Motor torque zero-crossing control method and device, vehicle, electronic equipment and medium

Abstract

The present application relates to the technical field of vehicles and discloses a motor torque zero-crossing control method and device, a vehicle, electronic equipment and a medium. The method controls the motor of the vehicle to output positive and negative periodic torques for multiple test periods when the wheels of the vehicle are in a braking stationary state, so that the gear performs different side-tooth movements, the mechanical angle of the motor rotor is monitored, the periodic transmission system gap is determined, the average transmission system gap is matched to obtain a target torque gradient correction value, the current torque zero-crossing gradient of the vehicle is determined based on the target torque gradient correction value and a preset basic zero-crossing torque gradient value, the torque of the motor of the vehicle is controlled to zero-cross, and the current torque zero-crossing gradient of the vehicle is corrected at different times in the life cycle of the vehicle. The adaptability of the current torque zero-crossing gradient to the vehicle is ensured, the zero-crossing abnormal sound problem of the vehicle is reduced, and the smoothness of the output torque of the power system of the vehicle is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more particularly to a method, device, vehicle, electronic device, and medium for controlling the zero-crossing torque of an electric motor. Background Technology

[0002] New energy vehicles are typically driven by a drive motor. A typical transmission system includes the motor, gearbox, differential, half-shafts, and wheels. There is a certain amount of backlash in the gearbox and differential gears, and as the vehicle ages, the backlash will change due to wear on the bearings or gears.

[0003] According to the four-quadrant principle of drive motors, their output torque and speed can have positive and negative values. Due to the presence of clearances in the transmission system, when the motor torque changes direction (i.e., when the torque crosses zero), there will be abnormal noise caused by gear grinding or tooth contact. Generally, the greater the driver depresses the accelerator pedal, the greater the motor output torque, and the more severe the abnormal noise in the transmission system. At the same time, the motor speed may also fluctuate after the torque crosses zero, causing torque oscillation in the transmission system and vehicle jerking, which in turn leads to driving comfort issues. By changing the torque gradient at the moment the drive motor torque crosses zero, the abnormal noise problem in the transmission system at this time can be improved and optimized. However, if the torque gradient is too large, it will not completely eliminate the tooth contact noise, while if it is too small, it will affect the torque response rate and even cause a subjective driving experience of power interruption. Therefore, it is necessary to reasonably select the torque gradient value at the moment the torque crosses zero.

[0004] In related technologies, the determination of the torque zero-crossing gradient value is usually achieved by calibrating a suitable torque zero-crossing gradient value on a test vehicle. The torque zero-crossing gradient value obtained in this way is fixed and applicable to other vehicles of the same type as the test vehicle. However, the torque gradient value obtained by this method is only effective for the test vehicle at present. Sometimes it cannot cover vehicle deviations, resulting in it being inapplicable to other vehicles of the same model. Or, it may be universal for other vehicles of the same model when they are first used, but as the vehicle is used, the transmission system changes, which makes the fixed torque zero-crossing gradient value no longer applicable. Summary of the Invention

[0005] This invention provides a method, device, vehicle, electronic device, and medium for controlling zero-crossing torque of a motor, to solve the technical problem in related technologies where controlling zero-crossing torque of a motor by using a fixed zero-crossing gradient value is effective for the test vehicle at present, but sometimes cannot cover vehicle deviations, making it inapplicable to other vehicles of the same model, or is universal for other vehicles of the same model when first used, but becomes inapplicable as the transmission system changes during vehicle use.

[0006] This invention provides a method for controlling the zero-crossing torque of a motor. The method includes: if the wheels of a vehicle are in a braking and stationary state, controlling the motor of the vehicle to output positive and negative periodic torque for multiple test cycles, so that the gears of the vehicle perform reciprocating lateral tooth movements, and obtaining the mechanical angle of the motor rotor at different test times; determining the maximum and minimum periodic angle values ​​in each test cycle based on the mechanical angles of the motor rotor at different test times, and determining the periodic transmission system clearance for each test cycle; determining the average transmission system clearance through at least a portion of the periodic transmission system clearance, matching the average transmission system clearance to obtain a target torque gradient correction value corresponding to the average transmission system clearance; determining the current torque zero-crossing gradient of the vehicle based on the target torque gradient correction value and a preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the motor of the vehicle.

[0007] In one embodiment of the present invention, the method for determining that the wheels are in a braking stationary state includes: obtaining the current state of the vehicle; if the current state of the vehicle is a target vehicle state, determining that the wheels of the vehicle are in a braking stationary state; the target vehicle state includes at least one of the following: the vehicle is in neutral, the vehicle is in parking gear, the vehicle's parking function is enabled, the brake pedal depth of the vehicle is greater than a preset depth and the vehicle is in drive gear.

[0008] In one embodiment of the present invention, before controlling the motor of the vehicle to output positive and negative cycle torque for multiple test cycles, the method further includes: obtaining an initial update identifier of the initial torque zero-crossing gradient of the vehicle, the initial update identifier including at least one of initial update time and initial update vehicle mileage; if the initial update identifier includes initial update time, determining a gradient update duration based on the initial update time and the current time; if the gradient update duration is greater than a preset duration threshold, determining that the vehicle meets a first trigger condition; if the initial update identifier includes initial update vehicle mileage, determining a gradient update mileage based on the initial update vehicle mileage and the current vehicle mileage; if the gradient update mileage is greater than a preset mileage threshold, determining that the vehicle meets a second trigger condition; if the wheels of the vehicle are in a braking stationary state, and the vehicle meets at least one of the first trigger condition and the second trigger condition, triggering control of the motor of the vehicle to output positive and negative cycle torque for multiple test cycles.

[0009] In one embodiment of the present invention, before controlling the motor of the vehicle to output positive and negative cycle torque for multiple test cycles, the method further includes: acquiring transmission system fault information of the vehicle; matching a fault handling plan based on the transmission system fault information; if the fault handling plan includes at least one of transmission system component replacement or transmission system component position adjustment, and the wheels of the vehicle are in a braking stationary state, triggering the control of the motor of the vehicle to output positive and negative cycle torque for multiple test cycles.

[0010] In one embodiment of the present invention, determining the maximum and minimum periodic angle values ​​in each test cycle based on the mechanical angles of the motor rotor at different test times, and determining the periodic transmission system clearance in each test cycle, includes: performing low-pass filtering on the mechanical angles of the motor rotor at different test times to obtain multiple filter values; taking the maximum filter value in each test cycle as the maximum periodic angle value, and taking the minimum filter value in each test cycle as the minimum periodic angle value; determining the angle difference between the maximum and minimum periodic angle values ​​in each test cycle, and using the angle difference as the periodic transmission system clearance for each test cycle.

[0011] In one embodiment of the present invention, determining the average transmission system clearance by at least a portion of the periodic transmission system clearances includes: determining a total clearance by summing the at least a portion of the periodic transmission system clearances; and determining the average transmission system clearance based on the quotient of the total clearance and the number of periods, wherein the number of periods is the number of periodic transmission system clearances.

[0012] In one embodiment of the present invention, matching the average transmission system gap to obtain a target torque gradient correction value corresponding to the average transmission system gap includes: matching the average transmission system gap with multiple preset transmission system gaps, determining a preset transmission system gap as a target transmission system gap; obtaining a preset torque gradient correction value corresponding to the target transmission system gap, and determining it as the target torque gradient correction value, wherein each preset transmission system gap is pre-set with a corresponding preset torque gradient correction value.

[0013] In one embodiment of the present invention, determining the current torque zero-crossing gradient of the vehicle based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value includes: obtaining the preset basic zero-crossing torque gradient value of the vehicle; and determining the product of the preset basic zero-crossing torque gradient value and the target torque gradient correction value as the current torque zero-crossing gradient of the vehicle.

[0014] In one embodiment of the present invention, after determining the current torque zero-crossing gradient of the vehicle based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, the method further includes: if an update of a one-dimensional table is detected, the one-dimensional table is used to store multiple preset transmission system gaps, a preset torque gradient correction value corresponding to each preset transmission system gap, and the correspondence between the preset transmission system gaps and the preset torque gradient correction values; re-execute the step of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles until the average transmission system gap is determined through at least a portion of the cycle transmission system gaps, to obtain a new average transmission system gap; query the updated one-dimensional table using the new average transmission system gap to obtain a new target torque gradient correction value; determine the new current torque zero-crossing gradient of the vehicle based on the new target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to continue to perform torque zero-crossing control on the vehicle's motor.

