A control method and device for a motor of an electric vehicle and a vehicle

Abstract

The embodiments of the present application relate to the field of automobile technology, and more specifically, to a control method, device and vehicle for a motor of an electric vehicle. The wheel speed difference at both ends of the differential is detected. When the wheel speed difference is greater than or equal to a preset threshold, the maximum available torque of the motor is obtained according to the wheel speed difference of the wheel speeds at both ends of the differential; the safe estimated torque is determined according to the wheel speed difference and the maximum available torque; and the safe estimated torque is output to the vehicle controller to reduce the current torque of the motor to the safe estimated torque. When the wheel speed difference is greater than or equal to the preset threshold, the current torque and the wheel speed difference at both ends are large, which can easily damage the differential. Therefore, the safe estimated torque that can enable the differential to operate safely is calculated through the wheel speed difference, and then the safe estimated torque is output to drive the motor to reduce the torque to the safe estimated torque, thereby reducing the wheel speed difference at both ends and protecting the differential.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of automobile technology, and more specifically, to a control method and device for a motor of an electric vehicle, and a vehicle. Background Art

[0002] With the rapid development of new energy vehicles, drive motors of different powers and speed ranges have also been widely used. In addition to wheel hub motors, electric drive systems are equipped with reduction gears to reduce speed and increase torque. In order to reduce tire wear, downshift power and fuel consumption, enhance the steering and braking capabilities of the car, and also due to cost constraints, reduction gears are generally equipped with differentials without differential locks. When the difference in wheel speed on both sides is too large and the output torque of the motor is relatively large, it will cause damage to the differential.

[0003] In the prior art, the torque is generally limited by directly monitoring the torque through the vehicle controller, which makes the interaction process of the vehicle controller regarding the torque more complicated, which in turn leads to disadvantages such as difficulty in implementing the method and a long time for vehicle calibration and debugging.

[0004] Application Contents

[0005] The embodiments of the present application provide a control method, device and vehicle for a motor of an electric vehicle, aiming to solve the problem that the interaction process of the vehicle controller regarding torque is relatively complex.

[0006] A first aspect of an embodiment of the present application provides a control method for a motor of an electric vehicle, based on a drive motor controller, the control method comprising:

[0007] Detecting a wheel speed difference between two ends of the differential, and when the wheel speed difference is greater than or equal to a preset threshold, obtaining a maximum available torque of the motor according to the wheel speed difference;

[0008] determining a safe estimated torque according to the wheel speed difference and the maximum available torque;

[0009] The safety estimated torque is output to a vehicle controller so that the current torque of the motor is reduced to the safety estimated torque.

[0010] Optionally, determining the maximum available torque of the motor according to the wheel speed difference between the wheel speeds at both ends of the differential includes:

[0011] Determining the wheel speed difference between the two ends of the differential according to the wheel speeds at both ends of the differential;

[0012] The maximum available torque corresponding to the wheel speed difference is determined in a preset torque external characteristic curve.

[0013] Optionally, determining the safety estimated torque according to the wheel speed difference and the maximum available torque includes:

[0014] Determine the torque limit coefficient and time coefficient of the differential according to the wheel speed difference and the timer;

[0015] The safe estimated torque of the differential is determined according to the maximum available torque, the torque limit coefficient and the time coefficient.

[0016] Optionally, determining the torque limiting coefficient and the time coefficient of the differential according to the wheel speed difference includes:

[0017] Substituting the wheel speed difference into a torque limit coefficient chart to obtain the torque limit coefficient corresponding to the wheel speed difference;

[0018] When the wheel speed difference is greater than or equal to a preset threshold, timing is started until the safe estimated torque is determined to obtain a time value, and the time value is substituted into a time coefficient chart to obtain the time coefficient corresponding to the time value.

[0019] Optionally, determining the safe estimated torque of the differential according to the maximum available torque, the torque limit coefficient and the time coefficient includes:

[0020] The maximum available torque, the torque limit coefficient, and the time coefficient are multiplied to obtain the safe estimated torque of the differential.

[0021] Optionally, determining the safe estimated torque of the differential according to the maximum available torque, the torque limit coefficient and the time coefficient includes:

[0022] The maximum available torque, the torque limit coefficient and the time coefficient are multiplied to obtain the safe estimated torque.

[0023] Optionally, outputting the safety estimated torque to a vehicle controller to reduce the current torque of the motor to the safety estimated torque includes:

[0024] Outputting the safety estimated torque to a vehicle controller;

[0025] receiving a safety estimated torque request returned by the vehicle controller in response to the safety estimated torque;

[0026] In response to the safety pre-estimated torque request, the electric machine is driven to reduce torque output to the safety pre-estimated torque based on the safety pre-estimated torque.

