Electronic differential control method for wheel drive electric vehicle and related device

Abstract

The application belongs to the technical field of electric vehicle control, and provides an electronic differential control method for wheel-side drive electric vehicles and related equipment, which comprises obtaining structural parameters and operating parameters of the wheel-side drive electric vehicle; calculating a proportional factor of the inner and outer wheel speeds of the wheel-side drive electric vehicle when turning based on the Ackermann steering principle, the structural parameters and the operating parameters; calculating the theoretical wheel speed of the inner and outer wheels of the wheel-side drive electric vehicle based on the mechanical differential principle, the proportional factor and the actual vehicle speed; calculating the slip rate of the inner and outer wheels according to the theoretical wheel speed and the actual wheel speed; and controlling the torque of the wheel-side drive electric vehicle according to the slip rate until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold. The application can reduce wheel wear and improve vehicle stability.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle control technology, specifically relating to an electronic differential control method and related equipment for wheel-side driven electric vehicles. Background Technology

[0002] Electric vehicles with wheel-side drive structures generally suffer from severe tire wear due to increased unsprung mass and the elimination of the mechanical differential, leading to increased operating costs and reduced vehicle stability, especially during cornering. The key to solving this problem lies in how to coordinate and control the torque of multiple wheel-side motors to reduce tire wear.

[0003] Traditional electronic differential control methods for electric vehicles mostly employ direct yaw moment control. However, this control method suffers from problems such as large fluctuations in vehicle slip ratio, inaccurate calculations, and inability to reach ideal values. Ultimately, the implementation effect is unsatisfactory, resulting in significant tire wear and an inability to effectively ensure vehicle stability during driving. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an electronic differential control method and related equipment for wheel-side driven electric vehicles, so as to reduce tire wear and improve vehicle stability.

[0005] In a first aspect, the present invention provides an electronic differential control method for a wheel-side driven electric vehicle, the method comprising the following steps:

[0006] Obtain the structural and operational parameters of wheel-side driven electric vehicles; structural parameters include wheelbase and track width, and operational parameters include steering angle, actual vehicle speed, and actual wheel speed.

[0007] Based on the Ackermann steering principle, structural parameters, and operating parameters, the scaling factor of the inner and outer wheel speeds during wheel-side drive electric vehicle steering is calculated; the scaling factor is used to describe the difference between the inner and outer wheel speeds.

[0008] Based on the principle of mechanical differential, the scaling factor, and the actual vehicle speed, the theoretical wheel speeds of the inner and outer wheels of the wheel-side driven electric vehicle are calculated; the theoretical wheel speeds represent the wheel speeds of the inner and outer wheels that satisfy the principle of mechanical differential.

[0009] Calculate the slip ratio of the inner and outer wheels based on the theoretical wheel speed and the actual wheel speed;

[0010] The torque of the wheel-side driven electric vehicle is controlled based on the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold.

[0011] Optionally, the scaling factor can be calculated as follows:

[0012]

[0013]

[0014]

[0015] Where f represents the scaling factor, v in This represents the actual wheel speed of the inner wheel, v. out R represents the actual wheel speed of the outer wheel. in R represents the turning radius of the inner wheel on the rear axle of a wheel-side driven electric vehicle. out δ represents the turning radius of the outer wheel on the rear axle of a wheel-driven electric vehicle, δ represents the average turning angle of the wheel of the wheel-driven electric vehicle, L represents the wheelbase, and H represents the track width.

[0016] Optionally, the theoretical wheel speed can be calculated as follows:

[0017]

[0018]

[0019] v in +v out =2v

[0020] Among them, v out,ref The theoretical wheel speed of the outer wheel, v in,ref This represents the theoretical wheel speed of the inner wheel, and v represents the actual vehicle speed.

[0021] Optionally, the slip ratio is either the drive slip ratio or the braking slip ratio. The drive slip ratio represents the slip ratio of the wheel-side driven electric vehicle when it is in a driving state, and the braking slip ratio represents the slip ratio of the wheel-side driven electric vehicle when it is in a braking state.

