Motor control method, motor controller and automobile

Abstract

The invention discloses a motor control method, a motor controller and an automobile, whether a motor is in a start-stop working condition or not is determined by acquiring a torque request value and a current rotating speed of the motor, and when it is determined that the motor is in the start-stop working condition, reverse compensation is performed on the torque request value to obtain a torque target value; the absolute value of the torque target value is made smaller than the absolute value of the torque request value. And the torque target value is applied to the motor, so that the torque of the motor is smaller than the torque request value, the control precision of the motor torque is optimized under the small torque and zero-crossing torque response working condition, the motor torque is prevented from being over-adjusted, and the impact force of the motor torque on the gear mechanism under the small torque and zero-crossing torque response working condition is reduced. And the gear knocking problem under the starting and stopping working conditions is further optimized, knocking noise generated by the gear is reduced, and the comfort of a driver and passengers is improved.

Description

Technical Field

[0001] The present application relates to the technical field of motor control, and in particular to a motor control method, a motor controller and a vehicle. Background Art

[0002] The reduction gear mechanism used in new energy vehicles inevitably has gear clearance, and the output torque of the drive motor has different degrees of torque ripple, especially in low torque and zero torque response conditions. When the vehicle is starting and stopping, if the motor controller does not control the motor output torque when the gear mechanism is close to the teeth, it will produce obvious knocking noise on the gears, affecting the comfort of the driver and passengers. The traditional method to reduce the knocking noise is to modify the spline or gear tooth shape and reduce the clearance of the matching tooth surface, but the clearance of the spline or gear is too small, which is not conducive to assembly, and it still cannot solve the knocking problem caused by the motor torque on the gears.

[0003] At present, in order to reduce the knocking noise generated by the gears, zero-crossing control is used in the process of controlling the current motor torque to change to the target motor torque. The zero-crossing control of the prior art includes reducing the torque slope of the motor when judging that the motor enters the zero-crossing interval based on the current motor torque to reduce the zero-crossing jitter. However, in the process of small torque and zero-crossing torque control, if the control accuracy is insufficient, it is easy to cause zero-crossing control errors. For example, when the motor is controlled to stop for zero-crossing control, the motor has stopped but the motor is still being controlled for zero-crossing, resulting in torque overmodulation, which will still produce abnormal noise and impact. Summary of the invention

[0004] In view of this, the present application provides a motor control method, a motor controller and a vehicle, which are used to improve the control accuracy under small torque and zero torque control, so as to better solve the problem of gear knocking noise. The technical solution of the present application is as follows: A first aspect of the present application provides a motor control method, comprising: obtaining a torque request instruction and a current speed of the motor, the torque request instruction comprising a torque request value; when confirming that the motor is in a start-stop condition based on the torque request value and the current speed, reversely compensating the torque request value to obtain a torque target value; wherein the absolute value of the torque target value is less than the absolute value of the torque request value; and applying the torque target value to the motor.

[0005] In one embodiment of the present application, obtaining the torque request value and current speed of the motor includes: obtaining the torque request instruction of the motor; when the torque request value is in the torque zero-crossing interval, obtaining the current speed; when the current speed is in the speed zero-crossing interval, confirming that the motor is in the start-stop operating condition.

[0006] In one embodiment of the present application, the torque request instruction also includes a request response rate; applying the torque target value to the motor includes: controlling the torque of the motor from a current torque to the torque target value at a preset response rate; the preset response rate is less than the request response rate; the preset response rate is determined by pre-calibration.

[0007] In one embodiment of the present application, obtaining the current rotational speed includes: receiving a speed signal output by a rotary transformer of the motor; and obtaining the current rotational speed according to the speed signal.

[0008] In an embodiment of the present application, the motor control method further includes: when it is confirmed that the motor is not in the start-stop condition based on the torque request value and the current speed, applying the torque request value to the motor.

