Wheel speed difference control method and system, vehicle control unit, electric vehicle and medium

Abstract

The present disclosure relates to a wheel speed difference control method and system, a vehicle control unit, an electric vehicle and a medium. The wheel speed difference control method comprises: obtaining a current vehicle speed, a current wheel speed and a current actual output torque of an electric motor; calculating a wheel speed difference between a driving wheel and a following wheel according to the current wheel speed; judging whether to activate a torque pullback function according to the current vehicle speed and the wheel speed difference; determining a target counter-drag torque according to the current actual output torque of the electric motor and a pullback coefficient in the case that the torque pullback function is activated; and requesting the target counter-drag torque to an electric motor controller. The present disclosure can monitor the wheel speed difference trend in real time, and smoothly reduce the wheel speed difference before the ABS is triggered by intelligently adjusting the request strategy of the counter-drag torque, thereby ensuring the continuity and efficiency of the energy recovery process, and improving the driving quality.

Description

Technical Field

[0001] This disclosure relates to the field of electric vehicle control technology, and in particular to a wheel speed difference control method and system, a vehicle controller, an electric vehicle, and a medium. Background Technology

[0002] With the increasing popularity of electric vehicles, energy recovery technology has become a key means to improve vehicle range. When a vehicle is coasting or braking, the drive motor switches from electric to generator mode, producing a counter-draft torque in the opposite direction of wheel rotation, thereby converting the vehicle's kinetic energy into electrical energy and storing it in the battery. Summary of the Invention

[0003] The inventors discovered a significant problem with the wheel speed difference control strategy in related technologies: during the application or increase of anti-drag torque, unexpected wheel speed differences may arise between the drive wheels (usually the rear wheels) and the steering wheels (usually the front wheels) due to factors such as vehicle load transfer, changes in road surface adhesion coefficient, or excessively rapid torque request. When this wheel speed difference exceeds the preset threshold of the anti-lock braking system (ABS) controller, the ABS misinterprets it as wheel lock-up and slippage, thus activating. After activation, the ABS sends an activation signal to the vehicle control unit (VCU) via the CAN network. To ensure safety, the VCU immediately instructs the drive motor to clear or significantly reduce the anti-drag torque. This process in related technologies leads to the following technical problems: the energy recovery process is suddenly interrupted, significantly reducing the vehicle's energy recovery efficiency and shortening the driving range.

[0004] In view of at least one of the above technical problems, this disclosure provides a wheel speed difference control method and system, a vehicle controller, an electric vehicle and a medium, which can monitor the wheel speed difference trend in real time and smoothly reduce the wheel speed difference before ABS is falsely triggered by intelligently adjusting the anti-drag torque request strategy.

[0005] According to one aspect of this disclosure, a wheel speed difference control method is provided, comprising:

[0006] Get the current vehicle speed, current wheel speed, and current actual output torque of the motor;

[0007] Calculate the wheel speed difference between the drive wheel and the follower wheel based on the current wheel speed;

[0008] Based on the current vehicle speed and the wheel speed difference, determine whether to activate the torque pull-back function;

[0009] When the torque pullback function is activated, the target anti-drag torque is determined based on the motor's current actual output torque and pullback coefficient.

[0010] The target reverse torque is requested from the motor controller.

[0011] In some embodiments of this disclosure, the wheel speed difference control method further includes:

[0012] Upon detecting an energy recovery start signal, the magnitude of the torque increase gradient is determined based on the range of the target anti-drag torque, wherein the torque increase gradient is the magnitude of the target anti-drag torque increased within a predetermined time period; the target anti-drag torque is increased based on the magnitude of the torque increase gradient.

[0013] In some embodiments of this disclosure, determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque includes: when the target anti-drag torque increases from 0 to a first predetermined torque, determining the magnitude of the torque increase gradient as a first torque increase gradient, wherein the first torque increase gradient is less than the predetermined torque increase gradient.

[0014] In some embodiments of this disclosure, increasing the target anti-drag torque according to the magnitude of the torque gradient includes: increasing the target anti-drag torque using the first torque gradient when the target anti-drag torque increases from 0 to the first predetermined torque.

[0015] In some embodiments of this disclosure, determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque includes: when the target anti-drag torque increases from the first predetermined torque to the second predetermined torque, determining the magnitude of the torque increase gradient as the second torque increase gradient, wherein the second predetermined torque is greater than the first predetermined torque, and the second torque increase gradient is greater than the first torque increase gradient.

[0016] In some embodiments of this disclosure, increasing the target anti-drag torque according to the magnitude of the torque gradient includes: when the target anti-drag torque increases from the first predetermined torque to the second predetermined torque, increasing the target anti-drag torque using the second torque gradient.

[0017] In some embodiments of this disclosure, determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque includes: when the target anti-drag torque increases from the second predetermined torque, determining the magnitude of the torque increase gradient as the first torque increase gradient.

[0018] In some embodiments of this disclosure, increasing the target anti-drag torque according to the magnitude of the torque gradient includes: increasing the target anti-drag torque using the first torque gradient.

[0019] In some embodiments of this disclosure, the wheel speed difference control method further includes: when the torque pull-back function is not activated, performing the step of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increasing the target anti-drag torque based on the magnitude of the torque increase gradient.

[0020] In some embodiments of this disclosure, calculating the wheel speed difference between the drive wheel and the follower wheel includes:

[0021] The wheel speed of the two drive wheels is determined by the average wheel speed of the two drive wheels.

[0022] The speed of the follower wheel is determined by the average speed of the two follower wheels.

[0023] The wheel speed difference is determined based on the difference between the speed of the driving wheel and the speed of the follower wheel.

[0024] In some embodiments of this disclosure, the pullback coefficient is greater than 0 and less than 1.

[0025] In some embodiments of this disclosure, determining the target anti-drag torque based on the motor's current actual output torque and pullback coefficient includes:

[0026] The target anti-drag torque is determined by multiplying the motor's current actual output torque by the pullback coefficient.

[0027] In some embodiments of this disclosure, determining whether to activate the torque pull-back function based on the current vehicle speed and wheel speed difference includes:

[0028] When the current vehicle speed and the wheel speed difference meet the activation conditions, the torque pull-back function is activated. The activation conditions include either a first activation condition or a second activation condition. The first activation condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined wheel speed difference. The second activation condition is that the current vehicle speed is greater than or equal to a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined proportion of the current vehicle speed. The first predetermined proportion is greater than 0 and less than 1.