[0022] If the wheel-side driven electric vehicle is in driving mode, then the calculation formula is used.

[0023]

[0024] Obtain the driving slip ratio S Drv ; where v i,m This represents the actual wheel speed of wheel i, where wheel i is either the inner or outer wheel. i,ref This represents the theoretical wheel speed of wheel i;

[0025] If the wheel-driven electric vehicle is in a braking state, then the calculation formula is used.

[0026]

[0027] Obtain the braking slip ratio S Brk .

[0028] Optionally, the torque of the wheel-side driven electric vehicle is controlled according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold, including:

[0029] If the slip ratio of the wheel-side driven electric vehicle is greater than the preset slip ratio threshold, then the torque of the wheel-side driven electric vehicle will be negatively compensated to reduce the torque until the difference between the actual wheel speed and the theoretical wheel speed is less than the preset difference threshold.

[0030] If the slip ratio of the wheel-side driven electric vehicle is less than zero, positive torque compensation is performed to increase the torque until the difference between the actual wheel speed and the theoretical wheel speed is less than the preset difference threshold.

[0031] Optionally, the preset slip ratio threshold is a value between 10% and 20%.

[0032] Optionally, the preset difference threshold is 300 RPM.

[0033] In a second aspect, the present invention provides an electronic differential control system for a wheel-side driven electric vehicle, comprising:

[0034] The data acquisition module is used to acquire the structural and operational parameters of wheel-side driven electric vehicles; the structural parameters include wheelbase and track width, and the operational parameters include steering angle, actual vehicle speed, and actual wheel speed.

[0035] The scaling factor calculation module is used to calculate the scaling factor of the inner and outer wheel speeds when the wheel-side driven electric vehicle is steering, based on the Ackermann steering principle, structural parameters, and operating parameters. The scaling factor is used to describe the difference between the inner and outer wheel speeds.

[0036] The theoretical wheel speed calculation module is used to calculate the theoretical wheel speeds of the inner and outer wheels of a wheel-side driven electric vehicle based on the principles of mechanical differentials, scaling factors, and actual vehicle speeds; the theoretical wheel speed represents the wheel speeds of the inner and outer wheels that satisfy the principles of mechanical differentials.

[0037] The slip ratio calculation module is used to calculate the slip ratio of the inner and outer wheels based on the theoretical wheel speed and the actual wheel speed.

[0038] The differential control module is used to control the torque of the wheel-side driven electric vehicle according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold.

[0039] Thirdly, the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described wheel-side drive electric vehicle electronic differential control method.

[0040] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described electronic differential control method for wheel-side driven electric vehicles.

[0041] The beneficial effects of this invention are:

[0042] The electronic differential control method for wheel-side driven electric vehicles provided by this invention is based on the Ackerman steering principle, structural parameters, and operating parameters. It calculates the proportional factor of the inner and outer wheel speeds during steering, then calculates the theoretical wheel speeds of the inner and outer wheels based on the mechanical differential principle, the proportional factor, and the actual vehicle speed. Next, it calculates the slip ratio of the inner and outer wheels based on the theoretical and actual wheel speeds. Finally, it controls the torque of the wheel-side driven electric vehicle based on the slip ratio and a pre-set torque compensation strategy. The proportional factor calculated based on the Ackerman steering principle accurately describes the difference between the inner and outer wheel speeds. Combined with the theoretical wheel speed calculated by the mechanical differential, it effectively ensures that the inner and outer wheels perform pure rolling motion, avoiding wheel slippage and spinning. Calculating the slip ratio of the inner and outer wheels based on the theoretical and actual wheel speeds, and finally controlling the torque based on the slip ratio, allows the actual wheel speed to approach the theoretical wheel speed. The smaller the difference between the two, the less likely the wheels of the wheel-side driven electric vehicle are to experience excessive slippage or lock-up, reducing wheel wear and improving the driving stability of the vehicle. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of a wheel-side driven electric vehicle according to one embodiment of the present invention;

[0044] Figure 2 This is a flowchart of the electronic differential control method for wheel-side driven electric vehicles in an embodiment of the present invention;

[0045] Figure 3 This is a simulation diagram of the steering state of a wheel-side driven electric vehicle in one embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the electronic differential control system for a wheel-side driven electric vehicle in one embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the structure of a terminal device in one embodiment of the present invention. Detailed Implementation

[0048] This invention discloses an electronic differential control method for wheel-side driven electric vehicles.

