A method, device and system for detecting the rotational speed of an electric motor

Abstract

The present invention provides a method, device and system for detecting the rotational speed of an electric motor. The method for detecting the rotational speed of an electric motor includes: controlling a laser generator of a double-beam interferometer to emit a laser signal with a first frequency to the rotor of the electric motor to be measured; obtaining a second frequency of the signal received by a photoelectric receiving device of the double-beam interferometer; and calculating the current rotational speed of the electric motor to be measured based on the first frequency and the second frequency by using the Doppler velocity measurement principle. By calculating the current rotational speed of the electric motor to be measured by using the first frequency and the second frequency obtained by the double-beam interferometer, the situation that external interference will affect the data of the electric motor itself is fully considered, and there is no need to detect the rotational speed of the electric motor by using the current / voltage data of the electric motor itself. While solving the problem of the decrease in the detection accuracy of the rotational speed of the electric motor under external interference and other conditions, the accuracy of the detection result is further improved.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular, to a method, device, and system for detecting the rotational speed of a motor. Background Art

[0002] Motors play an important role in production work, so it is necessary to ensure the stable and efficient operation of motors. When a motor works for a long time or is affected by external interference (such as a change in the electromagnetic environment), the rotational speed of the motor will be affected, and there may be a situation where it cannot operate at a specified rotational speed, which will have a negative impact on the overall production efficiency. In the prior art, the rotational speed of a motor is mostly detected by obtaining the current / voltage of the motor. However, this method still obtains data based on the operating conditions of the motor itself. When the motor is interfered with, the current / voltage of the motor itself will also be partially affected. At this time, detecting the rotational speed of the motor based on the current / voltage will generate errors, and the accuracy of the detection result will be greatly reduced. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect that when detecting the rotational speed of a motor using the current / voltage data of the motor itself in the prior art, the error of the data increases significantly when the motor is interfered with, resulting in a reduction in the accuracy of the detection result. Thus, a method, device, and system for detecting the rotational speed of a motor are provided.

[0004] According to a first aspect, an embodiment of the present invention provides a method for detecting the rotational speed of a motor, which is applied to a motor rotational speed detection system. The motor rotational speed detection system includes a double-beam interferometer. The method includes:

[0005] Controlling a laser generator of the double-beam interferometer to emit a laser signal with a first frequency towards the rotor of the motor to be measured;

[0006] Obtaining a second frequency of the signal received by a photoelectric receiving device of the double-beam interferometer;

[0007] Based on the first frequency and the second frequency, calculating the current rotational speed of the motor to be measured using the Doppler velocity measurement principle.

[0008] Optionally, the current rotational speed of the motor to be measured is calculated by the following formula:

[0009]

[0010] where f1 is the second frequency; f0 is the first frequency; v is the current rotational speed of the motor to be measured; and c is the speed of light.

[0011] Optionally, the method further includes:

[0012] Judging whether the current rotational speed is lower than the target rotational speed;

[0013] When the current rotational speed is lower than the target rotational speed, calculate the rotational speed difference between the current rotational speed and the target rotational speed;

[0014] Determine an adjustment voltage value based on the rotational speed difference;

[0015] Adjust the operating voltage of the motor under test based on the adjustment voltage value.

[0016] Optionally, the adjusting the operating voltage of the motor under test based on the adjustment voltage value includes:

[0017] Determine the current operating voltage corresponding to the second frequency based on the relationship between the preset frequency and the motor operating voltage;

[0018] Determine the target operating voltage based on the adjustment voltage value and the current operating voltage;

[0019] Control the motor under test to operate at the target operating voltage.

[0020] Optionally, after controlling the motor under test to operate at the target operating voltage, the method further includes:

[0021] Change the first frequency, and return to the step of controlling the laser generator of the double-beam interferometer to emit a laser signal with the first frequency to the rotor of the motor under test.

[0022] Optionally, after changing the first frequency and controlling the laser generator of the double-beam interferometer to emit a laser signal with the first frequency to the rotor of the motor under test, the method further includes:

[0023] Determine whether the changed current rotational speed is lower than the target rotational speed;

[0024] When the changed current rotational speed is lower than the target rotational speed, give an early warning prompt for motor abnormality.

