Motor load state identification method and device, and motor control chip

Abstract

The invention discloses a motor load state identification method and device, and a motor control chip. The method comprises the steps of obtaining a rotor acceleration when a motor is started; under the condition that the motor is determined to be in a no-load state according to the rotor acceleration, acquiring a bus current and a motor rotating speed in a motor operation process; and checking the no-load state of the motor according to the bus current and the rotating speed of the motor to determine the final load state of the motor. According to the method, the load state of the motor can be simply, accurately and automatically identified.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a method and device for identifying a motor load state, and a motor control chip. Background Art

[0002] In the field of motor control, the motor lead angle is one of the important parameters that need to be controlled in the motor control method, and the motor lead angle needs to be selected based on the motor load state, so the determination of the motor load state is an important part of the motor control method. In the current related technology, the method for determining the motor load is generally based on a comprehensive judgment based on parameters such as the motor's line voltage and speed. However, this type of load determination method is usually difficult to distinguish between loaded and unloaded states, and it is easy to identify the unloaded state as a loaded state, which has a low accuracy rate and will affect the control performance of the motor. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first object of the present invention is to provide a method for identifying the load state of a motor, by first obtaining the rotor acceleration of the motor when the motor starts to determine the load state of the motor, and then obtaining the bus current and motor speed during the operation of the motor when the motor is determined to be in an unloaded state, and determining the final load state of the motor according to the bus current and the motor speed, so that the load state of the motor can be automatically identified simply and accurately.

[0004] A second object of the present invention is to provide a computer-readable storage medium.

[0005] The third objective of the present invention is to provide a motor control chip.

[0006] A fourth objective of the present invention is to provide a device for identifying a motor load state.

[0007] A fifth object of the present invention is to provide a motor controller.

[0008] To achieve the above-mentioned purpose, the first aspect of the present invention proposes a method for identifying the load state of a motor, the method comprising: obtaining the rotor acceleration when the motor starts; when it is determined that the motor is in a no-load state based on the rotor acceleration, obtaining the bus current and the motor speed during the operation of the motor; and verifying the no-load state of the motor based on the bus current and the motor speed to determine the final load state of the motor.

[0009] According to the motor load state identification method of the embodiment of the present invention, when the motor starts, the rotor acceleration at the time of motor startup is first obtained to determine the motor load state. When it is determined that the motor is in a no-load state, the bus current and motor speed during the operation of the motor are obtained, and the final load state of the motor is determined based on the bus current and the motor speed, thereby being able to automatically identify the load state of the motor simply and accurately.

[0010] According to one embodiment of the present invention, obtaining the rotor acceleration when the motor is started includes: monitoring the change of the Hall detection value when the motor is started based on a fixed PWM duty cycle; determining the change interval time of the Hall detection value according to the change of the Hall detection value; and determining the rotor acceleration according to the change interval time.

[0011] According to an embodiment of the present invention, there is an inverse correlation between the rotor acceleration and the variation interval time.

[0012] According to an embodiment of the present invention, determining that the motor is in a no-load state according to the rotor acceleration includes: determining that the motor is in a no-load state when the rotor acceleration is greater than or equal to a first preset acceleration.

[0013] According to an embodiment of the present invention, when the rotor acceleration is less than the first preset acceleration, the method further includes: determining that the motor is in a loaded state.

[0014] According to one embodiment of the present invention, the no-load state of the motor is checked according to the bus current and the motor speed to determine the final load state of the motor, including: when the motor is running at a constant speed, if the bus current is greater than a preset bus current threshold, then determining that the final load state of the motor is a loaded state.

[0015] According to one embodiment of the present invention, the no-load state of the motor is checked according to the bus current and the motor speed to determine the final load state of the motor, including: when the motor is running at a constant current, if the motor speed is less than or equal to a preset speed threshold, then determining that the final load state of the motor is a loaded state.

[0016] To achieve the above-mentioned purpose, a second aspect of the present invention provides a computer-readable storage medium on which a motor load state identification program is stored. When the motor load state identification program is executed by a processor, the above-mentioned motor load state identification method is implemented.

[0017] According to the computer-readable storage medium of the embodiment of the present invention, the load state of the motor can be automatically and simply and accurately identified through the aforementioned motor load state identification method.