[0049] For ease of explanation, the structure of a wheel-side drive electric vehicle will be described first. For example... Figure 1 As shown in the embodiments of the present invention, an anti-lock braking system (ABS) is installed on each wheel of the wheel-side driven electric vehicle. The ABS can provide high-precision wheel speed signals. Wheel-side drive assemblies are installed at the left and right wheels of the rear axle, respectively. These assemblies mainly consist of wheel-side motors and reducers, and can drive the vehicle and perform regenerative braking. At the front axle, the steering system assembly is the main component, and the front axle is a non-drive axle. A steering wheel angle sensor is installed at the steering wheel to sense the driver's driving intention and can be used to determine whether the vehicle is traveling in a straight line or turning. A yaw rate sensor is installed at the vehicle's center of gravity to monitor the yaw rate in real time and determine whether the vehicle is at risk of instability. Wheel speed signals, steering wheel angle signals, and yaw rate signals are key input parameters for realizing electronic differential control. At the control layer, the left and right wheel-side drive assemblies share a common control assembly, which integrates inverter modules for two motor controllers, as well as auxiliary power control systems such as oil pumps and air pumps. Furthermore, the differential control algorithm of this system is integrated into the vehicle controller, eliminating the need for an additional differential controller and effectively reducing costs.

[0050] The electronic differential control method for wheel-side driven electric vehicles provided by this invention is described below, specifically as follows: Figure 2 As shown, the method includes the following steps:

[0051] Step 21: Obtain the structural and operational parameters of the wheel-side driven electric vehicle.

[0052] In embodiments of the present invention, the aforementioned structural parameters include wheelbase and track width, and the operating parameters include steering angle, actual vehicle speed, and actual wheel speed. Specifically, the wheelbase and track width are determined during the production of the wheel-side driven electric vehicle, and detailed structural configuration information of the wheel-side driven electric vehicle can be obtained from the manufacturer. The operating parameters can be obtained through sensing devices installed on the wheel-side driven electric vehicle; for example, the steering angle can be obtained through a steering wheel angle sensor, the actual vehicle speed can be obtained through a speed sensor, and the actual wheel speed can be obtained through the ABS on the wheels.

[0053] Step 22: Based on the Ackermann steering principle, structural parameters, and operating parameters, calculate the ratio factor of the inner and outer wheel speeds when the wheel-side driven electric vehicle is steering.

[0054] To make it easier to understand, we will first explain the Ackermann steering principle.

[0055] Ackermann steering is a modern automotive steering system where the inner and outer wheels rotate at different angles (typically 2-4 degrees) when the car turns. This results in the inner tire having a smaller turning radius than the outer tire, reducing tire wear. The basic principle of Ackermann steering geometry states that during vehicle movement (straight-line driving and turning), the trajectory of each wheel must perfectly conform to its natural motion path, ensuring pure rolling without slippage between the tire and the ground. In a vehicle conforming to Ackermann steering characteristics, when driving straight, the axes of all four wheels are parallel and perpendicular to the longitudinal center plane of the car; during turning, all wheels must roll in a circle around a momentary center point.

[0056] Figure 3 This illustration shows a simulated state of a wheel-side driven electric vehicle during steering, according to an embodiment of the present invention. (Reference) Figure 3 According to the Ackermann steering principle, all wheels move in a circle around the instantaneous center O. ∠AOC is the steering angle of the inner wheel, ∠BOC is the steering angle of the outer wheel, and ∠EOF is the average steering angle of the inner and outer wheels, denoted by δ. EF is the wheelbase, denoted by L, and CD is the track width, denoted by H. The steering radius of the inner rear wheel is OC, denoted by R. in This indicates that the turning radius of the outer wheel on the rear axle is OD, denoted by R. out express.