[0009] In one embodiment of the present application, the torque request instruction also includes a request response rate; when it is confirmed that the motor is not in the start-stop condition based on the torque request value and the current speed, the torque request value is applied to the motor, including: when the torque request value is not in the torque zero crossing interval and / or the current speed is not in the speed zero crossing interval, confirming that the motor is not in the start-stop condition; controlling the torque of the motor from the current torque to the torque request value at the request response rate.

[0010] In one embodiment of the present application, the reverse compensation of the torque request value to obtain the torque target value includes: reverse compensation of the torque request value with a preset torque compensation value to obtain the torque target value; the preset torque compensation value is determined by pre-calibration.

[0011] A second aspect of the present application provides a motor controller comprising: a memory for storing a computer program; and a processor for implementing the motor control method as described above when executing the computer program.

[0012] A second aspect of the present application provides a car, comprising a motor and a motor controller as described above, wherein the motor is electrically connected to the motor controller, and the motor controller is used to control the operation of the motor.

[0013] In one embodiment of the present application, the automobile further includes a vehicle controller and a communication bus, the vehicle controller is communicatively connected to the motor controller via the communication bus, and the vehicle controller is used to send a torque request instruction to the motor controller; the motor is provided with a rotary transformer connected to the motor controller, the rotary transformer is used to output a speed signal of the motor, and the motor controller is used to obtain the current speed of the motor according to the speed signal.

[0014] In the motor control method, motor controller and automobile of the present application, by obtaining the torque request value and current speed of the motor, it is confirmed whether the motor is in the start-stop condition. When it is confirmed that the motor is in the start-stop condition, the torque request value is reversely compensated to obtain the torque target value, so that the absolute value of the torque target value is smaller than the absolute value of the torque request value. Applying the torque target value to the motor can make the torque of the motor smaller than the torque request value, and then optimize the control accuracy of the motor torque in the low torque and zero torque response conditions, prevent the motor torque from overshooting, reduce the impact force of the motor torque on the gear mechanism in the low torque and zero torque response conditions, further optimize the gear knocking problem in the start-stop condition, reduce the knocking noise generated by the gear, and improve the comfort of the driver and passengers. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of a motor control method provided in an embodiment of the present application.

[0016] Figure 2 yes Figure 1 Detailed flowchart of step S100 in FIG.

[0017] Figure 3 yes Figure 2 Detailed flowchart of step S120 in FIG.

[0018] Figure 4 It is a flow chart of a motor control method provided in another embodiment of the present application.

[0019] Figure 5 yes Figure 4 Detailed flowchart of step S400.

[0020] Figure 6 It is a module schematic diagram of a motor controller provided in an embodiment of the present application.

[0021] Figure 7 It is a module schematic diagram of a car provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] It should be noted that in the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0023] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0024] Please refer to Figure 1 , Figure 1 The flowchart of a motor control method provided in an embodiment of the present application is shown in FIG. It can be understood that the motor control method can be executed by a motor controller.

[0025] like Figure 1 As shown, the motor control method may include: Step S100: Obtain the torque request instruction and current speed of the motor.

[0026] The torque request instruction includes a torque request value, and the torque request value can be provided by a device or terminal outside the motor controller. For example, when the motor controller is used in a car, the torque request value can be sent to the motor controller by a vehicle controller, a body controller, or other devices in the car. It can be understood that the greater the torque of the motor, the greater its speed.

[0027] Step S200: When it is confirmed that the motor is in a start-stop state according to the torque request value and the current speed, reverse compensation is performed on the torque request value to obtain a torque target value.

[0028] The start-stop condition refers to the state where the motor is in the initial start-up or about to stop state, that is, the motor speed initially increases from zero or is about to decrease to zero. Generally speaking, when the motor is initially started or about to stop, the motor is in a low torque or zero torque response state, and the torque request value and current speed are both small. Therefore, the motor controller can determine whether the motor is in the start-stop condition based on the torque request value and the current speed.

[0029] The absolute value of the torque target value is smaller than the absolute value of the torque request value.

[0030] Step S300: applying a torque target value to the motor.

