Electric vehicle and its motor control method, device and storage medium

Abstract

The present application belongs to the field of electric vehicles, and specifically relates to an electric vehicle and its motor control method, device, and storage medium. The electric vehicle motor control method of the present application includes the steps of: detecting a relative deformation amount of a transmission system between a driving tooth of a motor and a wheel end; determining a first speed difference value between a rotation speed of the first driving tooth and a converted rotation speed of the first wheel end when the relative deformation amount is a first threshold value, the first speed difference value being used to indicate that the driving tooth and the driven tooth of the transmission system start to separate, the rotation speed of the first driving tooth is the rotation speed of the driving tooth at the time of separation between the driving tooth and the driven tooth, and the converted rotation speed of the first wheel end is the rotation speed of the wheel end of the electric vehicle converted by a speed ratio at the time of separation; determining an output torque of the motor according to the first speed difference value; and controlling the driving tooth to move toward the driven tooth according to the output torque. This reduces or avoids the problem of large vibration and noise being generated in the motor and the transmission system.

Description

[Technical field]

[0001] The present application relates to the field of electric motor vehicles, and in particular to an electric vehicle and its motor control method, device and storage medium. [Background technology]

[0002] With the development of electric vehicle technology, the scope of application of electric vehicles is expanding. For users, driving comfort is one of the factors for selecting electric vehicles. On the other hand, when the output torque of the motor changes from positive to negative torque while the electric vehicle is in operation, the gear meshing direction of the motor changes, causing tooth strike, which generates vibrations and noise noticeable to the user and affects the ride comfort. In addition, tooth strike may damage the transmission mechanism such as gears and splines.

[0003] Conventionally, in order to solve the above problem, when changing the positive and negative torques of the motor output torque, it has been common to process the output torque using a filtering method (for example, a torque smoothing method) to reduce vibration and noise. However, this method still causes large vibrations and noises, which leads to a bad driving experience for the user. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present application provide a method, device, and storage medium for controlling an electric vehicle and its motor that solve the problem of large vibrations and noises occurring in a motor and its transmission system while the electric vehicle is running. [Means for solving the problem]

[0005] In a first aspect, an embodiment of the present application provides a motor control method for an electric vehicle, the motor control method comprising: Detecting a relative deformation of a transmission system between the driving teeth of the motor and a wheel end; determining a first speed difference value between the rotational speed of the first driving tooth and the converted rotational speed of the first wheel end when the relative deformation amount is a first threshold value, the first threshold value being used to indicate that the driving tooth and the driven tooth of the transmission system start to disengage, the rotational speed of the first driving tooth is the rotational speed of the driving tooth at the time when the driving tooth and the driven tooth disengage, and the converted rotational speed of the first wheel end is the rotational speed of the wheel end of the electric vehicle converted by a speed ratio at the time when the disengagement occurs; determining an output torque of the motor according to the first speed difference value; and controlling the output torque to move the drive teeth toward the driven teeth.

[0006] In one possible embodiment, the step of determining the output torque of the motor by the first speed difference value includes: determining a first product of a first velocity difference value and a first time length that is a duration from the time of disengagement to the time of contact between the drive tooth and the driven tooth; determining that the output torque includes a first torque and a second torque when the first product is less than a preset backlash value; The first torque and the second torque have opposite directions, the first torque being the torque required in the time interval from the time of release to the time of change in the acceleration / deceleration state of the motor, and the second torque being the torque required in the time interval from the time of change to the time of contact.

[0007] In one possible embodiment, the first torque and the second torque are determined as follows: At the conversion time, a second speed difference value between the current rotation speed of the driving teeth and a converted rotation speed of the second wheel end is determined according to the preset backlash value, the first speed difference value and the first time length, and the converted rotation speed of the second wheel end is a rotation speed obtained by converting the rotation speed of the wheel end of the electric vehicle at the conversion time by a speed ratio; Determine a rotation speed of a second driving tooth according to the second speed difference value and the converted rotation speed of the second wheel end, the rotation speed being the rotation speed of the driving tooth at the time of conversion; determining a first torque based on the rotational speed of the second drive tooth, the rotational speed of the first drive tooth, a duration between the disengagement time point and the conversion time point, and a sliding friction force of the drive tooth at the rotational speed of the second drive tooth; A second torque is determined based on the rotational speed of the second drive tooth, the rotational speed of the third drive tooth, the duration between the conversion time point and the contact time point, and the sliding friction force of the drive tooth at the rotational speed of the third drive tooth, where the rotational speed of the third drive tooth is the rotational speed of the drive tooth at the contact time point.

[0008] In one possible embodiment, the step of determining the output torque of the motor according to the first speed difference value further includes: determining a product of the first speed difference value and a second time length, which is a duration from the release time to the conversion time, as a second product when the first product is equal to or greater than a preset backlash value; determining that the output torque includes the first torque and the second torque when the second product is less than a preset backlash value; The first torque and the second torque have the same direction.

[0009] In one possible embodiment, the step of determining the output torque of the motor according to the first speed difference value further includes: a step of determining a converted rotational speed of a third wheel end at a target time when the second product is equal to or greater than a preset backlash value, the converted rotational speed of the third wheel end being a rotational speed obtained by converting the rotational speed of the wheel end of the electric vehicle at the target time by a speed ratio, the target time being a time when the driving tooth and the driven tooth re-contact each other during the second length of time; determining a third torque based on the converted rotational speed of the third wheel end, the rotational speed of the first drive tooth, and the duration between the take-off time and the target time, where the third torque is a required torque in the time interval from the take-off time to the target time, and the output torque includes the third torque.

[0010] In one possible embodiment, the relative deformation of the transmission between the driving teeth of the motor and the wheel end is detection The step of further comprises: determining a third speed difference value between the current rotation speed of the driving teeth and the current rotation speed of the driven teeth when a change in the output torque of the motor is detected; determining a relative displacement between the drive tooth and the driven tooth based on the third velocity difference value; and determining a relative deformation amount based on the relative displacement.

[0011] In a second aspect, embodiments of the present application provide a motor controller for an electric vehicle, the motor controller comprising: A detection module is used to detect the relative deformation of the transmission system between the driving teeth of the motor and the wheel end; a determination module used to determine a first speed difference value between the rotation speed of the first driving tooth and the converted rotation speed of the first wheel end when the relative deformation amount is a first threshold value, the relative deformation amount being the first threshold value is used to indicate that the driving tooth and the driven tooth of the transmission system start to disengage, the rotation speed of the first driving tooth is the rotation speed of the driving tooth at the time when the driving tooth and the driven tooth disengage, and the converted rotation speed of the first wheel end is the rotation speed of the wheel end of the electric vehicle converted by a speed ratio at the time when the disengagement occurs; a processing module adapted to determine an output torque of the motor according to the first speed difference value; and a control module adapted to control the output torque to cause the driving teeth to move toward each other relative to the driven teeth.

[0012] In a third aspect, embodiments of the present application provide an electric vehicle, the electric vehicle including a processor and a memory communicatively coupled to the processor; The memory stores computer executable instructions; The processor executes computer executable instructions stored in the memory to implement the electric vehicle motor control method of the first aspect.