[0025] According to a second aspect, an embodiment of the present invention provides a motor rotational speed detection device, which is applied to a motor rotational speed detection system. The motor rotational speed detection system includes a double-beam interferometer, and the device includes:

[0026] A generating module, configured to control the laser generator of the double-beam interferometer to emit a laser signal with the first frequency to the rotor of the motor under test;

[0027] An obtaining module, configured to obtain the second frequency of the signal received by the photoelectric receiving device of the double-beam interferometer;

[0028] A calculating module, configured to calculate the current rotational speed of the motor under test based on the first frequency and the second frequency by using the Doppler velocity measurement principle.

[0029] According to a third aspect, an embodiment of the present invention provides a motor speed detection system, including: a dual-beam interferometer and a controller, wherein,

[0030] The controller includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the method described in the first aspect or any optional implementation manner of the first aspect.

[0031] Optionally, the motor speed detection system further includes: an amplification module and a sampling module, wherein,

[0032] The input end of the amplification module is connected to the output end of the dual-beam interferometer, and the output end of the amplification module is connected to the input end of the sampling module, and is adapted to amplify the signal received by the dual-beam interferometer;

[0033] The output end of the sampling module is connected to the input end of the controller, and is adapted to sample the signal amplified by the amplification module and output it to the controller.

[0034] According to a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores computer instructions for causing a computer to execute the method described in the first aspect or any optional implementation manner of the first aspect.

[0035] The technical solution of the present invention has the following advantages:

[0036] The motor speed detection method and device provided by the present invention control a laser generator of the dual-beam interferometer to emit a laser signal of a first frequency to the rotor of a motor to be measured; obtain a second frequency of a signal received by a photoelectric receiving device of the dual-beam interferometer; and calculate the current speed of the motor to be measured based on the first frequency and the second frequency by using the Doppler velocity measurement principle. By calculating the current speed of the motor to be measured by using the first frequency and the second frequency obtained by the dual-beam interferometer, the situation that external interference will affect the motor's own data is fully considered, and there is no need to use the motor's own current / voltage data to detect the motor speed. While solving the problem of the decrease in the accuracy of motor speed detection under external interference and other conditions, the accuracy of the detection result is further improved.

[0037] The motor speed detection system provided by the present invention detects the current speed of the motor to be measured by setting a dual-beam interferometer to transmit and receive laser signals, and according to the first frequency corresponding to the laser signal and the second frequency of the received signal. On this basis, a controller is set up, without the need to additionally install detection equipment, which greatly reduces the detection cost. Considering that external interference will affect the motor's own data, without using the motor's own current / voltage data to detect the motor speed, the problem of the decrease in the detection accuracy of the motor speed under external interference and other conditions is solved, and the accuracy of the detection result is further improved.

[0038] The motor speed detection system provided by the present invention amplifies and samples the signals received by the dual-beam interferometer through a set amplification module and sampling module respectively, so that the controller can respond quickly based on the amplified signals, while solving the problem of the decrease in the detection accuracy of the motor speed under external interference and other conditions, and further improving the accuracy of the detection result. Brief Description of the Drawings

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is a schematic structural diagram of the motor speed detection system according to the embodiment of the present invention;

[0041] Figure 2 It is a schematic structural diagram of the controller according to the embodiment of the present invention;

[0042] Figure 3 It is a flowchart of the motor speed detection method according to the embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of the working process of the motor speed detection method according to the embodiment of the present invention;

[0044] Figure 5 It is a schematic structural diagram of the motor speed detection device according to the embodiment of the present invention. Detailed Embodiments

[0045] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" 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, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] An embodiment of the present invention provides a motor speed detection system, as Figure 1 shown. The motor speed detection system includes: a dual-beam interferometer 10 and a controller H. Among them, as Figure 2 shown, the controller H includes a processor 901 and a memory 902. The memory 902 and the processor 901 are communicatively connected to each other. The processor 901 and the memory 902 can be connected by a bus or other means. Figure 2 Taking the connection by bus as an example.

[0050] The processor 901 can be a central processing unit (CPU). The processor 901 can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. chips, or a combination of the above various types of chips.