[0031] The torque target value is obtained by reversely compensating the torque request value, so that the absolute value of the torque target value is smaller than the absolute value of the torque request value. The motor controller applies the torque target value to the motor, which can make the motor torque smaller than the torque request value, and then optimize the control accuracy of the motor torque under low torque and zero torque response conditions, prevent the motor torque from overshooting, reduce the impact of the motor torque on the gear mechanism under low torque and zero torque response conditions, further optimize the gear knocking problem under start-stop conditions, reduce the knocking noise generated by the gears, and improve the comfort of drivers and passengers.

[0032] It is understandable that the motor controller can adjust the torque of the motor to the torque target value by adjusting the driving current provided to the motor.

[0033] In some embodiments, Figure 2 As shown, step S100 may include: Step S110: Obtain the torque request instruction of the motor.

[0034] Step S120: When the torque request value is in the torque zero-crossing interval, obtain the current rotation speed.

[0035] When the torque request value is in the torque zero-crossing interval, it means that the motor is in a low torque or zero-crossing torque response condition. Then the current speed of the motor is further obtained, and then it can be confirmed whether the motor is in a start-stop condition based on the current speed. For example, the torque request value is T, and the torque zero-crossing interval is [-A, A]. When T is in [-A, A], the motor controller obtains the current speed of the motor. Among them, A can be set according to the parameters of the actual motor used. For example, A can be set to , , , Etc. A can be set according to the interval when those skilled in the art usually perform torque zero-crossing control on the motor.

[0036] Furthermore, if Figure 3 As shown, step S120 may include: Step S121, receiving a speed signal output by a rotary transformer of the motor.

[0037] A resolver (Resolver / Transformer) is an electromagnetic sensor, also known as a synchronous resolver, which can be used to measure the angular displacement and angular velocity of the rotating shaft of a rotating object. Therefore, a resolver can measure the angular displacement and angular velocity of the motor shaft and output a speed signal based on the measurement results.

[0038] Step S122: Obtain the current rotation speed according to the speed signal.

[0039] The current speed of the motor is obtained by the speed signal of the rotary transformer, so that the current speed of the motor can be obtained in real time, thereby improving the response speed and sampling accuracy of obtaining the current speed.

[0040] Step S130: when the speed is in the speed zero crossing interval, confirm that the motor is in the start-stop condition.

[0041] When the current speed of the motor is also in the speed zero-crossing interval, it means that the speed of the motor is also relatively small at this time, and it can be confirmed that the motor is in the start-stop state. That is, when the torque request value is in the torque zero-crossing interval and the current speed of the motor is in the speed zero-crossing interval, it is confirmed that the motor is in the start-stop condition. It can be understood that when the motor is controlled to cross zero, the torque of the motor is adjusted from a positive value to a negative value, or from a negative value to a positive value. When the torque of the motor is adjusted to near zero, the motor control method of the embodiment of the present application can also be used to adjust the torque of the motor to improve the control accuracy of the motor during zero-crossing control and prevent gear knocking noise.

[0042] In some embodiments, step S200 may include: The torque request value is reversely compensated with the preset torque compensation value to obtain the torque target value.

[0043] In the embodiment of the present application, the preset torque compensation value is determined by pre-calibration. It is understandable that the preset torque compensation value can be obtained by testing and calibrating the vehicle under actual working conditions. When calibrating, it is necessary to compare vehicles at different development stages, calibrate on prototype vehicles that have completed reliable durability tests, and verify the effect of the prototype vehicles under start-stop conditions. The torque compensation values ​​calibrated on different prototype vehicles are combined to obtain the optimal value as the preset torque compensation value to ensure that the vehicle can start and stop stably under start-stop conditions throughout its life cycle and reduce gear knocking noise.

[0044] In the embodiment of the present application, the preset torque compensation value may be less than the precision of the torque request value. For example, when the torque request value can only be an integer, the preset torque compensation value may be set to a decimal less than 1, for example Or when the torque request value precision is 2, the preset torque compensation value can be set to In this way, the torque control precision of the motor under low torque and zero torque conditions can be effectively improved, the accuracy of the motor torque control can be improved, the stability of the motor under low torque and zero torque conditions can be improved, and gear knocking can be prevented to reduce gear knocking noise.