[0027] Optionally, after the motor controller reduces the output torque, the control method further includes:

[0028] When the wheel speed difference is lower than a preset threshold, a preset torque is output to the vehicle controller so that the vehicle's motor outputs torque according to the preset torque, wherein the preset torque is a pre-execution torque of the motor that is not corrected according to the wheel speed difference.

[0029] A second aspect of an embodiment of the present application provides a control device for a motor of an electric vehicle, characterized in that the device comprises:

[0030] an acquisition module, used for detecting the wheel speeds at both ends of the differential, and when the wheel speed difference is greater than or equal to a preset threshold, acquiring the maximum available torque of the motor according to the wheel speed difference at both ends of the differential;

[0031] a determination module, configured to determine a safe estimated torque according to the wheel speed difference and the maximum available torque;

[0032] The execution module is used to output the safe estimated torque to a vehicle controller so as to reduce the current torque of the motor to the safe estimated torque.

[0033] A third aspect of an embodiment of the present application provides an electronic device, including:

[0034] Memory for storing computer programs;

[0035] A processor, configured to execute a computer program stored in the memory to implement the control method according to any one of claims 1 to 7.

[0036] A fourth aspect of an embodiment of the present application provides a vehicle, characterized in that it includes a control device, and the control device is used to implement the above-mentioned control method.

[0037] Beneficial effects:

[0038] The present application provides a control method, device and vehicle for the motor of an electric vehicle. During the driving process of the vehicle, the wheel speeds at both ends of the vehicle differential are obtained in real time, so as to obtain the wheel speed difference at both ends. When the wheel speed difference is greater than or equal to the preset threshold, the maximum available torque of the motor is obtained according to the wheel speed difference, and the safe estimated torque is determined according to the wheel speed difference and the maximum available torque. When the wheel speed difference is greater than or equal to the preset threshold, the current torque and the wheel speed difference at both ends are large, which can easily damage the differential. Therefore, the safe estimated torque that can enable the differential to operate safely is calculated by the wheel speed difference, and then the safe estimated torque is output to drive the motor to reduce the torque to the safe estimated torque, thereby reducing the wheel speed difference at both ends and protecting the differential. The torque of the motor is detected and limited by the motor controller, thereby reducing the wheel speed difference, which can effectively protect the differential and reduce the interaction process of the vehicle controller regarding torque, thereby reducing the vehicle calibration time and the test vehicle debugging time. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0040] Figure 1 It is a flowchart of a control method proposed in an embodiment of the present application;

[0041] Figure 2 is a schematic diagram of a process for determining the current torque proposed in an embodiment of the present application;

[0042] Figure 3 is a schematic diagram of a process for determining a safe torque according to an embodiment of the present application;

[0043] Figure 4 is a torque external characteristic curve diagram proposed in an embodiment of the present application;

[0044] Figure 5 It is a schematic diagram of a process of outputting a safe estimated torque proposed in an embodiment of the present application;

[0045] Figure 6 is a module schematic diagram of a control device proposed in an embodiment of the present application;

[0046] Figure 7 It is a module schematic diagram of an electronic device proposed in an embodiment of the present application.

[0047] Explanation of the reference numerals: 5, control device; 51, acquisition module; 52, determination module; 53, execution module. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] With the rapid development of new energy vehicles, drive motors of different powers and speed ranges have also been widely used. Electric drive systems are equipped with reduction gears to reduce speed and increase torque. In order to reduce tire wear, downshift power and fuel consumption, enhance the steering and braking capabilities of the car, and also due to cost constraints, reduction gears are generally equipped with differentials without differential locks. Limited by the capacity of the reduction gear differential, when the difference in wheel speed on both sides is too large and the output torque of the motor is relatively large, the differential will be damaged.

[0050] In the related technology, there are several ways to deal with differential protection for the existing new energy vehicles without differential locks:

[0051] 1. No protection, purely dependent on the ability of the differential;

[0052] 2. For the reduction box with a disengagement mechanism, emergency disengagement is performed when the wheel speed difference and torque reach the tolerance according to the external characteristic curve of the differential;

[0053] 3. This is achieved by limiting the motor torque through the vehicle controller.