[0013] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium having computer executable instructions stored thereon, the computer executable instructions being used, when executed by a processor, to implement the electric vehicle motor control method of the first aspect.

[0014] In a fifth aspect, an embodiment of the present application provides a computer program product, the computer program product including a computer program which, when executed by a processor, is used to implement the electric vehicle motor control method of the first aspect.

[0015] The electric vehicle motor control method, device, and storage medium provided by the embodiments of the present application analyze the dynamic process when the meshing direction of the driving teeth of the motor changes, and combine the features of measuring the position and rotation speed of the driving teeth of the motor with high accuracy and quickly adjusting the torque of the motor. When it is detected that the direction of the output torque of the motor is about to change, an active tooth approach operation is performed by controlling the torque of the driving teeth, and the speed difference when the driving teeth and the driven teeth separate and then recontact each other is calculated. value By reducing the above, vibration and noise between the driving teeth and the driven teeth due to inertial impact are reduced or eliminated. In addition, the present application does not require modification of the existing hardware of the electric vehicle or addition of new sensors, and realizes tooth approach control only by calculating the rotation speed of the wheel end, the rotation speed of the driving teeth of the motor, and backlash. The present application makes it possible to release the motor's constraints on the downward slope or upward slope of the output torque when the direction of the output torque is about to change to the maximum extent possible, making it possible to make the output torque of the motor follow the user's operation and request, and avoiding the problems in the related art of poor acceleration feeling after slackening the accelerator and poor responsiveness when the accelerator is depressed further due to limitations on the downward slope or upward slope of the output torque of the motor. [Brief description of the drawings]

[0016] In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings that need to be used in the description of the embodiments or the prior art. Of course, the drawings in the following description are part of the embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without having to perform creative work. [Figure 1] FIG. 2 is a curve schematic diagram of a torque filtering method provided by the related art; [Diagram 2] 1 is a schematic diagram of an electric vehicle provided according to an embodiment of the present application. [Diagram 3] 2 is a flowchart of a motor control method for an electric vehicle provided by an embodiment of the present application. [Figure 4] FIG. 2 is a schematic diagram showing the movement stroke of a driving tooth and a driven tooth provided by an embodiment of the present application. [Diagram 5] FIG. 13 is a schematic diagram of a curve for controlling the drive teeth to move inward according to an embodiment of the present application; [Figure 6] FIG. 6 is a schematic diagram of Example 1 of performing a geometric model simplification process on the shadow area in FIG. 5 provided by an embodiment of the present application. [Figure 7] FIG. 6 is a schematic diagram of Example 2 of performing a geometric model simplification process on the shadow area in FIG. 5 provided by an embodiment of the present application. [Figure 8] FIG. 8 is a schematic curve diagram of the output torque of the motor corresponding to FIG. 7 provided by an embodiment of the present application. [Figure 9] FIG. 6 is a schematic diagram of Example 3 of performing a geometric model simplification process on the shadow area in FIG. 5 provided by an embodiment of the present application. [Figure 10] FIG. 10 is a schematic curve diagram of the output torque of the motor corresponding to FIG. 9 provided by an embodiment of the present application. [Figure 11] 1 is a schematic diagram of a motor control device for an electric vehicle provided according to an embodiment of the present application; [Figure 12] FIG. 1 is a block diagram of an electric vehicle according to an illustrative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. Based on the embodiments of the present application, those skilled in the art can understand that all other embodiments taught by the embodiments of the present application belong to the scope of protection of the present application.

[0018] In the specification and claims of the present application, and in the drawings, the terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish between similar items without necessarily describing the order of determination or precedence. It should be understood that the embodiments of the present application described herein can be performed in an order other than that shown or described herein, and that the data used in appropriate combinations may be replaced. In addition, the terms "comprise", "have", and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus including a series of steps or elements is not necessarily limited to those explicitly described, and may include other steps or elements not explicitly described or inherent thereto.

[0019] Below, we will first interpret the nouns related to this application.

[0020] Torque is a special type of moment that rotates an object. Motor torque is the output torque of a motor.

[0021] Backlash is the clearance between the teeth of a pair of gears when they mesh. Backlash is a parameter necessary for smooth operation of meshing gears.

[0022] Relative deformation is the distortion that occurs when a non-rigid material is subjected to a force, and includes, but is not limited to, twist, bias, and the like.

[0023] The related art provided in the background art has at least the following technical problems.

[0024] As countries around the world strictly control their carbon emissions, 2 A schedule for peaking emissions and carbon neutrality will be presented, a schedule for banning the sale of fuel-powered vehicles will be presented, and new energy vehicles, i.e. electric vehicles, will be strongly encouraged and supported. Due to the current trend of expanding the scope of new energy applications, the development, production, and application scale of electric vehicles are all increasing at a high speed. The driving procedure of an electric vehicle is realized by controlling the output torque of the motor based on the target torque determined by the whole vehicle controller or the motor controller. When the motor experiences positive and negative torque changes, i.e., the direction of the motor's output torque changes, the gear meshing direction of the motor changes, causing the directions of force reception to differ, resulting in teeth strike, which generates vibrations and noise that can be perceived by the user, affecting the ride comfort. In addition, teeth strike may also damage the transmission mechanism, such as gears and splines.

[0025] In response to the above problem, in the related art, when the output torque of a motor is changed to positive or negative torque, the output torque is filtered to reduce vibration and noise, but this filtering method may be a torque smoothing method. As shown in Fig. 1, taking the process in which the output torque of a motor changes from positive to negative torque as an example, the speed difference between the rotation speed of the driving teeth and the rotation speed of the driven teeth in the process in which the driving teeth overcome the backlash is value The shadow area in the figure is the backlash value. In FIG. 1, the relative motion of the driving tooth and the driven tooth is JPEG0007689639000001.jpg8170 (hereinafter abbreviated as 1, 2, 3, and 4), of which the first stage is the positive torque reduction and elastic pressure release stage, the second stage is the driving teeth moving together process, the third stage is the contact and compression process between the driving teeth and the driven teeth, and the fourth stage is the motor negative torque increase and elastic pressure compression stage. ΔN in FIG. 1can be used to indicate the speed difference value between the converted rotational speed of the wheel end and the rotational speed of the driving tooth at the time when the driving tooth and the driven tooth disengage.

[0026] The above related technologies have the following problems: 1) The output torque is smoothed, so that the driving teeth pass through the backlash slowly to output a small torque or zero torque, and it takes time for the driving teeth to break through the backlash and convert positive and negative torque, so that the user feels that the motor's output torque response is discontinuous and interrupted, and the delay in power output is sensed, resulting in a poor driving experience. 2) The driving teeth and the driven teeth come into contact at the maximum value of the rotational speed difference value, so inertial impact and collision noise still occur, and there is no obvious improvement in vibration and noise. 3) The torque slope at the elastic pressure release stage of the driving teeth and the driven teeth is excessive, so ΔN 1 When the drive teeth overcome the backlash, the initial speed becomes too large, and the speed difference between the drive teeth and the driven teeth increases when they come into contact again. value becomes too large, the electric vehicle experiences large shocks and continuous shaking, and the torque slope of the elastic pressure release stage is limited in decreasing or increasing, so that the electric vehicle still accelerates after the user releases the accelerator, or the electric vehicle does not accelerate when the user applies the accelerator, resulting in poor dynamic response of the electric vehicle.