[0051] The memory 902, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the embodiments of the present invention. The processor 901 executes various functional applications and data processing of the processor 901 by running the non-transitory software programs, instructions, and modules stored in the memory 902, that is, to implement the methods in the following method embodiments.

[0052] The memory 902 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created by the processor 901 and the like. In addition, the memory 902 may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory 902 may optionally include a memory remotely provided with respect to the processor 901, and these remote memories can be connected to the processor 901 through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0053] One or more modules are stored in the memory 902 and, when executed by the processor 901, implement the methods in the following method embodiments.

[0054] For specific details of the above controller H, reference can be made to the corresponding related descriptions and effects in the following method embodiments for understanding, and details will not be elaborated here.

[0055] Specifically, in practical applications, the double-beam interferometer 10 can be a Michelson interferometer, but this is not limited to the actual situation. The type and number of the double-beam interferometers 10 can be changed according to the actual situation.

[0056] Such as Figure 1 As shown, taking the Michelson interferometer as the double-beam interferometer 10 as an example for illustration, the overall structure of the Michelson interferometer mainly includes a laser generator A, a beam splitter D, a fixed mirror B, and a photoelectric receiving device E. It should be noted that in addition to the fixed mirror B, the embodiments of the present invention are also provided with a movable mirror (not shown in the figure), and the movable mirror is placed on the fan blade of the motor C to be measured.

[0057] When the motor speed detection system starts to work, the laser generator A emits a laser beam. After passing through the beam splitter D, the beam is divided into two beams of light with 50% light energy, which are reflected on the movable mirror (located on the fan blade of the motor C to be measured) and the fixed mirror B respectively and then return to the beam splitter D. A part of these two beams of light is converged after passing through the beam splitter D, passes through the aperture (not shown in the figure) and reaches the photodiode (not shown in the figure). According to the Doppler velocity measurement principle, due to the optical path difference, the two beams of light will interfere, thus generating bright and dark interference fringes. Since the fixed mirror B is in a fixed state, its reflection frequency is the first frequency f0 emitted by the laser generator A, and f0 does not change. And the frequency difference between the two beams of light is small. When converging, beat frequency and interference phenomena occur, and thus the Doppler frequency f1 is generated. The specific value of f1 can be obtained through the photoelectric receiving device E.

[0058] It should be noted that the working principle of the Michelson interferometer can refer to the prior art and will not be elaborated here.

[0059] For a further description of the above motor speed detection system, refer to the relevant description of the embodiments of the motor speed detection method below, which will not be elaborated here.

[0060] Based on the Doppler velocity measurement principle and the Michelson interferometer principle, the embodiment of the present invention uses the method of laser interference to detect the speed of the motor C to be measured in real time and can perform feedback adjustment. Compared with the method of judging the speed of the motor C to be measured through current / voltage feedback, the embodiment of the present invention has the advantages of high efficiency, high detection accuracy and simple operation. Further, the controller H in the embodiment of the present invention can be the controller for controlling the motor C to be measured. Therefore, in practical applications, only one controller interface needs to be added to detect the current speed of the motor C to be measured, greatly saving the production cost.

[0061] The motor speed detection system provided by the embodiment of the present invention detects the current speed of the motor C to be measured by setting the double-beam interferometer 10 to send and receive laser signals and according to the first frequency corresponding to the laser signal and the second frequency of the received signal. On this basis, the controller H is set, without the need to additionally set up detection equipment, greatly reducing the detection cost. Considering the situation that external interference will affect the data of the motor itself, without using the current / voltage data of the motor itself to detect the motor speed, the problem of the decrease in the detection accuracy of the motor speed under external interference and other conditions is solved, and the accuracy of the detection result is further improved.

[0062] Specifically, in one embodiment, the motor speed detection system provided by the embodiment of the present invention further includes: an amplification module F and a sampling module G, where

[0063] The input end of the amplification module F is connected to the output end of the double-beam interferometer 10, and the output end of the amplification module F is connected to the input end of the sampling module C, which is adapted to amplify the signal received by the double-beam interferometer 10;

[0064] The output end of the sampling module C is connected to the input end of the controller H, which is adapted to sample the signal amplified by the amplification module F and output it to the controller H.