[0015] This invention also provides a motor torque zero-crossing control device, comprising: a start control module, configured to control the vehicle's motor to output positive and negative periodic torque for multiple test cycles when the vehicle's wheels are in a braking and stationary state, so that the vehicle's gears perform reciprocating lateral tooth movements and acquire the motor rotor mechanical angle at different test times; a periodic transmission system clearance determination module, configured to determine the maximum and minimum periodic angle values ​​in each test cycle based on the motor rotor mechanical angle at different test times, and determine the periodic transmission system clearance for each test cycle; a matching module, configured to determine the average transmission system clearance through at least a portion of the periodic transmission system clearance, and match the average transmission system clearance to obtain a target torque gradient correction value corresponding to the average transmission system clearance; and a current torque zero-crossing gradient determination module, configured to determine the vehicle's current torque zero-crossing gradient based on the target torque gradient correction value and a preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

[0016] This invention also provides a new energy vehicle, including a vehicle controller, a motor controller, a drive motor, and a transmission system. The motor controller is used to control the drive motor to output positive and negative periodic torques for multiple test cycles when the wheels are in a braking stationary state, so that the gears in the transmission system perform reciprocating lateral tooth movements, and to acquire and record the mechanical angle of the motor rotor at different test times. It also determines the maximum and minimum periodic angles in each test cycle based on the mechanical angles of the motor rotor at different test times, determines the periodic transmission system clearance for each test cycle, determines the average transmission system clearance through at least a portion of the periodic transmission system clearance, and sends the average transmission system clearance to the vehicle controller. The vehicle controller receives the average transmission system clearance, matches the average transmission system clearance to obtain a target torque gradient correction value corresponding to the average transmission system clearance, and determines the current torque zero-crossing gradient based on the target torque gradient correction value and a preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the drive motor.

[0017] This invention also provides an electronic 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 method described in any of the above embodiments.

[0018] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in any of the above embodiments.

[0019] In the above-mentioned solution implemented by the motor torque zero-crossing control method, device, vehicle, electronic equipment, and medium, the method controls the vehicle's motor to output positive and negative cycle torque for multiple test cycles while the vehicle's wheels are in a braked and stationary state. This causes the vehicle's gears to perform reciprocating lateral tooth movements, and the mechanical angle of the motor rotor is obtained at different test moments. The maximum and minimum cycle angle values ​​are determined for each test cycle, and the cycle transmission system clearance for each test cycle is determined. The average transmission system clearance is then determined, and a target torque gradient correction value corresponding to the average transmission system clearance is obtained. Based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, the current torque zero-crossing gradient of the vehicle is determined to control the vehicle's motor torque zero-crossing. By correcting the current torque zero-crossing gradient of the vehicle at different times in the vehicle's life cycle, the adaptability of the current torque zero-crossing gradient to the vehicle is ensured. This also avoids the problem of abnormal noise caused by changes in the transmission system due to vehicle use, which renders the fixed torque zero-crossing gradient value inapplicable. Furthermore, it avoids zero-crossing abnormal noise problems at the moment of starting or during torque reversal throughout the vehicle's life cycle, resulting in smooth torque output from the power system. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a typical transmission system for a new energy vehicle.

[0022] Figure 2 A schematic flowchart of a motor torque zero-crossing control method provided in an embodiment of the present invention;

[0023] Figure 3 A schematic flowchart of the transmission system backlash self-learning method provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the transmission system backlash self-learning process provided in an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the VCU control torque zero-crossing gradient provided in an embodiment of the present invention;

[0026] Figure 6 This is another specific flowchart illustrating the motor torque zero-crossing control method provided in this embodiment of the invention;

[0027] Figure 7 A schematic diagram of the motor torque zero-crossing control device provided in an embodiment of the present invention;

[0028] Figure 8 A schematic diagram of the structure of a new energy vehicle provided in an embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention;

[0030] Figure 10 This is another structural schematic diagram of an electronic device according to one embodiment of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] New energy vehicles are typically driven by a drive motor, and a typical transmission system consists of, for example, a drive motor. Figure 1 As shown, Figure 1 This is a schematic diagram of a typical transmission system for a new energy vehicle, such as... Figure 1 As shown, this typical transmission system includes a motor, a reduction gearbox, a differential and half-shafts, and wheels. There is a certain amount of clearance between the reduction gearbox and differential gears, and as the vehicle ages, the backlash will change due to wear on the bearings or gears.

[0033] Due to the meshing characteristics of motor gears, when the gear rotation direction changes from forward to reverse or from reverse to forward, the presence of clearance in the transmission system inevitably leads to abnormal noises such as gear tooth contact and grinding. After the torque crosses zero, the motor speed may also fluctuate, causing torque oscillation in the transmission system and vehicle jerking, which in turn causes driving comfort issues and reduces the user's driving experience.

[0034] By altering the torque gradient at the moment the drive motor's torque crosses zero, transmission system noise issues at this point can be improved and optimized. However, in related technologies, a preset torque zero-crossing gradient calibrated on the actual vehicle is typically used to reduce speed fluctuations caused by changes in torque direction. However, this preset gradient is manually calibrated at the vehicle's factory and is only effective for test vehicles at that time. Sometimes it cannot cover vehicle deviations, making it unsuitable for other vehicles of the same model. Alternatively, while it may be universally applicable to other vehicles of the same model initially, changes in the transmission system over time render the fixed torque zero-crossing gradient no longer applicable, meaning it cannot cover torque zero-crossing noise issues throughout the vehicle's entire lifecycle.

[0035] To address the aforementioned problems, this invention proposes a method, device, vehicle, electronic equipment, and medium for controlling zero-crossing torque of a motor. By actively controlling the output of positive and negative periodic torques of the drive motor when the vehicle is parked, the motor controller (PEU) ensures that the gears are aligned on different sides. The transmission system clearance is identified by the motor rotor angle and stored as a self-learning angle value. The vehicle controller (VCU) receives the clearance self-learning value and adaptively adjusts the zero-crossing gradient parameters of the drive motor's target torque. This solves the problem of abnormal noise during zero-crossing at start-up or torque reversal throughout the vehicle's lifespan, ensuring smooth torque output from the powertrain and improving driving comfort. The following detailed description of specific embodiments illustrates the solution provided by this invention.

[0036] Please see Figure 2 As shown, Figure 2 A flowchart illustrating a motor torque zero-crossing control method provided in an embodiment of the present invention includes the following steps:

[0037] In step S210, if the vehicle's wheels are in a braking and stationary state, control the vehicle's motor to output positive and negative cycle torque for multiple test cycles, so that the vehicle's gears can perform reciprocating side-to-side tooth movements, and obtain the mechanical angle of the motor rotor at different test times.

[0038] The vehicle can be any new energy vehicle, and there are no restrictions here. The motor mentioned here is the drive motor mentioned later.

[0039] In one embodiment, before step S210, that is, before controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles if the vehicle's wheels are in a braking stationary state, the method further includes: determining whether the vehicle's wheels are in a braking stationary state. An exemplary method for determining whether the wheels are in a braking stationary state includes: acquiring the vehicle's current state; if the vehicle's current state is a target vehicle state, determining that the vehicle's wheels are in a braking stationary state; the target vehicle state includes at least one of the following: the vehicle is in neutral, the vehicle is in park, the vehicle's parking function is enabled, the vehicle's brake pedal depth is greater than a preset depth, and the vehicle is in a drive gear. That is, when the vehicle is parked, it is in N (neutral), P (park), D (drive), or the parking function is enabled, such as when EPB (Electronic Park Brake) is engaged. All of the above target vehicle states can provide sufficient braking force to ensure that the wheels do not rotate (i.e., the wheels are in a braking stationary state), and this is used as the reference position for the wheel side of the entire transmission system's clearance self-learning function. The preset depth can be set by those skilled in the art, with the braking force corresponding to the pedal depth being sufficient to resist the forward driving force of the forward gear and ensure that the wheels do not rotate.

[0040] Since vehicles do not always require correction of the current torque zero-crossing gradient, performing this correction every time the vehicle is parked would result in a significant waste of resources. Therefore, certain correction trigger conditions can be set to control the correction frequency of the current torque zero-crossing gradient. These correction trigger conditions include, but are not limited to, at least one of the first trigger condition, the second trigger condition, and fault handling solutions such as replacement of transmission system components or adjustment of transmission system component positions provided in the following embodiments.

[0041] In other words, if the vehicle's wheels are in a braking and stationary state, it is first determined whether the vehicle meets the correction trigger condition. If the correction trigger condition is met, the vehicle's motor is controlled to output positive and negative cycle torque for multiple test cycles, so that the vehicle's gears can perform reciprocating side-to-side tooth movements and obtain the mechanical angle of the motor rotor at different test times. If the correction trigger condition is not met, the subsequent steps will not be executed.

