Motor control method, control circuit, and device

Abstract

The present application provides a motor control method, control circuit, and device. Among them, the motor control method includes: obtaining the first back EMF of the motor, the first back EMF is the electromotive force of the non-conducting phase of the motor; determining multiple zero crossing points based on the first back EMF; determining the first frequency of the motor based on the multiple zero crossing points and a preset electrical cycle; and compensating for the multiple zero crossing points based on the first frequency and a preset vibration frequency. The present application does not require additional motor vibration suppression materials and devices, and realizes motor frequency adjustment through zero crossing compensation, and the compensation amount is adjustable, which has the technical effects of good motor vibration suppression effect and low production cost.

Description

Technical Field

[0001] The present disclosure relates to the field of motor control technology, and in particular to a motor control method, a control circuit, and a device. Background Art

[0002] Motors are devices that convert electrical energy into mechanical energy and are widely used in transportation, industrial automation, and various scenarios that require power. During the operation of the motor, unexpected motor vibrations may occur due to electromagnetic, mechanical, or electromechanical reasons, thereby reducing the motor's operating efficiency, reducing the motor's reliability, and generating negative effects such as noise pollution. Therefore, the issue of suppressing motor vibration deserves attention. Summary of the invention

[0003] The present disclosure provides a motor control method, a control circuit, and a device to suppress motor vibration and improve the reliability of motor operation. In a first aspect, a motor control method is provided, including: obtaining a first back electromotive force of a motor, the first back electromotive force being the electromotive force of a non-conducting phase of the motor; determining multiple zero crossing points based on the first back electromotive force; determining a first frequency of the motor based on the multiple zero crossing points and a preset electrical cycle; and determining compensation for multiple zero crossing points based on the first frequency and a preset vibration frequency.

[0004] Optionally, determining the first frequency of the motor based on multiple zero crossings and a preset electrical cycle includes: determining the number of multiple zero crossings based on the preset electrical cycle; determining multiple zero crossing time intervals based on the number of multiple zero crossings; and determining the first frequency based on the multiple zero crossing time intervals.

[0005] Optionally, compensating for multiple zero-crossing points is determined based on the first frequency and the preset vibration frequency, including: when the first frequency is equal to the preset vibration frequency, compensating for multiple zero-crossing points; when the first frequency is not equal to the preset vibration frequency, not compensating for multiple zero-crossing points.

[0006] Optionally, the method further includes: determining a plurality of switching points based on the first back electromotive force, wherein the plurality of switching points change based on changes in a plurality of zero-crossing points.

[0007] Optionally, the multiple zero crossing points include: a first zero crossing point and a second zero crossing point, wherein the first zero crossing point is a falling edge zero crossing point of the first back electromotive force, the second zero crossing point is a rising edge zero crossing point of the first back electromotive force, and the first zero crossing point is adjacent to the second zero crossing point in timing.

[0008] Optionally, compensating for multiple zero-crossing points includes: adjusting the first zero-crossing point to lag behind a first preset phase; and adjusting the second zero-crossing point to advance ahead of a second preset phase.

[0009] Optionally, the multiple switching points include: a first switching point and a second switching point, wherein the first switching point is opposite to the first zero-crossing point, and the second switching point is opposite to the second zero-crossing point; when the first zero-crossing point lags behind the first preset phase, the first switching point lags behind the third preset phase; when the second zero-crossing point leads the second preset phase, the second switching point leads the fourth preset phase.

[0010] Optionally, it also includes: a third switching point, the third switching point is ahead of the first switching point; the third switching point is different from the adjusted first switching point by a first time interval; the adjusted first switching point is different from the adjusted second switching point by a second time interval; the first time interval is different from the second time interval.

[0011] In a second aspect, a motor control circuit is provided, comprising: a switching circuit for selecting a phase line of the motor; a detection circuit for detecting a first back electromotive force of the motor, the first back electromotive force being the electromotive force of a non-conducting phase of the motor; and a processing circuit for controlling the switching circuit and executing a motor control method as provided in the first aspect based on a detection result of the detection circuit.