[0065] The electrical signal collected by the double-beam interferometer 10 is effectively amplified and sampled by the amplification module F and the sampling module G, so as to ensure that the controller H can successfully collect the electrical signal and compare the current rotation speed of the motor C to be measured according to the sampled value of the electrical signal.

[0066] In the motor rotation speed detection system provided by the embodiment of the present invention, by setting the amplification module F and the sampling module G to amplify and sample the signal received by the double-beam interferometer 10 respectively, the controller H can respond quickly based on the amplified signal, while solving the problem of the decrease in the detection accuracy of the motor rotation speed under external interference and other conditions, and further improving the accuracy of the detection result.

[0067] The embodiment of the present invention provides a method for detecting the rotation speed of a motor, which is applied to the Figure 1 shown motor rotation speed detection system, wherein the motor rotation speed detection system includes a double-beam interferometer, as Figure 3 shown, and the method for detecting the rotation speed of the motor specifically includes the following steps:

[0068] Step S101: Control the laser generator of the double-beam interferometer to emit a laser signal with a first frequency to the rotor of the motor to be measured. In practical applications, the first frequency is the laser source frequency f0.

[0069] Step S102: Obtain the second frequency of the signal received by the photoelectric receiving device of the double-beam interferometer. In practical applications, the second frequency is the Doppler frequency f1 generated due to the beat frequency and interference phenomenon when the two beams of light passing through the double-beam interferometer converge.

[0070] Step S103: Calculate the current rotation speed of the motor to be measured based on the first frequency and the second frequency by using the Doppler velocity measurement principle.

[0071] Specifically, in practical applications, the embodiment of the present invention can calculate the current rotation speed of the motor to be measured through the following formula:

[0072]

[0073] where f1 is the second frequency; f0 is the first frequency; v is the current rotation speed of the motor to be measured; c is the speed of light.

[0074] By utilizing a first frequency and a second frequency and adopting the Doppler velocity measurement principle to detect the rotational speed of a motor to be measured, compared with the method of detecting the rotational speed of a motor based on the current / voltage data of the motor itself, the motor rotational speed detection method provided by the embodiments of the present invention is more objective, and its detection result is not only more accurate but also more persuasive.

[0075] By performing the above steps, the motor rotational speed detection method provided by the embodiments of the present invention calculates the current rotational speed of the motor to be measured by utilizing the first frequency and the second frequency obtained by a double-beam interferometer, fully considering the situation that external interference will affect the data of the motor itself, without using the current / voltage data of the motor itself to detect the rotational speed of the motor, while solving the problem of the decrease in the detection accuracy of the motor rotational speed under external interference and other situations, and further improving the accuracy of the detection result.

[0076] Specifically, in one embodiment, after performing the above step S103 of calculating the current rotational speed of the motor to be measured based on the first frequency and the second frequency by utilizing the Doppler velocity measurement principle, the following steps are specifically further included:

[0077] Step S201: Determine whether the current rotational speed is lower than the target rotational speed.

[0078] Step S202: When the current rotational speed is lower than the target rotational speed, calculate the rotational speed difference between the current rotational speed and the target rotational speed.

[0079] Step S203: Determine the adjusted voltage value based on the rotational speed difference.

[0080] Step S204: Adjust the working voltage of the motor to be measured based on the adjusted voltage value.

[0081] Specifically, in practical applications, the target rotational speed of the motor to be measured can be determined by referring to the working performance parameters of the motor to be measured. By comparing the current rotational speed with the target rotational speed, when the current rotational speed is lower than the target rotational speed, the embodiments of the present invention will calculate the rotational speed difference. According to the relationship between the rotational speed difference and the adjusted voltage value, the working voltage of the motor to be measured is adjusted, so as to ensure that the motor to be measured operates at the target rotational speed.

[0082] Specifically, for the relationship between the rotational speed difference of the motor and the adjusted voltage value, the embodiments of the present invention can test a standard motor in advance according to the motor model, working requirements and environmental conditions, and establish a rotational speed difference-adjusted voltage model curve table at different frequencies. Thus, when adjusting the working voltage of the motor to be measured, only the data in the rotational speed difference-adjusted voltage model curve table needs to be read to quickly adjust the value of the working voltage of the motor to be measured, so as to make the motor to be measured return to normal operation to the greatest extent.