[0042] The correction trigger condition can be determined by the PEU (Power Electronic Unit, motor controller). The motor drive system integrates an MCU (motor control unit). The PEU determines if self-learning has not been performed for a certain period (e.g., exceeding 5000 km) or if a transmission system-related fault has been reported (e.g., a broken axle may have led to the replacement of transmission system components), and if the vehicle's wheels are in a braked, stationary state. If so, the self-learning condition is considered met (the correction trigger condition is met). The system then controls the vehicle's motor to output positive and negative cycle torque for multiple test cycles, causing the vehicle's gears to reciprocate with different lateral tooth movements, and obtains the motor rotor mechanical angle at different test moments.

[0043] In one embodiment, before controlling the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles, the method further includes: obtaining an initial update identifier of the vehicle's initial torque zero-crossing gradient, the initial update identifier including at least one of an initial update time and an initial update vehicle mileage; if the initial update identifier includes an initial update time, determining a gradient update duration based on the initial update time and the current time; if the gradient update duration is greater than a preset duration threshold, determining that the vehicle meets a first trigger condition; if the initial update identifier includes an initial update vehicle mileage, determining a gradient update mileage based on the initial update vehicle mileage and the current vehicle mileage; if the gradient update mileage is greater than a preset mileage threshold, determining that the vehicle meets a second trigger condition; if the vehicle's wheels are in a braked stationary state, and the vehicle meets at least one of the first and second trigger conditions, triggering the control of the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles. The initial update time is the update time of the currently used torque zero-crossing gradient (initial torque zero-crossing gradient), and the initial update vehicle mileage is the actual mileage of the vehicle at the time of updating the currently used torque zero-crossing gradient (initial torque zero-crossing gradient).

[0044] For example, a new vehicle may be equipped with a preset torque zero-crossing gradient value. This preset torque zero-crossing gradient value is used as the initial torque zero-crossing gradient. The initial update time of this initial torque zero-crossing gradient is the time the vehicle is delivered for use, the time the vehicle rolls off the production line, or another time set by those skilled in the art. The initial updated vehicle mileage for this initial torque zero-crossing gradient is 0 km, or the vehicle mileage at the time of delivery for use, or another mileage value set by those skilled in the art. As another example, if a vehicle may have undergone multiple corrections to the torque zero-crossing gradient during use, the torque zero-crossing gradient obtained from the last correction is used as the initial torque zero-crossing gradient. The initial update time of this initial torque zero-crossing gradient is the time of the last correction. The initial updated vehicle mileage for this initial torque zero-crossing gradient is the actual mileage of the vehicle at the time of the last correction.

[0045] The time difference between the initial update time and the current time is determined as the gradient update duration. If the gradient update duration is greater than the preset duration threshold, the vehicle is determined to meet the first trigger condition, that is, the correction of the torque zero crossing gradient can be performed next time, that is, the drive motor of the vehicle is triggered to output positive and negative cycle torque for multiple test cycles. The preset duration threshold can be set by those skilled in the art as needed, and is not limited here.

[0046] The mileage difference between the initial updated vehicle mileage and the current vehicle mileage is determined as the gradient update mileage. If the gradient update mileage is greater than the preset mileage threshold, the vehicle is determined to meet the second trigger condition, that is, the correction of the torque zero crossing gradient can be performed next time, which triggers the drive motor of the vehicle to output positive and negative cycle torque for multiple test cycles. The preset mileage threshold can be set by those skilled in the art as needed, and is not limited here.

[0047] In another embodiment, before controlling the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles, the method further includes: acquiring vehicle transmission system fault information; matching a fault handling plan based on the transmission system fault information; if the fault handling plan includes at least one of replacing transmission system components or adjusting the position of transmission system components, and the vehicle's wheels are in a braking stationary state, triggering the control of the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles.

[0048] The transmission system fault information can be obtained through analysis of stored insurance claim information on a cloud server, user-reported faults, vehicle self-monitoring, or other methods known to those skilled in the art. The fault handling plan can be derived by matching the transmission system fault information with pre-defined fault handling plans for each fault. One or more fault handling plans can be set for each fault, and each fault, all corresponding fault handling plans, and the correlation between the fault and the plans are recorded. The vehicle's transmission fault information is then matched against all the previously set faults. If a match is successful, the corresponding fault handling plan is obtained. If a fault corresponds to multiple fault handling plans, and at least one plan requires replacement or adjustment of transmission components, it indicates that the vehicle's transmission may have been adjusted. Therefore, the original initial torque zero-crossing gradient may no longer be applicable and needs to be corrected. This can trigger the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles, and subsequent steps. For example, if the fault information of the transmission system is "Duanzhou", the corresponding fault handling solution may be to replace some transmission system components. In this case, it is necessary to correct the initial torque zero-crossing gradient.

[0049] In another embodiment, the determination of whether to correct the initial torque zero-crossing gradient can also be combined with the vehicle's planned route. That is, by obtaining the vehicle's planned driving route, the future road type of the vehicle can be determined based on the planned driving route. If the road type of the future driving route exceeding the preset mileage is mountainous, sandy, dirt road, etc., the correction trigger condition can be considered to have been met before the vehicle starts or during the parking period before reaching the mountainous, sandy, dirt road, etc., triggering the control of the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles and subsequent steps, so as to ensure a better handling experience on road sections with poor road conditions.

[0050] In one embodiment, the step of controlling the vehicle's motor to output positive and negative periodic torque for multiple test cycles to cause the vehicle's gears to reciprocate with different side-to-side tooth movements can be achieved by the PEU actively triggering the drive motor to output periodic positive and negative torque, maintaining an average torque of 0. The torque waveform can be set as needed, and different waveforms such as sine waves and triangular waves can be used. The torque amplitude is based on overcoming the friction torque of the transmission system, and the test cycle is 0.5s to 1s, lasting for several test cycles. The test cycle of 0.5s to 1s is only an example, and those skilled in the art can set it as needed. The torque amplitude can also be set according to the needs of those skilled in the art. That is, when the vehicle is parked, the motor controller (PEU) actively controls the drive motor to output positive and negative periodic torque to ensure that the gears are in contact with each other on different sides, which helps to determine the transmission system clearance.

[0051] In this embodiment, obtaining the motor rotor mechanical angle at different test moments can be achieved by sampling the motor rotor mechanical angle at multiple sampling points, or by continuous monitoring using a high-precision position sensor (such as a rotary transformer, eddy current speed sensor, etc.) installed on the motor output shaft. This means continuously monitoring the motor rotor mechanical angle to obtain the motor rotor mechanical angle at each test moment. This can be recorded using a PEU (Power Equipped Unit). Furthermore, the PEU simultaneously analyzes key signals such as speed and motor torque, storing information such as the fluctuation amplitude and period of speed and torque during the most recent self-learning processes, facilitating the tracing of historical self-learning information. That is, the history of motor torque zero-crossing control over a previous period can be traced by storing multiple historical updates of the current torque zero-crossing gradient (historical speed, historical motor torque, historical electronic rotor mechanical angle, and historical torque zero-crossing gradient).

[0052] When the motor torque fluctuates periodically, since the wheels are stationary, the gears in the shaft system will rotate from one side to the other, corresponding to the motor rotor position (motor rotor mechanical angle). rotor The maximum and minimum values ​​of .

[0053] In one embodiment, if the vehicle's wheels are in a braked, stationary state and the correction triggering condition is met, the method further includes prompting the user for correction via the vehicle's infotainment system or other notification system, and obtaining the user's response information. If the user agrees to the correction, the method then triggers a step to control the vehicle's motor to output positive and negative cycle torque for multiple test cycles. Since correcting the torque zero-crossing gradient may take some time, although the duration can be adjusted by controlling the number of test cycles, to better improve the user experience and avoid affecting the user's normal use of the vehicle, the user can be informed in advance that a torque zero-crossing gradient correction is needed. If the user agrees, the method executes the step of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles. If the user disagrees, the method asks the user again after a preset interval or after the vehicle has reached a certain mileage to confirm whether to perform the torque zero-crossing gradient correction. After the user agrees, the method can also inform the user of the duration of the correction process (the duration requirement for torque zero-crossing gradient correction) so that the user can make reasonable time arrangements.

[0054] In one embodiment, the method provided in this embodiment can also be associated with systems such as autonomous driving. Specifically, when the vehicle's wheels are in a braking and stationary state and the correction triggering conditions are met, the vehicle's current position is obtained to determine whether the vehicle is within a preset area such as a parking space, roadside, or intersection. When the vehicle is within a parking space or roadside, drivers often wait for a period of time before starting. This waiting time can be used to correct the torque zero-crossing gradient, that is, to trigger the step of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles. When the vehicle is at an intersection, relevant information about the traffic lights can be associated to determine the remaining duration of the red light. Some intersections may have red lights that last for two minutes. If the remaining duration of the red light meets the duration requirement for torque zero-crossing gradient correction, the step of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles can be triggered.

[0055] It should be noted that there is no explicit order between determining the triggering condition and confirming that the wheel is in a braking and stationary state. Those skilled in the art can choose the order of execution as needed.