[0012] In a third aspect, a motor control device is provided, comprising: a processor, which is used to couple to a memory, wherein the memory comprises instructions, and when the instructions are called by the processor, the processor executes the motor control method as in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following is a brief introduction to the drawings used in describing the embodiments of the present disclosure:

[0014] Figure 1 A schematic diagram of a motor control circuit structure provided in some embodiments of the present application is shown;

[0015] Figure 2 A schematic diagram showing the timing relationship between three-phase back electromotive force, zero-crossing point and commutation point provided in some embodiments of the present application is shown;

[0016] Figure 3 A schematic flow chart of a motor control method provided in some embodiments of the present application is shown;

[0017] Figure 4 A schematic flow chart of a method for determining a first frequency of a motor based on multiple zero crossing points and a preset electrical cycle provided in some embodiments of the present application is shown;

[0018] Figure 5 Another schematic diagram of the timing relationship between three-phase back electromotive force, zero-crossing point and commutation point provided in some embodiments of the present application is shown;

[0019] Figure 6 A schematic structural diagram of a motor control device provided in some embodiments of the present application is shown. DETAILED DESCRIPTION

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the specific implementation methods of the present disclosure will be described below with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other accompanying drawings or embodiments can be obtained based on these accompanying drawings or embodiments without paying creative work. The adjustments and improvements made without departing from the concept of the present disclosure all belong to the protection scope of the present disclosure.

[0021] In order to simplify the drawings, each of the drawings schematically shows only the parts related to the embodiments, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, only some structures or components are schematically depicted, and there may be more or fewer similar structures or components in reality.

[0022] The motor is a device that converts electrical energy into mechanical energy. It is widely used in transportation, industrial automation, and various scenarios that require power. During the operation of the motor, due to electromagnetic, mechanical or electromechanical reasons, unexpected motor vibration may occur, thereby reducing the working efficiency of the motor, reducing the reliability of the motor, and generating negative effects such as noise pollution. For example, when a three-phase DC brushless motor is controlled by a sensorless square wave, two phases of the motor are energized at each moment, and the third phase is suspended to form a synthetic magnetic field. The phases that are turned on are switched in a certain order to change the direction of the magnetic field. For example, after six switches, the motor can complete one rotation, and the reciprocating motor continues to operate. The order and time of energizing the phase coils are determined by the position of the motor rotor. In a motor without a position sensor, the rotor position can be obtained by collecting the motor back electromotive force. For example, the method of obtaining the rotor position may include a comparator method and an analog-to-digital conversion method. The comparator method includes inputting the back electromotive force of the three-phase motor to the positive end of the comparator of the processor after voltage division, and at the same time, the three back electromotive forces are added to construct the back electromotive force zero point and input it to the negative end of the comparator. When the comparator changes from high to low level, it is judged as a zero crossing point. In general, in order to avoid the interference of the continuous current when the MOSFET switches, the phase change point will be delayed 30 degrees after the zero crossing point. When the phase change point occurs, different coils are switched to energize to complete the motor operation. The analog-to-digital conversion method includes inputting the back electromotive force of the three-phase motor into the analog-to-digital conversion port of the processor after voltage division, constructing the zero point through software, and then judging that the zero crossing point is reached when the constructed zero point is equal to the collected back electromotive force ADC.

[0023] During operation, the motor may generate vibrations beyond the design requirements. The generation of these vibrations will bring harmful vibration noise, for example, noise pollution, or cause great harm to the stability of the system and the service life of the system, thereby causing unnecessary economic losses and other adverse consequences. Therefore, it is necessary to reduce and eliminate the vibration of the motor. The prior art usually adds additional vibration suppression devices or materials to the motor system. However, such solutions do not solve the source of vibration from the root, and increase the complexity and production cost of the motor system. At the same time, additional devices may introduce new risk points, and the stability and reliability of the system are difficult to guarantee. The present application detects the back electromotive force of the motor, and determines multiple zero crossings based on the theoretical zero crossing, and then determines whether there is unexpected vibration in the current frequency of the motor, so as to compensate for multiple zero crossings, change the frequency of the motor's partial cycle, avoid motor vibration, and improve the reliability of the motor operation.

