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 to sequentially output a first direction torque and a second direction torque when the vehicle is in a continuous high-speed sliding state, so that the gear moves on different sides of the teeth. The motor rotor angular velocity and the vehicle tire rotation angular velocity in this process are collected, the transmission system gap is determined, and the target torque gradient correction value is matched to determine the current torque zero-crossing gradient of the vehicle, thereby performing torque zero-crossing control on the motor of the vehicle. The current torque zero-crossing gradient is corrected during vehicle driving, and the determination and correction of the current torque zero-crossing gradient are personalized for each vehicle, thereby improving the adaptability of the current torque zero-crossing gradient, the smoothness of the power system output torque, and the user experience.

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 a vehicle is in a continuous high-speed coasting state, controlling the vehicle's motor to sequentially output a first directional torque and a second directional torque, so that the vehicle's gears perform different lateral gear movements; collecting the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different collection times during the different lateral gear movements, and determining the transmission system clearance; matching the transmission system clearance to obtain a target torque gradient correction value corresponding to the transmission system clearance; and determining 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.

[0007] In one embodiment of the present invention, before controlling the motor of the vehicle to sequentially output a first directional torque and a second directional torque, the method further includes: obtaining an update identifier of the vehicle's torque zero-crossing gradient, the update identifier including at least one of the previous update time and the previous updated vehicle mileage; if the update identifier includes the previous update time, determining a gradient update duration based on the previous update time and the current time; if the gradient update duration is greater than a preset gradient duration threshold, determining that the vehicle meets a first triggering condition; if the update identifier includes the previous updated vehicle mileage, determining a gradient update mileage based on the previous updated 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 triggering condition; if the vehicle is in a continuous high-speed coasting state, and the vehicle meets at least one of the first triggering condition and the second triggering condition, triggering control of the vehicle's motor to sequentially output the first directional torque and the second directional torque.

[0008] In one embodiment of the present invention, before controlling the motor of the vehicle to sequentially output a first directional torque and a second directional torque, 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 replacing transmission system components or adjusting the position of transmission system components, and the wheels of the vehicle are in a continuous high-speed coasting state, triggering the control of the motor of the vehicle to sequentially output the first directional torque and the second directional torque.

[0009] In one embodiment of the present invention, controlling the motor of the vehicle to sequentially output a first directional torque and a second directional torque includes: controlling the motor of the vehicle to output the first directional torque, monitoring the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; when the duration of the synchronization state is greater than a preset first duration threshold, controlling the motor of the vehicle to output the second directional torque, so that the synchronization state changes from synchronous to asynchronous and then back to synchronous.

[0010] In one embodiment of the present invention, the acquisition of the motor rotor angular velocity and the vehicle tire rotation angular velocity at different acquisition times during different side-mounted tooth movements includes: acquiring the motor rotor angular velocity and the vehicle tire rotation angular velocity from the initial acquisition time, wherein the initial acquisition time is the moment when the motor outputs a first directional torque; continuously acquiring the motor rotor angular velocity and the vehicle tire rotation angular velocity until the end acquisition time is reached, wherein the end acquisition time is the moment when the synchronization state reaches synchronization for the second time for a duration longer than a preset second duration threshold.

[0011] In one embodiment of the present invention, determining the transmission system clearance includes: calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment in a target time period, wherein the target start time of the target time period is greater than or equal to a first moment, and the target end time of the target time period is less than or equal to a second moment, wherein the first moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity undergoes the first abrupt change during different side-mounted gear movements, and the second moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity undergoes the second abrupt change during different side-mounted gear movements; and integrating the angular velocity deviation to obtain the transmission system clearance.

[0012] In one embodiment of the present invention, before calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment in the target time period, the method further includes: after controlling the vehicle motor to output a second directional torque, monitoring the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; determining the moment when the synchronization state changes abruptly from synchronous to asynchronous as the target start moment; determining the moment when the synchronization state changes abruptly from asynchronous to synchronous as the target end moment; and generating the target time period based on the target start moment and the target end moment.

[0013] In one embodiment of the present invention, matching the transmission system gap to obtain a target torque gradient correction value corresponding to the transmission system gap includes: matching the 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.

[0014] 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.

[0015] This invention also provides a motor torque zero-crossing control device, comprising: a start-up control module, used to control the vehicle's motor to sequentially output a first directional torque and a second directional torque when the vehicle is in a continuous high-speed coasting state, so that the vehicle's gears perform different lateral gear movements; a transmission system clearance determination module, used to collect the vehicle's motor rotor angular velocity and vehicle tire rotation angular velocity at different collection times during different lateral gear movements, and determine the transmission system clearance; a matching module, used to match the transmission system clearance to obtain a target torque gradient correction value corresponding to the transmission system clearance; and a current torque zero-crossing gradient determination module, used 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, if the vehicle is in a continuous high-speed coasting state, controls the drive motor to sequentially output a first-direction torque and a second-direction torque, causing the vehicle's gears to perform different lateral gear movements. It also collects the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different collection times during these lateral gear movements, determines the transmission system clearance, and sends the transmission system clearance to the vehicle controller. The vehicle controller receives the transmission system clearance, matches the transmission system clearance to obtain a target torque gradient correction value corresponding to the 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, thereby performing 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 motor to sequentially output torque in the first direction and torque in the second direction while the vehicle is in a continuous high-speed coasting state, causing the gears to move against each other on different sides. The method also collects the angular velocity of the motor rotor and the angular velocity of the vehicle tires during this process to determine the transmission system clearance. By matching this transmission system clearance, a target torque gradient correction value is obtained. Then, 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 motor's torque zero-crossing. By correcting the current torque zero-crossing gradient during vehicle operation, 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. Furthermore, it avoids zero-crossing abnormal noise problems during vehicle start-up or torque reversal throughout the vehicle's entire lifespan, resulting in smooth torque output from the power system. This improves the adaptability of the current torque zero-crossing gradient, enhances the smoothness of the powertrain's torque output, and improves the user experience. Furthermore, correcting the current torque zero-crossing gradient during vehicle operation avoids user waiting time, further improving the user experience. 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 a first and second torque of the drive motor during continuous high-speed coasting, the motor controller (PEU) ensures that the gears are engaged on different sides. The transmission system clearance is identified by the angular velocity of the motor rotor and the angular velocity of the vehicle tires, 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 ride 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] Step S210: If the vehicle is in a continuous high-speed coasting state, the motor controlling the vehicle sequentially outputs a first directional torque and a second directional torque to make the vehicle's gears perform different side-to-side gear movements.