[0056] In this way, with the vehicle parked, the vehicle motor is controlled to output positive and negative cycle torque for multiple test cycles, so that the gears perform reciprocating side-to-side tooth movements, and the corresponding motor rotor position is collected for subsequent determination of the transmission system clearance.

[0057] By judging the correction trigger conditions, the torque zero-crossing gradient can be corrected more scientifically and reasonably, rather than blindly, thus further improving the user experience.

[0058] Step S220: Determine the maximum and minimum values ​​of the periodic angle in each test cycle based on the mechanical angle of the motor rotor at different test times, and determine the periodic transmission system clearance in each test cycle.

[0059] In one embodiment, determining the maximum and minimum periodic angle values ​​in each test cycle based on the motor rotor mechanical angles at different test times, and determining the periodic transmission system clearance for each test cycle, includes: performing low-pass filtering on the motor rotor mechanical angles at different test times to obtain multiple filter values; taking the maximum filter value in each test cycle as the maximum periodic angle value, and taking the minimum filter value in each test cycle as the minimum periodic angle value; determining the angle difference between the maximum and minimum periodic angle values ​​in each test cycle, and using the angle difference as the periodic transmission system clearance for each test cycle.

[0060] As mentioned in the above embodiments, when the motor torque fluctuates periodically, and the wheels remain stationary, the shaft gears will rotate from one side to the other. This corresponds to the maximum and minimum values ​​of the electronic rotor position, which are also the maximum and minimum values ​​of the motor rotor mechanical angle. By performing low-pass filtering on all the collected motor rotor mechanical angles to remove fluctuations, multiple pairs of filtered steady-state angle maxima and minima can be obtained, with one pair per cycle. The low-pass filtering can be achieved using a first-order low-pass filter to remove signal glitches and fluctuations. Alternatively, the low-pass filtering can be implemented using methods known to those skilled in the art, which will not be elaborated upon here.

[0061] The clearance of a transmission system in a given cycle can be obtained by subtracting the minimum filter value from the maximum filter value and converting it into an angle.

[0062] In one embodiment, the minimum and maximum values ​​of the period angle can be determined for all test cycles containing the collected motor rotor mechanical angles, or the minimum and maximum values ​​of the period angle can be determined for a portion of the test cycles, and test cycles with many missing motor rotor mechanical angles can be excluded.

[0063] Step S230: Determine the average transmission system clearance through at least a portion of the periodic transmission system clearance, and match the average transmission system clearance to obtain the target torque gradient correction value corresponding to the average transmission system clearance.

[0064] Since there may be many test cycles, in order to reduce the amount of calculation, the full cycle transmission system clearance can be sampled (for example, the interval test cycles can be used as samples for subsequent calculation of the average transmission system clearance. In this case, the interval cycle method can also be used to determine the maximum and minimum cycle angles mentioned above. For unnecessary test cycles, no data processing is performed) to obtain a partial cycle transmission system clearance, and the average transmission system clearance is determined based on the partial cycle transmission system clearance.

[0065] In one embodiment, determining the average transmission system clearance using at least a portion of the periodic transmission system clearances includes: determining a total clearance by summing the at least a portion of the periodic transmission system clearances; and determining the average transmission system clearance based on the quotient of the total clearance and the number of periods, wherein the number of periods is the number of periodic transmission system clearances. That is, the average clearance can be obtained by averaging all the periodic transmission system clearances determined in the above embodiment, or by averaging the clearances of a portion of the periodic transmission system clearances.

[0066] One example of how to determine the average transmission system clearance is as follows:

[0067]

[0068] Where ΔGap is the average transmission system clearance, and n is the number of transmission system clearances in a cycle, i.e., the average transmission system clearance over n cycles, ag rotor _LP_max i ag is the maximum filter value in the i-th test period. rotor _LP_min i Let be the minimum filter value for the i-th test period, where i is the i-th test period and i ≤ n.

[0069] The average transmission system clearance can be determined as the transmission system clearance self-learning value, thus completing the transmission system clearance self-learning step, and storing the transmission system clearance self-learning value (average transmission system clearance).

[0070] In one embodiment, matching the average transmission system clearance to obtain the target torque gradient correction value corresponding to the average transmission system clearance includes: matching the average transmission system clearance with multiple preset transmission system clearances, determining one preset transmission system clearance as the target transmission system clearance; obtaining the preset torque gradient correction value corresponding to the target transmission system clearance, and determining the preset torque gradient correction value as the target torque gradient correction value, wherein each preset transmission system clearance is pre-set with a corresponding preset torque gradient correction value.

[0071] For example, the target torque gradient correction value can be determined using a pre-stored one-dimensional table. This one-dimensional table includes multiple preset transmission system gaps, a preset torque gradient correction value corresponding to each preset transmission system gap, and a correspondence between the preset transmission system gaps and the preset torque gradient correction values. By looking up the average transmission system gap in the table, the corresponding target torque gradient correction value is obtained. That is, the average transmission system gap is matched with multiple preset transmission system gaps, and the preset transmission system gap that is successfully matched is determined as the target transmission system gap. Based on the correspondence, the preset torque gradient correction value corresponding to the target transmission system gap is determined as the target torque gradient correction value.

[0072] It should be noted that matching the average transmission system clearance with multiple preset transmission system clearances does not necessarily mean that the average transmission system clearance is the same as a certain preset transmission system clearance. Alternatively, it can be done by calculating the difference between the average transmission system clearance and each preset transmission system clearance, with a difference less than a preset difference threshold considered a match, and the preset transmission system clearance with the smallest difference determined as the target transmission system clearance. If the difference between the average transmission system clearance and each preset transmission system clearance is greater than the preset difference threshold, the larger (or smaller) of the two preset transmission system clearances corresponding to the two smallest differences can be used as the target transmission system clearance. The choice between a larger or smaller value can also be based on the user's driving mode. For example, for Sport driving mode, a larger value corresponding to the torque zero-crossing gradient result can be selected; for Comfort driving mode, a smaller value corresponding to the torque zero-crossing gradient result can be selected.

[0073] In one embodiment, the one-dimensional table described above can be pre-stored in the vehicle, and can also be updated via OTA (Over-The-Air) upgrades. This update can update all values ​​or only some values. In this embodiment, the vehicle can store one or more one-dimensional tables. The target torque gradient correction values ​​determined based on different one-dimensional tables differ, resulting in different magnitudes of the final torque zero-crossing gradient. The corresponding one-dimensional table can be selected by acquiring the current driver's driving preferences, habits, and driving mode. Switching from the currently selected, active one-dimensional table also constitutes a form of one-dimensional table update. The current driver can be identified through biometric methods such as facial recognition at the driving position, or by the user's logged-in vehicle infotainment system.

[0074] Step S240: Determine the current torque zero-crossing gradient of the vehicle based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

[0075] The method of controlling the motor to zero torque using the current torque zero-crossing gradient can be achieved in a way known to those skilled in the art, and will not be elaborated here.

[0076] In one embodiment, determining the current torque zero-crossing gradient of a vehicle based on a target torque gradient correction value and a preset base zero-crossing torque gradient value includes: obtaining a preset base zero-crossing torque gradient value of the vehicle; and determining the current torque zero-crossing gradient of the vehicle by multiplying the preset base zero-crossing torque gradient value and the target torque gradient correction value.

[0077] The preset baseline zero-crossing torque gradient value is obtained through actual vehicle calibration, or it can be obtained through other methods known to those skilled in the art.

[0078] One method for determining the current torque zero-crossing gradient includes:

[0079] Grd1 = Grd0 × fac Grd Formula (2)

[0080] Where Grd1 is the current torque zero-crossing gradient, Grd0 is the preset base zero-crossing torque gradient value, and fac Grd This is the target torque gradient correction value.

[0081] In one embodiment, after determining the vehicle's current torque zero-crossing gradient based on the target torque gradient correction value and the preset baseline zero-crossing torque gradient value, the method further includes:

[0082] If an update to the one-dimensional table is detected, the one-dimensional table is used to store multiple preset transmission system gaps, a preset torque gradient correction value corresponding to each preset transmission system gap, and the correspondence between the preset transmission system gaps and the preset torque gradient correction values.

[0083] Steps S210-S220 are re-executed, that is, if the vehicle's wheels are in a braking and stationary state, the steps of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles are re-executed until the average transmission system gap is determined through at least a portion of the cycle transmission system gap, a new average transmission system gap is obtained, and the updated one-dimensional table is queried through the new average transmission system gap to obtain a new target torque gradient correction value.

[0084] The new current torque zero-crossing gradient of the vehicle is determined based on the new target torque gradient correction value and the preset base zero-crossing torque gradient value, so as to continue to control the torque zero-crossing of the vehicle's motor.