[0054] Since the vehicle controller detects and controls multiple related parameters of the differential, when the torque is directly monitored and limited by the vehicle controller, it is easy to make the vehicle's interaction process regarding torque more complicated, which in turn leads to disadvantages such as difficult implementation of the method to protect the differential, long vehicle calibration and debugging time, and low R&D efficiency.

[0055] In view of this, refer to Figure 1 In a first aspect, an embodiment of the present application provides a control method for a motor of an electric vehicle. Based on a drive motor controller, the control method includes:

[0056] S1, detecting the wheel speed difference at both ends of the differential, and when the wheel speed difference is greater than or equal to a preset threshold, obtaining the maximum available torque of the motor according to the wheel speed difference;

[0057] The wheel speeds at both ends of the shaft are monitored by the motor controller, and the wheel speeds at both ends are input into the motor controller. The wheel speed difference at both ends is calculated, and the maximum available torque corresponding to the wheel speed difference is determined according to the torque external characteristic curve. The maximum available torque is the maximum output torque of the motor that the differential can withstand under a certain wheel speed difference, measured in the laboratory, that is, the maximum available torque of the motor. When the output torque of the motor exceeds the maximum available torque, it is easy to cause damage to the differential.

[0058] S2, determining the safe estimated torque based on the wheel speed difference and the maximum available torque;

[0059] The torque corresponding to the preset threshold of the wheel speed difference is the critical value of the torque that is likely to cause damage to the differential under the current wheel speed difference. Different vehicles set the wheel speed difference threshold according to the differential performance and vehicle operating conditions.

[0060] When the wheel speed difference is greater than or equal to the preset threshold, the wheel speed difference at both ends of the differential is too large and is prone to damage. Therefore, the safe estimated torque that drives the differential to work safely is calculated based on the maximum available torque and the wheel speed difference.

[0061] S3, outputting the safe estimated torque to the vehicle controller to reduce the current torque of the motor to the safe estimated torque.

[0062] By outputting the safety estimated torque to the vehicle controller, the vehicle controller outputs request information about the obtained safety estimated torque to the motor controller. The motor controller drives the motor to reduce the current torque of the motor to the safety estimated torque, thereby reducing the wheel speed difference at both ends of the differential and protecting the differential.

[0063] During the driving process of the vehicle, the wheel speeds at both ends of the vehicle differential are obtained in real time, so as to obtain the wheel speed difference at both ends. When the wheel speed difference is greater than or equal to the preset threshold, the maximum available torque of the motor is obtained according to the wheel speed difference, and the safe estimated torque is determined according to the wheel speed difference and the maximum available torque. When the wheel speed difference is greater than or equal to the preset threshold, the current torque and the wheel speed difference at both ends are large, which can easily damage the differential. Therefore, the safe estimated torque that can enable the differential to operate safely is calculated through the wheel speed difference, and then the safe estimated torque is output to drive the motor to reduce the torque to the safe estimated torque, thereby reducing the wheel speed difference at both ends and protecting the differential. The torque of the motor is detected and limited by the motor controller, thereby reducing the wheel speed difference, which can effectively protect the differential and reduce the interaction process of the vehicle controller regarding torque, thereby reducing the vehicle calibration time and the test vehicle debugging time.

[0064] Among them, refer to Figure 2 , based on the wheel speed difference, determining the maximum available torque of the motor includes:

[0065] S101, determining a wheel speed difference between the wheel speeds at both ends of the differential according to the wheel speeds at both ends;

[0066] The wheel speeds at both ends of the shaft are monitored by the motor controller, and the wheel speeds at both ends are input into the motor controller. The wheel speeds at both ends are subtracted to obtain the absolute value of the value as the wheel speed difference.

[0067] S102: Determine a maximum available torque corresponding to the wheel speed difference in a preset torque external characteristic curve.

[0068] In this embodiment, the maximum available torque is T max, where the torque external characteristic curve is a curve diagram corresponding to the wheel speed difference and the maximum torque it can withstand. Through experiments, the maximum tolerable torques corresponding to different wheel speed differences are calibrated one by one to form a curve diagram, which is the torque external characteristic curve of the wheel speed difference.

[0069] Reference Figure 4 In one embodiment, the torque external characteristic curve is as follows: Figure 4 As shown, the vertical axis and the speed difference of the first row of the corresponding chart below are the wheel speed difference in this application, and the horizontal axis and the corresponding torque of the second row of the corresponding chart below are the maximum available torque in this application. The larger the wheel speed difference, the smaller the maximum available torque that the differential can withstand.