[0029] If the current vehicle speed and the wheel speed difference do not meet the activation conditions, the torque pull-back function will not be activated.

[0030] In some embodiments of this disclosure, the wheel speed difference control method further includes:

[0031] When the torque pull-back function is activated, determine whether to deactivate the torque pull-back function based on the current vehicle speed and wheel speed difference;

[0032] When the torque pull-back function is off, the steps of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increasing the target anti-drag torque based on the magnitude of the torque increase gradient are performed.

[0033] If the torque pullback function is not turned off, perform the step of determining the target anti-drag torque based on the motor's current actual output torque and pullback coefficient.

[0034] In some embodiments of this disclosure, determining whether to disable the torque recovery function based on the current vehicle speed and wheel speed difference includes:

[0035] When the current vehicle speed and the wheel speed difference meet the closing conditions, the torque pull-back function is turned off. The closing conditions include either a first closing condition or a second closing condition. The first closing condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined wheel speed difference. The second closing condition is that the current vehicle speed is greater than or equal to the predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined proportion of the current vehicle speed. The second predetermined proportion is greater than 0 and less than 1.

[0036] If the current vehicle speed and the wheel speed difference do not meet the closing conditions, the torque pull-back function will not be turned off.

[0037] In some embodiments of this disclosure, the second predetermined wheel speed difference is less than the first predetermined wheel speed difference.

[0038] In some embodiments of this disclosure, the second predetermined ratio is less than the first predetermined ratio.

[0039] In some embodiments of this disclosure, the energy recovery activation signal includes at least one of an accelerator pedal release signal and a brake pedal light depress signal.

[0040] According to another aspect of this disclosure, a vehicle controller is provided, comprising:

[0041] The parameter acquisition module is configured to acquire the current vehicle speed, the current wheel speed, and the current actual output torque of the motor.

[0042] The wheel speed difference calculation module is configured to calculate the wheel speed difference between the drive wheel and the follower wheel based on the current wheel speed;

[0043] The torque pullback judgment module is configured to determine whether to activate the torque pullback function based on the current vehicle speed and the wheel speed difference.

[0044] The anti-drag torque determination module is configured to determine the target anti-drag torque based on the motor's current actual output torque and the pull-back coefficient when the torque pull-back function is activated.

[0045] The anti-drag torque request module is configured to request the target anti-drag torque from the motor controller.

[0046] According to another aspect of this disclosure, a vehicle controller is provided, comprising:

[0047] Memory, used to store instructions;

[0048] A processor is configured to execute the instructions, causing the vehicle controller to implement the wheel speed difference control method as described in any of the above embodiments.

[0049] According to another aspect of this disclosure, a wheel speed difference control system is provided, including a vehicle controller as described in any of the above embodiments.

[0050] According to another aspect of this disclosure, an electric vehicle is provided, including a wheel speed difference control system as described in any of the above embodiments.

[0051] According to another aspect of this disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions that, when executed by a processor, implement the wheel speed difference control method as described in any of the above embodiments.

[0052] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, it implements the wheel speed difference control method as described in any of the above embodiments.

[0053] This invention can monitor wheel speed difference trends in real time and smoothly reduce wheel speed difference before ABS is falsely triggered by intelligently adjusting the anti-drag torque request strategy, thereby ensuring the continuous and efficient energy recovery process and improving the driving experience. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of some embodiments of the wheel speed difference control method disclosed herein.

[0056] Figure 2 This is a schematic diagram of some other embodiments of the wheel speed difference control method disclosed herein.

[0057] Figure 3 This is a schematic diagram of some embodiments of the vehicle controller disclosed herein.

[0058] Figure 4 This is a schematic diagram of the structure of some other embodiments of the vehicle controller disclosed herein.

[0059] Figure 5 This is a schematic diagram of some embodiments of the wheel speed difference control system disclosed herein. Detailed Implementation

[0060] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0061] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0062] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0063] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0064] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0065] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0066] The inventors discovered through research that when the wheel speed difference exceeds the preset threshold of the anti-lock braking system (ABS) controller, the ABS misinterprets it as a lock-up slippage of the drive wheels and is thus activated. This process leads to two main computational problems: First, the energy recovery process is abruptly interrupted, significantly reducing the overall energy recovery efficiency of the vehicle and shortening the driving range. Second, the instantaneous loss of anti-drag torque causes a noticeable jerkiness in the vehicle, severely affecting the smoothness and comfort of the ride.

[0067] Related technologies typically focus on safety responses after ABS is triggered, or simply limit the maximum recovery torque, but lack preventative control mechanisms to proactively identify and suppress wheel speed differences before ABS is triggered, thus failing to balance recovery efficiency and comfort while ensuring safety.

[0068] The present disclosure will now be described through specific embodiments.

[0069] Figure 1 This is a schematic diagram of some embodiments of the wheel speed difference control method of this disclosure. Preferably, this embodiment can be executed by the vehicle controller of this disclosure, the electric vehicle of this disclosure, or the wheel speed difference control system of this disclosure. Figure 1 As shown, Figure 1 The method of the embodiment may include at least one of steps 11 to 15.

[0070] In step 11, the current vehicle speed, the current wheel speed, and the current actual output torque of the motor are obtained.

[0071] In some embodiments of this disclosure, the current vehicle speed is the current speed of the electric vehicle.

[0072] In some embodiments of this disclosure, the current wheel speed is the wheel speed of all four wheels of the electric vehicle.

[0073] In some embodiments of this disclosure, the current actual output torque of the motor is the current actual output torque of the drive motor.

[0074] The present invention discloses an electric vehicle wheel speed difference control method designed in the above embodiments, which is executed by the vehicle controller (VCU), and its input signals include: vehicle speed, wheel speed of the four wheels, and the current actual output torque of the drive motor.

[0075] In step 12, the wheel speed difference between the drive wheel and the follower wheel is calculated based on the current wheel speed.

[0076] In some embodiments of this disclosure, step 12 may include at least one of steps 121 to 123.