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

[0039] A sustained high-speed coasting state can be understood as a vehicle coasting at high speed for a certain duration, with no braking requirement anticipated within a preset timeframe. This state is considered a sustained high-speed coasting state. In this embodiment, "high speed" can be a preset speed range defined by those skilled in the art; for example, a vehicle coasting at a speed of 70 km / h to 80 km / h is considered to be in a high-speed coasting state.

[0040] The first directional torque and the second directional torque have different directions. The positive torque can be output first, followed by the negative torque, or vice versa. After outputting the first directional torque, the motor rotor angular velocity and the vehicle tire rotation angular velocity are synchronized and stabilized for a certain period. Then, the second directional torque is output, causing the motor rotor angular velocity and the vehicle tire rotation angular velocity to change from synchronous to asynchronous, and then back to synchronous.

[0041] In this embodiment, the gears include, but are not limited to, gears in transmission systems such as gearboxes and differential gears.

[0042] Since vehicles do not always require correction of the current torque zero-crossing gradient, performing this correction every time the vehicle is coasting at high speed 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, a first trigger condition, a second trigger condition, and, as provided in the following embodiments, the adoption of fault handling schemes and one-dimensional table updates. The fault handling schemes include at least one of the following: replacement of transmission system components, adjustment of transmission system component positions, etc.

[0043] In other words, if the vehicle's wheels are in a continuous high-speed coasting 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 the first direction torque and the second direction torque in sequence, so that the vehicle's gears perform reciprocating side-to-side tooth movements. If the correction trigger condition is not met, the subsequent steps are not executed.

[0044] 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 resulted in 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), and the vehicle's motor is controlled to sequentially output torque in the first and second directions, causing the vehicle's gears to perform reciprocating side-to-side tooth movements.

[0045] In one embodiment, before step S210, that is, before the motor controlling the vehicle sequentially outputs the first directional torque and the second directional torque, the method further includes: obtaining an update identifier of the vehicle's torque zero-crossing gradient, the update identifier including at least one of the previous update time and the previous updated vehicle mileage; if the update identifier includes the previous update time, determining the gradient update duration based on the previous update time and the current time, and if the gradient update duration is greater than a preset gradient duration threshold, determining that the vehicle meets the first triggering condition; if the update identifier includes the previous updated vehicle mileage, determining the gradient update mileage based on the previous updated vehicle mileage and the current vehicle mileage, and if the gradient update mileage is greater than a preset mileage threshold, determining that the vehicle meets the second triggering condition; if the vehicle is in a continuous high-speed coasting state and the vehicle meets at least one of the first triggering condition and the second triggering condition, triggering the motor controlling the vehicle to sequentially output the first directional torque and the second directional torque.

[0046] The previous update time refers to the update time of the currently used torque zero-crossing gradient (initial torque zero-crossing gradient), and the previous updated vehicle mileage refers to the actual mileage of the vehicle at the time of the update of the currently used torque zero-crossing gradient (initial torque zero-crossing gradient).

[0047] 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 last update time of this initial torque zero-crossing gradient is the time the vehicle was delivered for use, the time the vehicle rolled off the production line, or another time set by those skilled in the art. The last 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 last update time of this initial torque zero-crossing gradient is the time of the last correction. The last updated vehicle mileage for this initial torque zero-crossing gradient is the actual mileage of the vehicle at the time of the last correction.

[0048] The time difference between the previous update time and the current time is determined as the gradient update duration. If the gradient update duration is greater than the preset gradient duration threshold, the vehicle is determined to meet the first trigger condition, that is, the next torque zero-crossing gradient correction can be performed, that is, the motor of the vehicle is triggered to output the first direction torque and the second direction torque in sequence. The preset gradient duration threshold can be set by those skilled in the art as needed, and is not limited here.

[0049] The mileage difference between the previously 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 next torque zero-crossing gradient correction can be performed, which triggers the motor of the vehicle to output the first directional torque and the second directional torque in sequence. The preset mileage threshold can be set by those skilled in the art as needed, and is not limited here.

[0050] In another embodiment, before the vehicle's motor sequentially outputs a first directional torque and a second directional torque, 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 continuous high-speed coasting state, triggering the vehicle's motor to sequentially output the first directional torque and the second directional torque.

[0051] 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.

[0052] 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 future driving road type beyond 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., and the vehicle's motor is triggered to output the first directional torque and the second directional torque in sequence and subsequent steps to ensure a better handling experience on road sections with poor road conditions.