[0024] The following is a description with reference to the accompanying drawings:

[0025] Please refer to Figure 1 , which shows a schematic diagram of a motor control circuit structure provided in some embodiments of the present application. The processing circuit 110 (such as a microcontroller) sends a PWM signal to the driving circuit 120 through a pulse width modulation module. The driving circuit 120 can drive the six MOS tubes (Q1-Q6) in the switch circuit 130 to realize the opening and closing of the MOS tube. Among them, only two MOS will be turned on at the same time at each moment, and there are a total of six opening combinations, please refer to Table 1:

[0026]

[0027] The detection circuit 140 detects the back electromotive force of the phase that is not turned on, and after appropriate adjustment through the operational amplifier circuit 160 and the filter circuit 150, it is sent to the processing circuit 110 for processing to determine the next phase change time. For example, when the U-phase MOS tube Q1 and the V-phase MOS tube Q4 are turned on, the processing circuit 110 monitors and detects the back electromotive force signal BEMFW of the W phase in real time. The back electromotive force (BEMF) of the motor refers to the electromotive force generated by the change of magnetic flux in the coil or winding during the operation of the motor. It is a manifestation of the principle of electromagnetic induction and one of the important factors affecting the performance of the motor. When it is detected that BEMFW is equal to the zero-crossing threshold, it is considered that there is a zero-crossing signal. Next, the microcontroller sends a control signal to switch the system to drive timing 2, that is, only turn on the U-phase MOS tube Q1 and the W-phase MOS tube Q6. During drive timing 2, the processing circuit 110 monitors and detects the back electromotive force signal BEMFV of the V phase in real time. When it is detected that BEMFV is equal to the zero-crossing threshold, it is considered that there is a zero-crossing signal. Next, the processing circuit 110 sends a control signal to switch the system to drive timing 3, that is, only turn on the V-phase MOS tube Q3 and the W-phase MOS tube Q6. This cycle is repeated. After a delay of 30 degrees at the zero-crossing moment, it can be used as a switching point for the drive timing. Figure 2 The following is a schematic diagram showing the timing relationship between the three-phase reverse electromotive force, the zero crossing point and the phase switching point provided in some embodiments of the present application. After a delay of 30 degrees at the zero crossing point, the switching point of the driving timing is used, that is, the phase switching point. Figure 2 It can be seen that the time interval between switching between each timing sequence is the same, and when the motor is running, the speed of the motor between each two timing sequences is also equal.

[0028] Figure 3 A schematic flow chart of a motor control method provided in some embodiments of the present application is shown. The method comprises at least the following steps:

[0029] S310: Acquire a first back electromotive force of the motor, where the first back electromotive force is the electromotive force of a non-conducting phase of the motor;

[0030] S320: Determine a plurality of zero-crossing points based on the first back electromotive force;

[0031] S330: Determine a first frequency of the motor based on a plurality of zero-crossing points and a preset electrical cycle;

[0032] S340: Determine and compensate for a plurality of zero-crossing points based on the first frequency and a preset vibration frequency.