[0083] Exemplarily, at a working frequency of 100 Hz (i.e., the second frequency f1), the current working voltage of a motor to be tested is 100 V, and the required target speed should be 5000 revolutions per minute. After detecting the current speed of the motor to be tested, the current speed is obtained as 4000 revolutions per minute, so the speed difference is 1000 revolutions per minute. It is determined through the speed difference - adjusted voltage model curve table that at a working frequency of 100 Hz, for every 5 V increase in voltage, the motor speed will increase by 500 revolutions per minute. By adjusting the current working voltage of the motor to be tested to 110 V, it can be ensured that the motor to be tested operates at the target speed of 5000 revolutions per minute. The actual situation is not limited to this, and the adjustment strategy can be adjusted according to actual production needs and equipment working standards, which will not be elaborated here.

[0084] Specifically, in one embodiment, the above step S204 adjusts the working voltage of the motor to be tested based on the adjusted voltage value, and specifically further includes the following steps:

[0085] Step S301: Determine the current working voltage corresponding to the second frequency based on the relationship between the preset frequency and the motor working voltage.

[0086] Step S302: Determine the target working voltage based on the adjusted voltage value and the current working voltage.

[0087] Step S303: Control the motor to be tested to operate at the target working voltage.

[0088] Specifically, in practical applications, for the convenience of technicians' operation, in the embodiments of the present invention, the standard motor is tested in advance according to the motor model, working requirements, and environmental conditions. By continuously changing the working voltage of the standard motor, the frequency change situation corresponding to the standard motor at different working voltages is obtained, and a frequency - working voltage model curve table is established.

[0089] When adjusting the working voltage of the motor to be tested based on the adjusted voltage value, in the embodiments of the present invention, the current working voltage of the motor to be tested can be obtained according to the frequency - working voltage model curve table. By summing the adjusted voltage value and the current working voltage, the target working voltage of the motor to be tested can be determined, and finally, the motor to be tested is controlled to operate at the target working voltage, so as to ensure that the speed of the motor to be tested meets the actual production needs.

[0090] Exemplarily, at a working frequency of 50 Hz (i.e., the second frequency f1), the current working voltage of the motor under test is determined to be 80 V through the frequency - working voltage model curve table. According to the production requirements, the target speed of the motor under test should be 5000 revolutions per minute. After detecting the current speed of the motor under test, the current speed is obtained as 4000 revolutions per minute, so the speed difference is 1000 revolutions per minute. It is determined through the speed difference - adjustment voltage model curve table that at a working frequency of 50 Hz, for every 10 V increase in voltage, the motor speed will increase by 500 revolutions per minute. Then the adjustment voltage value at this time is 20 V, and the target working voltage is 100 V. That is, controlling the motor under test to operate at a target working voltage of 100 V can ensure the production requirement of 5000 revolutions per minute.

[0091] Specifically, in practical applications, the embodiment of the present invention can also obtain a frequency - speed model curve table based on the working frequency and speed of the motor. On this basis, a speed - working voltage model curve table is established, and finally a speed - target working voltage model curve table is obtained based on the speed difference - adjustment voltage model curve table, which is more convenient for technicians to view and adjust the motor under test according to the speed - target working voltage model curve table.

[0092] Exemplarily, when the working frequency is 100 Hz, the target speed of a motor under test is 5000 revolutions per minute. After speed detection, the current speed is obtained as 4000 revolutions per minute, and the current working voltage is obtained as 90 V. It is determined through the above - mentioned speed difference - adjustment voltage model curve table that the working voltage of the motor under test needs to be increased by 10 V at this time. Then the target working voltage of the motor under test is 100 V. The speed - target working voltage correspondence of this motor under test at a working frequency of 100 Hz is: 4000 revolutions per minute corresponds to 100 V.

[0093] Specifically, in one embodiment, after performing step S303 to control the motor under test to operate at the target working voltage, the following steps are further included:

[0094] Step S401: Change the first frequency and return to the step of controlling the laser generator of the double - beam interferometer in step S101 to emit a laser signal with the first frequency to the rotor of the motor under test.