[0027] This application proposes a motor control method for electric vehicles. The method analyzes the dynamic process when the driving teeth of a motor change their meshing direction in a transmission system, and combines the features of measuring the position and rotation speed of the driving teeth of the motor with high accuracy and quickly adjusting the torque of the motor. When it is detected that the direction of the output torque of the motor is fluctuating, the driving teeth are controlled to perform an active tooth approach operation, and the speed difference when the driving teeth and the driven teeth separate and then recontact each other is calculated. value By reducing the size of the gap, vibration and noise between the driving teeth and the driven teeth due to inertial shock can be reduced or eliminated.

[0028] In one embodiment, the motor control method for an electric vehicle can be applied in one application scenario. Figure 2 is a schematic diagram of an electric vehicle provided by an embodiment of the present application, and as shown in Figure 2, the electric vehicle includes an electronic control unit (ECU), a left front wheel, a left front wheel speed sensor, a left front propeller shaft, a front motor rotary transformer, a front motor, a front motor control drive device, a front motor reduction differential, a right front propeller shaft, a right front wheel speed sensor, a right front wheel, a high-voltage battery, a left rear wheel, a left rear wheel speed sensor, a rear motor rotary transformer, a rear motor, a rear motor control drive device, a rear motor reduction differential, a left rear propeller shaft, a right rear propeller shaft, a right rear wheel speed sensor, and a right rear wheel.

[0029] In the above scene, the output torque of the front motor is transmitted to the left front wheel and the right front wheel via the front motor reduction differential, and the output torque of the rear motor is transmitted to the left rear wheel and the right rear wheel via the rear motor reduction differential, and the wheel speeds of the corresponding wheels are collected via the left front wheel speed sensor, the right front wheel speed sensor, the left rear wheel speed sensor, and the right rear wheel speed sensor. The speed values ​​detected by the left front wheel speed sensor, the right front wheel speed sensor, the left rear wheel speed sensor, and the right rear wheel speed sensor are collected and processed by the ECU. The ECU determines whether the torque direction of the output torque of the front motor and the rear motor has changed according to the acquired wheel speed. When the torque direction is changed, the drive teeth are controlled to perform a tooth approach operation, thereby achieving active control of the rotation speed of the drive teeth. This can reduce or avoid the problem that the initial speed is large and it takes a long time when the drive teeth overcome the backlash. Therefore, it is possible to reduce or avoid the problems of delay in power output, vibration, and noise. do.

[0030] Combining the above scenarios, the technical solution of the electric vehicle motor control method provided in the present application will be described in detail below through several specific examples.

[0031] The present application provides a motor control method for an electric vehicle. Figure 3 is a flow chart of a motor control method for an electric vehicle provided by an embodiment of the present application. As shown in Figure 3, the method includes the following steps:

[0032] S301, detecting the relative deformation of the transmission system between the driving teeth of the motor and the wheel end.

[0033] In this step, when the direction of the output torque of the motor is about to change, it can be determined whether the meshing direction between the driving teeth of the motor and the driven teeth of the transmission system is about to change, that is, when the direction of the output torque of the motor is about to change, it indicates that the driving teeth and the driven teeth are about to disengage, that is, the elastic force between the driving teeth and the driven teeth is released, the elastic force is reduced, and the relative deformation amount of the transmission system between the driving teeth and the wheel end is also reduced.

[0034] As an option, while the motor is operating, the meshing direction of the driving teeth and driven teeth of the motor may be continuously detected, and the relative deformation amount of the transmission system between the driving teeth and the wheel end may be continuously calculated, so that when it is detected that the direction of the motor output torque is about to change, the relative deformation amount of the transmission system between the driving teeth and the wheel end may be determined.

[0035] Optionally, the relative deformation of the transmission between the drive teeth and the wheel end may include gear deformation and shaft deformation.

[0036] S302, when the relative deformation amount is a first threshold value, determine a first speed difference value between the rotation speed of the first driving tooth and the converted rotation speed of the first wheel end.

[0037] In this step, the relative deformation amount being a first threshold is used to indicate that the driving tooth and the driven tooth of the transmission system start to separate, the rotation speed of the first driving tooth is the rotation speed of the driving tooth at the time when the driving tooth and the driven tooth separate, and the converted rotation speed of the first wheel end is the rotation speed converted by the speed ratio of the rotation speed of the wheel end of the electric vehicle at the time of separation. The relative deformation amount being a first threshold may be that the relative deformation amount is equal to zero, which is the separation time when separation between the driving tooth and the driven tooth starts. The separation and re-contact process between the driving tooth and the driven tooth can be as shown in FIG. 4. FIG. 4 is a schematic diagram showing the kinetic process of the driving tooth and the driven tooth provided by the first embodiment of the present application. do. In FIG. 4, this motion process may be a motion decomposition process between the driving tooth and the driven tooth after transforming the fixed coordinate system into a rotating coordinate system by coordinate (park) transformation. Here, the frequency of the rotating coordinate system is obtained by transforming the wheel speed (the wheel speed is relatively stable, and a relatively stable coordinate system frequency can be obtained). The relative motion between the driving tooth and the driven tooth is equivalent to six stages or periods, including a release elastic stage, a start point of separation between the driving tooth and the driven tooth, a free rotation stage of the driving tooth, a start point of re-engagement between the driving tooth and the driven tooth, a start point of contact between the driving tooth and the driven tooth, and an elastic compression stage.

[0038] Optionally, the start of separation between the drive tooth and the driven tooth may further be determined when a relative deformation recovery amount between the drive tooth and the driven tooth is equal to an elastic deformation amount during a recovery process of the elastic deformation between the drive tooth and the driven tooth.

[0039] Optionally, when the relative deformation is at a first threshold value, i.e., when the drive tooth and the driven tooth start to separate, a speed difference value between the rotation speed of the first drive tooth and the converted rotation speed of the first wheel end may be determined and referred to as a first speed difference value, which makes it easier to determine the output torque required for the motor based on the first speed difference value.

[0040] S303, determining the output torque of the motor according to the first speed difference value.

[0041] In this step, after the first speed difference value is determined, the output torque of the motor can be calculated by the first speed difference value, as shown in Fig. 5, which is a schematic curve diagram of controlling the driving teeth to move in accordance with an embodiment of the present application. Fig. 5 takes an example in which the output torque of the motor changes from positive torque to negative torque, and the relative motion of the driving teeth and the driven teeth can be decomposed into three stages, where the first stage is a positive torque decrease and elastic release stage, the second stage is a driving teeth move-in stage, and the third stage is a negative torque increase and elastic compression stage.

