Motor control method, motor controller and automobile

Abstract

The application discloses a motor control method, a motor controller and an automobile. The motor control method comprises the following steps: acquiring a torque request value and a current rotating speed of a motor; confirming whether the motor is in a start-stop working condition; when it is confirmed that the motor is in the start-stop working condition, performing reverse compensation on the torque request value to obtain a torque target value, so that the absolute value of the torque target value is smaller than the absolute value of the torque request value; and applying the torque target value to the motor, so that the torque of the motor is relatively smaller than the torque request value. In this way, the control accuracy of the motor torque can be optimized in a small torque and zero-crossing torque response working condition, the motor torque overshoot can be prevented, the impact force of the motor torque on a gear mechanism in the small torque and zero-crossing torque response working condition can be reduced, the gear knocking problem in the start-stop working condition can be further optimized, the knocking noise generated by the gear can be reduced, and the comfort of the driver and the passenger can be improved.

Description

Technical Field

[0001] This application relates to the field of motor control technology, specifically to a motor control method, a motor controller, and an automobile. Background Technology

[0002] The reduction gear mechanism used in new energy vehicles inevitably has gear backlash, and the output torque of the drive motor exhibits varying degrees of torque ripple, especially noticeable under low torque and zero-crossing torque response conditions. During vehicle start-up and parking, if the motor controller fails to properly control the motor output torque when the gears are engaged, it can generate significant knocking noise from the gears, affecting the comfort of the driver and passengers. Traditional methods to reduce knocking noise involve modifying the splines or gear tooth profile to reduce the clearance between mating tooth surfaces. However, excessively small spline or gear clearance is detrimental to assembly and still fails to resolve the knocking problem caused by the motor torque on the gears.

[0003] Currently, to reduce knocking noise from gears, zero-crossing control is used in the process of changing the current motor torque to the target motor torque. Existing zero-crossing control technology involves reducing the motor's torque slope when determining that the motor has entered the zero-crossing range based on the current motor torque magnitude, thereby reducing zero-crossing jitter. However, in the process of controlling small torques and zero-crossing torque, insufficient control precision can easily lead to zero-crossing control errors. For example, when the motor is stopped from zero-crossing control, if the motor has already stopped but the zero-crossing control continues, it will cause torque over-adjustment, still producing abnormal noise and impact. Summary of the Invention

[0004] In view of this, this application provides a motor control method, a motor controller, and an automobile to improve control accuracy under low torque and zero-crossing torque control, thereby better solving the problem of gear knocking noise. The technical solution of this application is as follows:

[0005] The first aspect of this application provides a motor control method, comprising: acquiring a torque request command and a current speed of a motor, wherein the torque request command includes a torque request value; when it is confirmed that the motor is in a start-stop condition based on the torque request value and the current speed, performing reverse compensation 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; and applying the torque target value to the motor.

[0006] In one embodiment of this application, obtaining the torque request value and current speed of the motor includes: obtaining the torque request command of the motor; obtaining the current speed when the torque request value is in the torque zero-crossing range; and confirming that the motor is in the start-stop condition when the current speed is in the speed zero-crossing range.

[0007] In one embodiment of this application, the torque request command further includes a request response rate; applying the target torque value to the motor includes: controlling the torque of the motor to change from the current torque to the target torque 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.

[0008] In one embodiment of this application, obtaining the current rotational speed includes: receiving a speed signal output by the rotary transformer of the motor; and obtaining the current rotational speed based on the speed signal.

[0009] In one embodiment of this 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.

[0010] In one embodiment of this application, the torque request command further includes a request response rate; the step of applying the torque request value to the motor when it is confirmed that the motor is not in the start-stop condition based on the torque request value and the current speed includes: confirming that the motor is not in the start-stop condition when the torque request value is not in the torque zero-crossing range and / or the current speed is not in the speed zero-crossing range; and controlling the torque of the motor to change from the current torque to the torque request value using the request response rate.

[0011] In one embodiment of this application, the step of performing reverse compensation on the torque request value to obtain the torque target value includes: performing reverse compensation on 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.

[0012] A second aspect of this application provides a motor controller comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the motor control method as described above.

[0013] A second aspect of this application provides an automobile, including an electric motor and a motor controller as described above, wherein the electric motor is electrically connected to the motor controller, and the motor controller is used to control the operation of the electric motor.

[0014] In one embodiment of this application, the vehicle further includes a vehicle controller and a communication bus. The vehicle controller is communicatively connected to the motor controller via the communication bus. The vehicle controller is used to send a torque request command to the motor controller. The motor is provided with a rotary transformer connected to the motor controller. The rotary transformer is used to output the speed signal of the motor. The motor controller is used to obtain the current rotational speed of the motor based on the speed signal.