[0095] Specifically, in practical applications, to ensure that the motor under test can work according to the target speed, the embodiment of the present invention will recalculate the current speed of the motor under test by changing the laser source frequency. When the current speed recalculated after changing the first frequency reaches the target speed, it can be determined that the motor under test has completed the speed detection and can continue to work. By changing the first frequency to detect the current speed of the motor under test again, the accuracy of the detection result is further ensured, and the working performance of the motor under test is improved.

[0096] Specifically, in one embodiment, after performing the above step S401, the following steps are further included:

[0097] Step S501: Determine whether the changed current speed is lower than the target speed.

[0098] Step S502: When the changed current speed is lower than the target speed, give an early warning prompt for motor abnormality.

[0099] Specifically, in practical applications, when the changed current speed is still lower than the target speed, it can be determined that the motor to be tested may have a fault. At this time, if the motor to be tested continues to work, it may not meet the production requirements, and further serious production accidents may occur. In the embodiment of the present invention, when the changed current speed is lower than the target speed, an early warning prompt for motor abnormality is given to prompt the technician to perform fault troubleshooting in time. This not only solves the problem of reduced detection accuracy caused by using the motor's own current / voltage data for speed detection under external interference and other conditions, but also can control the motor to be tested to stop working immediately at the first time to eliminate potential safety hazards.

[0100] By performing the above steps, the motor speed detection method provided by the embodiment of the present invention calculates the current speed of the motor to be tested by using the first frequency and the second frequency obtained by the double-beam interferometer, fully considering the situation that external interference will affect the motor's own data, and does not need to use the motor's own current / voltage data to detect the motor speed. While solving the problem of reduced motor speed detection accuracy under external interference and other conditions, the accuracy of the detection result is further improved.

[0101] Next, a specific application example will be used to explain in detail the motor speed detection method provided by the embodiment of the present invention.

[0102] Combined with Figure 1 、 Figure 3 and Figure 4 As shown, when starting to detect the motor speed, the laser generator in the double-beam interferometer in the motor speed detection system will start to emit laser light, and the Doppler frequency f1 received by the photoelectric receiving device will be converted into an electrical signal. For the convenience of the controller to collect, the electrical signal will be amplified by the amplification module, so that the controller can obtain the amplified electrical signal through the sampling module. After receiving the amplified electrical signal, the controller outputs the speed corresponding to the current electrical signal by referring to the pre-established frequency-speed model curve table. When the current speed is inconsistent with the target speed, the embodiment of the present invention can adjust the working voltage of the motor to be tested through the speed difference-adjusted voltage model curve table, so as to control the motor to be tested to work at the target speed.

[0103] By performing the above steps, the motor speed detection method provided by the embodiments of the present invention calculates the current speed of the motor to be measured by using the first frequency and the second frequency obtained by the double-beam interferometer, fully considering the situation that external interference will affect the motor's own data, without using the motor's own current / voltage data to detect the motor speed. While solving the problem of the decrease in the motor speed detection accuracy in the case of external interference and the like, the accuracy of the detection result is further improved.

[0104] Embodiments of the present invention provide a motor speed detection device, which is applied to a motor speed detection system as shown in Figure 1 The motor speed detection system includes a double-beam interferometer, as shown in Figure 5 The device includes:

[0105] A generating module 101, configured to control the laser generator of the double-beam interferometer to emit a laser signal with a first frequency to the rotor of the motor to be measured. For the detailed content, refer to the relevant description of step S101 in the above method embodiment, and details will not be described herein again.

[0106] An obtaining module 102, configured to obtain a second frequency of the signal received by the photoelectric receiving device of the double-beam interferometer. For the detailed content, refer to the relevant description of step S102 in the above method embodiment, and details will not be described herein again.

[0107] A calculating module 103, configured to calculate the current speed of the motor to be measured based on the first frequency and the second frequency by using the Doppler velocity measurement principle. For the detailed content, refer to the relevant description of step S103 in the above method embodiment, and details will not be described herein again.

[0108] For a further description of the above motor speed detection device, refer to the relevant description of the motor speed detection method embodiment above, and details will not be described herein again.