[0042] In Figure 5, T 12 may be used to indicate the first torque required to actively control the drive teeth to converge, whose function is to accelerate the motor rotor (drive teeth) so that the motor shaft quickly passes through the gear clearance area. T 23 may be used to indicate a second torque required to actively control the drive teeth to move inward, the function of which is to reduce the rotational speed difference value at the time of gear meshing surface contact and reduce the inertial impact due to the rotational speed difference value. t 0 may be used to indicate the point at which the motor's output torque begins to decrease when the user releases the accelerator. t 1 may be used to indicate the point in time when the driving and driven teeth begin to disengage. t 2 is T 12 The first torque action deadline It may be used to indicate the point in time at which the rotational speed of the drive tines changes from accelerating to decelerating, which may be at a pre-set point in time. t 3 is T 23 The action of the second torque deadline It may also be used to indicate the point in time when the driving and driven teeth re-contact. t 01 may be used to indicate the duration of time from when the user releases the accelerator until the drive and driven teeth begin to disengage. t12 is T 12 may be used to indicate the length of time that the first torque was applied. t 23 is T 23 may be used to indicate the length of time that the second torque was applied. t 13 t 12 +t 23 may be used to indicate the total time, i.e., the length of time that the drive teeth are actively controlled to move inward. N O may be used to indicate the rotational speed obtained by converting the rotational speed of the wheel end into a speed ratio, and is abbreviated as the converted rotational speed of the wheel end. N O1 t 1 It may also be used to indicate the reduced rotational speed of the wheel end at a given point in time. N O2 t 2 It may also be used to indicate the reduced rotational speed of the wheel end at a given point in time. N O3 t 3 It may also be used to indicate the reduced rotational speed of the wheel end at a given point in time. N R may be used to indicate the rotational speed of the motor rotor, i.e., the rotational speed of the drive tines. N R1 t 01 The rotational speed of the driving tooth when the rotation of the driving tooth ends, i.e., t 1 It may also be used to indicate the rotational speed of the drive tines at a given point in time. N R2 t 12 The rotational speed of the driving tooth when the rotation of the driving tooth ends, i.e., t 2 It may also be used to indicate the rotational speed of the drive tines at a given point in time. ΔN 1 t 1 At this point N O1 and N R1 It may also be used to indicate the speed difference value between the converted rotational speed of the wheel end and the rotational speed of the driving tooth at the time when the driving tooth and the driven tooth separate. ΔN 2 t 2At this point N O2 and N R2 The speed difference value between 12 The first torque action deadline It may also be used to indicate the rotational speed difference value between the converted rotational speed of the wheel end and the rotational speed of the drive tooth at a given point in time.

[0043] Optionally, the speed difference value between the driving tooth and the driven tooth may be integrated over time during the process in which the driving tooth overcomes the backlash, i.e., the shadow area in FIG. 5, and the shadow area is the backlash value. The first speed difference value, i.e., ΔN 1 By determining the motor output torque, i.e., ΔT 12 and T 23 is calculated.

[0044] Optionally, in one step in Fig. 5, the integral range of the elastic release deformation may be from when the driven tooth leaves the accelerator after the user releases the accelerator until the output torque of the motor is 0 or the integral value of the elastic release deformation is equal to the elastic deformation preset value. Here, the elastic deformation preset value may be represented by a mapping table of the output torque and the elastic release deformation, and when the integrated value of the elastic release deformation reaches the elastic deformation preset value, the elastic release deformation is deemed to be completed. The method of presetting the mapping table may be statically applying different blocking torques to the motor in the whole vehicle or the assembly of the transmission system, and measuring the rotation angle of the motor shaft at the blocking torque.

[0045] In the two stages in FIG. 5, the backlash integral range may be from the end of the elastic release deformation to the time when the backlash integral value reaches a preset backlash value S or a self-learned backlash value S.

[0046] In the three stages in FIG. 5, the integral range of the elastic compressive deformation may be from the end of the backlash integral to the time when the driving teeth and the driven teeth mesh again.

[0047] Optionally, the integral formula can be shown as follows: L=ΣΔω Δω=ΔN×2π / 60 If the sampling frequency is Δt, L t =L t-1 +Δω×Δt Here, L may be used to indicate the integral of the relative position difference between the driving tooth and the driven tooth, and both the elastic deformation integral and the backlash integral can be indicated by this value, and the unit is radians rad, and ΔN is the speed difference between the driving tooth and the driven tooth. value may be used to denote the speed difference between the driving and driven teeth in units of revolutions per minute (rpm), and ω is the speed difference between the driving and driven teeth in units. value may be used to indicate the speed, and has units of rad / s.

[0048] S304: The drive teeth are controlled to move toward the driven teeth by the output torque.

[0049] In this step, active control of the rotation speed of the drive teeth is realized by controlling the output torque of the motor. Therefore, by controlling the output torque of the motor, the drive teeth are controlled to move toward the driven teeth, and thus the speed difference between the drive teeth and the driven teeth at the time of tooth contact is value By reducing this, the inertial impact at the time of tooth contact can be reduced, thereby eliminating vibration and noise.

[0050] The electric vehicle motor control method provided by this embodiment incorporates elastic deformation during the change of the motor output torque, calculates the elastic deformation, identifies the relative initial speed due to the elastic deformation, implements the corresponding control policy of the motor output torque according to the initial speed, and actively controls the driving teeth to perform active tooth approach, thereby reducing, avoiding or eliminating the inertial shock at the time of tooth contact, thereby canceling vibration and noise. In addition, by actively controlling the driving teeth to approach, the contact and compression stage in the torque smoothing processing method is eliminated, the time for the driving teeth to pass through the backlash is reduced, and the process of changing the tooth meshing surface is reduced, that is, the time for changing the positive torque and negative torque is reduced, thereby improving the torque response and providing better driving performance.

[0051] In one embodiment, the step of determining the output torque of the motor using the first speed difference value includes the steps of: determining a first product as a product of the first speed difference value and a first time length, which is a duration from the disengagement time to the contact time between the driving tooth and the driven tooth; and, if the first product is smaller than a predetermined backlash value, determining that the output torque includes a first torque and a second torque, the first torque and the second torque having opposite directions, the first torque being a torque required in a time interval from the disengagement time to a time when the acceleration / deceleration state of the motor changes, and the second torque being a torque required in a time interval from the change time to the contact time.

[0052] In this method, when the output torque of the motor is determined based on the first speed difference value, the product of the first speed difference value and the first time length may be determined first. 1 ×(t 12 +t 23 ) and ΔN 1 ×(t 12 +t 23 )<2S (where S may be used to indicate a default backlash value, and it is optimal to set the preset backlash value to 2S), the first torque T calculated with the first speed difference value 12and the second torque T 23 The direction of the torque is reversed, and the output torque curve at this time can be shown as in Figure 5.

[0053] Optionally, the motor output Determine the torque 、 By actively controlling the rotational speed of the drive teeth, i.e., by performing torque control by decelerating and then accelerating (or accelerating and then decelerating depending on the direction of change in the motor output torque), the time it takes for the drive teeth to overcome the backlash is reduced, and the problem of slow power response is reduced or avoided. The rotational speed difference at the time of re-contact between the drive teeth and the driven teeth is controlled. value By reducing the rotation speed difference, value can be reduced to zero, completely eliminating vibration and noise.