[0070] After the wheel speed difference is obtained, the wheel speed difference is substituted into the torque external characteristic curve to obtain the torque threshold value corresponding to the wheel speed difference, which is the maximum available torque that the current differential can withstand.

[0071] Reference Figure 3 In some embodiments, determining the safe estimated torque according to the wheel speed difference and the maximum available torque includes:

[0072] S201, determining a torque limiting coefficient and a time coefficient of a differential according to the wheel speed difference and a timer;

[0073] When calculating the safe estimated torque, it is necessary to correct the maximum available torque that the motor will execute based on the current wheel speed difference and the time when the wheel speed difference is greater than or equal to the preset threshold, so as to obtain the target torque that can reduce the current wheel speed difference when the motor torque is reduced. The required target torque is the safe estimated torque.

[0074] Among them, the torque limit coefficient and time coefficient of the differential are determined according to the wheel speed difference, including:

[0075] Substitute the wheel speed difference into the torque limit coefficient chart to obtain the torque limit coefficient corresponding to the wheel speed difference.

[0076] In this embodiment, the torque limit coefficient is μ l , the torque external characteristic curve of the wheel speed difference is calculated by interpolation method, so as to obtain the torque limit coefficient chart of the wheel speed difference and the torque limit coefficient. Substituting the wheel speed difference into the torque limit coefficient chart, the torque limit coefficient μ corresponding to the current wheel speed difference can be obtained. l .

[0077] Referring to Table 1, in one embodiment, the torque limit coefficient chart is shown in Table 1, wherein the speed difference in the first row is the wheel speed difference in this application, in units of / rpm, the second row is another unit of measurement of the wheel speed difference Kp / h, and the third row is the value of the torque limit coefficient corresponding to different wheel speed differences. The larger the wheel speed difference, the smaller the maximum available torque that the differential can withstand, and therefore the smaller the safety estimated torque that needs to be executed.

[0078] Table 1

[0079] Wheel speed difference / rpm ≤50 100 150 200 250 300 350 400 450 ≥500 Speed ​​difference / Kp / h ≤6.01 12.03 18.04 24.05 30.07 36.08 42.09 48.1 54.12 ≥60.13 Torque limit coefficient 1 0.965 0.912 0.842 0.754 0.649 0.526 0.386 0.228 0

[0080] When the wheel speed difference is greater than or equal to the preset threshold, the timer starts timing until the safe estimated torque is determined, and the time value is obtained. The time value is substituted into the time coefficient chart to obtain the time coefficient corresponding to the time value.

[0081] In this embodiment, the time coefficient is μ t When the wheel speed difference is greater than or equal to the preset threshold, the wheel speed difference exceeds the safety range. In this case, the longer the differential runs, the greater the damage to the differential, and the faster the wheel speed difference needs to be reduced. Therefore, it is necessary to dynamically correct the torque that can reduce the current wheel speed difference when the motor torque is reduced according to the length of time the wheel speed difference exceeds the safety range. Therefore, when the wheel speed difference exceeds the safety range, counting begins, and the time value of the wheel speed difference exceeding the safety range is obtained. According to the interval where the time value is located in the time coefficient chart, the time coefficient μ is obtained. t .

[0082] Referring to Table 2, in one embodiment, the time coefficient chart is shown in Table 2, wherein the times in the first row is the time value when the wheel speed difference exceeds the safety range in the present application, in seconds, and the second row is the value of the time coefficient corresponding to the point in the interval where the time value is located. The larger the time value, the more it is necessary to reduce the wheel speed difference as soon as possible, and therefore the smaller the safety estimated torque that needs to be executed.

[0083] Table 2

[0084] Time value / s t≤0.5 0.5＜t≤1 1＜t≤2.5 2.5＜t≤5 5＜t≤7.5 t＞7.5 Time coefficient 1 0.8 0.5 0.2 0.05 0

[0085] S202: Determine a safe estimated torque of the differential according to the maximum available torque, the torque limit coefficient, and the time coefficient.

[0086] The safe estimated torque of the differential is determined according to the maximum available torque, the torque limit coefficient and the time coefficient, including: multiplying the maximum available torque, the torque limit coefficient and the time coefficient to obtain the safe estimated torque of the differential.

[0087] The maximum available torque T max Through the torque limit coefficient μ l and the time coefficient μ t Make corrections, namely:

[0088] T=T max ·μ l ·μ t

[0089] Thus, the safe estimated torque T is obtained.