[0018] To achieve the above-mentioned purpose, the third aspect of the present invention proposes a motor control chip, including a memory, a processor, and a motor load state identification program stored in the memory and executable on the processor. When the processor executes the motor load state identification program, the aforementioned motor load state identification method is implemented.

[0019] The motor control chip according to the embodiment of the present invention can automatically and simply and accurately identify the load state of the motor through the aforementioned motor load state identification method, and then can control the motor to run stably based on the motor load state, thereby optimizing the motor control performance.

[0020] To achieve the above-mentioned purpose, the fourth aspect of the present invention proposes a motor load state identification device, including: an acquisition module, used to obtain the rotor acceleration when the motor starts, and when the motor is determined to be in a no-load state based on the rotor acceleration, obtain the bus current and motor speed during the operation of the motor; a verification module, used to verify the no-load state of the motor based on the bus current and the motor speed to determine the final load state of the motor.

[0021] According to the motor load state identification device of the embodiment of the present invention, when the motor starts, the rotor acceleration of the motor is obtained by using the acquisition module. When it is determined that the motor is in a no-load state according to the rotor acceleration, the bus current and the motor speed during the operation of the motor are obtained by the acquisition module. Finally, the final load state of the motor is determined according to the bus current and the motor speed by the verification module, so that the load state of the motor can be automatically identified simply and accurately.

[0022] To achieve the above-mentioned purpose, a fifth aspect of the present invention provides a motor controller, including the aforementioned motor control chip or the aforementioned motor load state identification device.

[0023] According to the motor controller of the embodiment of the present invention, through the aforementioned motor control chip or the aforementioned load state recognition state, it is possible to simply and accurately automatically identify the load state of the motor during the operation of the motor, and then control the motor to operate stably based on the motor load state, thereby optimizing the motor control performance.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of a method for identifying a motor load state according to an embodiment of the present invention;

[0026] Figure 2 is a flow chart of a method for identifying a motor load state according to another embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of the structure of a motor control chip according to an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of the structure of a motor load state identification device according to an embodiment of the present invention;

[0029] Figure 5a-5b FIG. 4 is a schematic diagram of the structure of a motor controller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0031] The following describes a motor load state identification method and device, a computer-readable storage medium, a motor control chip, and a motor controller proposed in embodiments of the present invention with reference to the accompanying drawings.

[0032] Figure 1 is a flow chart of a method for identifying a motor load state according to an embodiment of the present invention, referring to Figure 1 As shown, the method includes:

[0033] S11, obtaining the rotor acceleration when the motor starts.

[0034] Specifically, when the motor starts, due to the difference in rotational inertia, the rotor acceleration will be significantly different at startup. At the same time, when the motor load is large, the motor's rotational inertia is also large. Therefore, the motor's rotor acceleration can be obtained first to determine the motor's rotational inertia, and then determine the motor load.

[0035] In some embodiments, obtaining the rotor acceleration when the motor is started includes: monitoring the change of the Hall detection value when the motor is started based on a fixed PWM duty cycle; determining the change interval time of the Hall detection value according to the change of the Hall detection value; and determining the rotor acceleration according to the change interval time.

[0036] Furthermore, there is an inverse correlation between the rotor acceleration and the change interval time.

[0037] Specifically, the Hall detection value refers to the Hall value that can reflect the position of the motor rotor, which can be detected by installing a Hall sensor in the motor. By recording the changed values ​​in two consecutive sets of Hall detection values, the time interval when the Hall detection value changes can be monitored. Since the motor is started based on a fixed PWM duty cycle at this time, the rotor torque is a fixed value, and the motor rotor acceleration should also be a fixed value when the load state does not change. At the same time, since the mechanical position of the Hall sensor is fixed, the time interval when the Hall detection value changes can reflect the acceleration of the motor rotor at this time, and the time interval is inversely correlated with the rotor acceleration, that is, the smaller the change interval, the greater the motor rotor acceleration.

[0038] S12, when it is determined according to the rotor acceleration that the motor is in a no-load state, obtaining the bus current and the motor speed during the operation of the motor.