[0053] In one embodiment, the step of controlling the vehicle's motor to sequentially output a first directional torque and a second directional torque to cause the vehicle's gears to reciprocate with teeth on different sides can be achieved by the PEU actively triggering the drive motor to output the first and second directional torques. This method is applicable to correcting different types of zero-crossing target torques, such as linear and quadratic functions, and can also be used to correct the length of time the torque remains at 0 Nm when crossing zero. That is, when the vehicle is in a continuous high-speed coasting state, the motor controller (PEU) actively controls the vehicle's motor to sequentially output the first and second directional torques to ensure that the gears are teeth on different sides, which helps to determine the transmission system clearance.

[0054] In one embodiment, if the vehicle's wheels are in a continuous high-speed coasting state and the correction trigger condition is met, the method further includes prompting the user to perform the correction through the vehicle's infotainment system or other prompting system, and obtaining the user's response information. If the user agrees to the correction, the method then triggers the step of controlling the vehicle's motor to sequentially output torque in the first direction and torque in the second direction. Since the correction of the torque zero-crossing gradient may take a certain amount of time, in order 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 the torque zero-crossing gradient correction is needed. If the user agrees, the method executes the step of controlling the vehicle's motor to sequentially output torque in the first direction and torque in the second direction. If the user does not agree, the method asks the user again after a preset interval or after the vehicle has reached a certain mileage. When the user agrees, the method can also inform the user of the duration of the correction process (the duration requirement of the torque zero-crossing gradient correction) so that the user can make reasonable time arrangements and further monitor the vehicle's driving status.

[0055] In one embodiment, the switching timing between the first directional torque and the second directional torque can be determined in the following manner: at this time, the vehicle motor is controlled to output the first directional torque and the second directional torque in sequence, including: controlling the vehicle motor to output the first directional torque, monitoring the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; when the duration of the synchronization state is greater than a preset first duration threshold, controlling the vehicle motor to output the second directional torque, so that the synchronization state changes from synchronous to asynchronous and then back to synchronous.

[0056] When the angular velocity of the motor rotor and the angular velocity of the vehicle tires are equal, or the difference between them is less than a preset threshold, the synchronization state is determined to be synchronous. When the difference is greater than the preset threshold, the synchronization state is determined to be asynchronous. After controlling the motor to output torque in the first direction, the angular velocity of the motor rotor and the angular velocity of the vehicle tires can be synchronized. After stabilization (i.e., the duration of synchronization is greater than a preset first duration threshold), the torque is switched to the second direction. Due to the change in torque direction and the presence of gear backlash, the angular velocity of the motor rotor and the angular velocity of the vehicle tires will become inconsistent. At this point, the synchronization state abruptly changes to asynchrony. After a certain period of time, the gears shift from one side to the other, and the angular velocity of the motor rotor and the angular velocity of the vehicle tires are synchronized again. After the synchronization state is achieved again for a certain duration (i.e., the duration of the synchronization is greater than a preset second duration threshold), the self-learning process can be considered complete. The preset first duration threshold and the preset second duration threshold can be the same or different, and can be set by those skilled in the art.

[0057] It should be noted that there is no explicit restriction on the order of execution between the determination of the triggering condition and the determination of the continuous high-speed gliding state. Those skilled in the art can choose the order of execution as needed.

[0058] By using the above method, the current torque zero-crossing gradient can be corrected during the time interval of high-speed coasting, making the overall correction of the current torque zero-crossing gradient more seamless and timely. Users do not need to spend extra time specifically correcting the current torque zero-crossing gradient, thus improving the user experience.

[0059] 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.

[0060] Step S220: Collect the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different collection times during different side-mounted tooth movements, and determine the transmission system clearance.

[0061] The angular velocity of the motor rotor can be obtained using a high-precision position sensor mounted on the motor output shaft, such as a rotary transformer or an eddy current speed sensor. The rotor angle can also be acquired simultaneously.

[0062] The angular velocity of the vehicle's tires can be obtained from the wheel speed signal collected by the ESP controller or PEU. The wheel speed can be converted into the angular velocity at the motor output shaft end based on parameters such as the wheel transmission system speed ratio and tire radius. That is, the angular velocity of the vehicle's tires at the motor output shaft end.

[0063] The angular velocity of a vehicle tire can be determined using methods known to those skilled in the art. The following provides an exemplary method for calculating the angular velocity of a vehicle tire:

[0064] ω veh =vVeh*r*I Formula (1)

[0065] Where, ω veh Let vE be the angular velocity of the vehicle's tires, vVeh be the wheel speed or vehicle speed, r be the wheel radius, and I be the overall gear ratio. The wheel radius can be obtained from the tire size information. Units for all parameters need to be standardized during the calculation process.

[0066] Theoretically, the angular velocity of a vehicle's tires and the angular velocity of its motor rotor should sometimes be equal, i.e., synchronized. However, errors in the sensors that collect these parameters can cause discrepancies in the readings. In such cases, the deviation can be compensated for by pre-learning the relevant sensors. In other words, before implementing zero-crossing control of the motor torque, it is necessary to calibrate the relevant sensors, such as those collecting the motor rotor's angular velocity and those collecting wheel speed, to meet the required accuracy.

[0067] In one embodiment, the acquisition of the motor rotor angular velocity and vehicle tire rotation angular velocity at different acquisition times during different side-mounted tooth movements includes: acquiring the motor rotor angular velocity and vehicle tire rotation angular velocity from the initial acquisition time, where the initial acquisition time is the moment when the motor outputs torque in the first direction; continuously acquiring the motor rotor angular velocity and vehicle tire rotation angular velocity until the end acquisition time is reached, where the end acquisition time is the moment when the synchronization state reaches synchronization for the second time for a duration longer than a preset second duration threshold.