[0054] In one embodiment, the first torque and the second torque are determined as follows: at the conversion time, a second speed difference value between the current rotation speed of the driving teeth and the converted rotation speed of the second wheel end is determined based on the preset backlash value, the first speed difference value and the first time length; the converted rotation speed of the second wheel end is the rotation speed obtained by converting the rotation speed of the wheel end of the electric vehicle at the conversion time by a speed ratio; and the rotation speed of the driving teeth at the conversion time is determined according to the second speed difference value and the converted rotation speed of the second wheel end. determine a rotational speed of the second drive tooth which is a rotational speed of the first drive tooth, the rotational speed of the second drive tooth, the duration between the release time point and the conversion time point, and the sliding friction force of the drive tooth at the rotational speed of the second drive tooth; determine a second torque based on the rotational speed of the second drive tooth, the rotational speed of the third drive tooth, the duration between the conversion time point and the contact time point, and the sliding friction force of the drive tooth at the rotational speed of the third drive tooth, the rotational speed of the third drive tooth being the rotational speed of the drive tooth at the contact time.

[0055] In this method, a geometric model simplification process can be performed on the shadow area in FIG. 5, and the output torque of the motor can be determined by the simplified model shown in FIG. 6. do.

[0056] As can be seen from the simplified model, N O1 , N R1 , t 12 , t 23 Once this is confirmed, N O2 , N O3 is the determined value, and N R2 The time component of N O1 , N O3 , N R1 , N R2 The backlash value S within the enclosed area is also a definite value.

[0057] From the above conditions, ΔN 2 , N R2 The velocity components of the line segment N can be calculated. R1 N R2 Differentiate with respect to the rate of change of speed a 12 We can find the line segment N R2 N 03 Differentiate with respect to the rate of change of speed a 23 The rate of change of speed a 12 and a 23 Therefore, the first torque T 12 and the second torque T 23 It is possible to determine the following equation: 2S=ΔN 1 ×t 12 +ΔN 2 ×(t 12 +t 23 ) ΔN 2 =(2S-ΔN 1 ×t 12 ) / (t 12 +t 23 ) N R2 =N O2 -ΔN 2 =N O2 -(2S-ΔN 1 ×t 12 ) / (t 12 +t 23 ) a 12 =(N R2 -N R1 ) / t12 a 23 =(N O3 -N R2 ) / t 23

[0058] The moment of inertia of the motor rotor is known and the first torque T 12 and the second torque T 23 can be calculated from the moment of inertia I of the motor rotor and expressed as the following formula: T 12 = I × a 12 +T F T 23 = I × a 23 +T F

[0059] Here, one or more tables can be determined according to different driving modes of the electric vehicle, and the rotation speed of the driving teeth (or the vehicle speed) and t 12 , t 23 Since we can memorize the mapping relationship between t 12 , t 23 can be obtained by querying the table, T F may be used to indicate the sliding friction force during rotation of the drive tines at the current rotation speed and temperature of the drive tines, and can be obtained by bench testing.

[0060] Optionally, the reduced rotational speed of the wheel end N 0 can be determined by the following formula: N O =N*i

[0061] The vehicle speed prediction equation can be determined by the following equation. V=V 1 +a×Δt=V 1 +a F ×Δt-sinθ×g×Δt+F / m×Δt=(N O1 +a O ×Δt)×2πr / K / i K=N 1 ×2πr / V 1

[0062] The equation for the acceleration of the vehicle speed can be determined by the following equation: a=a F -sinθ×g+F / m

[0063] Then, a F ×Δt-sinθ×g×Δt+F / m×Δt=a O ×Δt×2πr / K / i The acceleration formula for wheel speed is, a O =a / (Δt×2πr×K)=(-a F -sinθ×g+F / m) / (2πr / K / i) and The wheel speed prediction formula is: N OΔt =N O1 +a O ×Δt=N O1 +(-a F -sinθ×g+F / m)×Δt / (2πr / K / i) and Here, K may be used to indicate the tire slip coefficient, N may be used to indicate the wheel speed, and N 1 may be used to indicate the wheel speed at a given time, and N 0 may be used to indicate the reduced rotational speed of the wheel end, V may be used to indicate the vehicle speed of the electric vehicle, and V 1 may be used to indicate the vehicle speed of an electric vehicle at a certain point in time, a may be used to indicate the acceleration of the vehicle speed, F may be used to indicate the wheel end torque, where F=0 when the driving teeth overcome the backlash, and a F may be used to indicate the deceleration due to total vehicle skid resistance (wind resistance + wheel end friction force + transmission mechanical friction force), which can be obtained by a coast curve, a 0may be used to indicate the acceleration of the wheel speed, r may be used to indicate the radius of the wheel, θ may be used to indicate the slope, i may be used to indicate the speed ratio between the wheel and the motor rotor, Δt may be used to indicate the length of time in a period of time, g may be used to indicate the acceleration due to gravity, and m may be used to indicate the mass of the electric vehicle.

[0064] Optionally, t 12 , t 23 In addition to controlling the completion of the tooth approaching operation of the driving teeth by determining the output torque of the motor based on the determination of T 12 and T 23 The value of may complete the tooth approaching operation of the driving teeth, and one or more tables can be determined according to different operating modes.

[0065] The table contains the rotation speed of the driving teeth (or the vehicle speed) and T 12 , T 23 It is stored as a mapping relationship with T 12 , T 23 can be obtained by querying the table, T 12 , T 23 By determining the time corresponding to the above, the tooth approaching operation of the driving teeth can be completed, which can be expressed by the following formula: a 12 =I / T 12 a 23 =I / T 23 2S=ΔN 1 ×t 12 +ΔN 2 ×(t 12 +t 23 ) ΔN 2 = ΔN 1 -a 13 ×t 12 +a 12 ×t 12 ΔN 1 +a 12 ×t 12 =a 23 ×t23 +a 13 ×(t 12 +t 23 ) t 23 =(ΔN 1 +a 12 ×t 12 -a 13 ×t 12 ) / (a 13 +a 23 ) 2S=ΔN 1 ×t 12 +(ΔN 1 -a 13 ×t 12 +a 12 ×t 12 )×(t 12 +(ΔN 1 +a 12 ×t 12 -a 13 ×t 12 ) / (a 13 +a 23 ))

[0066] Here, a 13 is the line segment N O1 N O3 It may also be used to indicate the rate of change of speed obtained by differentiating with respect to

[0067] First torque T 12 The time t 12 and the second torque T 23 The time t 23 , that is, the entire tooth approach process can be determined by the above formula.

[0068] Optionally, N O1 , N O3 , N R1 , N R2 If the enclosed area of ​​is determined to be the backlash S, then N O1 and N R1 has been determined, and T 12 , T 23 , t 12 , t 23 , t 13The entire tooth approach process may be determined by determining any two of the above.

[0069] Optionally, the rotational speed of the drive teeth can be actively controlled, i.e., torque controlled by slowing down and then accelerating (or accelerating and then decelerating, depending on the direction the motor output torque is trying to change), thereby reducing the time it takes for the drive teeth to overcome backlash and reducing or avoiding the problem of slow power response. do. The rotation speed of the driving tooth is controlled, and the rotation speed difference at the time when the driving tooth and the driven tooth re-contact each other is calculated. value By reducing the rotation speed difference, value can be reduced to zero, completely eliminating vibration and noise.