[0039] Specifically, after the motor is determined to be in an unloaded state based on the rotor acceleration, since the unloaded state of the motor determined by the rotor acceleration has a certain error probability, it is necessary to further verify whether the motor is in an unloaded state. For example, at this time, the bus current and motor speed during the operation of the motor can be obtained to determine whether the motor is in an unloaded state, so as to improve the reliability of load identification.

[0040] In some embodiments, determining that the motor is in a no-load state according to the rotor acceleration includes: determining that the motor is in a no-load state when the rotor acceleration is greater than or equal to a first preset acceleration.

[0041] Furthermore, when the rotor acceleration is less than the first preset acceleration, the method further includes: determining that the motor is in a loaded state.

[0042] Specifically, the first rotor acceleration is the motor rotor acceleration corresponding to the no-load state of the motor, which can be obtained by pre-testing or the like. When the motor is started according to a fixed PWM cycle, the torque current of the motor is determined, so the torque of the motor is also a fixed value. At this time, the rotor acceleration of the motor is inversely proportional to the motor moment of inertia. Therefore, when the rotor acceleration is greater than or equal to the first preset acceleration, it means that the motor moment of inertia is less than or equal to the motor moment of inertia when the motor is no-load. At this time, it can be determined that the motor is in a no-load state. When the rotor acceleration of the motor is less than the first preset acceleration, it can be determined that the motor is in a loaded state. Thus, the function of determining that the motor is in a no-load state according to the rotor acceleration is realized, and in the determination process, it is only necessary to measure multiple sets of Hall detection values ​​of the motor and perform related calculations. The acquisition and calculation methods are simple, so the load state of the motor can be identified in a relatively simple way.

[0043] S13, verifying the no-load state of the motor according to the bus current and the motor speed to determine the final load state of the motor.

[0044] Specifically, when the motor is running, the bus current and motor speed of the motor need to be adapted to the load of the motor. Generally speaking, the heavier the load of the motor, the greater the bus current of the motor and the smaller the speed. Therefore, the final load state of the motor can be determined based on the motor bus current and motor speed obtained in S12, thereby improving the accuracy of identifying the motor load state in the embodiment of the present invention, thereby achieving accurate judgment of the motor load state.

[0045] In the related art, since it is difficult to accurately determine the no-load state of the motor, the motor operation can only be controlled by selecting the lead angle according to the load condition when the motor is no-load, which results in low stability of the motor. However, the load identification method of the embodiment of the present invention can simply and accurately identify the load state of the motor, so that various control devices of the motor can easily identify the no-load state of the motor, and then corresponding measures can be taken to control the motor, such as using the preset lead angle corresponding to the no-load state as the lead angle of the current motor, so as to make the motor run stably, thereby improving the reliability of motor control.

[0046] In some embodiments, the no-load state of the motor is checked based on the bus current and the motor speed to determine the final load state of the motor, including: when the motor is running at a constant speed, if the bus current is greater than a preset bus current threshold, then determining that the final load state of the motor is a loaded state.

[0047] Specifically, the preset bus current threshold is the bus current value of the motor at different speeds when the motor is in a no-load state. The bus current threshold can be used to verify whether the motor is in a no-load state. For example, the preset bus current threshold corresponding to different speeds of the motor in a no-load state can be recorded in advance. When the motor starts running, the motor can be controlled to run at a constant speed first. At this time, the bus current of the motor is positively correlated with the motor load; then, based on the motor speed obtained in S12, the bus current threshold corresponding to the speed is determined by table lookup or the like; then the motor bus current obtained in S12 is compared with the determined bus current threshold. When the bus current is greater than the preset bus current threshold, it can be determined that the final load state of the motor is a loaded state. When the bus current is less than or equal to the bus current threshold, it can be determined that the motor is in a no-load state.

[0048] In some embodiments, the no-load state of the motor is checked based on the bus current and the motor speed to determine the final load state of the motor, including: when the motor is running at a constant current, if the motor speed is less than or equal to a preset speed threshold, then determining that the final load state of the motor is a loaded state.