[0057] To describe the difference in wheel speed between the inner and outer wheels, this invention proposes the concept of a scaling factor, the calculation formula of which is as follows:

[0058]

[0059]

[0060]

[0061] Where f represents the scaling factor, v in This represents the actual wheel speed of the inner wheel, v. out R represents the actual wheel speed of the outer wheel. in R represents the turning radius of the inner wheel on the rear axle of a wheel-side driven electric vehicle. out δ represents the turning radius of the outer wheel on the rear axle of a wheel-driven electric vehicle, δ represents the average turning angle of the wheel of the wheel-driven electric vehicle, L represents the wheelbase, and H represents the track width.

[0062] The scaling factor can accurately describe the speed relationship between the inner and outer wheels of a vehicle, providing a basis for subsequent differential control.

[0063] Step 23: Based on the principle of mechanical differential, the scaling factor and the actual vehicle speed, calculate the theoretical wheel speed of the inner and outer wheels of the wheel-side driven electric vehicle.

[0064] To facilitate understanding, let's first explain the principle of a mechanical differential. Specifically, with a mechanical differential, when turning, the outer wheel slips while the inner wheel spins. This generates two opposing additional forces on the two drive wheels. Due to the "principle of minimum energy consumption," this inevitably leads to different rotational speeds on both sides, disrupting the balance between the three components. This is reflected through the half-shafts to the planetary gears, forcing them to rotate. This slows down the inner half-shaft and speeds up the outer half-shaft, thus achieving the difference in wheel speeds. When the car is turning or driving on uneven surfaces, this allows the left and right wheels to roll at different speeds, ensuring pure rolling motion on both sides. Furthermore, an open mechanical differential has the characteristic of "differential speed but not differential torque." When the car is turning or driving on uneven surfaces, although the speeds of the two wheels are different, the torque is evenly distributed.

[0065] For a mechanical differential, the wheel speeds of the inner and outer wheels and the rotational speed of the input shaft satisfy the following relationship:

[0066] n in +n out =2n

[0067] Where, n in n represents the wheel speed of the inner wheel. out This represents the wheel speed of the outer wheel, and n represents the input shaft speed.

[0068] The torque of the inner and outer wheels of the mechanical differential and the torque of the input shaft satisfy the following relationship:

[0069]

[0070] Among them, F in For the inner wheel torque, F out F represents the torque of the outer wheel and F represents the total torque of the input shaft.

[0071] For electronic differential controllers, the principle of mechanical differential controllers can be referenced to ensure that the rotational speed (wheel speed) of the inner and outer wheels is consistent with that of the mechanical differential control under steering or uneven road conditions, so as to meet the theoretical relationship of the mechanical differential controller.

[0072] This invention calculates the theoretical wheel speed of the inner and outer wheels of a wheel-side driven electric vehicle based on the principle of mechanical differential, scaling factor, and actual vehicle speed.

[0073] Specifically, the formula for calculating the theoretical wheel speed is as follows:

[0074]

[0075]

[0076] v in +v out =2v

[0077] Among them, v out，ref The theoretical wheel speed of the outer wheel, v in，ref This represents the theoretical wheel speed of the inner wheel, and v represents the actual vehicle speed.

[0078] It should be understood that when the vehicle is traveling in a straight line, v out,ref =v in,ref When the vehicle turns, v out，ref >v in,ref .

[0079] Step 24: Calculate the slip ratio of the inner and outer wheels based on the theoretical wheel speed and the actual wheel speed.

[0080] Specifically, in the embodiments of the present invention, the slip ratio is the driving slip ratio or the braking slip ratio. The driving slip ratio represents the slip ratio of the wheel-side driven electric vehicle in the driving state, and the braking slip ratio represents the slip ratio of the wheel-side driven electric vehicle in the braking state, corresponding to two different working conditions of the wheel-side driven electric vehicle (driving steering and braking steering).

[0081] If the wheel-side driven electric vehicle is in a driving state, then it is calculated using the formula...