[0068] As mentioned in the above embodiments, during the process of controlling the vehicle's motor to sequentially output a first directional torque and a second directional torque to cause the vehicle's gears to perform different lateral gear movements, the acquisition of the motor rotor angular velocity and the vehicle tire rotation angular velocity begins at the moment the motor outputs the first directional torque. Alternatively, the acquisition of the motor rotor angular velocity and the vehicle tire rotation angular velocity could begin before the motor sequentially outputs the first and second directional torques, but this would result in the acquisition of a large amount of useless data, leading to resource waste. During this process, the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity goes through a "synchronous-asynchronous-synchronous" state. The acquisition of the motor rotor angular velocity and the vehicle tire rotation angular velocity can be terminated after the second synchronization state has lasted for a certain period of time, which serves as the end point of acquisition.

[0069] In this embodiment, determining the transmission system clearance includes: calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment in the target time period. The target start time of the target time period is greater than or equal to the first moment, and the target end time of the target time period is less than or equal to the second moment. The first moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity changes abruptly for the first time during different side-tooth movements, and the second moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity changes abruptly for the second time during different side-tooth movements. The angular velocity deviation is integrated to obtain the transmission system clearance. The specific integration method can be found in formula (3). Since the time interval of the acquired data is longer than the target time period, the first moment and the second moment can be found by time-aligning the acquired motor rotor angular velocity data and vehicle tire rotation angular velocity data and then analyzing them.

[0070] The target time period can be a relatively large time period, including periods where the angular velocity deviation is greater than the preset deviation range, and at least some periods where the angular velocity deviation is less than the preset deviation range. Since one possible case is that the angular velocity deviation is 0 in the at least some periods where the angular velocity deviation is less than the preset deviation range, even if the target time period is a relatively large time period, the final integral value is consistent with the case that only includes periods where the angular velocity deviation is greater than the preset deviation range.

[0071] In one embodiment, before calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment within the target time period, the method further includes: after controlling the vehicle's motor to output a second-direction torque, monitoring the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; determining the moment when the synchronization state abruptly changes from synchronous to asynchronous as the target start moment; determining the moment when the synchronization state abruptly changes from asynchronous to synchronous as the target end moment; and generating the target time period based on the target start moment and the target end moment. In this embodiment, the target time period is the time period where the angular velocity deviation is greater than a preset deviation range. This results in a smaller data volume for the determined target time period, improving computation speed and reducing resource consumption.

[0072] In one embodiment, since only one different side-mounted gear movement is used as a sample for calculating the transmission system clearance during steps S210-S220, to ensure the accuracy of the transmission system clearance data, steps S210-S220 can be executed multiple times to obtain multiple transmission system clearances. Based on the deviations between the multiple transmission system clearances, the final transmission system clearance is determined, and the subsequent target torque gradient correction value is matched. For example, the average value, mode, median, etc., of the multiple obtained transmission system clearances can be taken.

[0073] In another embodiment, if the gap deviation between the transmission system clearance determined when the vehicle first meets the correction trigger condition and the transmission system clearance determined when the correction trigger condition is met for the second time is less than a preset gap threshold, the current torque zero-crossing gradient is maintained. This avoids the risks associated with frequently adjusting the current torque zero-crossing gradient. For example, when a new transmission system clearance is calculated, it can be compared with the previously obtained transmission system clearance. If the gap deviation is less than the preset gap threshold, the process stops, and the current torque zero-crossing gradient is not adjusted.

[0074] The above method allows for a simple and quick determination of the transmission system clearance. This clearance can be stored as a self-learning value for later retrieval. It can also be used to assist in adjusting the current torque zero-crossing gradient.

[0075] Step S230: Match the transmission system clearance to obtain the target torque gradient correction value corresponding to the transmission system clearance.

[0076] The transmission system clearance can be determined as the transmission system clearance self-learning value, thus completing the transmission system clearance self-learning step, and the transmission system clearance self-learning value (transmission system clearance) is stored.

[0077] In one embodiment, matching the transmission system clearance to obtain the target torque gradient correction value corresponding to the transmission system clearance includes: matching the transmission system clearance with multiple preset transmission system clearances, determining a 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 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.

[0078] 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 transmission system gaps in the table, the corresponding target torque gradient correction value can be obtained. That is, the transmission system gaps are 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.

[0079] It should be noted that matching the transmission system clearance with multiple preset transmission system clearances does not necessarily mean that the transmission system clearance is identical to a single preset clearance. Alternatively, it can be done by calculating the difference between the transmission system clearance and each preset clearance, with a difference less than a preset threshold considered a match, and the preset clearance with the smallest difference being designated as the target transmission system clearance. If the difference between the transmission system clearance and each preset clearance is greater than the preset threshold, the larger (or smaller) of the two preset 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 mode, a larger value corresponding to the torque zero-crossing gradient result can be selected, while for Comfort mode, a smaller value corresponding to the torque zero-crossing gradient result can be selected.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] One method for determining the current torque zero-crossing gradient includes:

[0086] Grd1 = Grd0 × fac Grd Formula (2)

[0087] 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.

[0088] In one embodiment, after determining 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, the method further includes: if an update to a one-dimensional table is detected, the one-dimensional table is used to store multiple preset transmission system gaps, the 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 steps S210-S220, that is, re-execute the step of controlling the vehicle's motor to output a first-direction torque and a second-direction torque sequentially if the vehicle is in a continuous high-speed coasting state, so that the vehicle's gears perform different lateral tooth movements; collect the vehicle's motor rotor angular velocity and vehicle tire rotation angular velocity at different collection times during different lateral tooth movements, and determine a new transmission system gap; query the updated one-dimensional table through the new transmission system gap to obtain a new target torque gradient correction value; 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 to control the vehicle's motor to zero torque.