[0015] In the motor control method, motor controller, and automobile of this application, the motor's torque request value and current speed are obtained to determine whether the motor is in a start-stop condition. When the motor is confirmed to be in a start-stop condition, the torque request value is reverse-compensated to obtain a torque target value, making the absolute value of the torque target value smaller than the absolute value of the torque request value. Applying the torque target value to the motor makes the motor torque relatively smaller than the torque request value, thereby optimizing the control accuracy of the motor torque in low torque and zero-crossing torque response conditions, preventing over-adjustment of the motor torque, reducing the impact force of the motor torque on the gear mechanism in low torque and zero-crossing torque response conditions, further optimizing the gear knocking problem in start-stop conditions, reducing the knocking noise generated by the gears, and improving the comfort of the driver and passengers. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating a motor control method provided in an embodiment of this application.

[0017] Figure 2 yes Figure 1 A detailed flowchart of step S100 in the process.

[0018] Figure 3 yes Figure 2 A detailed flowchart of step S120 is shown.

[0019] Figure 4 This is a flowchart illustrating a motor control method provided in another embodiment of this application.

[0020] Figure 5 yes Figure 4 A detailed flowchart of step S400.

[0021] Figure 6 This is a schematic diagram of a motor controller module provided in an embodiment of this application.

[0022] Figure 7 This is a schematic diagram of a car module provided in an embodiment of this application. Detailed Implementation

[0023] It should be noted that in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or sequence.

[0024] It should also be noted that the methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchanged, and some steps can also be deleted.

[0025] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating a motor control method provided in an embodiment of this application. It can be understood that the motor control method can be executed by a motor controller.

[0026] like Figure 1 As shown, the motor control method may include:

[0027] Step S100: Obtain the motor torque request command and current speed.

[0028] The torque request command includes a torque request value, which can be provided by devices or terminals outside the motor controller. For example, when the motor controller is used in an automobile, the torque request value can be sent to the motor controller from devices such as the vehicle controller or body controller. It can be understood that the greater the torque of the motor, the higher its speed.

[0029] Step S200: When the motor is confirmed to be in start-stop condition based on the torque request value and the current speed, reverse compensation is performed on the torque request value to obtain the torque target value.

[0030] Start-stop operation refers to the state in which the motor is initially starting or about to stop, that is, the motor speed initially increases from zero or is about to decrease to zero. Generally speaking, when the motor is initially starting or about to stop, it is in a low torque or zero-crossing torque response state, and both the torque request value and the current speed are relatively small. Therefore, the motor controller can determine whether the motor is in a start-stop state based on the torque request value and the current speed.

[0031] The absolute value of the target torque value is less than the absolute value of the requested torque value.

[0032] Step S300: Apply the target torque value to the motor.

[0033] The target torque value is obtained by inversely compensating for the requested torque value, ensuring that the absolute value of the target torque value is less than the absolute value of the requested torque value. When the motor controller applies the target torque value to the motor, the motor torque becomes smaller relative to the requested torque value. This optimizes the control accuracy of the motor torque under low torque and zero-crossing torque response conditions, preventing over-adjustment of the motor torque, reducing the impact force of the motor torque on the gear mechanism under these conditions, further optimizing gear knocking during start-stop operations, reducing gear knocking noise, and improving the comfort of the driver and passengers.

[0034] Understandably, the motor controller can adjust the motor torque to the target torque value by regulating the drive current supplied to the motor.

[0035] In some embodiments, such as Figure 2 As shown, step S100 may include:

[0036] Step S110: Obtain the motor torque request command.

[0037] Step S120: When the torque request value is in the torque zero-crossing range, obtain the current speed.

[0038] When the torque request value is within the torque zero-crossing range, it indicates that the motor is in a low-torque or zero-crossing torque response condition. Therefore, the current motor speed is further obtained, and the motor's start-stop condition can be confirmed based on this speed. For example, if the torque request value is T and the torque zero-crossing range is [-A, A], then when T is within [-A, A], the motor controller obtains the motor's current speed. Here, A can be set according to the parameters of the actual motor used; for example, A can be set to... , , , And so on. Among them, A can be set according to the range that those skilled in the art typically use for torque zero-crossing control of motors.

[0039] Furthermore, such as Figure 3 As shown, step S120 may include:

[0040] Step S121: Receive the speed signal output by the motor's rotary transformer.