[0033] In the motor control method of the present application, the zero crossing point refers to the position where the AC voltage or current waveform changes from a positive value to a negative value, or from a negative value to a positive value on the time axis, that is, the moment when the instantaneous value of the waveform is zero. In the detection of the back electromotive force, the current position of the rotor can be determined by detecting the zero crossing point of the back electromotive force. After detecting the zero crossing point, the processing circuit needs to add a phase offset (such as an electrical angle of 30 degrees) to determine the accurate commutation point. The commutation point refers to the moment when the processing circuit of the motor needs to switch the power supply phase, that is, the position where the current direction in the motor winding needs to be changed or the power supply phase sequence needs to be switched. The commutation point determines the relative position between the motor stator electromagnetic field and the rotor magnetic field, thereby ensuring the efficiency and stability of the motor operation. By obtaining the first back electromotive force of the motor, multiple zero crossing points can be determined. Through multiple zero crossing points and a preset electrical cycle, the motor operation cycle formed by multiple zero crossing points can be determined, thereby determining the first frequency of the motor under the operation cycle (the frequency is the inverse of the cycle). For example, continue to refer to Figure 2 , where the time interval between the zero crossing points is t1-t6 (each zero crossing point is 30 degrees ahead of the commutation point). The preset vibration frequency can be a vibration frequency that has a greater impact on the operation of the motor. The motor running at this frequency may have an adverse effect on the motor itself or its load. In order to avoid the occurrence of the preset vibration frequency, the position of the zero crossing point in the back electromotive force timing diagram can be adjusted by compensating for multiple zero crossing points. For example, two adjacent zero crossing points are compensated forward and backward in timing, respectively, so as to change the time interval. Due to the existence of different time intervals, the frequency of the motor operation in the corresponding time period is also not equal, so that the frequency of the motor does not work at the preset vibration frequency, avoiding the vibration effect on the motor itself and its load, and improving the reliability of the motor operation. At the same time, the motor control method of the present application does not need to add additional devices to the motor or its control circuit, and can use the control circuit of the motor itself to achieve the purpose of motor vibration suppression, thereby reducing production costs and improving the reliability and maintainability of the motor operation.

[0034] In some embodiments of the present application, Figure 4 A schematic flow chart of a method for determining a first frequency of a motor based on multiple zero crossings and a preset electrical cycle provided in some embodiments of the present application is shown. Step S330 determines the first frequency of the motor based on multiple zero crossings and a preset electrical cycle, including:

[0035] S410: Determine the number of multiple zero-crossing points based on a preset electrical cycle;

[0036] S420: Determine a plurality of zero-crossing point time intervals based on the number of the plurality of zero-crossing points;

[0037] S430: Determine a first frequency based on a plurality of zero-crossing time intervals.

[0038] The preset electrical cycle refers to the length of time it takes for the motor to rotate once. In this preset electrical cycle, the number of multiple zero crossing points can be determined, such as reference Figure 2 The relationship diagram provided shows that in a preset electrical cycle, 6 zero crossing points are included, and the sum of the time intervals between each zero crossing point is the same as the complete time interval of the preset electrical cycle. The first frequency of the motor in the electrical cycle can be determined by the sum of the time intervals. After determining the first frequency, it can be determined whether the motor is in a non-ideal vibration state by judging whether the first frequency is consistent with the preset vibration frequency.

[0039] In some embodiments of the present application, step S340 determines to compensate for multiple zero crossings based on the first frequency and the preset vibration frequency, including: when the first frequency is equal to the preset vibration frequency, compensating for multiple zero crossings; when the first frequency is not equal to the preset vibration frequency, not compensating for multiple zero crossings.

[0040] In the present application, when the first frequency is equal to the preset vibration frequency, the first frequency may have an adverse effect on the motor and the load of the motor, so the current frequency of the motor can be changed to avoid the preset vibration frequency. In some embodiments, the value of the first frequency can be equal to the preset vibration frequency within a certain range. For example, if the preset vibration frequency is 55Hz, then the first frequency can be equal to the preset vibration frequency within the range of 53 to 57Hz, and it is not limited to the two being necessarily equal. When the first frequency is not equal to the preset vibration frequency, the motor may be operating in a relatively ideal working condition, so compensation for multiple zero crossings may not be performed.

[0041] In some embodiments of the present application, the method further includes: determining a plurality of switching points based on the first back electromotive force, wherein the plurality of switching points change based on changes in a plurality of zero-crossing points.