[0077] In step 121, the wheel speed of the drive wheel is determined based on the average wheel speed of the two drive wheels.

[0078] In step 122, the speed of the follower wheel is determined based on the average speed of the two follower wheels.

[0079] In step 123, the wheel speed difference is determined based on the difference between the speed of the driving wheel and the speed of the follower wheel.

[0080] In some embodiments of this disclosure, step 12 may include: for a rear-wheel drive electric vehicle, the VCU calculates in real time the wheel speed difference (ΔV) between the drive wheel (the average speed of the left and right wheels of the rear axle) and the follower wheel (the average speed of the left and right wheels of the front axle).

[0081] In step 13, based on the current vehicle speed and the wheel speed difference, it is determined whether to activate the torque pull-back function.

[0082] In some embodiments of this disclosure, the torque pull-back function can be manifested through a torque pull-back signal.

[0083] In some embodiments of this disclosure, step 13 may include at least one of steps 131 to 132.

[0084] In step 131, the torque pull-back function is activated when the current vehicle speed and the wheel speed difference meet the activation conditions. The activation conditions include either a first activation condition or a second activation condition. The first activation condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined wheel speed difference. The second activation condition is that the current vehicle speed is greater than or equal to a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined proportion of the current vehicle speed. The first predetermined proportion is greater than 0 and less than 1.

[0085] In some embodiments of this disclosure, the predetermined vehicle speed may be 40 km / h.

[0086] In some embodiments of this disclosure, the first predetermined wheel speed difference may be 2 km / h.

[0087] In some embodiments of this disclosure, the first predetermined ratio may be 5%.

[0088] In some embodiments of this disclosure, the first activation condition may be the current vehicle speed V < 40 km / h and the wheel speed difference |ΔV| > 2 km / h.

[0089] In some embodiments of this disclosure, the second activation condition can be the current vehicle speed V≥40km / h and the wheel speed difference |ΔV|>V×5%.

[0090] In some embodiments of this disclosure, the activation condition may be: the torque pull-back function is activated if any of the following conditions are met.

[0091] 1. The current vehicle speed V < 40 km / h, and the wheel speed difference |ΔV| > 2 km / h.

[0092] 2. The current vehicle speed V≥40km / h, and the wheel speed difference |ΔV|>V×5%.

[0093] The embodiments disclosed above enhance the adaptability and reliability of the system, and can make judgments based on adaptive thresholds of vehicle speed, so that the strategy can maintain good control performance under various operating conditions at high and low speeds.

[0094] In step 132, if the current vehicle speed and the wheel speed difference do not meet the activation condition, the torque pull-back function is not activated.

[0095] In step 14, when the torque pullback function is activated, the target anti-drag torque is determined based on the motor's current actual output torque and the pullback coefficient K.

[0096] In some embodiments of this disclosure, step 14 may include: when the torque pullback function is activated, determining the target anti-drag torque based on the product of the motor's current actual output torque and the pullback coefficient K.

[0097] In some embodiments of this disclosure, step 14 may include: determining the target anti-drag torque according to formula (1) when the torque pull-back function is activated.

[0098] Target requested torque = motor current actual output torque × (pull-back coefficient K) (1)

[0099] In some embodiments of this disclosure, the pullback coefficient K is greater than 0 and less than 1.

[0100] In some embodiments of this disclosure, the pullback coefficient K = 0.7. In the above embodiments of this disclosure, the VCU requests the motor to pull back at 70% of the current output torque, that is, reduces the requested anti-drag torque instead of directly resetting it to zero, thereby achieving smooth intervention.

[0101] In step 15, the target anti-drag torque is requested from the motor controller.

[0102] The embodiments disclosed above design a feedback control logic based on wheel speed difference. When it is detected that the wheel speed difference is increasing to the point of triggering ABS, it actively intervenes and pulls back the current torque proportionally, so as to control the wheel speed difference within a certain safe range.

[0103] The present disclosure provides a method for controlling wheel speed difference in electric vehicles. This method monitors vehicle speed and wheel speed in real time, dynamically adjusts the gradient and magnitude of the anti-drag torque request for energy recovery, and actively suppresses the excessively rapid increase in the wheel speed difference between the drive wheels and the follower wheels. This effectively avoids false triggering of the ABS system and achieves a simultaneous improvement in energy recovery efficiency and driving comfort.

[0104] Figure 2 This is a schematic diagram of some other embodiments of the wheel speed difference control method of this disclosure. Preferably, this embodiment can be executed by the vehicle controller of this disclosure, the electric vehicle of this disclosure, or the wheel speed difference control system of this disclosure. Figure 2 As shown, Figure 2 The method of the embodiment may include at least one of steps 10, 11 to 17. Figure 2 Steps 11 to 15 of the embodiment are respectively with Figure 1 Steps 11 to 15 of the embodiment are the same or similar.

[0105] In step 10, energy recovery begins.

[0106] In some embodiments of this disclosure, step 10 may include: upon detecting an energy recovery start signal, determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque; and increasing the target anti-drag torque based on the magnitude of the torque increase gradient, wherein the torque increase gradient is the magnitude of the target anti-drag torque increased within a predetermined time period.

[0107] The embodiments described above can determine different torque-increasing gradients based on different target anti-drag torques.

[0108] In some embodiments of this disclosure, the energy recovery activation signal may include at least one of an accelerator pedal release signal and a brake pedal light depress signal.

[0109] In some embodiments of this disclosure, step 10 may include: when the driver releases the accelerator pedal or lightly presses the brake pedal to trigger energy recovery, the VCU requests a target anti-drag torque from the motor controller (MCU), the change of which follows a preset nonlinear gradient.

[0110] In some embodiments of this disclosure, step 10, which involves determining the magnitude of the torque-increasing gradient based on the range of the target anti-drag torque and increasing the target anti-drag torque based on the magnitude of the torque-increasing gradient, may include at least one of steps 101 to 103.

[0111] In step 101, when the target anti-drag torque increases from 0 to a first predetermined torque, the magnitude of the torque increase gradient is determined to be a first torque increase gradient, and the target anti-drag torque is increased using the first torque increase gradient, wherein the first torque increase gradient is less than the predetermined torque increase gradient.

[0112] In some embodiments of this disclosure, step 101 may be a first stage (initial gradual increase stage).