[0049] Specifically, the preset speed threshold is the motor speed value of the motor under different bus currents when the motor is in a no-load state. The preset speed threshold can also be used to verify whether the motor is in a no-load state. For example, the preset motor speed threshold corresponding to different bus currents when the motor is in a no-load state can be recorded in advance. When the motor starts running, the motor is first controlled to run in a constant current mode. At this time, the motor speed is inversely correlated with the motor load; then, based on the motor bus current obtained in S12, the preset speed threshold corresponding to the bus current value is determined by table lookup; then the motor speed obtained in S12 is compared with the preset speed threshold. When the motor speed is less than or equal to the preset speed threshold, it can be determined that the final load state of the motor is a loaded state; otherwise, the motor is determined to be in a no-load state. In this way, the function of verifying the no-load state of the motor according to the bus current and the motor speed, and then determining the final load state of the motor is realized.

[0050] As a specific example, see Figure 2 As shown, the motor load state identification method may include:

[0051] S101, motor starts;

[0052] S102, determining the motor rotor acceleration when the motor starts, and executing S103;

[0053] S103, determining whether the motor is unloaded based on the motor rotor acceleration, if not, executing S104, if yes, executing S105;

[0054] S104, no-load flag position 0 (0 means the motor is loaded);

[0055] S105, no-load flag position 1 (1 indicates the motor is in no-load state), execute S106;

[0056] S106, during the operation of the motor, obtain the bus current and speed of the motor, and execute S107;

[0057] S107, based on the bus current and speed of the motor, determine whether the motor is no-load, if not, execute S104, if yes, execute S105.

[0058] During the operation of the motor, S105 to S107 perform automatic cyclic detection to continuously update the load status of the motor during the operation of the motor, so that the load status of the motor can be fed back in real time when the motor is in an unloaded state. Other controllers of the motor can quickly and accurately determine whether the motor is in an unloaded state by reading the unloaded flag.

[0059] In summary, according to the motor load state identification method of an embodiment of the present invention, when the motor starts, the rotor acceleration at the time of motor startup is first obtained to determine the motor load state. When it is determined that the motor is in an unloaded state, the bus current and motor speed during the operation of the motor are obtained, and the final load state of the motor is determined based on the bus current and the motor speed. In this way, the load state of the motor can be automatically identified simply and accurately, providing favorable conditions for motor control.

[0060] Corresponding to the above embodiment, an embodiment of the present invention further provides a computer-readable storage medium, on which a motor load state identification program is stored. When the motor load state identification program is executed by a processor, the above motor load state identification method is implemented.

[0061] According to the computer-readable storage medium of the embodiment of the present invention, the motor load state can be automatically identified simply and accurately through the aforementioned motor load state identification method, which provides favorable conditions for motor control.

[0062] Corresponding to the above embodiment, the embodiment of the present invention further provides a motor control chip, referring to Figure 3 As shown, the motor control chip 100 includes a memory 110, a processor 120, and a motor load state identification program stored in the memory 110 and executable on the processor 120. When the processor 120 executes the motor load state identification program, the aforementioned motor load state identification method is implemented.

[0063] The motor control chip according to the embodiment of the present invention can automatically and simply and accurately identify the load state of the motor through the aforementioned motor load state identification method, and then can control the motor to run stably based on the motor load state, thereby optimizing the motor control performance.

[0064] Corresponding to the above embodiment, the embodiment of the present invention further provides a motor load state identification device, referring to Figure 4 As shown, the device 200 includes: an acquisition module 210 and a verification module 220.

[0065] Among them, the acquisition module 210 is used to obtain the rotor acceleration when the motor starts, and when the motor is determined to be in a no-load state based on the rotor acceleration, obtain the bus current and motor speed during the operation of the motor; the verification module 220 is used to verify the no-load state of the motor based on the bus current and the motor speed to determine the final load state of the motor.

[0066] According to one embodiment of the present invention, the acquisition module 210 is also used to: monitor the change of the Hall detection value when the motor is started based on a fixed PWM duty cycle; determine the change interval time of the Hall detection value according to the change of the Hall detection value; and determine the rotor acceleration according to the change interval time.

[0067] According to an embodiment of the present invention, there is an inverse correlation between the rotor acceleration and the variation interval time.

[0068] According to an embodiment of the present invention, the acquisition module 210 is further configured to: determine that the motor is in a no-load state when the rotor acceleration is greater than or equal to a first preset acceleration.

[0069] According to an embodiment of the present invention, the acquisition module 210 is further used to: determine whether the motor is in a loaded state.