[0042] The zero crossing point is the moment when the voltage or current waveform passes through zero, and the commutation point is the moment when the motor switches the power supply phase. Therefore, the commutation point can be determined based on the zero crossing point, for example, the commutation point lags behind the zero crossing point by 30 degrees of electrical angle.

[0043] In some embodiments of this application, please refer to Figure 5 , which shows another schematic diagram of the timing relationship of three-phase back electromotive force, zero crossing point and switching point provided in some embodiments of the present application. The multiple zero crossing points include: a first zero crossing point G1 and a second zero crossing point G2, wherein the first zero crossing point G1 is the zero crossing point of the falling edge of the first back electromotive force, and the second zero crossing point G2 is the zero crossing point of the rising edge of the first back electromotive force, and the first zero crossing point G1 is adjacent to the second zero crossing point G2 in timing.

[0044] Compensating for multiple zero-crossing points includes: adjusting the first zero-crossing point G1 to lag behind a first preset phase; and adjusting the second zero-crossing point G2 to advance ahead of a second preset phase.

[0045] The multiple switching points include: a first switching point H1 and a second switching point H2, wherein the first switching point H1 is opposite to the first zero-crossing point G1, and the second switching point H2 is opposite to the second zero-crossing point G2; when the first zero-crossing point G1 lags behind the first preset phase, the first switching point H1 lags behind the third preset phase; when the second zero-crossing point G2 leads the second preset phase, the second switching point H2 leads the fourth preset phase.

[0046] It also includes: a third switching point, the third switching point is ahead of the first switching point; the third switching point is different from the adjusted first switching point by a first time interval; the adjusted first switching point is different from the adjusted second switching point by a second time interval; the first time interval is different from the second time interval.

[0047] In the embodiments of the present application, for example, Figure 2 Taking the control timing t1 and t2 in the back electromotive force BEFMV as an example, the zero crossing points of the back electromotive force BEFMV and the back electromotive force BEFMW are compensated. In the back electromotive force BEFMW, the first zero crossing point G1 lags behind the first preset phase after compensation to form the compensated first zero crossing point G11. Correspondingly, the first switching point H1 lags behind the third preset phase to form the compensated first switching point H11. Among them, the first preset phase and the third preset phase may be the same or different. In the back electromotive force BEFMV, the second zero crossing point G2 is advanced by the second preset phase after compensation to form the compensated second zero crossing point G21. Correspondingly, the second switching point H2 is advanced by the fourth preset phase to form the compensated second switching point H21. Among them, the second preset phase and the fourth preset phase may be the same or different. Moreover, the first preset phase and the second preset phase may be the same or different. Furthermore, under the action of the compensated zero-crossing point and the adjusted commutation point, the new control sequence action time and the original sequence action time have changed, and n1>n2, and the sum of the t1-t6 sequence action time is equal to the sum of the 1n-6n action time. The operating frequency of the motor in a period of time is the reciprocal of the time. Since the 1n and 2n times are not equal, the motor operation frequency in the corresponding time period is also not equal. The motor frequency is recorded as F1n when 1n, and the motor frequency is recorded as F2n when 2n. Therefore, the preset vibration frequency Fx is not equal to F1n, and the preset vibration frequency Fx is not equal to F2n. Since the sum of the t1-t6 sequence action time is equal to the sum of the 1n-6n action time, the average frequency of the motor before and after compensation is consistent, thereby effectively suppressing the vibration at the Fx frequency. The change of the above phase difference causes the time intervals between adjacent zero-crossing points and adjacent commutation points to change. Correspondingly, the change of the above time interval will also cause the operating frequency of the motor to change during this time interval, thereby avoiding the motor running within the preset vibration frequency range, causing undesirable vibration of the motor, causing damage to the motor itself and its load, and improving the reliability of the motor operation.