[0070] In one embodiment, the step of determining the output torque of the motor based on the first speed difference value further includes the steps of: determining a second product as a product of the first speed difference value and a second time length, which is a duration from the release time to the conversion time, when the first product is equal to or greater than a preset backlash value; and determining that the output torque includes a first torque and a second torque when the second product is smaller than the preset backlash value, where the first torque and the second torque have the same direction.

[0071] In this method, when the calculated first product is equal to or greater than the preset backlash value 2S, it is necessary to determine the product of the first speed difference value and the second time length. That is, ΔN 1 ×(t 12 +t 23 ) ≧ 2S, then ΔN 1 ×t 12 It is necessary to calculate

[0072] Optionally, ΔN 1 ×t 12 If <2S, then a geometric model simplification process can be performed on the shadow area in FIG. 5, and a simplified model as shown in FIG. 7 may be obtained, where the first torque T 12 and the second torque T23 The formula for determining ΔN 1 ×(t 12 +t 23 ) < 2S, but ΔN 1 ×t 12 If <2S, the first torque T 12 and the second torque T 23 and the output torque curve may be as shown in FIG.

[0073] Optionally, in Figure 8, the dashed line T 1 may be used to show a torque curve in which a stage of reduced output torque is possible. The torque curve may be expressed as a torque down slope u, a separation point t 1 , the initial velocity difference when the driving tooth and the driven tooth separate value ΔN 1 Here, u is the time from when the motor output torque starts to decrease when the user releases the accelerator to when the driving teeth and the driven teeth start to separate (t 0 From 1 may be used to indicate the average slope along which the torque falls, i.e., the torque downslope.

[0074] Optionally, the rotational speed of the drive teeth can be actively controlled, i.e., torque controlled by decelerating and then accelerating (or accelerating and then decelerating depending on the direction of change in the motor output torque), thereby reducing the time it takes for the drive teeth to overcome backlash and reducing or avoiding the problem of slow power response. do. The rotation speed of the driving tooth is controlled, and the rotation speed difference at the time when the driving tooth and the driven tooth re-contact each other is calculated. value By reducing the rotation speed difference, value can be reduced to zero, completely eliminating vibration and noise.

[0075] In one embodiment, the step of determining the output torque of the motor using the first speed difference value further includes the steps of: determining a reduced rotational speed of the third wheel end at a target time if the second product is greater than or equal to a preset backlash value, where the reduced rotational speed of the third wheel end is the rotational speed of the wheel end of the electric vehicle at the target time converted by the speed ratio, and the target time is the time when the driving teeth and the driven teeth re-contact each other during the second time length; and determining a third torque based on the reduced rotational speed of the third wheel end, the rotational speed of the first driving teeth, and the duration between the disengagement time and the target time, where the third torque is a required torque in the time interval from the disengagement time to the target time, and the output torque includes the third torque.

[0076] In this method, when the second product is equal to or greater than a preset backlash value, i.e., ΔN 1 ×t 12 If t ≧2S, the shadow area in FIG. 5 may be subjected to a geometric model simplification process to obtain a simplified model as shown in FIG. 9. In this case, t 1 From 2’ All you need to do is calculate the torque required for the time period 、 t 2’ is the target time, and t 1 from t 2’ This is also the point in time when the driving and driven teeth re-contact each other.

[0077] Optionally, ΔN 1 ×t 12 The output torque (third torque) of the motor when ≧2S can be determined by the following equation. ΔN 1 ×t 12' =2S t 12' =2S / ΔN 1 N O2' =N O1 -a 13 ×t 12' a 12' =(N O2' -NR1 ) / t 12' T 12' = I × a 12'

[0078] Here, t 12′ is 1 From 2′ The time length until O2′ is 2′ The converted rotational speed of the wheel when the driving teeth and the driven teeth come into contact again at the time a 12′ is line segment N O1 N O2′ The rate of change of speed obtained by differentiating with respect to T 12′ may be used to denote the third torque, respectively.

[0079] Optionally, ΔN 1 ×t 12 When ≧2S, the output torque curve may be as shown in FIG. 10. In FIG. 10, the dashed line T 1 may be used to show a torque curve in which a stage of reduced output torque is possible. The torque curve may be expressed as a torque down slope u, a separation point t 1 , the initial speed difference value ΔN when the driving tooth and the driven tooth separate 1 Depends on the dotted line T 2 t 12′ It may be used to show selectable torque curves over a period of time.

[0080] Optionally, the rotational speed of the drive teeth can be actively controlled, i.e., torque controlled by decelerating and then accelerating (or accelerating and then decelerating depending on the direction of change in the motor output torque), thereby reducing the time it takes for the drive teeth to overcome backlash and reducing or avoiding the problem of slow power response. do. The rotation speed of the driving tooth is controlled, and the rotation speed difference at the time when the driving tooth and the driven tooth re-contact each other is calculated. value By reducing the rotation speed difference, value can be reduced to zero, completely eliminating vibration and noise.

[0081] In one embodiment, the step of detecting the relative deformation of the transmission system between the driving teeth of the motor and the wheel end includes the steps of determining whether a direction of the output torque of the motor has changed, determining whether a meshing direction between the driving teeth and the driven teeth of the motor is about to change when the direction of the output torque is about to change, and determining the amount of relative deformation when the meshing direction between the driving teeth and the driven teeth is about to change.

[0082] In this method, the torque transmitted by the transmission system between the drive teeth and the wheel generates a relative deformation in the transmission system between the drive teeth and the wheel end. On the other hand, the elastic force due to the deformation of the transmission system between the drive teeth and the wheel end is 、 The relative speed difference between the rotation speed of the driving teeth and the converted rotation speed of the wheel end during the output torque change value The relative velocity difference value By recognizing the difference in relative velocity, value The present invention implements different output torque control policies for the vehicle, which can effectively reduce or eliminate the problem in the related art that the vehicle still accelerates even when the accelerator pedal is released, or the vehicle does not accelerate even when the accelerator pedal is depressed, resulting in poor dynamic response of the vehicle. do. By this measure, the torque slope during the elastic release phase is increased, which allows for rapid positive and negative torque variations and optimizes the dynamic response of the electric vehicle.

[0083] Optionally, it may be determined whether the direction of the output torque of the motor is about to change, and whether the direction of the output torque is about to change. Various situations may be included in the direction of the output torque, such as from positive to negative, from negative to positive, zero positive, zero negative, etc. When the direction of the output torque is about to change, it may be determined whether the meshing direction between the driving teeth and the driven teeth of the motor is about to change. Then, it determines the relative deformation amount of the transmission system between the driving teeth of the motor and the wheel end when the meshing direction between the driving teeth and the driven teeth changes.

[0084] In one embodiment, the relative deformation of the transmission between the driving teeth of the motor and the wheel end is detectionThe step of determining further includes the steps of: determining a third speed difference value between the current rotational speed of the driving tooth and the rotational speed of the driven tooth when a change in the output torque of the motor is detected; determining a relative displacement between the driving tooth and the driven tooth based on the third speed difference value; and determining a relative deformation amount based on the relative displacement.