[0045] It can be understood that when the torque request value is in the torque zero-crossing interval [-A, A], the torque target value is in [-A+α, A-α], where α is the preset torque compensation value. Specifically, when the torque request value is T and is in [-A, A], when T<0, the torque target value is T+α. When T>0, the torque target value is T-α.

[0046] In some embodiments, the torque request command may also include a request response rate. Accordingly, step S300 may include: The motor torque is controlled to change from the current torque to the torque target value at a preset response rate.

[0047] Among them, the preset response rate is less than the requested response rate, which can control the motor to change from the current torque to the torque target value at a slower rate, making the torque change of the motor smoother, thereby further reducing torque shock and tooth knocking noise.

[0048] It can be understood that the preset response rate is also determined by pre-calibration. Similar to the preset torque compensation value, the preset response rate also needs to be compared with vehicles at different development stages, calibrated on prototype vehicles that have completed reliable durability tests, and verified under start-stop conditions. The response rates calibrated on different prototype vehicles are combined to obtain the optimal value as the preset response rate.

[0049] In an embodiment of the present application, the preset response rate and the preset torque compensation value can be tested and calibrated at the same time, and the torque compensation values ​​and response rates calibrated on different sample vehicles are combined to obtain the optimal torque compensation value and response rate as the preset torque compensation value and preset response rate.

[0050] In some embodiments, when the motor is used in a hybrid vehicle, the control of the engine cylinder stop position can be increased during test calibration to ensure that the gear shaft tooth position is consistent each time the engine is stopped, thereby obtaining a better preset torque compensation value and preset response rate.

[0051] It should be noted that a hybrid vehicle refers to a vehicle whose vehicle drive system is composed of two or more single drive systems that can operate simultaneously, and the vehicle's driving power is provided by the single drive systems individually or jointly according to the actual vehicle driving state.

[0052] Hybrid vehicles are usually referred to as hybrid electric vehicles (HEV), which use a traditional internal combustion engine (diesel or gasoline engine) and an electric motor as power sources. Some engines have been modified to use other alternative fuels, such as compressed natural gas, propane and ethanol fuel.

[0053] In some embodiments, Figure 4 As shown, the motor control method may further include: Step S400: When it is confirmed that the motor is not in a start-stop condition according to the torque request value and the current speed, the torque request value is applied to the motor.

[0054] When the motor is not in the start-stop condition, the motor can be in the normal operation condition or the torque zero-crossing control condition. At this time, although the motor is in the torque zero-crossing control condition, its speed has not yet dropped to the speed zero-crossing interval, so the torque zero-crossing control of the motor is maintained.

[0055] Furthermore, if Figure 5 As shown, step S400 may include: Step S410: When the torque request value is not in the torque zero-crossing interval and / or the current speed is not in the speed zero-crossing interval, confirm that the motor is not in the start-stop condition.

[0056] When the torque request value is not in the torque zero-crossing interval, it means that the current torque of the motor is large, and the motor is in normal operating condition at this time, and the normal motor control strategy can be used to control the motor torque. When the torque request value is in the torque zero-crossing interval, but the current speed is not in the speed zero-crossing interval, although the motor is in the torque zero-crossing control condition, the motor can be controlled by torque zero-crossing control, and there is no need to use steps S100 to S300 for torque control.

[0057] Step S420: Control the torque of the motor to change from the current torque to the torque request value at the requested response rate.

[0058] See also Figure 6 The embodiment of the present application further provides a motor controller 10, comprising a memory 110 and a processor 120. The memory 110 is used to store a computer program. The processor 120 is used to implement the motor control method as described above when executing the computer program.

[0059] See also Figure 7 The embodiment of the present application further provides a car 100 , comprising the motor controller 10 and the motor 20 as described above, the motor 20 is electrically connected to the motor controller 10 , and the motor controller 10 is used to control the operation of the motor 20 .