[0085] It is understandable that the correction triggering conditions also include the update event of the one-dimensional table. Once the one-dimensional table is updated, the current torque zero-crossing gradient needs to be re-determined. The determination logic of the new target torque gradient correction value and the new current torque zero-crossing gradient is similar to that of the target torque gradient correction value and the current torque zero-crossing gradient in the above embodiments, and will not be elaborated here.

[0086] The motor torque zero-crossing control method provided in the above embodiments controls the vehicle's motor to output positive and negative cycle torque for multiple test cycles when the vehicle's wheels are in a braked and stationary state. This causes the vehicle's gears to perform reciprocating side-to-side tooth movements, and the mechanical angle of the motor rotor at different test moments is obtained. The maximum and minimum cycle angle values ​​are determined for each test cycle, and the cycle transmission system clearance for each test cycle is determined. The average transmission system clearance is then determined, and a target torque gradient correction value corresponding to the average transmission system clearance is obtained. Based on the target torque gradient correction value and a preset base zero-crossing torque gradient value, the current torque zero-crossing gradient of the vehicle is determined to control the vehicle's motor torque zero-crossing. By correcting the current torque zero-crossing gradient during vehicle use, the determination and correction of the current torque zero-crossing gradient can be personalized for each vehicle. This avoids the poor compatibility with other vehicles of the same model caused by a fixed torque zero-crossing gradient value, and also avoids the problem of abnormal vehicle noise caused by changes in the transmission system during vehicle use, which renders the fixed torque zero-crossing gradient value inapplicable. Furthermore, it avoids zero-crossing noise problems during vehicle start-up or torque reversal throughout the vehicle's entire lifespan, resulting in smooth torque output from the power system.

[0087] The motor torque zero-crossing control method provided in the above embodiments has a wide range of applications and can be used for different types of motors such as PMSM (Permanent Magnet Synchronous Motor) and ASM (AC asynchronous motor), as well as different pure electric and hybrid topologies.

[0088] The motor torque zero-crossing control method provided in the above embodiments can be applied to correct different types of zero-crossing target torques, such as linear and quadratic function types. It can also be used to correct the duration of the torque remaining at 0 Nm when it crosses zero. By controlling the reasonable selection of the target torque gradient correction value, and thus selecting a reasonable current torque zero-crossing gradient, the duration of the time interval where the torque zero crosses can be controlled.

[0089] The following is an exemplary description of the motor torque zero-crossing control method provided in the above embodiments through a specific example. This specific motor torque zero-crossing control method includes two stages: 1. Identifying the shaft clearance of the transmission system; 2. Adjusting the vehicle's zero-crossing torque gradient.

[0090] In the first stage of identifying transmission system shaft clearance, if the average transmission system clearance is used as the self-learning value for transmission system clearance, please refer to [link to relevant documentation]. Figure 3 , Figure 3 A schematic flowchart of the transmission system backlash self-learning method provided in an embodiment of the present invention is shown below. Figure 3 As shown, the system first determines whether the self-learning conditions are met, that is, whether the correction triggering conditions and the vehicle's wheels are in a braking and stationary state are met. For example, the transmission system clearance self-learning function is activated when the following conditions are met after the vehicle stops:

[0091] a) N / P gear (or press the brake and shift to D gear);

[0092] b) When the parking function is activated, such as when EPB is engaged, sufficient braking force is provided to ensure that the wheels do not rotate, and this serves as the reference position for the wheel side of the entire transmission system clearance self-learning function.

[0093] c) The PEU determines that there is no self-learning value at present, or that self-learning has not been performed for a certain period of time (such as more than 5000km), or that a transmission system-related fault has been reported (such as the replacement of transmission system components after a half-shaft breakage fault occurs).

[0094] It should be noted that satisfying at least one of conditions a and b above is sufficient to activate the transmission system backlash self-learning function, triggering the vehicle's motor to output positive and negative torque for multiple test cycles and subsequent steps. Alternatively, satisfying at least one of conditions a and b, as well as condition c, is also required to trigger the vehicle's motor to output positive and negative torque for multiple test cycles and subsequent steps. Condition c is used to adjust the transmission system backlash self-learning frequency, avoiding unnecessary system load caused by excessively frequent backlash self-learning.

[0095] After meeting the basic conditions for self-learning (meeting the correction trigger condition and the vehicle wheels being in a braking and stationary state), the transmission system gap self-learning is executed. This means the PEU actively triggers the drive motor to output periodic positive and negative torque, maintaining an average torque of 0. The torque waveform can be set as needed, using different waveforms such as sine waves and triangular waves. The torque amplitude is based on overcoming the transmission system friction torque, with a torque period of 0.5–1 second, lasting for several cycles. The PEU internally records key variables such as speed, motor torque, and motor rotor mechanical angle. The motor rotor mechanical angle is obtained by a high-precision position sensor mounted on the motor output shaft (such as a rotary transformer or eddy current speed sensor). Other signals (such as gear position and vehicle mileage) are received from other controllers, such as the VCU, via the CAN bus. By recording, analyzing, and storing data from the most recent self-learning processes (key variables such as speed, motor torque, motor rotor mechanical angle, gear position, and vehicle mileage during multiple transmission system gap self-learning sessions), traceability is facilitated. Data such as gear position and vehicle mileage used to determine whether the conditions for activating the transmission system gap self-learning function are met can be obtained from other controllers via the CAN bus.

[0096] When the motor torque fluctuates periodically, since the wheels are stationary, the gears in the shaft system will rotate from one side of the toothed shaft to the other side, corresponding to the motor rotor position ag. rotor The maximum and minimum values ​​of the value affect the mechanical angle ag of the motor rotor. rotor The filtered value ag is obtained by performing a certain low-pass filtering. rotor _LP, the maximum filtered value ag rotor _LP_max minus the minimum filter value ag rotor _LP_min is the clearance of the periodic transmission system (converted to angle). Taking the average clearance of the periodic transmission system over n test cycles, the final self-learning value of the transmission system clearance (average transmission system clearance) can be calculated using the above formula (1). Please refer to... Figure 4 , Figure 4 A schematic diagram of the transmission system backlash self-learning process provided in an embodiment of the present invention is shown below. Figure 4 As shown, the horizontal axis represents time t, the vertical axis of the upper periodic torque line represents torque, and the vertical axis of the lower motor rotor mechanical angle line represents the motor rotor mechanical angle. Taking two cycles as an example, the lower motor rotor mechanical angle ( Figure 4 The motor mechanical angles shown in the image are represented by two lines. The dashed curve is drawn based on the motor rotor mechanical angles before filtering, while the broken line is drawn based on the motor rotor mechanical angles after filtering. The smoothest part of the filtered broken line is... Figure 4 The maximum and minimum filter values ​​are the mechanical angles of the motor rotor at any given time, where the line segment (which is approximately parallel to or parallel to the horizontal axis) is located. Figure 4In the motor torque graph, the line parallel to the dashed line on the horizontal axis represents 0 Nm; similarly, in the motor mechanical angle graph, the line parallel to the dashed line on the horizontal axis represents 0 degrees. Figure 4 Taking two cycles, cycle 1 and cycle 2, as an example, those skilled in the art can choose multiple cycles, and the number is not limited here.

[0097] Determine if self-learning was successful. If successful, obtain the gap self-learning value and store it. Figure 3 The process ends if the self-learning value is not met, or if the self-learning fails or the self-learning conditions are not met.

[0098] In the second stage of vehicle zero-crossing torque gradient adjustment, the PEU sends the transmission system clearance self-learning value ΔGap (average transmission system clearance) to the VCU (vehicle controller) via CAN communication. The VCU then retrieves the target torque gradient correction value facGrd using a pre-stored one-dimensional table. This one-dimensional table stores multiple preset transmission system clearances, the preset torque gradient correction value corresponding to each preset transmission system clearance, and the correspondence between preset transmission system clearances and preset torque gradient correction values. The target torque gradient correction value fac is determined by querying the one-dimensional table using ΔGap. Grd Please refer to Table 1, which is an example of a one-dimensional table. The self-learned transmission system clearance value is used as the preset transmission system clearance, and the zero-crossing torque gradient correction value is used as the preset torque gradient correction value.

[0099] Table 1

[0100] Transmission system backlash self-learning value ΔGap_1 ΔGap_2 … ΔGap_x Zero-crossing torque gradient correction value <![CDATA[fac Grd _1]]> <![CDATA[fac Grd _2]]> … <![CDATA[fac Grd _x]]>

[0101] The VCU pre-stores the preset basic zero-crossing torque gradient value Grd0 obtained through vehicle calibration. The gradient value (current torque zero-crossing gradient) used to drive the target torque zero-crossing of the motor can be obtained by formula (2).