[0070] According to an embodiment of the present invention, the verification module 220 is further used to: when the motor is running at a constant speed, if the bus current is greater than a preset bus current threshold, determine that the final load state of the motor is a loaded state.

[0071] According to an embodiment of the present invention, the verification module 220 is further used to: when the motor is running at a constant current, if the motor speed is less than or equal to a preset speed threshold, determine that the final load state of the motor is a loaded state.

[0072] It should be noted that, for the description of the motor load state identification device of the present application, please refer to the aforementioned related description of the motor load state identification method, which will not be repeated here.

[0073] According to the motor load state identification device of the embodiment of the present invention, when the motor starts, the rotor acceleration of the motor is obtained by using the acquisition module. When it is determined that the motor is in a no-load state according to the rotor acceleration, the bus current and the motor speed during the operation of the motor are obtained by the acquisition module. Finally, the final load state of the motor is determined according to the bus current and the motor speed by the verification module, so that the load state of the motor can be automatically identified simply and accurately, which provides favorable conditions for motor control.

[0074] Corresponding to the above embodiment, the embodiment of the present invention further provides a motor controller, referring to Figure 5a-5b As shown, the motor controller 1000 includes the aforementioned motor control chip 100 or the aforementioned motor load state identification device 200 .

[0075] According to the motor controller of the embodiment of the present invention, through the aforementioned motor control chip or the aforementioned load state recognition state, it is possible to simply and accurately automatically identify the load state of the motor during the operation of the motor, and then control the motor to operate stably based on the motor load state, thereby optimizing the motor control performance.

[0076] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0077] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0078] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0079] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0080] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for identifying a motor load state, characterized in that: The method comprises: Get the rotor acceleration when the motor starts; When it is determined according to the rotor acceleration that the motor is in a no-load state, obtaining a bus current and a motor speed during operation of the motor; The no-load state of the motor is verified according to the bus current and the motor speed to determine the final load state of the motor.

2. The method according to claim 1, characterized in that: Get the rotor acceleration when the motor starts, including: When the motor is started based on a fixed PWM duty cycle, monitoring a change in a Hall detection value; Determine the change interval of the Hall detection value according to the change of the Hall detection value; The rotor acceleration is determined according to the change interval time.

3. The method according to claim 2, characterized in that The rotor acceleration and the change interval time are inversely correlated.

4. The method according to any one of claims 1 to 3, characterized in that Determining that the motor is in a no-load state according to the rotor acceleration includes: When the rotor acceleration is greater than or equal to a first preset acceleration, it is determined that the motor is in a no-load state.

5. The method according to claim 4, characterized in that When the rotor acceleration is less than a first preset acceleration, the method further includes: It is determined that the motor is in a loaded state.

6. The method according to claim 1, characterized in that The no-load state of the motor is verified according to the bus current and the motor speed to determine the final load state of the motor, including: When the motor is running at a constant speed, if the bus current is greater than a preset bus current threshold, it is determined that the final load state of the motor is a loaded state.

7. The method according to claim 1, characterized in that The no-load state of the motor is verified according to the bus current and the motor speed to determine the final load state of the motor, including: In the case where the motor is running at a constant current, if the motor speed is less than or equal to a preset speed threshold, it is determined that the final load state of the motor is a loaded state.

8. A computer-readable storage medium, characterized in that: A motor load state identification program is stored thereon, and when the motor load state identification program is executed by a processor, the motor load state identification method according to any one of claims 1-7 is implemented.

9. A motor control chip, characterized in that: The invention comprises a memory, a processor and a motor load state identification program stored in the memory and executable on the processor. When the processor executes the motor load state identification program, the motor load state identification method according to any one of claims 1 to 7 is implemented.

10. A motor load state identification device, characterized in that: include: An acquisition module, used to acquire the rotor acceleration when the motor is started, and when it is determined that the motor is in a no-load state according to the rotor acceleration, acquire the bus current and the motor speed during the operation of the motor; The verification module is used to verify the no-load state of the motor according to the bus current and the motor speed to determine the final load state of the motor.

11. A motor controller, characterized in that: It comprises the motor control chip according to claim 9 or the motor load state identification device according to claim 10.

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