[0113] In some embodiments of this disclosure, the first predetermined torque can be -50 Nm (the negative sign indicates braking torque).

[0114] In some embodiments of this disclosure, the first torque gradient can be 100 Nm / s.

[0115] In some embodiments of this disclosure, step 101 may include: a first stage (initial gradual increase stage): when the requested torque increases from 0 Nm to -50 Nm, the first torque increase gradient is 100 Nm / s. In the above embodiments of this disclosure, the torque in the first stage (initial stage, initial gradual increase stage) is relatively small, and the gradual increase can avoid impacting the transmission system and allow the tires sufficient time to establish stable ground adhesion.

[0116] In step 102, when the target anti-drag torque increases from the first predetermined torque to the second predetermined torque, the magnitude of the torque increase gradient is determined as the second torque increase gradient, and the target anti-drag torque is increased using the second torque increase gradient, wherein the second predetermined torque is greater than the first predetermined torque, and the second torque increase gradient is greater than the first torque increase gradient.

[0117] In some embodiments of this disclosure, step 102 may be a second stage (rapid ascent stage).

[0118] In some embodiments of this disclosure, the second predetermined torque can be -350 Nm (the negative sign indicates braking torque).

[0119] In some embodiments of this disclosure, the second torque gradient can be 400 Nm / s.

[0120] In some embodiments of this disclosure, step 102 may include: a second stage (rapid climb stage): when the requested torque increases from -50 Nm to -350 Nm, the torque increase gradient is 400 Nm / s. In the above embodiments of this disclosure, during the second stage (intermediate stage, rapid climb stage), the vehicle has sufficient kinetic energy, and the rapid torque increase can seize the efficient recovery window, improving the overall energy recovery efficiency.

[0121] In step 103, when the target anti-drag torque increases from the second predetermined torque, the magnitude of the torque increase gradient is determined to be the first torque increase gradient, and the target anti-drag torque is increased using the first torque increase gradient.

[0122] In some embodiments of this disclosure, step 103 may be a third stage (terminal gradual increase stage).

[0123] In some embodiments of this disclosure, step 103 may include: a third stage (end-stage gradual increase): when the requested torque exceeds -350 Nm, the torque increase gradient is restored to 100 Nm / s. In the above embodiments of this disclosure, the torque in the third stage (end-stage gradual increase) is already relatively large, close to the tire adhesion limit. Gradual increase can prevent sudden torque changes from causing a sharp increase in the slip ratio of the drive wheel, thus ensuring stability.

[0124] The embodiments disclosed above employ a nonlinear torque-increasing gradient strategy of "gradual increase followed by rapid increase followed by gradual increase," which smoothly changes torque during the periods of low and high torque, avoiding initial and final impacts.

[0125] In step 11, the current vehicle speed, the current wheel speed, and the current actual output torque of the motor are obtained.

[0126] In step 12, the wheel speed difference is calculated.

[0127] In some embodiments of this disclosure, step 12 may include at least one of steps 121 to 123.

[0128] In step 13, it is determined whether the torque pull-back function is activated. If the torque pull-back function is activated, steps 14 and 16 are executed; otherwise, if the torque pull-back function is activated, step 17 is executed.

[0129] In some embodiments of this disclosure, step 13 may include at least one of steps 131 to 132.

[0130] In step 14, with the torque pull-back function activated, the target pull-back torque is calculated. Then, step 15 is executed.

[0131] In some embodiments of this disclosure, when the torque pull-back function is activated, the target anti-drag torque is the pull-back target torque.

[0132] In some embodiments of this disclosure, step 14 may include: when the torque pullback function is activated, determining the target anti-drag torque based on the motor's current actual output torque and the pullback coefficient K.

[0133] In step 16, if the torque pull-back function is activated, determine whether to disable the torque pull-back function. If the torque pull-back function is disabled, proceed to step 17; otherwise, if the torque pull-back function is not disabled, proceed to step 14.

[0134] In the embodiments described above, when the pull-back signal is turned off, the VCU will resume normal calculation (calculated in accordance with at least one of steps 101 to 103) of the target requested torque, gradually increasing from the current torque value to the target value.

[0135] In some embodiments of this disclosure, step 16 may include: when the torque pull-back function is activated, determining whether to disable the torque pull-back function based on the current vehicle speed and wheel speed difference.

[0136] In some embodiments of this disclosure, step 16, the step of determining whether to turn off the torque pull-back function, may include at least one of steps 161 to 162.

[0137] In step 161, if the current vehicle speed and the wheel speed difference meet the closing conditions, the torque pull-back function is turned off. The closing conditions include either a first closing condition or a second closing condition. The first closing condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined wheel speed difference. The second closing condition is that the current vehicle speed is greater than or equal to the predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined proportion of the current vehicle speed. The second predetermined proportion is greater than 0 and less than 1.

[0138] In some embodiments of this disclosure, the second predetermined wheel speed difference is less than the first predetermined wheel speed difference.

[0139] In some embodiments of this disclosure, the second predetermined ratio is less than the first predetermined ratio.

[0140] The above embodiments of this disclosure set the threshold of the shutdown condition to be lower than the activation threshold, forming a hysteresis function, thereby preventing torque jitter caused by frequent signal jumps near the critical point.

[0141] In some embodiments of this disclosure, the second constant wheel speed difference can be 1.5 km / h.

[0142] In some embodiments of this disclosure, the second predetermined ratio may be 3%.

[0143] In some embodiments of this disclosure, the first shut-off condition may be the current vehicle speed V < 40 km / h and the wheel speed difference |ΔV| < 1.5 km / h.

[0144] In some embodiments of this disclosure, the second shut-off condition can be the current vehicle speed V ≥ 40 km / h, and the wheel speed difference |ΔV| <V×3%。

[0145] In some embodiments of this disclosure, the shutdown condition may be: the torque pull-back function is shut down if any of the following conditions are met.

[0146] 1. The current vehicle speed V < 40 km / h, and the wheel speed difference |ΔV| < 1.5 km / h.

[0147] 2. The current vehicle speed V ≥ 40 km / h, and the wheel speed difference |ΔV| <V×3%。

[0148] The embodiments disclosed above enhance the adaptability and reliability of the system, and can make judgments based on adaptive thresholds of vehicle speed, so that the strategy can maintain good control performance under various operating conditions at high and low speeds.