[0085] With this means, when the output torque is changed, a third speed difference value between the rotational speed of the drive tooth and the rotational speed of the driven tooth can be calculated in real time during the subsequent movement of the drive tooth and the driven tooth, and the speed difference value within each time period can be obtained for a plurality of consecutive time periods. Then, the relative displacement between the drive tooth and the driven tooth can be calculated based on the speed difference value for each time period and the time length of the corresponding time period, thereby obtaining the amount of relative deformation between the drive tooth and the driven tooth.

[0086] Optionally, since the relative initial speeds of the drive teeth due to different relative deformation amounts are different, different output torque control policies can be implemented for different initial speeds to achieve rapid conversion of positive and negative torque and optimize the dynamic response of the electric vehicle.

[0087] The electric vehicle motor control method provided by the present application actively controls the output torque of the motor when the meshing direction between the drive teeth and the driven teeth changes, thereby shortening the time it takes for the drive teeth and the driven teeth to re-contact each other, accelerating the conversion of positive and negative torque, shortening the power output delay, and improving drivability. In addition, by actively controlling the output torque of the motor when the meshing direction between the drive teeth and the driven teeth changes, the speed difference when the drive teeth and the driven teeth come into contact with each other is reduced. value This eliminates the noise and impact caused by inertial collision. Also, the speed difference when the driving teeth and the driven teeth come into contact with each other by applying a deceleration torque is eliminated. value By reducing or eliminating the torque slope, the elastic release phase torque slope can be increased, and the positive and negative torque can be quickly converted, reducing or avoiding the problem of the vehicle still accelerating when the accelerator is released, or the vehicle not accelerating when the accelerator is depressed, thereby optimizing the dynamic response of the electric vehicle.

[0088] Overall, the technical solution provided by this application is a technical method that can optimize the driving performance of electric vehicles while eliminating noise and impact caused by inertial collision.

[0089] The present application further provides a motor control device for an electric vehicle. FIG. 11 is a schematic diagram of a motor control device for an electric vehicle provided by an embodiment of the present application. As shown in FIG. 11, the motor control device 1100 for an electric vehicle includes: A detection module 1101 is used to detect the relative deformation of the transmission system between the driving teeth of the motor and the wheel end; A determination module 1102 is used to determine a first speed difference value between the rotation speed of the first driving tooth and the converted rotation speed of the first wheel end when the relative deformation amount is a first threshold value, where the relative deformation amount is the first threshold value, which is used to indicate that the driving tooth and the driven tooth of the transmission system start to disengage, the rotation speed of the first driving tooth is the rotation speed of the driving tooth at the time when the driving tooth and the driven tooth disengage, and the converted rotation speed of the first wheel end is the rotation speed of the wheel end of the electric vehicle converted by a speed ratio at the time of disengagement; A processing module 1103 is used to determine the output torque of the motor according to the first speed difference value; and a control module 1104 that is used to control the driving teeth to move toward each other relative to the driven teeth by the output torque.

[0090] Optionally, when the processing module 1103 determines the output torque of the motor according to the first speed difference value, it specifically determines a first product of the first speed difference value and a first time length, which is a duration from the disengagement time to the contact time between the driving tooth and the driven tooth, and if the first product is smaller than a preset backlash value, it is used to determine that the output torque includes a first torque and a second torque, where the first torque and the second torque have opposite directions, the first torque is a torque required in a time interval from the disengagement time to a time when the acceleration / deceleration state of the motor changes, and the second torque is a torque required in a time interval from the time when the change time to the time when the contact time occurs.

[0091] Optionally, the electric vehicle motor control device 1100 may further include a 2 Decision module ( figure (not shown), the third determination module specifically determines the first torque and the second torque as follows: at the conversion time, a second speed difference value between the current rotation speed of the driving tooth and the converted rotation speed of the second wheel end is determined according to the preset backlash value, the first speed difference value and the first time length, the converted rotation speed of the second wheel end is the rotation speed of the wheel end of the electric vehicle converted by the speed ratio at the conversion time, and the second speed difference value and the converted rotation speed of the second wheel end are determined according to the second speed difference value and the converted rotation speed of the second wheel end at the conversion time. a first torque is determined based on the rotational speed of the second drive tooth, the rotational speed of the first drive tooth, the duration between the release time point and the conversion time point, and the sliding friction force of the drive tooth at the rotational speed of the second drive tooth; and a second torque is determined based on the rotational speed of the second drive tooth, the rotational speed of the third drive tooth, the duration between the conversion time point and the contact time point, and the sliding friction force of the drive tooth at the rotational speed of the third drive tooth, where the rotational speed of the third drive tooth is the rotational speed of the drive tooth at the contact time.

[0092] Optionally, the processing module 1103 is used to determine the output torque of the motor according to the first speed difference value, and further specifically determine a second product as a product of the first speed difference value and a second time length, which is a duration length from the release time to the conversion time, when the first product is equal to or greater than a preset backlash value, and determine that the output torque includes a first torque and a second torque when the second product is smaller than the preset backlash value, where the first torque and the second torque have the same direction.

[0093] Optionally, when the processing module 1103 determines the output torque of the motor according to the first speed difference value, specifically when the second product is equal to or greater than the preset backlash value, it further determines a reduced rotation speed of the third wheel end at the target time, the reduced rotation speed of the third wheel end being the rotation speed of the wheel end of the electric vehicle at the target time converted by the speed ratio, the target time being the time when the driving tooth and the driven tooth re-contact in the second time length, and is used to determine a third torque based on the reduced rotation speed of the third wheel end, the rotation speed of the first driving tooth, and the duration between the disengagement time and the target time, where the third torque is the required torque in the time interval from the disengagement time to the target time, and the output torque includes the third torque.

[0094] Optionally, detection When determining the relative deformation of the transmission between the driving teeth of the motor and the wheel end, the module 1101: Ingredients Specifically, when a change in the output torque of the motor is detected, a third speed difference value between the current rotation speed of the driving teeth and the rotation speed of the driven teeth is calculated. detection The third velocity difference value can then be used to determine a relative displacement between the driving tooth and the driven tooth based on the third velocity difference value, and to determine a relative deformation amount based on the relative displacement.

[0095] The electric vehicle motor control device provided in the embodiments of the present application is a technical solution for implementing the electric vehicle motor control method in the method embodiments, and the implementation principles and technical effects are similar, so a description thereof will be omitted here.

[0096] An embodiment of the present application further provides an electric vehicle. FIG. 12 is a block diagram of an electric vehicle according to an exemplary embodiment. As shown in FIG. 12, the electric vehicle 1200 includes: A processor 1211, a memory 1212, and an interactive interface 1213 are included. Here, the processor 1211 is communicatively connected to the memory 1212, and the memory 1212 is used to store computer-executable instructions executable by the processor 1211, Here, the processor 1211 is configured to execute the technical solution of the motor control method for the electric vehicle by executing computer-implemented instructions.

[0097] Optionally, the memory 1212 may be separate or integrated with the processor 1211 .