[0109] Through the coordinated cooperation of the above-mentioned respective components, the motor speed detection device provided by the embodiments of the present invention calculates the current speed of the motor to be measured by using the first frequency and the second frequency obtained by the double-beam interferometer, fully considering the situation that external interference will affect the motor's own data, without using the motor's own current / voltage data to detect the motor speed. While solving the problem of the decrease in the motor speed detection accuracy in the case of external interference and the like, the accuracy of the detection result is further improved.

[0110] Those skilled in the art can understand that to implement all or part of the processes in the above-described embodiment methods, it can be completed by instructing relevant hardware through a computer program. The implemented program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above various methods. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memories.

[0111] Obviously, the above embodiments are merely examples given for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A method for detecting the rotational speed of an electric motor, characterized in that, Applied to a motor speed detection system, wherein the motor speed detection system includes a double-beam interferometer, and the method includes: Controlling a laser generator of the double-beam interferometer to emit a laser signal with a first frequency to the rotor of the motor to be measured; Obtaining a second frequency of the signal received by the photoelectric receiving device of the double-beam interferometer; Calculating the current speed of the motor to be measured based on the first frequency and the second frequency by using the Doppler speed measurement principle; The method further includes: Judging whether the current speed is lower than the target speed; When the current speed is lower than the target speed, calculating a speed difference between the current speed and the target speed; Determining an adjustment voltage value based on the speed difference; Adjusting the working voltage of the motor to be measured based on the adjustment voltage value to control the motor to be measured to operate at a target working voltage; After controlling the motor to be measured to operate at the target working voltage, changing the first frequency and returning to the step of controlling the laser generator of the double-beam interferometer to emit a laser signal with the first frequency to the rotor of the motor to be measured.

2. The method according to claim 1, wherein Calculating the current speed of the motor to be measured through the following formula: Wherein, f1 is the second frequency; f0 is the first frequency; v is the current speed of the motor to be measured; c is the speed of light.

3. The method according to claim 1, characterized in that, The adjusting the working voltage of the motor to be measured based on the adjustment voltage value includes: Determining the current working voltage corresponding to the second frequency based on the relationship between the preset frequency and the motor working voltage; Determining the target working voltage based on the adjustment voltage value and the current working voltage; Controlling the motor to be measured to operate at the target working voltage.

4. The method according to claim 1, wherein After changing the first frequency and controlling the laser generator of the double-beam interferometer to emit a laser signal with the first frequency to the rotor of the motor to be measured, the method further includes: Judging whether the changed current speed is lower than the target speed; When the changed current speed is lower than the target speed, giving an early warning prompt for motor abnormality.

5. A motor speed detection device, characterized in that, Applied to a motor speed detection system, wherein the motor speed detection system includes a double-beam interferometer, and the device includes: A generating module for controlling a laser generator of the double-beam interferometer to emit a laser signal with a first frequency to the rotor of the motor to be measured; An obtaining module for obtaining a second frequency of the signal received by the photoelectric receiving device of the double-beam interferometer; A calculating module for calculating the current speed of the motor to be measured based on the first frequency and the second frequency by using the Doppler speed measurement principle; judging whether the current speed is lower than the target speed; when the current speed is lower than the target speed, calculating a speed difference between the current speed and the target speed; determining an adjustment voltage value based on the speed difference; adjusting the working voltage of the motor to be measured based on the adjustment voltage value to control the motor to be measured to operate at a target working voltage; after controlling the motor to be measured to operate at the target working voltage, changing the first frequency and returning to the step of controlling the laser generator of the double-beam interferometer to emit a laser signal with the first frequency to the rotor of the motor to be measured.

6. A motor speed detection system, characterized in that, Including: A double-beam interferometer and a controller, wherein, The controller includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the method according to any one of claims 1-4.

7. The motor speed detection system according to claim 6, wherein Further included are: an amplification module and a sampling module, wherein, the input end of the amplification module is connected to the output end of the double-beam interferometer, and the output end of the amplification module is connected to the input end of the sampling module, adapted to amplify the signal received by the double-beam interferometer; the output end of the sampling module is connected to the input end of the controller, adapted to sample the signal amplified by the amplification module and output it to the controller.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a computer to execute the method according to any one of claims 1-4.

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