[0082]

[0083] Obtain the driving slip ratio S Drv ; where v i，m This represents the actual wheel speed of wheel i, where wheel i is either the inner or outer wheel. i，ref This represents the theoretical wheel speed of wheel i;

[0084] If the wheel-driven electric vehicle is in a braking state, then the calculation formula is used.

[0085]

[0086] Obtain the braking slip ratio S Brk .

[0087] It should be noted that a higher wheel slip ratio indicates a greater proportion of slippage during braking; a higher wheel spin ratio indicates a greater proportion of spin during driving. Generally, the slip ratio or spin ratio is controlled within the range of 10%-20% to ensure good adhesion between the wheel and the road surface, resulting in optimal driving or braking capabilities.

[0088] Step 25: Control the torque of the wheel-side driven electric vehicle according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than the preset difference threshold.

[0089] Specifically, if the slip ratio of the wheel-side driven electric vehicle is greater than a preset slip ratio threshold, then negative compensation is applied to the torque of the wheel-side driven electric vehicle to reduce the torque until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold. For example, in one embodiment of the present invention, the preset difference threshold is 300 RPM (revolutions per minute).

[0090] If the slip ratio of the wheel-side driven electric vehicle is less than zero, positive torque compensation is performed to increase the torque until the difference between the actual wheel speed and the theoretical wheel speed is less than the preset difference threshold.

[0091] By controlling the slip ratio or rotation ratio of the inner and outer wheels in real time, the inner and outer wheels are always in a natural motion state, thereby ensuring vehicle stability and reducing tire wear.

[0092] When the reference slip ratio exceeds a threshold, torque is compensated in real time, thereby ensuring that the actual wheel speeds of the inner and outer wheels are as close as possible to the wheel speeds of the mechanical differential structure, thus reducing tire wear. Vehicle testing has verified that this method effectively reduces tire wear.

[0093] As described above, the electronic differential control method for wheel-side driven electric vehicles provided by this invention is based on the Ackerman steering principle, structural parameters, and operating parameters. It calculates the proportional factor of the inner and outer wheel speeds when the wheel-side driven electric vehicle is steering. Then, based on the mechanical differential principle, the proportional factor, and the actual vehicle speed, it calculates the theoretical wheel speeds of the inner and outer wheels of the wheel-side driven electric vehicle. Next, based on the theoretical wheel speed and the actual wheel speed, it calculates the slip ratio of the inner and outer wheels. Finally, based on the slip ratio and a pre-set torque compensation strategy, it controls the torque of the wheel-side driven electric vehicle. Among them, the scaling factor calculated based on the Ackerman steering principle can accurately describe the difference between the inner and outer wheel speeds. Combined with the theoretical wheel speed calculated by the mechanical differential, it can effectively ensure that the inner and outer wheels make pure rolling motion and avoid wheel slippage and spin. Based on the theoretical wheel speed and the actual wheel speed, the slip ratio of the inner and outer wheels is calculated. Finally, the torque is controlled according to the slip ratio, which can make the actual wheel speed close to the theoretical wheel speed. The smaller the difference between the two, the less likely the wheels of the wheel-side driven electric vehicle will experience excessive slippage and lock-up, reducing wheel wear and improving the driving stability of the wheel-side driven electric vehicle.

[0094] The electronic differential control system for wheel-side driven electric vehicles provided by this invention will be described below.

[0095] like Figure 4 As shown, the wheel-side drive electric vehicle electronic differential control system 400 includes:

[0096] The data acquisition module 401 is used to acquire the structural parameters and operating parameters of the wheel-side driven electric vehicle; the structural parameters include wheelbase and track width, and the operating parameters include steering angle, actual vehicle speed and actual wheel speed.

[0097] The scaling factor calculation module 402 is used to calculate the scaling factor of the inner and outer wheel speeds when the wheel-side driven electric vehicle is steering, based on the Ackermann steering principle, structural parameters, and operating parameters; the scaling factor is used to describe the difference between the inner and outer wheel speeds.