[0089] 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.

[0090] The motor torque zero-crossing control method provided in the above embodiments controls the motor to sequentially output torque in a first direction and torque in a second direction when the vehicle is in a continuous high-speed coasting state, causing the gears to move against each other on different sides. The method also collects the angular velocity of the motor rotor and the angular velocity of the vehicle tires during this process to determine the transmission system clearance. A target torque gradient correction value is obtained by matching this transmission system clearance. Then, 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 motor's torque zero-crossing. By correcting the current torque zero-crossing gradient during vehicle operation, the method allows for personalized determination and correction of the current torque zero-crossing gradient 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. 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. This improves the adaptability of the current torque zero-crossing gradient, enhances the smoothness of the powertrain's torque output, and improves the user experience. Furthermore, correcting the current torque zero-crossing gradient during vehicle operation avoids user waiting time, further improving the user experience.

[0091] The motor torque zero-crossing control method provided in the above embodiments can optimize the drivability of new energy vehicles. The vehicle controller actively requests the drive motor to output positive and negative torque. The motor controller identifies the transmission system clearance based on the integral of the deviation between the wheel angular velocity (vehicle tire rotation angular velocity) and the motor angular velocity (motor rotor angular velocity), and stores it in the form of self-learning values. The vehicle controller receives the clearance self-learning values ​​and adaptively adjusts the motor torque zero-crossing gradient parameters to ensure that the target torque zero-crossing gradient of the drive motor is optimal. This can solve the problem of zero-crossing 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 also taking into account the power response time and improving driving comfort.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] In the first stage of identifying transmission system shaft clearance, if the 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 motor controller PEU first requests the transmission system to perform self-learning of the gap. The VCU then determines whether the self-learning conditions are met, that is, whether the correction trigger conditions are met and whether the vehicle is in a continuous high-speed coasting state.

[0096] For example, the transmission system clearance self-learning function is activated when the vehicle meets the following conditions:

[0097] a) If the PEU determines that self-learning has not been performed for a certain period of time (e.g., more than 5000km) or has reported a transmission system-related fault (e.g., transmission system components may have been replaced after a broken shaft), it will request transmission system clearance self-learning from the VCU via the CAN line.

[0098] b) The VCU determines that the vehicle is in a high-speed coasting state and has no braking requirement.

[0099] It should be noted that the transmission system clearance self-learning frequency is adjusted by using condition a to avoid excessively frequent transmission system clearance self-learning, which would cause unnecessary burden on the system.

[0100] After meeting the basic conditions for self-learning (meeting the correction trigger condition and the vehicle's wheels being in a continuous high-speed coasting state), the transmission system clearance self-learning is executed. This means the VCU requests the PEU to output negative (or positive) torque and sends a self-learning permission signal to the PEU. The PEU's gear clearance self-learning function is activated and responds to the VCU's torque request, recording key variables such as drive wheel speed (connected to the drive motor) and motor angular velocity. Then, the VCU requests the PEU to output positive (or negative) torque in the direction of the drive wheel. After maintaining this for a certain period, the learning process ends. The PEU determines that self-learning was successful, stores the self-learning value, and stops sending self-learning requests. Among the key variables monitored by the PEU, the wheel speed signal comes from the ESP (Electronic Stability Program) controller or the wheel speed signal collected by the PEU. The motor rotor angle is obtained by a high-precision position sensor (such as a rotary transformer or eddy current speed sensor) mounted on the motor output shaft, and the rotor angular velocity can also be obtained. 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 several 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 received from other controllers via the CAN bus.

[0101] See also Figure 3 If the PEU self-learning fails, the process of requesting transmission system clearance self-learning from the PEU to determining whether the PEU self-learning was successful is re-executed. If the VCU determines that the self-learning conditions are not met, the process of requesting transmission system clearance self-learning from the PEU is re-executed. Please refer to [link to relevant documentation]. 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), and the vertical axis represents angular velocity (rad / s). Figure 4There are two solid lines in the middle; the darker line above represents the motor's angular velocity ω. rotor (That is, the angular velocity of the motor rotor), the lighter-colored line below represents the wheel angular velocity ω referred to the motor output. veh (That is, the angular velocity of the vehicle's tires). For example... Figure 4 As shown, the self-learning process begins at the initial acquisition time t0. At time t1, assuming the VCU requests the PEU to output negative torque, the wheel speed and motor speed reach synchronization (i.e., the two speeds are equal; if they are unequal due to sensor errors, the deviation can be covered by mutual self-learning). Based on parameters such as the wheel transmission system speed ratio and tire radius, the wheel speed is converted into the angular velocity ω at the motor output shaft end. veh The angular velocity of the motor rotor is ω rotor After the VCU requests the PEU to output positive torque (i.e., torque reverses), the vehicle angular velocity and rotor angular velocity deviate due to the gear backlash. The gears shift from one side to the other. At time t2, the wheel speed and motor speed synchronize again. The transmission system backlash self-learning value can be calculated using the following formula:

[0102]

[0103] Where ΔGap is the transmission system clearance, i.e., the transmission system clearance self-learning value, t1 is the target start time, t2 is the target end time, and ω rotor Let ω be the angular velocity of the motor rotor. veh Let ω be the angular velocity of the vehicle's tires, and dt be the sampling interval of the discrete points. rotor -ω veh ) represents the angular velocity deviation.

[0104] Once the wheel speed and motor speed are synchronized again, and the duration exceeds the preset second duration threshold, the data collection ends at time t3. At this point, the self-learning process can be considered complete, and the data collection can be stopped.