[0090] Reference Figure 5 In some embodiments, outputting a safe estimated torque to a vehicle controller to reduce the current torque of the motor to the full estimated torque includes:

[0091] S301, outputting a safety estimated torque to a vehicle controller;

[0092] S302, receiving a safety estimated torque request returned by a vehicle controller in response to the safety estimated torque;

[0093] After obtaining the safety estimated torque, the motor controller cannot directly execute the safety estimated torque, so the obtained safety estimated torque is transmitted to the vehicle controller, and then the vehicle controller issues a request instruction to execute the safety estimated torque to the motor controller.

[0094] S303 , in response to the safety predicted torque request, driving the motor to reduce the torque output to the safety predicted torque based on the safety predicted torque.

[0095] When the motor controller receives the request instruction regarding the safe estimated torque from the vehicle controller, it drives the motor to execute the safe estimated torque according to the request instruction.

[0096] As the time when the wheel speed difference is greater than or equal to the preset threshold continues to increase, the safety estimated torque gradually decreases until the current torque is less than the maximum available torque, causing the motor to reduce the current torque to the safety estimated torque, thereby reducing the wheel speed difference of the differential and protecting the differential.

[0097] In some embodiments, after the motor controller reduces the output torque, the control method further includes:

[0098] S4, when the wheel speed difference is lower than a preset threshold, output a preset torque to the vehicle controller so that the vehicle's motor outputs torque according to the preset torque, wherein the preset torque is a pre-execution torque of the motor that is not corrected according to the wheel speed difference.

[0099] After the current torque is reduced, the wheel speed difference of the differential is reduced, and the differential enters a safe state, so that the vehicle's motor performs the motor pre-torque according to the motor that is not corrected according to the wheel speed difference, so that the vehicle regains power.

[0100] Based on the same inventive concept, the second aspect of the embodiment of the present application proposes a control device for a motor of an electric vehicle, referring to Figure 6 , the control device 5 comprises:

[0101] An acquisition module 51 is used to detect the wheel speed difference at both ends of the differential, and when the wheel speed difference is greater than or equal to a preset threshold, the maximum available torque of the motor is acquired according to the wheel speed difference;

[0102] In one embodiment, the acquisition module includes a motor controller for detecting wheel speeds at both ends of the differential and determining the wheel speed difference according to the wheel speeds at both ends.

[0103] A determination module 52, configured to determine a safe estimated torque according to the wheel speed difference and the maximum available torque;

[0104] The execution module 53 is used to output the safe estimated torque to the vehicle controller so as to reduce the current torque of the motor to the safe estimated torque.

[0105] In some embodiments, the determination module 52 and the execution module 53 are integrated on a driving motor controller, so that the above method is executed by the motor controller.

[0106] The acquisition module 51 is further used to perform the following steps:

[0107] According to the wheel speeds at both ends of the differential, determine the wheel speed difference between the two ends;

[0108] The maximum available torque corresponding to the wheel speed difference is determined from a predefined torque characteristic curve.

[0109] The determination module 52 is further configured to perform the following steps:

[0110] Determine the torque limiting coefficient and time coefficient of the differential according to the wheel speed difference and the timer;

[0111] The safe estimated torque of the differential is determined based on the maximum available torque, torque limit coefficient and time coefficient.

[0112] The determination module 52 is further configured to perform the following steps:

[0113] Substitute the wheel speed difference into the torque limit coefficient chart to obtain the torque limit coefficient corresponding to the wheel speed difference;

[0114] When the wheel speed difference is greater than or equal to the preset threshold, timing starts until the safe estimated torque is determined, and a time value is obtained. The time value is substituted into the time coefficient chart to obtain a time coefficient corresponding to the time value.

[0115] The determination module 52 is further configured to perform the following steps:

[0116] Multiply the maximum available torque, the torque limit coefficient and the time coefficient to obtain the safe estimated torque of the differential.

[0117] The execution module 53 is further configured to execute the following steps:

[0118] Outputting safety estimated torque to the vehicle controller;

[0119] Receiving a safety estimated torque request returned by the vehicle controller for the safety estimated torque;

[0120] In response to the safe predicted torque request, the electric machine is driven to reduce the torque output to the safe predicted torque based on the safe predicted torque.

[0121] The execution module 53 is further configured to execute the following steps:

[0122] When the wheel speed difference is lower than a preset threshold, a preset torque is output to the vehicle controller so that the vehicle's motor outputs torque according to the preset torque, wherein the preset torque is a pre-execution torque of the motor that is not corrected according to the wheel speed difference.