[0149] In step 162, if the current vehicle speed and the wheel speed difference do not meet the closing condition, the torque pull-back function is not turned off.

[0150] In step 17, if the torque pull-back function is not activated, calculate the target torque. Then proceed to step 15.

[0151] In some embodiments of this disclosure, the target torque may be a target anti-drag torque.

[0152] In some embodiments of this disclosure, step 17 may include: when the torque pull-back function is not activated, performing the step of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increasing the target anti-drag torque based on the magnitude of the torque increase gradient.

[0153] In some embodiments of this disclosure, step 17 may include: calculating the target anti-drag torque in the manner of at least one of steps 101 to 103 if the torque pull-back function is not activated.

[0154] In the above embodiments of this disclosure, when the pull-back signal is not activated or is turned off, the VCU will resume the normally calculated target requested torque (calculated according to steps 101 to 103), gradually increasing from the current torque value to the target value.

[0155] Steps 14 and 17 of the above embodiments of this disclosure are based on dynamic torque adjustment of the pull-back signal.

[0156] According to the above embodiments of this disclosure, based on whether the pullback signal calculated in steps 13 and 16 is activated, steps 14 and 17 are used to calculate the final requested torque sent to the MCU.

[0157] In step 15, the target anti-drag torque is requested from the motor controller.

[0158] The embodiments disclosed above design a feedback control logic based on wheel speed difference. When it is detected that the wheel speed difference is increasing to the point of triggering ABS, it actively intervenes and proportionally pulls back the current torque to control the wheel speed difference within a certain safe range.

[0159] The above embodiments of this disclosure provide an active preventive wheel speed difference control method for electric vehicles, which is a method for optimizing wheel speed difference control during energy recovery.

[0160] The embodiments of this disclosure present a preventative wheel speed difference control method for electric vehicles, executed by the vehicle control unit (VCU). The input signals include vehicle speed, wheel speeds of the four wheels, and the current actual output torque of the drive motor. These embodiments employ a nonlinear anti-drag torque request gradient of "slow-fast-slow," setting different torque increase rates in different torque ranges to achieve smooth torque increase. The embodiments also feature adaptive wheel speed difference threshold management based on vehicle speed, combined with hysteresis comparison logic, ensuring precise and stable intervention. Furthermore, the embodiments utilize a proportional pull-back torque intervention mechanism, smoothly adjusting based on the motor's current actual output torque, ensuring continuous energy recovery, improving vehicle range, and guaranteeing driving comfort.

[0161] The embodiments of this disclosure introduce a method to actively prevent ABS triggering by judging wheel speed differences. The wheel speed difference judgment in the embodiments of this disclosure can more accurately determine whether ABS is about to be triggered. The embodiments of this disclosure do not require complex algorithms, and the pull-back torque is not noticeable to the driver, eliminating the feeling of sudden acceleration due to a sudden stop in braking, thus having a wider range of application scenarios.

[0162] The embodiments of this disclosure present a dual control architecture employing "feedforward + feedback". The feedforward control of the embodiments of this disclosure uses a nonlinear torque request gradient of "slow-fast-slow" to actively and gradually change the torque at the initial and final stages of torque application, thereby suppressing the generation of wheel speed difference from the source. The feedback control of the embodiments of this disclosure monitors the wheel speed difference in real time and uses an adaptive hysteresis threshold based on vehicle speed for judgment. Once the wheel speed difference approaches the danger threshold, a proportional pullback mechanism based on the current actual torque is triggered, achieving smooth and gradual torque intervention.

[0163] The energy recovery method of this disclosure will be described below through specific embodiments.

[0164] Suppose a rear-wheel-drive electric vehicle is coasting at a certain speed and entering energy recovery mode.

[0165] At a certain moment, due to a slight decrease in road surface adhesion, the wheel speed difference |ΔV| calculated by the VCU does not yet meet the activation condition of step 13, so the torque pull-back function remains off, and the motor torque continues to increase according to the strategy in step 10.

[0166] Subsequently, when the wheel speed difference increases to the point that the activation condition in step 13 is met due to the increased torque, the VCU immediately activates the torque pullback function. Assuming the actual output torque of the motor is -200 Nm at this time, and the pullback coefficient K = 0.7, then the final requested torque sent by the VCU to the MCU is -200 Nm × 0.7 = -140 Nm.

[0167] As the reverse torque decreases, rear wheel slippage is suppressed. When the wheel speed difference begins to decrease to meet the closing condition of step 16, the torque pull-back function is released, the VCU's requested torque returns to normal, and the motor torque continues to increase according to the strategy in step 10.

[0168] Through this dynamic adjustment, the wheel speed difference in the above-described embodiments of the present disclosure is always suppressed below the ABS trigger threshold throughout the entire process. The ABS is not activated, the energy recovery process is not interrupted, and the torque change is gradual, thus ensuring the stability and comfort of vehicle driving.

[0169] The embodiments disclosed above, based on the field of pure electric vehicle controllers, develop an active torque management strategy to prevent ABS false triggering. Key features of the embodiments disclosed above include: 1. Employing a "slow-fast-slow" nonlinear anti-drag torque request gradient, setting different torque increase rates in different torque ranges to achieve smooth torque increase; 2. Adaptive wheel speed difference threshold management based on vehicle speed, combined with hysteresis comparison logic, to ensure precise and stable intervention; 3. Employing a proportional pull-back torque intervention mechanism, using the current actual output torque of the motor as a benchmark for smooth adjustment, ensuring continuous energy recovery, improving vehicle range, and guaranteeing driving comfort.

[0170] Figure 3 This is a schematic diagram of some embodiments of the vehicle controller disclosed herein. For example... Figure 3 As shown, the vehicle controller disclosed herein may include a parameter acquisition module 31, a wheel speed difference calculation module 32, a pullback judgment module 33, a reverse drag torque determination module 34, and a reverse drag torque request module 35.

[0171] The parameter acquisition module 31 is configured to acquire the current vehicle speed, the current wheel speed, and the current actual output torque of the motor.

[0172] The wheel speed difference calculation module 32 is configured to calculate the wheel speed difference between the drive wheel and the follower wheel based on the current wheel speed.