[0048] The present application is not limited to the phase adjustment of leading or lagging the zero crossing point, and can be adjusted according to the specific frequency adjustment requirements, such as the leading preset phase adjustment of the first zero crossing point G1 mentioned above, and the lagging preset phase adjustment of the second zero crossing point G2. Alternatively, the leading preset phase adjustment of the first zero crossing point G1 mentioned above, and the leading preset phase adjustment of the second zero crossing point G2. Alternatively, the lagging preset phase adjustment of the first zero crossing point G1 mentioned above, and the lagging preset phase adjustment of the second zero crossing point G2. The total time interval after compensation of multiple zero crossings remains unchanged, and is still equal to the complete preset electrical cycle, thereby ensuring the stable operation of the motor.

[0049] Based on the same technical concept, the present application also provides a motor control circuit, including: a switching circuit for selecting the phase line of the motor; a detection circuit for detecting the first back electromotive force of the motor, the first back electromotive force being the electromotive force of the non-conducting phase of the motor; a processing circuit for controlling the switching circuit, and based on the detection result of the detection circuit, executing the motor control method provided in the above embodiment.

[0050] Based on the same technical concept, Figure 6 The schematic diagram of the structure of a motor control device provided in some embodiments of the present application is shown. The motor control device 600 includes: a processor 610, which is used to couple to a memory 620, and the memory 620 includes instructions, and when the instructions are called by the processor 610, the processor 620 executes the motor control method as in the above embodiment.

[0051] The present application does not limit the type of processor. A processor is a circuit with the ability to process signals. For example, a processor includes a circuit with the ability to read and run instructions, such as a CPU, a microprocessor, a graphics processing unit (GPU) or a digital signal processor (DSP), etc.; for another example, a processor can be implemented through the logical relationship of a hardware circuit, and the logical relationship of the hardware circuit is fixed or reconfigurable, for example, a processor includes a hardware circuit implemented by an ASIC or PLD, such as a hardware circuit implemented by a field programmable gate array (FPGA). In a reconfigurable hardware circuit, the process of the processor loading a configuration document to implement the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. For another example, a processor includes a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), or a deep learning processing unit (DPU). One or more of the above.

[0052] It can be seen that each unit in the above signal processing device can be one or more processors (or processing circuits) configured to implement the above method, such as: CPU, GPU, NPU, TPU, DPU, microprocessor, DSP, ASIC, FPGA, or a combination of at least two of these processor forms.

[0053] In addition, all or part of the units in the above signal processing device can be integrated together, or can be implemented independently. In one implementation, these units are integrated together and implemented in the form of a system on a chip (SOC). The SOC may include at least one processor for implementing any of the above signal processing methods or implementing the functions of the above signal processing devices.

[0054] The present application does not limit the type of memory. For example, the memory may include a read-only memory (ROM) or a random access memory (RAM). For example, it may include a non-volatile memory or a volatile memory. For example, it may include an on-chip storage resource or an off-chip storage resource. ROM includes, for example, a mask ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash ROM, etc.; RAM includes, for example, a static random-access memory (SRAM) or a dynamic random-access memory (DRAM), etc. On-chip storage resources refer to storage circuits integrated inside the chip, which are integrated with other circuits of the chip (such as processing circuits) to provide storage space for the chip, such as static random access memory (SRAM) resources on the chip, or space resources of configuration registers on the chip, etc. Off-chip storage resources refer to independent storage circuits or chips, such as off-chip double data rate synchronous dynamic RAM (DDRSDRAM, DDR for short), etc.

[0055] In this disclosure, unless otherwise expressly specified and limited, ordinal numbers, such as "first", "second", etc., are only used to distinguish and describe related objects, and cannot be understood as indicating or implying the relative importance or order between related objects. In addition, ordinal numbers do not represent the number of related objects.

[0056] "Plurality" includes two or more, and other quantifiers are similar.