[0105] like Figure 4 As shown, M represents the self-learning interval, T represents the target time period, and Δt represents the duration of the target time period, which is the difference between the target end time t2 and the target start time t1, i.e., the self-learning value calculation interval. The target time period can be... Figure 4 The two moments t1 and t2 where the mutation occurs can be represented, or they can be a range larger than the current target time period.

[0106] In the second stage of vehicle zero-crossing torque gradient adjustment, the PEU sends the self-learned transmission system clearance value ΔGap (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.

[0107] Table 1

[0108] 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]]>

[0109] 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 motor to the target torque zero crossing can be obtained by formula (2).

[0110] 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 5 The 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.

[0111] 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:

[0112] Step S601: Determine whether the correction trigger condition is met.

[0113] Specific examples of the modified triggering conditions can be found in the descriptions in the above embodiments, and will not be repeated here.

[0114] 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.

[0115] If the correction trigger condition is not met, the process ends.

[0116] Step S602: Determine whether the wheel is in a continuous high-speed gliding state.

[0117] The specific method for determining whether the wheel is in a continuous high-speed gliding state can be determined by those skilled in the art based on known methods, and will not be elaborated here. If an interruption event occurs during the execution of this method, such as sudden braking, the process will terminate.

[0118] 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, i.e., steps S603 to S605.

[0119] Before starting step S603, the user can be prompted in advance to receive their permission to proceed with subsequent steps. Execution only occurs after user permission. The estimated time for the process can be displayed to the user, allowing them to plan their actions accordingly. Simultaneously, it reminds the user to prioritize vehicle driving safety, improving safety. Furthermore, the corresponding one-dimensional table can be determined by acquiring the user's driving mode and habits. That is, the vehicle pre-stores multiple one-dimensional tables corresponding to different driving modes or habits, and the appropriate table is selected based on the user's driving mode and habits to match and determine the subsequent target torque gradient correction value.

[0120] Of course, the update can also be performed without notifying the user at all, achieving a "seamless" update effect.

[0121] In step S603, the motor of the vehicle is controlled to output a first directional torque and a second directional torque in sequence, so that the gears of the vehicle can perform reciprocating side-to-side tooth movements.

[0122] The motors of a vehicle can be controlled by a motor controller such as a PEU to output torque in the first direction and torque in the second direction in sequence.

[0123] Step S604: Collect the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different collection times during different side-mounted tooth movements.

[0124] The mechanical angle of the motor rotor can be obtained by a high-precision position sensor installed on the motor output shaft.

[0125] Step S605: Determine the transmission system clearance.

[0126] The specific implementation of step S605 above can be found in the description of the above embodiments, and is not limited here.

[0127] Step S606: Match the target torque gradient correction value corresponding to the transmission system clearance.

[0128] 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.

[0129] Step S607: 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.

[0130] Step S608: Perform torque zero-crossing control on the vehicle's motor.

[0131] 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.

[0132] Step S609: Determine whether the one-dimensional table has been updated.

[0133] If the one-dimensional table is updated, then steps S601-S608 are re-executed; otherwise, if the one-dimensional table is not updated, then the process ends.

[0134] 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.

[0135] 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 transmission system clearance 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:

[0136] The start control module 701 is used to control the vehicle's motor to output torque in the first direction and torque in the second direction sequentially when the vehicle is in a continuous high-speed coasting state, so that the vehicle's gears can perform different lateral gear movements; the transmission system clearance determination module 702 is used to collect the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tire rotation at different collection times during different lateral gear movements, and determine the transmission system clearance; the matching module 703 is used to match the transmission system clearance to obtain the target torque gradient correction value corresponding to the 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.

[0137] In one embodiment, the device further includes a trigger condition determination module, used to obtain an update identifier of the vehicle's torque zero-crossing gradient before the vehicle's motor sequentially outputs a first directional torque and a second directional torque. The update identifier includes at least one of the previous update time and the previous updated vehicle mileage. If the update identifier includes the previous update time, the gradient update duration is determined based on the previous update time and the current time. If the gradient update duration is greater than a preset gradient duration threshold, the vehicle is determined to meet a first trigger condition. If the update identifier includes the previous updated vehicle mileage, the gradient update mileage is determined based on the previous updated 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 trigger condition. If the vehicle is in a continuous high-speed coasting state and the vehicle meets at least one of the first and second trigger conditions, the vehicle's motor is triggered to sequentially output the first directional torque and the second directional torque.

[0138] In one embodiment, the trigger condition judgment module is further configured to: obtain vehicle transmission system fault information before controlling the vehicle's motor to output first directional torque and second directional torque in sequence; 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 continuous high-speed coasting state, trigger the control of the vehicle's motor to output first directional torque and second directional torque in sequence.

[0139] In one embodiment, the start control module is further configured to: control the vehicle's motor to output a first directional torque, monitor the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; when the duration of the synchronization state is greater than a preset first duration threshold, control the vehicle's motor to output a second directional torque, so that the synchronization state changes from synchronous to asynchronous and then back to synchronous.

[0140] In one embodiment, the transmission system clearance determination module is configured to: acquire the motor rotor angular velocity and the vehicle tire rotation angular velocity from the initial acquisition time, the initial acquisition time being the moment when the motor outputs torque in the first direction; continuously acquire the motor rotor angular velocity and the vehicle tire rotation angular velocity until the end acquisition time is reached, the end acquisition time being the moment when the synchronization state reaches synchronization for the second time for a duration longer than a preset second duration threshold.