[0102] Please see Figure 5 , Figure 5 A schematic diagram of the VCU control torque zero-crossing gradient provided in an embodiment of the present invention is shown below. Figure 5 As shown in the example, with a torque of -5Nm to 5Nm considered as remaining in the 0Nm range, the curve on the left represents the target torque, and the curve on the right represents the actual torque after correction using the method provided in this embodiment (i.e., controlled using the current torque zero-crossing gradient determined by the method of this embodiment, i.e.) Figure 5 The zero-crossing torque gradient (calibrated value * correction value) is shown in the middle curve, which is the original torque zero-crossing gradient calibrated using the actual vehicle calibration (i.e., ...). Figure 5The torque curve corrected by the zero-crossing torque gradient (calibrated value) shows that the solution provided in this embodiment can correct the length of time the torque stays at 0 Nm when it crosses zero, and can effectively avoid the problem of abnormal vehicle noise caused by the fixed torque zero-crossing gradient value no longer being applicable.

[0103] Please see Figure 6 , Figure 6 This is another specific flowchart illustrating the motor torque zero-crossing control method provided in this embodiment of the invention, as shown below. Figure 6 As shown, the specific method includes:

[0104] Step S601: Determine whether the correction trigger condition is met.

[0105] Specific examples of the modified triggering conditions can be found in the descriptions in the above embodiments, and will not be repeated here.

[0106] This method can be started after the user has used the vehicle for a period of time or immediately after taking delivery of the vehicle. The correction trigger condition can also be initiated by the user. When the user initiates the motor torque zero-crossing control process, it is considered that the correction trigger condition has been met.

[0107] If the correction trigger condition is not met, the process ends.

[0108] Step S602: Determine whether the wheel is in a braking and stationary state.

[0109] The specific method for determining whether the wheels are in a braking and stationary state can be found in the description of the above embodiments, and will not be repeated here. If the wheels are rolling, that is, the vehicle is in motion, the process ends.

[0110] The order of steps S601 and S602 is not limited. If the requirements of steps S601 and S602 are met, the vehicle is determined to meet the self-learning conditions and the transmission system clearance self-learning steps can be executed, namely steps S603 to S607.

[0111] For example, after the vehicle starts, it idles in the parking space. If the correction trigger condition is met and the wheels are in a braked, stationary state, the process can begin. Before starting step S603, the user can be prompted in advance to receive instructions on whether to allow the execution of subsequent steps. Execution will only proceed after the user's permission. The user can be informed of the estimated time for the process so that they can plan accordingly. Furthermore, the corresponding one-dimensional table can be determined by obtaining the user's driving mode and driving habits. That is, the vehicle pre-stores multiple one-dimensional tables corresponding to driving modes or driving habits, and the corresponding one-dimensional table is selected based on the user's driving mode and driving habits to match and determine the subsequent target torque gradient correction value.

[0112] Of course, the update can also be performed without notifying the user at all, achieving a "seamless" update effect.

[0113] Step S603: Control the vehicle's motor to output positive and negative cycle torque for multiple test cycles, so that the vehicle's gears can perform reciprocating side-to-side tooth movements.

[0114] The motor output of the vehicle can be controlled by a motor controller such as PEU to control the positive and negative cycle torque of multiple test cycles, keeping the average torque at 0. The torque waveform is not limited here. The torque amplitude is based on overcoming the friction torque of the transmission system. The torque cycle is 0.5 to 1 second and lasts for several cycles.

[0115] Step S604: Obtain the mechanical angle of the motor rotor at different test times.

[0116] The mechanical angle of the motor rotor can be obtained by a high-precision position sensor installed on the motor output shaft.

[0117] Step S605: Low-pass filtering is performed on the mechanical angle of the motor rotor at different test times to obtain multiple filter values.

[0118] Step S606: Determine the periodic transmission system clearance for each test cycle.

[0119] Step S607: Determine the average transmission system clearance.

[0120] The specific implementation of steps S605-S607 above can be found in the description of the above embodiments, and is not limited here.

[0121] Step S608: Match the target torque gradient correction value corresponding to the average transmission system clearance.

[0122] As mentioned above, if there is only one one-dimensional table, the target torque gradient correction value is obtained by looking up that table. If there are multiple one-dimensional tables, one of them needs to be selected based on factors such as driving mode to obtain the target torque gradient correction value.

[0123] Step S609: Determine the vehicle's current torque zero-crossing gradient based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value.

[0124] Step S610: Perform torque zero-crossing control on the vehicle's motor.

[0125] Through the above steps, the current torque zero-crossing gradient of the vehicle is corrected. In subsequent normal driving of the vehicle, this current torque zero-crossing gradient is used for torque zero-crossing control.

[0126] Step S611: Determine whether the one-dimensional table has been updated.

[0127] If the one-dimensional table is updated, then steps S601-S611 are re-executed; otherwise, if the one-dimensional table is not updated, then the process ends.

[0128] The zero-crossing torque control method for new energy vehicles provided in the above embodiments optimizes the zero-crossing torque gradient. Specifically, when the vehicle is parked, the motor controller (PEU) actively controls the output of positive and negative periodic torque of the drive motor to ensure that the gears are aligned on different sides. The transmission system clearance is identified by the motor rotor angle and stored in the form of angle self-learning values. The vehicle controller (VCU) receives the clearance self-learning values ​​and adaptively adjusts the zero-crossing gradient parameters of the drive motor target torque to ensure that the zero-crossing gradient of the drive motor target torque is optimal. This can solve the problem of abnormal noise at the moment of starting or during torque reversal throughout the vehicle's entire life cycle, making the power system output torque smooth while taking into account the power response time and improving driving comfort.

[0129] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0130] In one embodiment, a motor torque zero-crossing control device is provided, which corresponds one-to-one with the motor torque zero-crossing control method described in the above embodiments. Please refer to [link to relevant documentation]. Figure 7 , Figure 7 A schematic diagram of the motor torque zero-crossing control device provided in an embodiment of the present invention is shown below. Figure 7 As shown, the motor torque zero-crossing control device 700 includes a start-up control module 701, a periodic transmission system gap determination module 702, a matching module 703, and a current torque zero-crossing gradient determination module 704. Detailed descriptions of each functional module are as follows:

[0131] The starting control module 701 is used to control the vehicle's motor to output positive and negative cycle torque for multiple test cycles when the vehicle's wheels are in a braking and stationary state, so that the vehicle's gears can perform reciprocating side-to-side tooth movements and obtain the mechanical angle of the motor rotor at different test times; the cycle transmission system clearance determination module 702 is used to determine the maximum and minimum cycle angles in each test cycle based on the mechanical angle of the motor rotor at different test times, and determine the cycle transmission system clearance for each test cycle; the matching module 703 is used to determine the average transmission system clearance through at least a portion of the cycle transmission system clearances, and match the average transmission system clearance to obtain the target torque gradient correction value corresponding to the average transmission system clearance; the current torque zero-crossing gradient determination module 704 is used to determine the vehicle's current torque zero-crossing gradient based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

[0132] In one embodiment, the motor torque zero-crossing control device further includes a first condition judgment module for determining whether the wheel is in a braking stationary state. The module is configured to: acquire the current state of the vehicle; if the current state of the vehicle is the target vehicle state, determine that the wheel of the vehicle is in a braking stationary state; the target vehicle state includes at least one of the following: the vehicle is in neutral, the vehicle is in parking gear, the vehicle's parking function is enabled, the vehicle's brake pedal depth is greater than a preset depth, and the vehicle is in drive gear.

[0133] In one embodiment, the motor torque zero-crossing control device further includes a second condition judgment module, used to obtain an initial update identifier of the vehicle's initial torque zero-crossing gradient before controlling the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles. The initial update identifier includes at least one of an initial update time and an initial update vehicle mileage. If the initial update identifier includes an initial update time, the gradient update duration is determined based on the initial update time and the current time. If the gradient update duration is greater than a preset duration threshold, the vehicle is determined to meet a first triggering condition. If the initial update identifier includes an initial update vehicle mileage, the gradient update mileage is determined based on the initial update vehicle mileage and the current vehicle mileage. If the gradient update mileage is greater than a preset mileage threshold, the vehicle is determined to meet a second triggering condition. If the vehicle's wheels are in a braking stationary state and the vehicle meets at least one of the first and second triggering conditions, the vehicle's drive motor is triggered to output positive and negative cycle torque for multiple test cycles.

[0134] In one embodiment, the motor torque zero-crossing control device further includes a third condition judgment module, used to obtain vehicle transmission system fault information before controlling the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles; to obtain a fault handling plan based on the transmission system fault information; if the fault handling plan includes at least one of the following: replacement of transmission system components or adjustment of transmission system component positions, and the vehicle's wheels are in a braking stationary state, the device triggers the control of the vehicle's drive motor to output positive and negative cycle torque for multiple test cycles.