[0041] A resolver / transformer is an electromagnetic sensor, also known as a synchrotron, used to measure the angular displacement and angular velocity of a rotating object's shaft. Therefore, a resolver can measure the angular displacement and angular velocity of a motor's shaft and output a speed signal based on the measurement results.

[0042] Step S122: Obtain the current rotational speed based on the speed signal.

[0043] By obtaining the current speed of the motor through the speed signal of the rotary transformer, the current speed of the motor can be obtained in real time, improving the response speed and sampling accuracy of obtaining the current speed.

[0044] Step S130: When the speed is in the zero-crossing range, confirm that the motor is in start-stop condition.

[0045] When the current speed of the motor is also within the zero-crossing range, it indicates that the motor speed is relatively low, and the motor can be confirmed to be in a start-stop state. That is, when the torque request value is within the torque zero-crossing range and the current speed of the motor is also within the zero-crossing range, the motor is confirmed to be in a start-stop condition. It can be understood that when zero-crossing control is performed on the motor, the motor torque is adjusted from a positive value to a negative value, or from a negative value to a positive value. When the motor torque is adjusted to near zero, the motor control method of this application embodiment can also be used to adjust the motor torque to improve the control accuracy during zero-crossing control and prevent gear knocking noise.

[0046] In some embodiments, step S200 may include:

[0047] The torque target value is obtained by reverse compensation of the torque request value with a preset torque compensation value.

[0048] In this embodiment, the preset torque compensation value is determined through pre-calibration. It can be understood that the preset torque compensation value can be obtained by testing and calibrating the vehicle under actual operating conditions. During calibration, vehicles at different development stages need to be compared, and calibration is performed on prototype vehicles that have completed reliability and durability testing. The effectiveness of the prototype vehicles under start-stop conditions is then verified. The optimal value is obtained by combining the torque compensation values ​​calibrated on different prototype vehicles, ensuring stable start-stop operation throughout the vehicle's entire lifecycle and reducing gear knocking noise.

[0049] In this embodiment, the preset torque compensation value can be less precise than the torque request value. For example, when the torque request value can only be an integer, the preset torque compensation value can be set to a decimal less than 1. Alternatively, when the torque request value has a precision of 2, the preset torque compensation value can be set to... This effectively improves the torque control accuracy of the motor under low torque and zero-crossing torque conditions, enhances the accuracy of motor torque control, improves the stability of motor operation under low torque and zero-crossing torque conditions, and prevents gear knocking to reduce knocking noise.

[0050] It can be understood that when the requested torque value is within the torque zero-crossing interval [-A, A], the target torque value is within [-A+α, A-α], where α is the preset torque compensation value. Specifically, when the requested torque value is T and is within [-A, A], then when T < 0, the target torque value is T+α. And when T > 0, the target torque value is T-α.

[0051] In some embodiments, the torque request command may further include a request for a response rate. Correspondingly, step S300 may include:

[0052] The motor torque is controlled to change from the current torque to the target torque value at a preset response rate.

[0053] The preset response rate is less than the requested response rate, which can control the motor to change from the current torque to the target torque value at a slower rate, making the torque change of the motor smoother, thereby further reducing torque impact and tooth knocking noise.

[0054] It is understandable that the preset response rate is also determined through 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 reliability and durability tests, and the effect of the prototype vehicles under start-stop conditions is verified. The optimal value is obtained by combining the response rates calibrated on different prototype vehicles.

[0055] In this embodiment, the preset response rate and preset torque compensation value can be determined by testing and calibration simultaneously. The optimal torque compensation value and response rate are obtained by combining the torque compensation value and response rate calibrated on different prototype vehicles as the preset torque compensation value and preset response rate.

[0056] In some embodiments, when the electric motor is used in a hybrid vehicle, during test calibration, control over the engine cylinder deactivation position can be increased to ensure that the gear shaft tooth position is consistent each time the engine stops, thereby obtaining a better preset torque compensation value and preset response rate.

[0057] It should be noted that a hybrid vehicle is a vehicle whose drive system is composed of two or more individual drive systems that can operate simultaneously. The vehicle's driving power is provided by the individual drive systems alone or in combination, depending on the actual driving conditions.

[0058] Hybrid vehicles, as commonly referred to, generally refer to hybrid electric vehicles (HEVs), which use a traditional internal combustion engine (diesel or gasoline engine) and an electric motor as power sources. Some engines are also modified to use other alternative fuels, such as compressed natural gas, propane, and ethanol.