[0057] The terms "or" and "and / or" in the present disclosure are used to describe the relationship between associated objects, which represents non-exclusive inclusion. For example, "A and / or B" and "A or B" may include: "A alone", "B alone", or "A and B", where "A" and "B" may include a single object or multiple objects. For another example, "A, B and / or C", "A, B or C" and "A, B and C" may include: "A alone", "B alone", "C alone", "A and B", "A and C", "B and C", or "A, B and C", where "A", "B" and "C" may include a single object or multiple objects. In addition, " / " in the present disclosure is used to represent the "or" relationship between the associated objects before and after. In the present disclosure, "at least one of A or B" and "one or more of A and B" have the same meaning as the above "A or B", and "one or more of A, B and C" and "at least one of A, B or C" have the same meaning as the above "A, B or C". "One or more of A, B and C" has the same meaning as the above "A, B or C".

[0058] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. In addition, the above embodiments can be freely combined as needed.

Claims

1. A motor control method, characterized in that: For suppressing motor vibration, the method comprises: Acquire a first back electromotive force of the motor, where the first back electromotive force is the electromotive force of a non-conducting phase of the motor; determining a plurality of zero crossing points based on the first back EMF; determining a first frequency of the motor based on the plurality of zero crossings and a preset electrical cycle; Determine and compensate for the plurality of zero crossing points based on the first frequency and a preset vibration frequency; Wherein, determining the first frequency of the motor based on the multiple zero crossing points and the preset electrical cycle includes: determining the number of the multiple zero crossing points based on the preset electrical cycle; determining multiple zero crossing time intervals based on the number of the multiple zero crossing points; and determining the first frequency based on the multiple zero crossing time intervals. The method of determining and compensating the multiple zero-crossing points based on the first frequency and the preset vibration frequency includes: when the first frequency is equal to the preset vibration frequency, compensating the multiple zero-crossing points; when the first frequency is not equal to the preset vibration frequency, not compensating the multiple zero-crossing points.

2. The motor control method according to claim 1, characterized in that: Also includes: A plurality of commutation points are determined based on the first back electromotive force, and the plurality of commutation points vary based on a variation of the plurality of zero-crossing points.

3. The motor control method according to claim 2, characterized in that: The multiple zero-crossing points include: a first zero-crossing point and a second zero-crossing point, wherein the first zero-crossing point is a falling edge zero-crossing point of the first back electromotive force, the second zero-crossing point is a rising edge zero-crossing point of the first back electromotive force, and the first zero-crossing point is adjacent to the second zero-crossing point in timing.

4. The motor control method according to claim 3, characterized in that: The compensating for the multiple zero crossing points comprises: Adjust the first zero-crossing point to lag behind a first preset phase; The second zero-crossing point is adjusted to advance a second preset phase.

5. The motor control method according to claim 4, characterized in that: The multiple switching points include: a first switching point and a second switching point, wherein the first switching point is opposite to the first zero-crossing point, and the second switching point is opposite to the second zero-crossing point; When the first zero-crossing point lags behind the first preset phase, the first commutation point lags behind a third preset phase; When the second zero-crossing point leads the second preset phase, the second commutation point leads the fourth preset phase.

6. The motor control method according to claim 5, characterized in that: Also includes: a third commutation point, the third commutation point being ahead of the first commutation point; The third switching point is different from the adjusted first switching point by a first time interval; The first phase switching point after adjustment is different from the second phase switching point after adjustment by a second time interval; The first time interval is different from the second time interval.

7. A motor control circuit, characterized in that: include: A switching circuit for switching on the phase line of the motor; A detection circuit, used for detecting a first back electromotive force of the motor, wherein the first back electromotive force is an electromotive force of a non-conducting phase of the motor; A processing circuit is used to control the switch circuit and execute the motor control method according to any one of claims 1 to 6 based on the detection result of the detection circuit.

8. A motor control device, characterized in that: It comprises: a processor, which is used to couple to a memory, wherein the memory comprises instructions, and when the instructions are called by the processor, the processor executes the motor control method as described in any one of claims 1-6.

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