[0135] In one embodiment, the periodic transmission system gap determination module is configured to: perform low-pass filtering on the mechanical angle of the motor rotor at different test times to obtain multiple filtered values; take the maximum filtered value in each test cycle as the maximum periodic angle and the minimum filtered value in each test cycle as the minimum periodic angle; determine the angle difference between the maximum and minimum periodic angles in each test cycle, and use the angle difference as the periodic transmission system gap for each test cycle.

[0136] In one embodiment, the matching module includes an average value determination module and a correction value determination module, wherein the average value determination module is used to determine the average transmission system gap through at least a portion of the periodic transmission system gaps, the average value determination module being configured to: determine the total gap by summing the at least a portion of the periodic transmission system gaps; and determine the average transmission system gap based on the quotient of the total gap and the number of periods, where the number of periods is the number of periodic transmission system gaps.

[0137] In this embodiment, the correction value determination module is configured to: match the average transmission system clearance with multiple preset transmission system clearances, determine a preset transmission system clearance as the target transmission system clearance; obtain the preset torque gradient correction value corresponding to the target transmission system clearance, and determine it as the target torque gradient correction value, wherein each preset transmission system clearance is pre-set with a corresponding preset torque gradient correction value.

[0138] In one embodiment, the current torque zero-crossing gradient determination module is configured to: obtain a preset basic zero-crossing torque gradient value of the vehicle; and determine the current torque zero-crossing gradient of the vehicle by multiplying the preset basic zero-crossing torque gradient value by the target torque gradient correction value.

[0139] In one embodiment, the motor torque zero-crossing control device further includes an update module, configured to: if an update of a one-dimensional table is detected, the one-dimensional table storing multiple preset transmission system gaps, a preset torque gradient correction value corresponding to each preset transmission system gap, and the correspondence between the preset transmission system gaps and the preset torque gradient correction values; re-execute the step of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles until the average transmission system gap is determined through at least a portion of the cycle transmission system gaps, obtaining a new average transmission system gap; query the updated one-dimensional table using the new average transmission system gap to obtain a new target torque gradient correction value; and determine the vehicle's new current torque zero-crossing gradient based on the new target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to continue torque zero-crossing control of the vehicle's motor.

[0140] This invention provides a motor torque zero-crossing control device. By optimizing the zero-crossing torque gradient, the motor controller (PEU) actively controls the drive motor to output positive and negative periodic torques when the vehicle is parked, ensuring that the gears are aligned on different sides. The transmission system clearance is identified by the motor rotor angle and stored as an angle self-learning value. The vehicle controller (VCU) receives the clearance self-learning value and adaptively adjusts the target torque zero-crossing gradient parameters of the drive motor to ensure that the target torque zero-crossing gradient of the drive motor is optimal. This can solve the problem of abnormal noise during zero-crossing at the moment of starting or torque reversal throughout the vehicle's entire life cycle, making the power system output torque smooth, while also taking into account the power response time and improving driving comfort.

[0141] Specific limitations regarding the motor torque zero-crossing control device can be found in the limitations of the motor torque zero-crossing control method described above, and will not be repeated here. Each module in the aforementioned motor torque zero-crossing control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the electronic device in hardware form or independently of it, or stored in the memory of the electronic device in software form, so that the processor can call and execute the corresponding operations of each module.

[0142] In this embodiment, the device is essentially configured with multiple modules to execute the methods in any of the above embodiments. The specific functions and technical effects can be referred to in the above embodiments, and will not be repeated here.

[0143] In one embodiment, a new energy vehicle is provided for executing the motor torque zero-crossing control method described in the above embodiment. Please refer to... Figure 8 , Figure 8 A structural schematic diagram of a new energy vehicle provided in an embodiment of the present invention, such as... Figure 8 As shown, the new energy vehicle 800 includes a vehicle controller 801, a motor controller 802, a drive motor 803, and a transmission system 804, wherein:

[0144] The motor controller 802 is used to control the drive motor 803 to output positive and negative periodic torque for multiple test cycles when the wheel is in a braking and stationary state, so that the gear in the transmission system 804 can perform reciprocating lateral tooth movements, and to acquire and record the mechanical angle of the motor rotor at different test times; and to determine the maximum and minimum periodic angles in each test cycle based on the mechanical angles of the motor rotor at different test times, and to determine the periodic transmission system clearance in each test cycle, to determine the average transmission system clearance through at least a portion of the periodic transmission system clearance, and to send the average transmission system clearance to the vehicle controller 801;

[0145] The vehicle controller 801 is used to receive the average transmission system clearance, match the average transmission system clearance to obtain the target torque gradient correction value corresponding to the average transmission system clearance, and determine the current torque zero-crossing gradient based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the drive motor 803.

[0146] The vehicle controller determines the current torque zero-crossing gradient and adjusts the motor's requested torque to obtain the final motor requested torque, which is then sent to the motor controller. The motor controller performs smooth torque zero-crossing control on the drive motor according to the final motor requested torque.

[0147] The new energy vehicle provided in the above embodiments controls the vehicle's motor to output positive and negative cycle torque for multiple test cycles when the vehicle's wheels are in a braked and stationary state. This causes the vehicle's gears to perform reciprocating side-to-side tooth movements, and the mechanical angle of the motor rotor is obtained at different test moments. The maximum and minimum cycle angle values ​​are determined for each test cycle, and the cycle transmission system clearance for each test cycle is determined. Then, the average transmission system clearance is determined, and a target torque gradient correction value corresponding to the average transmission system clearance is obtained. Based on the target torque gradient correction value and a preset basic zero-crossing torque gradient value, the current torque zero-crossing gradient of the vehicle is determined to control the torque zero-crossing of the vehicle's motor. By correcting the current torque zero-crossing gradient during vehicle use, the determination and correction of the current torque zero-crossing gradient can be personalized for each vehicle. This avoids the poor compatibility with other vehicles of the same model caused by a fixed torque zero-crossing gradient value, and also avoids the problem of abnormal noise caused by changes in the transmission system during vehicle use, which renders the fixed torque zero-crossing gradient value inapplicable. It also avoids zero-crossing abnormal noise problems at the moment of starting or during torque reversal throughout the vehicle's entire life cycle, resulting in smooth torque output from the power system.

[0148] In this embodiment, the new energy vehicle is essentially equipped with multiple modules to execute the methods in any of the above embodiments. The specific functions and technical effects are the same as in the above embodiments and will not be repeated here. In one embodiment, an electronic device is provided, which can be a server, and its internal structure diagram can be as follows. Figure 9 As shown, the electronic device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile and / or volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface is used to communicate with external clients via a network connection. When the computer program is executed by the processor, it implements the functions or steps of a motor torque zero-crossing control method on the server side.

[0149] In one embodiment, an electronic device is provided, which may be a client, and its internal structure diagram may be as follows: Figure 10As shown, the electronic device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface is used to communicate with an external server via a network connection. When the computer program is executed by the processor, it implements the functions or steps of a motor torque zero-crossing control method on the client side.

[0150] In one embodiment, an electronic device is provided, 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 perform the following steps:

[0151] If the vehicle's wheels are in a braking and stationary state, control the vehicle's motor to output positive and negative cycle torque for multiple test cycles, so that the vehicle's gears can perform reciprocating side-to-side tooth movements, and obtain the mechanical angle of the motor rotor at different test moments.

[0152] The maximum and minimum values ​​of the periodic angle in each test cycle are determined based on the mechanical angle of the motor rotor at different test times, and the periodic transmission system clearance in each test cycle is determined.

[0153] The average transmission system clearance is determined by at least a portion of the periodic transmission system clearance, and the target torque gradient correction value corresponding to the average transmission system clearance is obtained by matching the average transmission system clearance.

[0154] The current torque zero-crossing gradient of the vehicle is determined based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

[0155] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0156] If the vehicle's wheels are in a braking and stationary state, control the vehicle's motor to output positive and negative cycle torque for multiple test cycles, so that the vehicle's gears can perform reciprocating side-to-side tooth movements, and obtain the mechanical angle of the motor rotor at different test moments.

[0157] The maximum and minimum values ​​of the periodic angle in each test cycle are determined based on the mechanical angle of the motor rotor at different test times, and the periodic transmission system clearance in each test cycle is determined.

[0158] The average transmission system clearance is determined by at least a portion of the periodic transmission system clearance, and the target torque gradient correction value corresponding to the average transmission system clearance is obtained by matching the average transmission system clearance.

[0159] The current torque zero-crossing gradient of the vehicle is determined based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

[0160] It should be noted that the functions or steps that can be implemented by the computer-readable storage medium or electronic device described above can be referred to the relevant descriptions on the server side and client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.

[0161] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0162] 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 used as 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.