[0098] The theoretical wheel speed calculation module 403 is used to calculate the theoretical wheel speed of the inner and outer wheels of the wheel-side driven electric vehicle based on the mechanical differential principle, the scaling factor and the actual vehicle speed; the theoretical wheel speed represents the wheel speed of the inner and outer wheels that satisfy the mechanical differential principle.

[0099] The slip ratio calculation module 404 is used to calculate the slip ratio of the inner and outer wheels based on the theoretical wheel speed and the actual wheel speed.

[0100] The differential control module 405 is used to control the torque of the wheel-side driven electric vehicle according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold.

[0101] It should be noted that the information interaction and execution process between the above modules are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0102] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0103] like Figure 5 As shown, embodiments of the present invention provide a terminal device, such as... Figure 5 As shown, the terminal device D10 of this embodiment includes: at least one processor D100 ( Figure 5The diagram shows only one processor, a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100, which, when executing the computer program D102, implements the steps in any of the above method embodiments.

[0104] Specifically, when the processor D100 executes the computer program D102, it acquires the structural and operational parameters of the wheel-side driven electric vehicle; based on the Ackerman steering principle, structural parameters, and operational parameters, it calculates the proportional factor of the inner and outer wheel speeds when the wheel-side driven electric vehicle is steering; based on the mechanical differential principle, proportional factor, and actual vehicle speed, it calculates the theoretical wheel speeds of the inner and outer wheels of the wheel-side driven electric vehicle; based on the theoretical and actual wheel speeds, it calculates the slip ratio of the inner and outer wheels; and based on the slip ratio, it controls the torque of the wheel-side driven electric vehicle until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold. Among them, the scaling factor calculated based on the Ackerman steering principle can accurately describe the difference between the inner and outer wheel speeds. Combined with the theoretical wheel speed calculated by the mechanical differential, it can effectively ensure that the inner and outer wheels make pure rolling motion and avoid wheel slippage and spin. Based on the theoretical wheel speed and the actual wheel speed, the slip ratio of the inner and outer wheels is calculated. Finally, the torque is controlled according to the slip ratio, which can make the actual wheel speed close to the theoretical wheel speed. The smaller the difference between the two, the less likely the wheels of the wheel-side driven electric vehicle will experience excessive slippage and lock-up, reducing wheel wear and improving the driving stability of the wheel-side driven electric vehicle.

[0105] The processor D100 can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0106] In some embodiments, the memory D101 may be an internal storage unit of the terminal device D10, such as a hard disk or memory of the terminal device D10. In other embodiments, the memory D101 may be an external storage device of the terminal device D10, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the terminal device D10. Furthermore, the memory D101 may include both internal and external storage units of the terminal device D10. The memory D101 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory D101 can also be used to temporarily store data that has been output or will be output.

[0107] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0108] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the steps described in the various method embodiments above.

[0109] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0110] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A method for electronic differential control of a wheel-side driven electric vehicle, characterized in that, include: Obtain the structural and operational parameters of the wheel-side driven electric vehicle; the structural parameters include wheelbase and track width, and the operational parameters include steering angle, actual vehicle speed, and actual wheel speed. Based on the Ackermann steering principle, the structural parameters, and the operating parameters, a scaling factor for the wheel speeds of the inner and outer wheels during steering of the wheel-side driven electric vehicle is calculated. This scaling factor describes the difference between the wheel speeds of the inner and outer wheels. The formula for calculating the scaling factor is as follows: in, This represents the scaling factor. This indicates the actual wheel speed of the inner wheel. This indicates the actual wheel speed of the outer wheel. This indicates the turning radius of the inner wheel on the rear axle of the wheel-side driven electric vehicle. This indicates the turning radius of the outer wheel on the rear axle of the wheel-side driven electric vehicle. This represents the average steering angle of the wheel of the wheel-driven electric vehicle. Indicates the wheelbase, Indicates the wheelbase; Based on the principle of the mechanical differential, the scaling factor, and the actual vehicle speed, the theoretical wheel speeds of the inner and outer wheels of the wheel-side driven electric vehicle are calculated; the theoretical wheel speeds represent the wheel speeds of the inner and outer wheels that satisfy the principle of the mechanical differential; the formula for calculating the theoretical wheel speeds is as follows: in, This indicates the theoretical wheel speed of the outer wheel. This indicates the theoretical wheel speed of the inner wheel. This indicates the actual vehicle speed; Calculate the slip ratio of the inner and outer wheels based on the theoretical wheel speed and the actual wheel speed; The torque of the wheel-side driven electric vehicle is controlled according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold.