[0141] In one embodiment, the transmission system clearance determination module is further configured to: calculate the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment in the target time period, wherein the target start time of the target time period is greater than or equal to a first moment, and the target end time of the target time period is less than or equal to a second moment, wherein the first moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity changes abruptly for the first time during different side tooth movements, and the second moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity changes abruptly for the second time during different side tooth movements; and integrate the angular velocity deviation to obtain the transmission system clearance.

[0142] In this embodiment, the transmission system clearance determination module is further configured to: before calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment in the target time period, after controlling the vehicle motor to output the second direction torque, monitor the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; determine the moment when the synchronization state changes abruptly from synchronous to asynchronous as the target start time; determine the moment when the synchronization state changes abruptly from asynchronous to synchronous as the target end time; and generate the target time period based on the target start time and the target end time.

[0143] In one embodiment, the matching module is configured to: match the transmission system gap with multiple preset transmission system gaps, determine one preset transmission system gap as the target transmission system gap; obtain the preset torque gradient correction value corresponding to the target transmission system gap, and determine 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.

[0144] In one embodiment, the current torque zero-crossing gradient determination module is used to obtain a preset basic zero-crossing torque gradient value of the vehicle; and to 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.

[0145] This invention provides a motor torque zero-crossing control device. By optimizing the zero-crossing torque gradient, when the vehicle is in a continuous high-speed coasting state, the motor controller (PEU) actively controls the output of positive and negative torque of the drive motor to ensure that the gears are in contact 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.

[0146] 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.

[0147] 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.

[0148] 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:

[0149] The motor controller 802 is used to control the drive motor 803 to output the first direction torque and the second direction torque in sequence if the wheel is in a continuous high-speed sliding state, so that the gear in the transmission system 804 performs different lateral tooth movements, and to collect the angular velocity of the motor rotor and the angular velocity of the vehicle tire at different collection times during the different lateral tooth movements, and to determine the transmission system clearance and send the transmission system clearance to the vehicle controller 801.

[0150] The vehicle controller 801 is used to receive the transmission system clearance, match the transmission system clearance to obtain the target torque gradient correction value corresponding to the 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.

[0151] 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.

[0152] The new energy vehicle provided in the above embodiments optimizes the zero-crossing torque gradient. Specifically, when the vehicle is in a continuous high-speed coasting state, the motor controller (PEU) actively controls the output of positive and negative 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 also taking into account the power response time and improving driving comfort.

[0153] In this embodiment, the new energy vehicle is actually equipped 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.

[0154] In one embodiment, an electronic device is provided, which may be a server, and its internal structure diagram may 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.

[0155] 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.

[0156] 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:

[0157] If the vehicle is in a continuous high-speed coasting state, the motor controlling the vehicle will output torque in the first direction and torque in the second direction in sequence, so that the vehicle's gears will perform different side-to-side gear movements.

[0158] The angular velocities of the vehicle's motor rotor and tires were collected at different times during different side-mounted tooth movements, and the transmission system clearance was determined.

[0159] The target torque gradient correction value corresponding to the transmission system clearance is obtained by matching the transmission system clearance;

[0160] 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.

[0161] 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:

[0162] If the vehicle is in a continuous high-speed coasting state, the motor controlling the vehicle will output torque in the first direction and torque in the second direction in sequence, so that the vehicle's gears will perform different side-to-side gear movements.

[0163] The angular velocities of the vehicle's motor rotor and tires were collected at different times during different side-mounted tooth movements, and the transmission system clearance was determined.

[0164] The target torque gradient correction value corresponding to the transmission system clearance is obtained by matching the transmission system clearance;

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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 above device can be divided into different functional units or modules to complete all or part of the functions described above.

[0169] The embodiments provided above 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 is in a continuous high-speed coasting state, the vehicle's motor is controlled to sequentially output a first directional torque and a second directional torque to cause the vehicle's gears to perform different lateral gear movements. Controlling the vehicle's motor to sequentially output the first directional torque and the second directional torque includes: controlling the vehicle's motor to output the first directional torque and monitoring the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; when the duration of the synchronization state is greater than a preset first duration threshold, the vehicle's motor is controlled to output the second directional torque to cause the synchronization state to change from synchronous to asynchronous and then back to synchronous. The system collects the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different acquisition moments during different lateral gear movements, and determines the transmission system clearance. The collection of the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different acquisition moments during different lateral gear movements includes: collecting the angular velocity of the motor rotor and the angular velocity of the vehicle's tires from an initial acquisition moment, where the initial acquisition moment is the moment when the motor outputs torque in a first direction; and collecting the angular velocity of the motor rotor and the angular velocity of the vehicle's tires until an end acquisition moment is reached, where the end acquisition moment is the moment when the synchronization state reaches synchronization for the second time for a duration exceeding a preset second duration threshold. Determining the transmission system clearance includes: calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition moment during the target time period, wherein the target start time of the target time period is greater than or equal to a first moment, and the target end time of the target time period is less than or equal to a second moment, wherein the first moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity undergoes the first abrupt change during different side-mounted gear movements, and the second moment is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity undergoes the second abrupt change during different side-mounted gear movements; integrating the angular velocity deviation to obtain the transmission system clearance; The target torque gradient correction value corresponding to the transmission system clearance is obtained by matching the clearance of the transmission system. 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, Before controlling the vehicle's motor to sequentially output a first directional torque and a second directional torque, the method further includes: Obtain the update identifier of the torque zero-crossing gradient of the vehicle, wherein the update identifier includes at least one of the previous update time and the previous update vehicle mileage; If the update identifier includes the previous update time, the gradient update duration is determined based on the previous update time and the current time. If the gradient update duration is greater than a preset gradient duration threshold, the vehicle is determined to meet the first triggering condition. If the update identifier includes the mileage of the vehicle in the previous update, the gradient update mileage is determined based on the mileage of the vehicle in the previous update and the mileage of the current vehicle. If the gradient update mileage is greater than a preset mileage threshold, the vehicle is determined to meet the second trigger condition. If the vehicle is in a continuous high-speed coasting state, and the vehicle meets at least one of the first triggering condition and the second triggering condition, the motor of the vehicle is triggered to output the first directional torque and the second directional torque in sequence.