[0098] Optionally, if the memory 1212 is a separate device from the processor 1211, the electronic device 1200 may further include a bus connecting said devices.

[0099] Optionally, the memory may be, but is not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), etc. Here, the memory stores a program, and the processor executes the program upon receiving an execution instruction. The software programs and modules in the memory may further include an operating system, and may include various software components and / or drives for managing system tasks such as memory management, memory device control, power management, etc. It is capable of communicating with various hardware and software components, thereby providing an operating environment for other software components.

[0100] Optionally, the processor may be an integrated circuit chip having a signal processing capability. The processor may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc. Each method, procedure, and logic block diagram disclosed in the embodiments of the present application may be realized or executed, and the general-purpose processor may be a microprocessor, and the processor may be any conventional processor.

[0101] An embodiment of the present application further provides a computer readable storage medium having computer executable instructions stored thereon, which, when executed by a processor, are used to implement the electric vehicle motor control method provided by the method embodiment.

[0102] An embodiment of the present application further provides a computer program product including a computer program which, when executed by a processor, is used to implement the electric vehicle motor control method provided by the method embodiment.

[0103] Those skilled in the art can understand that all or part of the steps for implementing the above-mentioned method embodiments can be achieved by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above-mentioned method embodiments, and the storage medium includes various media capable of storing program codes, such as ROM, RAM, magnetic disk, or optical disk.

[0104] It should be noted that the above embodiments are for the purpose of explaining the present invention, and are not limited thereto. Although the present application has been described in detail with reference to the above embodiments, it should be understood that a person skilled in the art may still modify the technical means described in the above embodiments. Or, the same replacement may be made for part or all of these technical features, and these modifications or replacements do not deviate the essence of the technical means from the scope of the technical means of the embodiments of the present application.

Claims

1. A method for controlling a motor of an electric vehicle, comprising: Detecting a relative deformation of a transmission line between a driving tooth of the motor and a wheel end; determining a first speed difference value between the rotational speed of the first driving tooth and the converted rotational speed of the first wheel end when the amount of relative deformation is a first threshold value, the amount of relative deformation being a first threshold value being used to indicate that the driving tooth and the driven tooth of the transmission system start to disengage, the rotational speed of the first driving tooth being the rotational speed of the driving tooth at the time of disengagement between the driving tooth and the driven tooth, and the converted rotational speed of the first wheel end being the rotational speed of the wheel end of the electric vehicle converted by a speed ratio at the time of disengagement; determining an output torque of the motor according to the first speed difference value; and controlling the drive teeth to move toward the driven teeth by the output torque.

2. A method for controlling a motor of an electric vehicle.

2. The step of determining an output torque of the motor using the first speed difference value includes: determining a first product of the first velocity difference value and a first time length that is a duration from the time of disengagement to a time of contact between the drive tooth and the driven tooth; determining that the output torque includes a first torque and a second torque when the first product is less than a preset backlash value; The first torque and the second torque have opposite directions, the first torque is a torque required in a time interval from the time of separation to a time of change in the acceleration / deceleration state of the motor, and the second torque is a torque required in a time interval from the time of change to the time of contact.

2. The motor control method according to claim 1.

3. The first torque and the second torque are determined as follows: At the time of conversion, a second speed difference value between the current rotation speed of the driving teeth and a converted rotation speed of a second wheel end is determined based on the preset backlash value, the first speed difference value, and the first time length, and the converted rotation speed of the second wheel end is a rotation speed obtained by converting the rotation speed of the wheel end of the electric vehicle at the time of conversion by a speed ratio; determining a rotational speed of a second driving tooth, which is the rotational speed of the driving tooth at the time of the conversion, according to the second speed difference value and the converted rotational speed of the second wheel end; determining the first torque based on a rotational speed of the second drive tooth, a rotational speed of the first drive tooth, a duration between the disengagement time point and the transition time point, and a sliding frictional force of the drive tooth at the rotational speed of the second drive tooth; determining the second torque based on a rotational speed of the second drive tooth, a rotational speed of a third drive tooth, a duration between the conversion time point and the contact time point, and a sliding friction force of the drive tooth at the rotational speed of the third drive tooth, the rotational speed of the third drive tooth being the rotational speed of the drive tooth at the contact time point; 3. The motor control method according to claim 2.

4. The step of determining the output torque of the motor using the first speed difference value further includes: determining a product of the first speed difference value and a second time length, which is a duration from the separation time point to the conversion time point, as a second product when the first product is equal to or greater than the preset backlash value; determining that the output torque comprises the first torque and the second torque if the second product is less than the preset backlash value; The first torque and the second torque have the same direction.

3. The motor control method according to claim 2.

5. The step of determining the output torque of the motor using the first speed difference value further includes: a step of determining a converted rotational speed of a third wheel end at a target time when the second product is equal to or greater than the preset backlash value, the converted rotational speed of the third wheel end being a rotational speed obtained by converting the rotational speed of the wheel end of the electric vehicle at the target time by a speed ratio, the target time being a time when the driving tooth and the driven tooth re-contact each other during the second length of time; determining a third torque based on the converted rotational speed of the third wheel end, the rotational speed of the first drive tooth, and a duration between the take-off time and the target time, the third torque being a required torque in a time interval from the take-off time to the target time, and the output torque including the third torque.

5. The motor control method according to claim 4.

6. The step of detecting a relative deformation of a transmission system between the driving teeth of the motor and a wheel end includes: determining a third speed difference value between a current rotation speed of the driving teeth and a current rotation speed of the driven teeth when a change in the output torque of the motor is detected; determining a relative displacement between the drive tooth and the driven tooth based on the third velocity difference value; and determining the relative deformation based on the relative displacement.

6. The motor control method according to claim 1, wherein the motor control method is a step of controlling a motor.

7. A motor control device for an electric vehicle, A detection module is used to detect the relative deformation of the transmission system between the driving teeth of the motor and the wheel end; a determination module used to determine a first speed difference value between the rotational speed of the first driving tooth and the converted rotational speed of the first wheel end when the relative deformation amount is a first threshold value, the first threshold value being used to indicate that the driving tooth and the driven tooth of the transmission system start to disengage, the rotational speed of the first driving tooth is the rotational speed of the driving tooth at the time when the driving tooth and the driven tooth disengage, and the converted rotational speed of the first wheel end is the rotational speed of the wheel end of the electric vehicle converted by a speed ratio at the time when the disengagement occurs; a processing module adapted to determine an output torque of the motor according to the first speed difference value; a control module used for controlling the drive teeth to move toward the driven teeth by the output torque.

2. A motor control device for an electric vehicle.

8. 1. An electric vehicle including a processor and a memory communicatively coupled to the processor, The memory stores computer executable instructions; The processor executes computer executable instructions stored in the memory to realize the electric vehicle motor control method according to any one of claims 1 to 5.

9. A computer-readable storage medium having computer-executable instructions stored thereon, The computer executable instructions, when executed by a processor, are used to implement the electric vehicle motor control method according to any one of claims 1 to 5. A computer-readable storage medium comprising:

10. A computer program comprising: The computer program, when executed by a processor, is used to realize the electric vehicle motor control method according to any one of claims 1 to 5. A computer program comprising:

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