[0163] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for controlling the zero-crossing torque of a motor, characterized in that, The method includes: If the vehicle's wheels are in a braking and stationary state, control the vehicle's motor to output positive and negative cycle torque for multiple test cycles, so that the vehicle's gears can perform reciprocating side-to-side tooth movements, and obtain the motor rotor mechanical angle at different test times. The determination of the maximum and minimum cycle angle values ​​in each test cycle based on the motor rotor mechanical angle at different test times, and the determination of the cycle transmission system clearance in each test cycle, includes: performing low-pass filtering on the motor rotor mechanical angle at different test times to obtain multiple filter values; taking the maximum filter value in each test cycle as the maximum cycle angle value, and taking the minimum filter value in each test cycle as the minimum cycle angle value; determining the angle difference between the maximum and minimum cycle angle values ​​in each test cycle, and using the angle difference as the cycle transmission system clearance for each test cycle. The average transmission system gap is determined by at least a portion of the periodic transmission system gaps. The average transmission system gap is then matched to obtain a target torque gradient correction value corresponding to the average transmission system gap. The matching process for obtaining the target torque gradient correction value includes: matching the average transmission system gap with multiple preset transmission system gaps, determining one preset transmission system gap as the target transmission system gap; obtaining the preset torque gradient correction value corresponding to the target transmission system gap, and determining it as the target torque gradient correction value. Each preset transmission system gap has a pre-set preset torque gradient correction value. The current torque zero-crossing gradient of the vehicle is determined based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

2. The motor torque zero-crossing control method as described in claim 1, characterized in that, Methods for determining whether a wheel is in a braking, stationary state include: Obtain the current state of the vehicle; if the current state of the vehicle is the target vehicle state, determine that the wheels of the vehicle are in a braking and stationary state. The target vehicle state includes at least one of the following: the vehicle is in neutral, the vehicle is in park, the vehicle's parking function is enabled, the vehicle's brake pedal depth is greater than a preset depth, and the vehicle is in drive.

3. The motor torque zero-crossing control method as described in claim 1, characterized in that, Before controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles, the method further includes: Obtain the initial update identifier of the initial torque zero-crossing gradient of the vehicle, wherein the initial update identifier includes at least one of the initial update time and the initial update vehicle mileage; If the initial update identifier includes an initial update time, the gradient update duration is determined based on the initial update time and the current time. If the gradient update duration is greater than a preset duration threshold, the vehicle is determined to meet the first triggering condition. If the initial update identifier includes the initial update vehicle mileage, the gradient update mileage is determined based on the initial update vehicle mileage and the current vehicle mileage. If the gradient update mileage is greater than a preset mileage threshold, the vehicle is determined to meet the second triggering condition. If the vehicle's wheels are in a braking and stationary state, and the vehicle meets at least one of the first and second triggering conditions, the vehicle's motor is triggered to output positive and negative cycle torque for multiple test cycles.

4. The motor torque zero-crossing control method as described in claim 1, characterized in that, Before controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles, the method further includes: Obtain fault information of the vehicle's transmission system; A fault handling plan is obtained by matching the fault information of the transmission system. If the fault handling solution includes at least one of the following: replacement of transmission system components or adjustment of the position of transmission system components, and the wheels of the vehicle are in a braked and stationary state, the motor of the vehicle is triggered to output positive and negative cycle torque for multiple test cycles.

5. The motor torque zero-crossing control method according to any one of claims 1-4, characterized in that, Determining the average transmission system clearance by at least a portion of the periodic transmission system clearance includes: The total clearance is determined by summing the clearances of at least a portion of the periodic transmission system; The average transmission system clearance is determined based on the quotient of the total clearance and the number of cycles, where the number of cycles is the number of clearances in the periodic transmission system.

6. The motor torque zero-crossing control method according to any one of claims 1-4, characterized in that, Determining the vehicle's current torque zero-crossing gradient based on the target torque gradient correction value and the preset baseline zero-crossing torque gradient value includes: Obtain the preset baseline zero-crossing torque gradient value of the vehicle; The product of the preset baseline zero-crossing torque gradient value and the target torque gradient correction value is determined as the current torque zero-crossing gradient of the vehicle.

7. The motor torque zero-crossing control method according to any one of claims 1-4, characterized in that, After determining the vehicle's current torque zero-crossing gradient based on the target torque gradient correction value and the preset baseline zero-crossing torque gradient value, the method further includes: If an update to the one-dimensional table is detected, the one-dimensional table is used to store multiple preset transmission system gaps, a preset torque gradient correction value corresponding to each preset transmission system gap, and the correspondence between the preset transmission system gaps and the preset torque gradient correction values. If the vehicle's wheels are in a braking and stationary state, the steps of controlling the vehicle's motor to output positive and negative cycle torque for multiple test cycles are repeated until the average transmission system clearance is determined through at least a portion of the cycle transmission system clearance, a new average transmission system clearance is obtained, and the updated one-dimensional table is queried through the new average transmission system clearance to obtain a new target torque gradient correction value. The new current torque zero-crossing gradient of the vehicle is determined based on the new target torque gradient correction value and the preset base zero-crossing torque gradient value, so as to continue to control the torque zero-crossing of the vehicle's motor.

8. A motor torque zero-crossing control device, characterized in that, The device includes: The start control module is used to control the vehicle's motor to output positive and negative cycle torque for multiple test cycles if the vehicle's wheels are in a braking and stationary state, so that the vehicle's gears can perform reciprocating lateral tooth movements and obtain the motor rotor mechanical angle at different test times. The periodic transmission system clearance determination module is used to determine the maximum and minimum periodic angle values ​​in each test cycle based on the mechanical angle of the motor rotor at different test times, and to determine the periodic transmission system clearance in each test cycle. This includes: performing low-pass filtering on the mechanical angle of the motor rotor at different test times to obtain multiple filter values; taking the maximum filter value in each test cycle as the maximum periodic angle value, and taking the minimum filter value in each test cycle as the minimum periodic angle value; determining the angle difference between the maximum and minimum periodic angle values ​​in each test cycle, and using the angle difference as the periodic transmission system clearance for each test cycle. A matching module is configured to determine an average transmission system gap through at least a portion of the periodic transmission system gaps, and to match the average transmission system gap to obtain a target torque gradient correction value corresponding to the average transmission system gap. The matching process to obtain the target torque gradient correction value includes: matching the average transmission system gap with multiple preset transmission system gaps, determining one preset transmission system gap as the target transmission system gap; obtaining the preset torque gradient correction value corresponding to the target transmission system gap, and determining it as the target torque gradient correction value, wherein each preset transmission system gap has a pre-set preset torque gradient correction value. The current torque zero-crossing gradient determination module is used to determine the current torque zero-crossing gradient of the vehicle based on the target torque gradient correction value and the preset basic zero-crossing torque gradient value, so as to perform torque zero-crossing control on the vehicle's motor.

9. A new energy vehicle, characterized in that, This includes the vehicle controller, motor controller, drive motor, and transmission system; The motor controller is used to control the drive motor to output positive and negative periodic torque for multiple test cycles when the wheel is in a braking and stationary state, so that the gears in the transmission system perform reciprocating lateral tooth movements, and to acquire and record the mechanical angle of the motor rotor at different test times; and to determine the maximum and minimum periodic angle values ​​in each test cycle based on the mechanical angle of the motor rotor at different test times, and to determine the periodic transmission system clearance in each test cycle, to determine the average transmission system clearance through at least a portion of the periodic transmission system clearance, and to send the average transmission system clearance to the vehicle controller. Specifically, determining the maximum and minimum periodic angle values ​​in each test cycle based on the mechanical angle of the motor rotor at different test times, and determining the periodic transmission system clearance in each test cycle includes: performing low-pass filtering on the mechanical angle of the motor rotor at different test times to obtain multiple filter values; taking the maximum filter value in each test cycle as the maximum periodic angle value, and the minimum filter value in each test cycle as the minimum periodic angle value; determining the angle difference between the maximum and minimum periodic angle values ​​in each test cycle, and using the angle difference as the periodic transmission system clearance for each test cycle. The vehicle controller is used to receive the average transmission system gap, match the average transmission system gap to obtain a target torque gradient correction value corresponding to the average transmission system gap, and determine the current torque zero-crossing gradient based on the target torque gradient correction value and a preset basic zero-crossing torque gradient value to perform torque zero-crossing control on the drive motor. The process of matching the average transmission system gap to obtain the target torque gradient correction value corresponding to the average transmission system gap includes: matching the average transmission system gap with multiple preset transmission system gaps, determining one preset transmission system gap as the target transmission system gap; obtaining the preset torque gradient correction value corresponding to the target transmission system gap, and determining it as the target torque gradient correction value, wherein each preset transmission system gap is pre-set with a corresponding preset torque gradient correction value.

10. An electronic 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 method as described in any one of claims 1 to 7.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 7.

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