3. The motor torque zero-crossing control method as described in claim 1, characterized in that, Before controlling the vehicle's motor to sequentially output a first directional torque and a second directional torque, 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 vehicle's wheels are in a continuous high-speed coasting state, the motor of the vehicle is triggered to output a first directional torque and a second directional torque in sequence.

4. The motor torque zero-crossing control method as described in claim 1, characterized in that, Before calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition time within the target time period, the method further includes: After controlling the motor of the vehicle to output torque in the second direction, monitor the synchronization status of the motor rotor angular velocity and the vehicle tire rotation angular velocity; The moment when the synchronization state abruptly changes from synchronous to asynchronous is determined as the target start time; The moment when the synchronization state abruptly changes from asynchronous to synchronous is determined as the target end time; The target time period is generated based on the target start time and the target end time.

5. The motor torque zero-crossing control method according to any one of claims 1-4, characterized in that, Matching the transmission system clearance to obtain the target torque gradient correction value corresponding to the transmission system clearance includes: The transmission system gap is matched with multiple preset transmission system gaps, and one preset transmission system gap is determined as the target transmission system gap; Obtain the preset torque gradient correction value corresponding to the target transmission system gap, and determine it as the target torque gradient correction value. Each preset transmission system gap is pre-set with a corresponding preset torque gradient correction value.

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. A motor torque zero-crossing control device, characterized in that, The device includes: The activation control module is used to control the vehicle's motor to sequentially output a first directional torque and a second directional torque if the vehicle is in a continuous high-speed coasting state, so that the vehicle's gears perform different lateral gear movements. Controlling the vehicle's motor to sequentially output the first directional torque and the second directional torque includes: controlling the vehicle's motor to output the first directional torque and monitoring the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity; when the duration of the synchronization state is greater than a preset first duration threshold, controlling the vehicle's motor to output the second directional torque, so that the synchronization state changes from synchronous to asynchronous and then back to synchronous. The transmission system clearance determination module is used to collect the angular velocity of the vehicle's motor rotor and the angular velocity of the vehicle's tires at different collection moments during different lateral gear movements, and to determine the transmission system clearance. The collection of the angular velocities of the vehicle's motor rotor and tires at different collection moments during different lateral gear movements includes: collecting the angular velocities of the motor rotor and tires from an initial collection moment, where the initial collection moment is the moment when the motor outputs torque in a first direction; and collecting the angular velocities of the motor rotor and tires until an end collection moment is reached, where the end collection moment is the duration of the second synchronization exceeding a preset second time. The time when the long threshold is reached; determining the transmission system clearance includes: calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire rotation angular velocity at each acquisition time in the target time period, wherein the target start time of the target time period is greater than or equal to a first time, and the target end time of the target time period is less than or equal to a second time, wherein the first time is the time when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity changes abruptly for the first time during different side tooth movements, and the second time is the time when the synchronization state of the motor rotor angular velocity and the vehicle tire rotation angular velocity changes abruptly for the second time during different side tooth movements; integrating the angular velocity deviation to obtain the transmission system clearance; The matching module is used to match the clearance of the transmission system to obtain the target torque gradient correction value corresponding to the clearance of the transmission system; 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.

8. 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 sequentially output a first directional torque and a second directional torque when the vehicle is in a continuous high-speed coasting state, so that the vehicle's gears perform different lateral gear movements. It also collects the motor rotor angular velocity and vehicle tire rotational angular velocity at different sampling moments during the different lateral gear movements, determines the transmission system clearance, and sends the transmission system clearance to the vehicle controller. Controlling the vehicle's motor to sequentially output the first directional torque and the second directional torque includes: controlling the vehicle's motor to output the first directional torque and monitoring the synchronization state of the motor rotor angular velocity and vehicle tire rotational angular velocity; when the duration of the synchronization state is greater than a preset first duration threshold, controlling the vehicle's motor to output the second directional torque, so that the synchronization state changes from synchronous to asynchronous and then back to synchronous; collecting the motor rotor angular velocity and vehicle tire rotational angular velocity at different sampling moments during the different lateral gear movements includes: collecting the motor rotor angular velocity from the initial sampling moment. The system acquires the speed and the angular velocity of the vehicle tires. The initial acquisition time is the moment when the motor outputs torque in the first direction. The motor rotor angular velocity and the vehicle tire angular velocity are acquired until the acquisition ends. The acquisition end time is the moment when the synchronization state reaches a second synchronization duration that is greater than a preset second duration threshold. The transmission system clearance is determined by: calculating the angular velocity deviation between the motor rotor angular velocity and the vehicle tire angular velocity at each acquisition time in the target time period. The target start time of the target time period is greater than or equal to a first time, and the target end time of the target time period is less than or equal to a second time. The first time is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire angular velocity undergoes the first abrupt change during different side-tooth movements, and the second time is the moment when the synchronization state of the motor rotor angular velocity and the vehicle tire angular velocity undergoes the second abrupt change during different side-tooth movements. The angular velocity deviation is integrated to obtain the transmission system clearance. The vehicle controller is used to receive the transmission system gap, match the transmission system gap to obtain the target torque gradient correction value corresponding to the transmission system gap, 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.

9. 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 6.

10. 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 6.

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