[0123] Based on the same inventive concept, the present application also provides an electronic device, referring to Figure 7 , electronic equipment includes:

[0124] Memory for storing computer programs;

[0125] The processor is used to execute the computer program stored in the memory to implement the above control method.

[0126] Based on the same inventive concept, an embodiment of the present application also proposes a vehicle, comprising the above-mentioned control device, which is used to implement the above-mentioned control method.

[0127] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0128] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, devices, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0129] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0133] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0134] It should also be noted that, in this article, the orientation or position relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations, nor can they be understood as indicating or implying relative importance. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. Without more restrictions, an element defined by the phrase "comprising a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device comprising the element.

[0135] The technical solution provided by the present application is described in detail above. The principle and implementation method of the present application are described in this article using specific examples. The description of the above embodiments is only used to help understand the present application, and the content of this specification should not be understood as limiting the present application. At the same time, for those of ordinary skill in the art, according to the present application, there will be different forms of changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived therefrom are still within the scope of protection of the present application.

Claims

1. A method for controlling a motor of an electric vehicle, characterized in that: The control method comprises: Detecting the wheel speed difference between the two ends of the differential, and when the wheel speed difference is greater than or equal to a preset threshold, obtaining the maximum available torque of the motor according to the wheel speed difference; determining the torque limit coefficient and time coefficient of the differential according to the wheel speed difference and a timer; Determine the safe estimated torque of the differential according to the maximum available torque, the torque limit coefficient and the time coefficient; wherein the step of determining the time coefficient comprises: when the wheel speed difference is greater than or equal to a preset threshold, start timing until the safe estimated torque is determined, obtain a time value, substitute the time value into a time coefficient chart, and obtain the time coefficient corresponding to the time value; The safety estimated torque is output to a vehicle controller so that the current torque of the motor is reduced to the safety estimated torque.

2. The control method according to claim 1, characterized in that: Determining the maximum available torque of the motor according to the wheel speed difference includes: Determining the wheel speed difference between the two ends of the differential according to the wheel speeds at both ends of the differential; The maximum available torque corresponding to the wheel speed difference is determined in a preset torque external characteristic curve.

3. The control method according to claim 1, characterized in that: The steps to determine the torque limit coefficient include: Substitute the wheel speed difference into the torque limit coefficient chart to obtain the torque limit coefficient corresponding to the wheel speed difference.

4. The control method according to claim 1, characterized in that: Determining the safe estimated torque of the differential according to the maximum available torque, the torque limit coefficient and the time coefficient includes: The maximum available torque, the torque limit coefficient, and the time coefficient are multiplied to obtain the safe estimated torque.

5. The control method according to claim 1, characterized in that: Outputting the safety estimated torque to a vehicle controller so as to reduce the current torque of the motor to the safety estimated torque includes: Outputting the safety estimated torque to a vehicle controller; receiving a safety estimated torque request returned by the vehicle controller in response to the safety estimated torque; In response to the safety pre-estimated torque request, the electric machine is driven to reduce torque output to the safety pre-estimated torque based on the safety pre-estimated torque.

6. The control method according to claim 1, characterized in that: After the motor controller reduces the output torque, the control method further includes: When the wheel speed difference is lower than a preset threshold, a preset torque is output to the vehicle controller so that the vehicle's motor outputs torque according to the preset torque, wherein the preset torque is a pre-execution torque of the motor that is not corrected according to the wheel speed difference.

7. A control device for a motor of an electric vehicle, characterized in that: The device comprises: an acquisition module, for detecting the wheel speed difference at both ends of the differential, and when the wheel speed difference is greater than or equal to a preset threshold, acquiring the maximum available torque of the motor according to the wheel speed difference; a determination module, for determining the torque limit coefficient and time coefficient of the differential according to the wheel speed difference and a timer, and determining the safe estimated torque of the differential according to the maximum available torque, the torque limit coefficient and the time coefficient; wherein the step of determining the time coefficient comprises: starting the timing when the wheel speed difference is greater than or equal to the preset threshold until the safe estimated torque is determined, obtaining a time value, substituting the time value into a time coefficient chart, and obtaining the time coefficient corresponding to the time value; The execution module is used to output the safety estimated torque to the vehicle controller so that the current torque of the motor is reduced to the safety estimated torque.

8. An electronic device, characterized in that: include: Memory for storing computer programs; A processor, configured to execute a computer program stored in the memory to implement the control method according to any one of claims 1 to 6.

9. A vehicle, characterized in that: The invention comprises the control device according to claim 7, wherein the control device is used to implement the control method according to any one of claims 1 to 6.

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