[0060] In some embodiments, the automobile 100 may further include a vehicle controller 30 and a communication bus 40. The vehicle controller 30 is connected to the motor controller 10 through the communication bus 40, and the vehicle controller 30 is used to send a torque request instruction to the motor controller 10. The motor 20 is provided with a rotary transformer 50 connected to the motor controller 10, and the rotary transformer 50 is used to output a speed signal of the motor 20, and the motor controller 10 is used to obtain the current speed of the motor 20 according to the speed signal.

[0061] Among them, the beneficial effects that can be achieved by the motor controller 10 and the automobile 100 can refer to the corresponding beneficial effects of the motor 20 control method in the aforementioned embodiment, and will not be repeated here.

[0062] The embodiment of the present application further provides a computer storage medium, which stores a computer program. When the computer program is executed by the motor controller 10, the motor controller 10 executes the above-mentioned motor 20 control method.

[0063] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer storage medium or transmitted through a computer storage medium. The computer instructions can be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer storage medium can be any available medium that can be accessed by the computer or a data storage device such as a server or a data center that contains one or more available media integrated. Available media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, digital versatile discs (DVD)), or semiconductor media (eg, solid state disks (SSD)), etc.

[0064] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes. In the absence of conflict, the technical features in this embodiment and the implementation scheme can be combined arbitrarily.

[0065] The above embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the protection scope of the claims of the present application.

Claims

1. A motor control method, characterized in that: include: Acquire a torque request instruction and a current speed of the motor, wherein the torque request instruction includes a torque request value; When it is confirmed that the motor is in a start-stop state according to the torque request value and the current speed, reverse compensation is performed on the torque request value to obtain a torque target value; wherein the absolute value of the torque target value is less than the absolute value of the torque request value; The torque target value is applied to the motor.

2. The control method according to claim 1, characterized in that: The step of obtaining the torque request value and current speed of the motor includes: obtaining the torque request instruction of the motor; When the torque request value is in the torque zero-crossing interval, acquiring the current speed; When the current speed is in the speed zero crossing interval, it is confirmed that the motor is in the start-stop operating condition.

3. The control method according to claim 2, characterized in that: The torque request command also includes a request response rate; and applying the torque target value to the motor includes: The torque of the motor is controlled to change from the current torque to the torque target value at a preset response rate; the preset response rate is less than the requested response rate; and the preset response rate is determined by pre-calibration.

4. The control method according to claim 2, characterized in that: The obtaining of the current rotation speed comprises: Receiving a speed signal output by a rotary transformer of the motor; The current rotation speed is obtained according to the speed signal.

5. The control method according to claim 1, characterized in that: Also includes: When it is determined according to the torque request value and the current speed that the motor is not in the start-stop state, the torque request value is applied to the motor.

6. The control method according to claim 5, characterized in that: The torque request command also includes a requested response rate; When it is confirmed according to the torque request value and the current speed that the motor is not in the start-stop operating state, applying the torque request value to the motor comprises: When the torque request value is not in the torque zero-crossing interval and / or the current speed is not in the speed zero-crossing interval, confirming that the motor is not in the start-stop working condition; The torque of the electric machine is controlled to change from the current torque to the torque request value at the request response rate.

7. The control method according to claim 1, characterized in that: The performing reverse compensation on the torque request value to obtain the torque target value includes: The torque target value is obtained by reversely compensating the torque request value with a preset torque compensation value; the preset torque compensation value is determined by pre-calibration.

8. A motor controller, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the motor control method as described in any one of claims 1 to 7 when executing the computer program.

9. A car, characterized in that: It comprises a motor and the motor controller as claimed in claim 8, wherein the motor is electrically connected to the motor controller, and the motor controller is used to control the operation of the motor.

10. The automobile according to claim 9, characterized in that It also includes a vehicle controller and a communication bus, the vehicle controller is communicatively connected to the motor controller via the communication bus, and the vehicle controller is used to send a torque request instruction to the motor controller; the motor is provided with a rotary transformer connected to the motor controller, the rotary transformer is used to output a speed signal of the motor, and the motor controller is used to obtain the current rotation speed of the motor according to the speed signal.

Images