[0173] In some embodiments of this disclosure, the wheel speed difference calculation module 32 can be configured to determine the wheel speed of the driving wheel based on the average wheel speed of the two driving wheels; determine the wheel speed of the follower wheel based on the average wheel speed of the two follower wheels; and determine the wheel speed difference based on the difference between the wheel speed of the driving wheel and the wheel speed of the follower wheel.

[0174] The torque pullback judgment module 33 is configured to determine whether to activate the torque pullback function based on the current vehicle speed and the wheel speed difference.

[0175] In some embodiments of this disclosure, the torque pullback judgment module 33 can be configured to activate the torque pullback function when the current vehicle speed and the wheel speed difference meet the activation conditions. The activation conditions include either a first activation condition or a second activation condition. The first activation condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined wheel speed difference. The second activation condition is that the current vehicle speed is greater than or equal to a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined proportion of the current vehicle speed. The first predetermined proportion is greater than 0 and less than 1. If the current vehicle speed and the wheel speed difference do not meet the activation conditions, the torque pullback function is not activated.

[0176] The anti-drag torque determination module 34 is configured to determine the target anti-drag torque based on the motor's current actual output torque and the pull-back coefficient when the torque pull-back function is activated;

[0177] In some embodiments of this disclosure, the pullback coefficient is greater than 0 and less than 1.

[0178] In some embodiments of this disclosure, the anti-drag torque determination module 34 is configured to determine the target anti-drag torque based on the product of the motor's current actual output torque and the pull-back coefficient when the torque pull-back function is activated.

[0179] The anti-drag torque request module 35 is configured to request the target anti-drag torque from the motor controller.

[0180] The embodiments disclosed above employ a proportional pullback torque intervention mechanism. When the torque pullback function is activated, the torque is not directly reset to zero. This proportional pullback method can achieve smooth and gradual adjustment of torque, which can maximize the linearity and comfort of vehicle deceleration changes.

[0181] In some embodiments of this disclosure, the vehicle controller may also be configured to, upon detecting an energy recovery start signal, determine the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increase the target anti-drag torque based on the magnitude of the torque increase gradient, wherein the torque increase gradient is the magnitude of the target anti-drag torque increased within a predetermined time period.

[0182] In some embodiments of this disclosure, the energy recovery activation signal includes at least one of an accelerator pedal release signal and a brake pedal light depress signal.

[0183] In some embodiments of this disclosure, when the vehicle controller determines the magnitude of the torque increase gradient based on the range of the target anti-drag torque and increases the target anti-drag torque based on the magnitude of the torque increase gradient, it can be configured to determine the magnitude of the torque increase gradient as a first torque increase gradient when the target anti-drag torque increases from 0 to a first predetermined torque, and use the first torque increase gradient to increase the target anti-drag torque, wherein the first torque increase gradient is less than the predetermined torque increase gradient.

[0184] In some embodiments of this disclosure, the vehicle controller of this disclosure, when determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque and increasing the target anti-drag torque based on the magnitude of the torque increase gradient, can also be configured to determine the magnitude of the torque increase gradient as a second torque increase gradient when the target anti-drag torque increases from the first predetermined torque to the second predetermined torque, and use the second torque increase gradient to increase the target anti-drag torque, wherein the second predetermined torque is greater than the first predetermined torque, and the second torque increase gradient is greater than the first torque increase gradient.

[0185] In some embodiments of this disclosure, the vehicle controller of this disclosure, when determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque and increasing the target anti-drag torque based on the magnitude of the torque increase gradient, may also be configured to determine the magnitude of the torque increase gradient as the first torque increase gradient when the target anti-drag torque increases from the second predetermined torque, and use the first torque increase gradient to increase the target anti-drag torque.

[0186] The embodiments disclosed above employ a nonlinear anti-drag torque request gradient strategy. This gradient design method can achieve smooth torque increase and avoid shocks and slippage.

[0187] In some embodiments of this disclosure, the vehicle controller may also be configured to perform the operation of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque and increasing the target anti-drag torque based on the magnitude of the torque increase gradient when the torque pull-back function is not activated.

[0188] In some embodiments of this disclosure, the vehicle controller may also be configured to, when the torque pullback function is activated, determine whether to disable the torque pullback function based on the current vehicle speed and wheel speed difference; when the torque pullback function is disabled, execute the step of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increasing the target anti-drag torque based on the magnitude of the torque increase gradient; when the torque pullback function is not disabled, execute the step of determining the target anti-drag torque based on the motor's current actual output torque and pullback coefficient.

[0189] In some embodiments of this disclosure, when the vehicle controller determines whether to disable the torque retraction function based on the current vehicle speed and the wheel speed difference, it can be configured to disable the torque retraction function if the current vehicle speed and the wheel speed difference meet the disabling conditions. The disabling conditions include either a first disabling condition or a second disabling condition. The first disabling condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined wheel speed difference. The second disabling condition is that the current vehicle speed is greater than or equal to a predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined proportion of the current vehicle speed, where the second predetermined proportion is greater than 0 and less than 1. If the current vehicle speed and the wheel speed difference do not meet the disabling conditions, the torque retraction function is not disabled.

[0190] In some embodiments of this disclosure, the second predetermined wheel speed difference is less than the first predetermined wheel speed difference.

[0191] In some embodiments of this disclosure, the second predetermined ratio is less than the first predetermined ratio.

[0192] The embodiments disclosed above employ adaptive wheel speed difference threshold management and hysteresis control to protect the logic of dynamically activating torque pull-back function based on wheel speed difference.

[0193] In some embodiments of this disclosure, the vehicle controller of this disclosure can be configured to perform the wheel speed difference control method as described in any of the above embodiments.

[0194] Figure 4 This is a schematic diagram of the structure of some other embodiments of the vehicle controller disclosed herein. For example... Figure 4 As shown, the vehicle controller disclosed herein includes a memory 41 and a processor 42.

[0195] The memory 41 is used to store instructions, and the processor 42 is coupled to the memory 41. The processor 42 is configured to execute the wheel speed difference control method involved in the above embodiments based on the instructions stored in the memory.

