A motor cluster electromagnetic wave remote detection device and method based on SDR technology

Abstract

The invention discloses an electromagnetic wave remote detection device for a motor cluster based on SDR technology. The detection antenna comprises an omnidirectional standing wave antenna, an omnidirectional white noise measurement antenna, a Yagi directional antenna and a directional antenna receiver. The omnidirectional standing wave antenna and the omnidirectional white noise measurement antenna face a motor array, and the Yagi directional antenna and the corresponding directional antenna receiver face a specific direction of the motor array and can perform angle adjustment within the motor array. The omnidirectional standing wave antenna, the omnidirectional white noise measurement antenna, the Yagi directional antenna and the directional antenna receiver are respectively connected to a signal coupler through a coaxial cable, and the signal coupler, a filter amplifier, a software defined radio receiver and a background processing terminal are connected in sequence. In combination with the remote detection method of the invention, radio wave remote sensing signals leaked during motor operation are collected, and artificial intelligence data analysis and comparison are performed, thereby realizing single-system overall remote detection of a plurality of motor clusters, without the need to arrange various sensors, single-chip microcomputers and signal transmitters for each motor.

Description

Technical Field

[0001] The present invention relates to a motor cluster electromagnetic wave remote detection device and a remote detection method based on SDR technology for use in the field of motor detection. Background Art

[0002] At present, remote operation and maintenance of motors has become the mainstream technology of smart motors. It can detect the operating data of motors in real time and send it to the computers or mobile phones of users and maintenance personnel through the cloud. It can also play a certain alarm and early warning role, thereby enhancing the added value of services.

[0003] There are two main types of commonly used motor remote operation and maintenance technologies:

[0004] 1. The actual measurement type uses a variety of voltage, current, temperature, vibration and other measurement sensors arranged on the motor to collect the motor's operating signals in real time, and then uses the chip in the acquisition box to perform analog-to-digital conversion and data processing, and uploads the data to the cloud using communication methods such as 4G, WiFi and Bluetooth. The system has high accuracy and good real-time performance, but the system is complex and costly, and is connected to the motor's main circuit, which has unpredictable effects on the motor's life.

[0005] 2. Algorithm type: low-performance edge sensors such as temperature, magnetism and vibration are integrated in the external acquisition box. By comparing the different parameter performances of the motor in normal state and fault state, the motor abnormality is discovered through big data. The system has general accuracy, low cost and simple installation. Since it is not connected to the motor body circuit, it generally requires an independent battery. In order to avoid frequent battery replacement, relatively low-power chips and power-saving control strategies are generally used. Therefore, the sampling frequency is low, the real-time performance is poor, and the life is short.

[0006] As smart motors are used more and more widely, multiple motors and even motor clusters are constantly appearing in the same factory or room. The main goal of technicians is to develop a technology that can remotely detect the operating parameters of the motor without affecting the motor's main circuit and life, and to make the detection accuracy and real-time better at a lower cost. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a motor cluster electromagnetic wave remote detection device and remote detection method based on SDR technology, which can utilize the leakage electromagnetic waves generated by the operation of the motor to perform spectrum analysis and remote operation and maintenance.

[0008] A technical solution to achieve the above object is: a motor cluster electromagnetic wave remote detection device based on SDR technology, which is used to remotely detect the operating status of the motor cluster, wherein the motor cluster array is set up, characterized in that it includes a detection antenna array, a signal coupler, a pre-filter amplifier, a software defined radio receiver and a background processing terminal;

[0009] The detection antenna comprises an omnidirectional standing wave antenna, an omnidirectional white noise measurement antenna, a Yagi directional antenna and a directional antenna receiver, wherein the omnidirectional standing wave antenna and the omnidirectional white noise measurement antenna face the motor array, and the Yagi directional antenna and the directional antenna receiver thereof face a specific direction of the motor array and can be adjusted in angle within the range of the motor array;

[0010] The omnidirectional standing wave antenna, the omnidirectional white noise measurement antenna, the Yagi directional antenna and the directional antenna receiver are respectively connected to the signal coupler through coaxial cables, and the signal coupler, the filter amplifier, the software defined radio receiver and the background processing terminal are connected in sequence.

[0011] Furthermore, the directional antenna receiver is connected to an arc-shaped electromagnetic wave reflecting plate through a set of antenna insulating brackets and is located at the focus of the electromagnetic wave reflecting plate.