2. The electronic differential control method for wheel-side driven electric vehicles according to claim 1, characterized in that, The slip ratio is either the driving slip ratio or the braking slip ratio. The driving slip ratio represents the slip ratio of the wheel-side driven electric vehicle when it is in a driving state, and the braking slip ratio represents the slip ratio of the wheel-side driven electric vehicle when it is in a braking state. If the wheel-side driven electric vehicle is in a driving state, then it is calculated using the formula... The driving slip ratio is obtained ;in, Indicates wheel Actual wheel speed, wheel For the inner wheel or the outer wheel, Indicates wheel Theoretical wheel speed; If the wheel-side driven electric vehicle is in a braking state, then it is calculated using the formula... The braking slip ratio is obtained .

3. The electronic differential control method for wheel-side driven electric vehicles according to claim 1, characterized in that, The step of controlling the torque of the wheel-side driven electric vehicle according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold includes: If the slip ratio of the wheel-side driven electric vehicle is greater than a preset slip ratio threshold, then the torque of the wheel-side driven electric vehicle is negatively compensated to reduce the torque until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold. If the slip ratio of the wheel-side driven electric vehicle is less than zero, positive compensation is applied to the torque to increase the torque until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold.

4. The electronic differential control method for wheel-side driven electric vehicles according to claim 3, characterized in that, The preset slip ratio threshold is a value between 10% and 20%.

5. The electronic differential control method for wheel-side driven electric vehicles according to claim 4, characterized in that, The preset difference threshold is 300 RPM.

6. An electronic differential control system for a wheel-side driven electric vehicle, characterized in that, include: The data acquisition module is used to acquire the structural parameters and operating parameters of the wheel-side driven electric vehicle; the structural parameters include wheelbase and track width, and the operating parameters include steering angle, actual vehicle speed and actual wheel speed. The scaling factor calculation module is used to calculate the scaling factor of the inner and outer wheel speeds when the wheel-side driven electric vehicle is steering, based on the Ackermann steering principle, the structural parameters, and the operating parameters; the scaling factor is used to describe the difference between the inner and outer wheel speeds; the calculation formula for the scaling factor is as follows: in, This represents the scaling factor. This indicates the actual wheel speed of the inner wheel. This indicates the actual wheel speed of the outer wheel. This indicates the turning radius of the inner wheel on the rear axle of the wheel-side driven electric vehicle. This indicates the turning radius of the outer wheel on the rear axle of the wheel-side driven electric vehicle. This represents the average steering angle of the wheel of the wheel-driven electric vehicle. Indicates the wheelbase, Indicates the wheelbase; The theoretical wheel speed calculation module is used to calculate the theoretical wheel speeds of the inner and outer wheels of the wheel-side driven electric vehicle based on the mechanical differential principle, the scaling factor, and the actual vehicle speed. The theoretical wheel speed represents the wheel speed of the inner and outer wheels that satisfies the mechanical differential principle. The formula for calculating the theoretical wheel speed is as follows: in, This indicates the theoretical wheel speed of the outer wheel. This indicates the theoretical wheel speed of the inner wheel. This indicates the actual vehicle speed; The slip ratio calculation module is used to calculate the slip ratio of the inner and outer wheels based on the theoretical wheel speed and the actual wheel speed. The differential control module is used to control the torque of the wheel-side driven electric vehicle according to the slip ratio until the difference between the actual wheel speed and the theoretical wheel speed is less than a preset difference threshold.

7. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the electronic differential control method for wheel-side driven electric vehicles as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the electronic differential control method for wheel-side driven electric vehicles as described in any one of claims 1 to 5.

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