[0059] In some embodiments, such as Figure 4 As shown, the motor control method may also include:

[0060] Step S400: When it is confirmed that the motor is not in start-stop condition based on the torque request value and the current speed, apply the torque request value to the motor.

[0061] When the motor is not in start-stop mode, it can be in normal operation mode or torque zero-crossing control mode. At this time, although the motor is in torque zero-crossing control mode, its speed has not yet dropped to the speed zero-crossing range, so the torque zero-crossing control of the motor is maintained.

[0062] Furthermore, such as Figure 5 As shown, step S400 may include:

[0063] Step S410: When the torque request value is not in the torque zero-crossing range and / or the current speed is not in the speed zero-crossing range, confirm that the motor is not in the start-stop condition.

[0064] When the requested torque value is not in the torque zero-crossing range, it indicates that the current torque of the motor is relatively large. In this case, the motor is in normal operating condition, and normal motor control strategy can be used to control the torque of the motor. When the requested torque value is in the torque zero-crossing range, but the current speed is not in the speed zero-crossing range, the motor is in torque zero-crossing control condition, but torque zero-crossing control can be used for the motor, and there is no need to use steps S100 to S300 for torque control.

[0065] Step S420: Control the motor torque to change from the current torque to the requested torque value at the request response rate.

[0066] Please see Figure 6 This application also provides a motor controller 10, including a memory 110 and a processor 120. The memory 110 stores a computer program. The processor 120 executes the computer program to implement the motor control method described above.

[0067] Please see Figure 7 This application embodiment also provides an automobile 100, including a motor controller 10 and a 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.

[0068] In some embodiments, the vehicle 100 may further include a vehicle controller 30 and a communication bus 40. The vehicle controller 30 is communicatively connected to the motor controller 10 via the communication bus 40, and the vehicle controller 30 is used to send torque request commands to the motor controller 10. The motor 20 is provided with a rotary transformer 50 connected to the motor controller 10. 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 rotational speed of the motor 20 based on the speed signal.

[0069] The beneficial effects that the motor controller 10 and the vehicle 100 can achieve can be referred to the corresponding beneficial effects of the motor 20 control method in the aforementioned embodiments, and will not be repeated here.

[0070] This application embodiment also provides a computer storage medium storing a computer program. When the computer program is executed by the motor controller 10, the motor controller 10 performs the above-described motor 20 control method.

[0071] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. 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 or transmitted through a computer storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0072] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and its implementation can be combined arbitrarily.

[0073] The above embodiments are merely preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A motor control method, characterized in that, include: Obtain the motor's torque request command and current speed, wherein the torque request command includes a torque request value; When the motor is confirmed to be in start-stop condition based on the torque request value and the current speed, the torque request value is reverse-compensated to obtain the torque target value; wherein, the absolute value of the torque target value is less than the absolute value of the torque request value; The target torque value is applied to the motor.

2. The control method as described in claim 1, characterized in that, The process of obtaining the requested torque value and current speed of the motor includes: Obtain the torque request command from the motor; When the torque request value is in the torque zero-crossing range, the current speed is obtained; When the current speed is in the zero-crossing range, it is confirmed that the motor is in the start-stop condition.

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

4. The control method as described in claim 2, characterized in that, The process of obtaining the current rotation speed includes: Receive the speed signal output from the rotary transformer of the motor; The current rotational speed is obtained based on the speed signal.

5. The control method as described in claim 1, characterized in that, Also 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, the torque request value is applied to the motor.

6. The control method as described in claim 5, characterized in that, The torque request command also includes a request response rate; When it is confirmed based on the torque request value and the current speed that the motor is not in the start-stop condition, applying the torque request value to the motor includes: When the torque request value is not in the torque zero-crossing range and / or the current speed is not in the speed zero-crossing range, it is confirmed that the motor is not in the start-stop condition; The torque of the motor is controlled to change from the current torque to the requested torque value at the requested response rate.

7. The control method as described in claim 1, characterized in that, The step of obtaining the target torque value by performing reverse compensation on the requested torque value includes: The torque target value is obtained by reverse compensation of 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, used to store computer programs; A processor for executing the computer program to implement the motor control method as described in any one of claims 1-7.

9. A car, characterized in that, It includes a motor and a motor controller as described 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 as described in claim 9, characterized in that, It also includes a vehicle controller and a communication bus. The vehicle controller is connected to the motor controller via the communication bus. The vehicle controller is used to send torque request commands to the motor controller. The motor is equipped with a rotary transformer connected to the motor controller. The rotary transformer is used to output the speed signal of the motor. The motor controller is used to obtain the current speed of the motor based on the speed signal.

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