[0196] like Figure 4 As shown, the vehicle controller also includes a communication interface 43 for exchanging information with other devices. Additionally, the vehicle controller includes a bus 44, through which the processor 42, communication interface 43, and memory 41 communicate with each other.

[0197] The memory 41 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk storage device. The memory 41 may also be a memory array. The memory 41 may also be divided into blocks, and the blocks may be combined into virtual volumes according to certain rules.

[0198] Furthermore, processor 42 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present disclosure.

[0199] Figure 5 This is a schematic diagram of some embodiments of the wheel speed difference control system disclosed herein. For example... Figure 5 As shown, the wheel speed difference control system disclosed herein may include a vehicle speed acquisition device 51, a wheel speed acquisition device 52, a torque acquisition device 53, a vehicle controller 54, and a motor controller 55.

[0200] The vehicle speed acquisition device 51 is configured to acquire the current speed of the electric vehicle and send the current speed of the electric vehicle to the vehicle controller 54.

[0201] The wheel speed acquisition device 52 is configured to acquire the wheel speeds of the four wheels of the electric vehicle and transmit the wheel speeds of the four wheels of the electric vehicle to the vehicle controller 54.

[0202] The torque acquisition device 53 is configured to acquire the current actual output torque of the drive motor and transmit the current actual output torque of the drive motor to the vehicle controller 54.

[0203] In some embodiments of this disclosure, the vehicle speed acquisition device 51, wheel speed acquisition device 52, and torque acquisition device 53 can all be implemented using existing sensors (vehicle speed sensor, wheel speed sensor) of the electric vehicle.

[0204] The vehicle controller 54 is configured to acquire the current vehicle speed, the current wheel speed, and the current actual output torque of the motor; calculate the wheel speed difference between the drive wheel and the follower wheel based on the current wheel speed; determine whether to activate the torque pull-back function based on the current vehicle speed and the wheel speed difference; if the torque pull-back function is activated, determine the target anti-drag torque based on the current actual output torque of the motor and the pull-back coefficient; and request the target anti-drag torque from the motor controller 55.

[0205] In some embodiments of this disclosure, the vehicle controller 54 may be a vehicle controller as described in any of the above embodiments.

[0206] The design schemes of the embodiments disclosed above are entirely based on existing vehicle wheel speed sensors and controllers (VCU, MCU), requiring no additional hardware costs and can be deployed on existing electric vehicle platforms solely through software upgrades. The pure algorithmic solutions of the embodiments disclosed above offer clear pathways, convenient implementation, and high reliability, effectively addressing industry challenges related to energy recovery interruptions and driving jerks, demonstrating extremely high application feasibility.

[0207] According to another aspect of this disclosure, an electric vehicle is provided, including a wheel speed difference control system as described in any of the above embodiments.

[0208] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, it implements the wheel speed difference control method as described in any of the above embodiments.

[0209] According to another aspect of this disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions that, when executed by a processor, implement the wheel speed difference control method as described in any of the above embodiments.

[0210] In some embodiments of this disclosure, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

[0211] The above-described embodiments of this disclosure innovatively introduce an active preventive wheel speed difference control mechanism. Unlike traditional technologies that passively respond after ABS is triggered, the above-described embodiments of this disclosure actively and smoothly intervene in the motor torque before the critical point when ABS is about to be triggered by real-time monitoring of the wheel speed difference trend, thus eliminating the problem in its infancy. This represents a shift in technical thinking from "passive safety" to "active prevention".

[0212] The above-described embodiments of this disclosure significantly improve energy recovery efficiency and driving range. By effectively avoiding interruption of energy recovery due to ABS mis-triggering, the continuity and integrity of the energy recovery process are ensured, enabling the vehicle to recover more energy during coasting and braking, thereby directly improving the vehicle's driving range.

[0213] The above-described embodiments of this disclosure greatly optimize the smoothness and comfort of driving. Through the "gradual-fast-gradual" torque increase gradient and the "proportional pullback" torque intervention, the change of the anti-drag torque is always smooth and controllable, completely eliminating the jerking feeling caused by the instantaneous loss of torque, and providing a linear braking feel that is closer to or better than the anti-drag of a traditional fuel vehicle engine.

[0214] The embodiments disclosed above enhance the adaptability and reliability of the system. Based on adaptive threshold judgment according to vehicle speed, this strategy maintains good control performance under various operating conditions, both high and low speeds. The embodiments of this disclosure employ hysteresis comparison logic to avoid frequent switching of control signals, thus improving system stability. This algorithm is entirely based on existing sensor signals (vehicle speed, wheel speed), requiring no additional hardware costs, making it easy to implement and apply on existing electric vehicle platforms, resulting in significant economic benefits.

[0215] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, apparatus, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0216] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0217] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0218] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0219] The vehicle controller, parameter acquisition module, wheel speed difference calculation module, pullback judgment module, anti-drag torque determination module, and anti-drag torque request module described above can be implemented as a general-purpose processor, programmable logic controller (PLC), digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof for performing the functions described in this application.

[0220] This concludes the detailed description of the present disclosure. To avoid obscuring the concept of the disclosure, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0221] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing the relevant hardware to implement them. The program can be stored in a non-transitory computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0222] The description in this disclosure is provided for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the disclosure to its forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of this disclosure and to enable those skilled in the art to understand this disclosure and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A wheel speed difference control method, comprising: Get the current vehicle speed, current wheel speed, and current actual output torque of the motor; Calculate the wheel speed difference between the drive wheel and the follower wheel based on the current wheel speed; Based on the current vehicle speed and the wheel speed difference, determine whether to activate the torque pull-back function; When the torque pullback function is activated, the target anti-drag torque is determined based on the motor's current actual output torque and pullback coefficient. Request the target anti-drag torque from the motor controller; When an energy recovery start signal is detected, the magnitude of the torque increase gradient is determined according to the range of the target anti-drag torque, wherein the torque increase gradient is the magnitude of the target anti-drag torque increased within a predetermined time period. Determining the magnitude of the torque increase gradient according to the range of the target anti-drag torque includes: when the target anti-drag torque increases from 0 to a first predetermined torque, the magnitude of the torque increase gradient is determined to be a first torque increase gradient, wherein the first torque increase gradient is less than the predetermined torque increase gradient. The target anti-drag torque is increased according to the magnitude of the torque increase gradient, wherein increasing the target anti-drag torque according to the magnitude of the torque increase gradient includes: when the target anti-drag torque increases from 0 to the first predetermined torque, the target anti-drag torque is increased using the first torque increase gradient.

