An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of the method described in Embodiment 1 are implemented.

[0135] Since the storage medium provided by the embodiment of the present invention can execute the method provided by Embodiment 1 of the present invention, it has corresponding functional modules and beneficial effects for executing the method.

[0136] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0137] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified function in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0138] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the specified function in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0139] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the specified function in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0140] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for controlling differential torque of an electric vehicle, characterized in that: The following steps are involved: Obtaining an inner wheel adhesion coefficient and an outer wheel adhesion coefficient, and obtaining a torque distribution coefficient under a preset working condition according to the inner wheel adhesion coefficient and the outer wheel adhesion coefficient; wherein the torque distribution coefficient under the preset working condition is represented by a vehicle speed; Obtaining the vehicle speed, the inner wheel speed, and the outer wheel speed, calculating a first estimated vehicle speed according to the vehicle speed and the inner wheel speed, and calculating a second estimated vehicle speed according to the vehicle speed and the outer wheel speed; calculating a torque correction proportional factor according to the first estimated vehicle speed and the second estimated vehicle speed; Acquire actual torque, calculate torque difference according to the torque distribution coefficient and the torque correction proportional factor, calculate inner wheel torque and outer wheel torque according to the torque difference and the actual torque, and complete torque distribution; The obtaining of the inner wheel adhesion coefficient and the outer wheel adhesion coefficient specifically includes: When the vehicle is turning, the wheel on the side close to the turning center is the inner wheel, and the wheel on the other side is the outer wheel; The expression of the inner wheel adhesion coefficient is as follows: ； Where: is the inner wheel adhesion coefficient; is the adhesion of the inner wheel; is the vertical load on the inner wheel; The expression of the outer wheel adhesion coefficient is as follows: ； Where: is the adhesion coefficient of the outer wheel; is the adhesion of the outer wheel; is the vertical load on the outer wheel; The obtaining of the torque distribution coefficient under the preset working condition specifically includes: Under the preset working conditions, the expressions of the inner wheel adhesion coefficient and the outer wheel adhesion coefficient are as follows: ； The expression of torque distribution coefficient is as follows: ； Where: is the torque distribution coefficient; It is obtained that the expression of the torque distribution coefficient under the preset working condition is as follows: ； Where: L is the wheelbase of the vehicle; W is the horizontal distance from the center of gravity of the vehicle to the rear axle; H is the height from the center of gravity of the vehicle to the ground; B is the wheelbase of the vehicle; is the acceleration due to gravity; is the wheel angle, which is obtained by the steering wheel sensor; v is the vehicle speed; The calculating the first estimated vehicle speed and the calculating the second estimated vehicle speed specifically include: According to the instantaneous center theorem, we know that: ； Where: R is the turning radius of the vehicle; is the linear speed of the inner wheel; is the turning radius of the inner wheel; is the outer wheel linear speed; is the turning radius of the outer wheel; Among them, the vehicle turning radius The expression is as follows: ； According to the vehicle speed and the inner wheel speed, a first estimated vehicle speed is calculated, and according to the vehicle speed and the outer wheel speed, a second estimated vehicle speed is calculated, and the expression is as follows: ； Where: is the first estimated vehicle speed; is the second estimated vehicle speed; is the inner wheel speed; is the outer wheel speed.

2. The electric vehicle differential torque control method according to claim 1, characterized in that: The expression for calculating the torque correction proportional factor is as follows: ； Where: is the torque correction proportional factor, is the proportionality coefficient.

3. The electric vehicle differential torque control method according to claim 2, characterized in that: The obtaining of the actual torque specifically includes: Get the total required power and the current accelerator pedal opening, and get the actual torque based on the total required power and the current accelerator pedal opening. The expression is as follows: ； Where: is the total required power; is the maximum power of the motor; is the current accelerator pedal opening; is the current accelerator pedal output voltage; X is the maximum accelerator pedal output voltage; is the actual torque.

4. The electric vehicle differential torque control method according to claim 3, characterized in that: The torque difference is calculated, and the inner wheel torque and the outer wheel torque are calculated according to the torque difference and the actual torque. The specific expression is as follows: ； Where: is the torque difference; is the inner wheel torque; is the outer wheel torque.

5. A method and device for controlling differential torque of an electric vehicle, based on the method for controlling differential torque of an electric vehicle according to any one of claims 1 to 4, characterized in that: The device comprises: A first calculation module: used to obtain the inner wheel adhesion coefficient and the outer wheel adhesion coefficient, and obtain the torque distribution coefficient under a preset working condition according to the inner wheel adhesion coefficient and the outer wheel adhesion coefficient; wherein the torque distribution coefficient under the preset working condition is represented by the vehicle speed; A second calculation module: used for obtaining the vehicle speed, the inner wheel speed and the outer wheel speed, calculating a first estimated vehicle speed according to the vehicle speed and the inner wheel speed, and calculating a second estimated vehicle speed according to the vehicle speed and the outer wheel speed; A third calculation module: used for calculating a torque correction proportional factor according to the first estimated vehicle speed and the second estimated vehicle speed; Distribution module: used to obtain actual torque, calculate the torque difference according to the torque distribution coefficient and the torque correction proportional factor, calculate the inner wheel torque and the outer wheel torque according to the torque difference and the actual torque, and complete torque distribution.

6. A terminal, characterized in that: including processor and storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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