2. The wheel speed difference control method according to claim 1, wherein: Determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque includes: when the target anti-drag torque increases from the first predetermined torque to the second predetermined torque, determining the magnitude of the torque increase gradient as the second torque increase gradient, wherein the second predetermined torque is greater than the first predetermined torque, and the second torque increase gradient is greater than the first torque increase gradient. The step of increasing the target anti-drag torque according to the magnitude of the torque increase gradient includes: when the target anti-drag torque increases from the first predetermined torque to the second predetermined torque, the target anti-drag torque is increased by using the second torque increase gradient.

3. The wheel speed difference control method according to claim 2, wherein: Determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque includes: when the target anti-drag torque increases from the second predetermined torque, determining the magnitude of the torque increase gradient as the first torque increase gradient; The step of increasing the target anti-drag torque according to the magnitude of the torque gradient includes: increasing the target anti-drag torque using the first torque gradient.

4. The wheel speed difference control method according to any one of claims 1 to 3, further comprising: If the torque pull-back function is not activated, the steps of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increasing the target anti-drag torque based on the magnitude of the torque increase gradient are performed.

5. The wheel speed difference control method according to any one of claims 1 to 3, wherein, The calculation of the wheel speed difference between the driving wheel and the follower wheel includes: The wheel speed of the two drive wheels is determined by the average wheel speed of the two drive wheels. The speed of the follower wheel is determined by the average speed of the two follower wheels. The wheel speed difference is determined based on the difference between the speed of the driving wheel and the speed of the follower wheel.

6. The wheel speed difference control method according to any one of claims 1 to 3, wherein, The pullback coefficient is greater than 0 and less than 1. The step of determining the target anti-drag torque based on the motor's current actual output torque and pullback coefficient includes: The target anti-drag torque is determined by multiplying the motor's current actual output torque by the pullback coefficient.

7. The wheel speed difference control method according to any one of claims 1 to 3, wherein, The step of determining whether to activate the torque recovery function based on the current vehicle speed and the wheel speed difference includes: When the current vehicle speed and the wheel speed difference meet the activation conditions, the torque pull-back function is activated. The activation conditions include either a first activation condition or a second activation condition. The first activation condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined wheel speed difference. The second activation condition is that the current vehicle speed is greater than or equal to a predetermined vehicle speed and the absolute value of the wheel speed difference is greater than a first predetermined proportion of the current vehicle speed. The first predetermined proportion is greater than 0 and less than 1. If the current vehicle speed and the wheel speed difference do not meet the activation conditions, the torque pull-back function will not be activated.

8. The wheel speed difference control method according to claim 7 further includes: When the torque pull-back function is activated, determine whether to deactivate the torque pull-back function based on the current vehicle speed and wheel speed difference; When the torque pull-back function is off, the steps of determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increasing the target anti-drag torque based on the magnitude of the torque increase gradient are performed. If the torque pullback function is not turned off, perform the step of determining the target anti-drag torque based on the motor's current actual output torque and pullback coefficient.

9. The wheel speed difference control method according to claim 8, wherein, The method of determining whether to disable the torque recovery function based on the current vehicle speed and wheel speed difference includes: When the current vehicle speed and the wheel speed difference meet the closing conditions, the torque pull-back function is turned off. The closing conditions include either a first closing condition or a second closing condition. The first closing condition is that the current vehicle speed is less than a predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined wheel speed difference. The second closing condition is that the current vehicle speed is greater than or equal to the predetermined vehicle speed and the absolute value of the wheel speed difference is less than a second predetermined proportion of the current vehicle speed. The second predetermined proportion is greater than 0 and less than 1. If the current vehicle speed and the wheel speed difference do not meet the closing conditions, the torque pull-back function will not be turned off.

10. The wheel speed difference control method according to claim 9, wherein: The second predetermined wheel speed difference is less than the first predetermined wheel speed difference; The second predetermined ratio is less than the first predetermined ratio.

11. The wheel speed difference control method according to any one of claims 1 to 3, wherein, The energy recovery activation signal includes at least one of the accelerator pedal release signal and the brake pedal lightly depressed signal.

12. A vehicle controller, comprising: The parameter acquisition module is configured to acquire the current vehicle speed, the current wheel speed, and the current actual output torque of the motor. The wheel speed difference calculation module is configured to calculate the wheel speed difference between the drive wheel and the follower wheel based on the current wheel speed; The torque pullback judgment module is configured to determine whether to activate the torque pullback function based on the current vehicle speed and the wheel speed difference. The anti-drag torque determination module is configured to determine the target anti-drag torque based on the motor's current actual output torque and the pull-back coefficient when the torque pull-back function is activated. The anti-drag torque request module is configured to request the target anti-drag torque from the motor controller; The vehicle controller is configured to, upon detecting an energy recovery start signal, determine the magnitude of the torque increase gradient based on the range of the target anti-drag torque, and increase the target anti-drag torque based on the magnitude of the torque increase gradient. The vehicle controller, when determining the magnitude of the torque increase gradient based on the range of the target anti-drag torque and increasing the target anti-drag torque based on the magnitude of the torque increase gradient, is configured to determine the magnitude of the torque increase gradient as a first torque increase gradient when the target anti-drag torque increases from 0 to a first predetermined torque, and use the first torque increase gradient to increase the target anti-drag torque, wherein the first torque increase gradient is less than the predetermined torque increase gradient.

13. A vehicle controller, comprising: Memory, used to store instructions; A processor is configured to execute the instructions, causing the vehicle controller to implement the wheel speed difference control method as described in any one of claims 1-11.

14. A wheel speed difference control system, comprising the vehicle controller as described in claim 12 or 13.

15. An electric vehicle, comprising the wheel speed differential control system as described in claim 14.

16. A computer-readable storage medium, wherein, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the wheel speed difference control method as described in any one of claims 1-11.

17. A computer program product comprising a computer program, wherein, When the computer program is executed by the processor, it implements the wheel speed difference control method as described in any one of claims 1-11.

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