[0012] Furthermore, the omnidirectional standing wave antenna, the omnidirectional white noise measurement antenna, the Yagi directional antenna, the directional antenna receiver, the signal coupler, the filter amplifier, and the software defined radio receiver are integrated on a mobile cart, and the mobile cart is arranged in the center of the motor array.

[0013] A method for remote detection using a motor cluster electromagnetic wave remote detection device based on SDR technology, wherein the detection antenna array receives the frequency change of electromagnetic waves emitted by the motor, transmits the signal to a signal coupler without distortion through a coaxial cable, fits a time domain signal curve of the full frequency range of 0Hz-50MHz, and then passes through a pre-filter amplifier to filter signals outside the frequency range of 20KHz-30MHz, amplifies signals within the frequency range of 20KHz-30MHz by 30-50db, and then enters a software defined radio receiver for analog-to-digital conversion, and then enters a background processing terminal to perform a fast Fourier transform (FFT) of the time domain signal to generate a frequency spectrum of the motor abnormal signal, and makes a difference in each frequency between the frequency spectrum and the white noise measured by the omnidirectional white noise measurement antenna, so as to find the frequency distribution and corresponding amplitude parameters of the abnormal signal and the motor abnormality.

[0014] Furthermore, before using the method to perform remote motor detection, multiple comparative measurements are performed first, common motor faults are artificially generated to obtain spectrograms of corresponding faults, which are stored in a database for classification and preservation to form an expert comparative diagnosis system. After that, the on-site motor is detected, and the spectrograms obtained by monitoring are automatically matched and screened with the expert system, and a self-diagnosis report is intelligently generated to provide motor fault alarms and warnings to users and service personnel, and feedback adjustment of motor operating parameters is performed for motor systems with DCS systems.

[0015] The present invention discloses a motor cluster electromagnetic wave remote detection device and remote detection method based on SDR technology, which utilizes leakage electromagnetic waves generated by the operation of the motor to perform spectrum analysis and remote operation and maintenance, avoiding the installation of detection components inside the motor structure and in the motor body loop, thereby ensuring the integrity and reliability of the motor structure. At the same time, the electromagnetic wave spectrum analysis is stable and reliable, and combined with the fault spectrum database and expert diagnosis system, it can realize intelligent detection and early warning of motor faults, and has broad application prospects in the field of intelligent operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a motor cluster electromagnetic wave remote detection device based on SDR technology of the present invention;

[0017] Figure 2 A schematic top view of a motor cluster electromagnetic wave remote detection device based on SDR technology of the present invention arranged in the center of a motor array;

[0018] Figure 3 This is a structural schematic diagram of a motor cluster electromagnetic wave remote detection device based on SDR technology integrated on a mobile platform of the present invention. DETAILED DESCRIPTION

[0019] In order to better understand the technical solution of the present invention, the following is a detailed description through specific embodiments:

[0020] See also Figure 1 The present invention provides a motor cluster electromagnetic wave remote detection device based on SDR technology, which is used for remote detection of the operation status of the motor cluster, and the motor cluster 6 is arranged in an array. The specific structure of the detection device includes a detection antenna array, a signal coupler 12, a pre-filter amplifier 11, a software defined radio receiver (SDR) 10 and a background processing terminal 9.

[0021] Among them, the detection antenna includes an omnidirectional standing wave antenna 1, an omnidirectional white noise measurement antenna 2, a Yagi directional antenna 4 and a directional antenna receiver 8. The omnidirectional white noise measurement antenna 2 is used to measure the basic electromagnetic wave signal when the motor is not turned on or in a stable state, and provide a basic reference threshold for subsequent spectrum analysis. The omnidirectional standing wave antenna 1 can detect the frequency and amplitude of the overall electromagnetic wave signal of the motor cluster, and roughly find abnormal signals based on the electromagnetic wave power density and distribution. The Yagi directional antenna 4 and the directional antenna receiver 8 can scan within the motor array range to find abnormal motors. The directional antenna receiver 8 is connected to an arc-shaped electromagnetic wave reflection plate 3 through a set of antenna insulation brackets 7, and is located at the focus of the electromagnetic wave reflection plate 3. The electromagnetic wave reflection plate 3 can improve the sensitivity and accuracy of the directional antenna receiver 8.

[0022] The omnidirectional standing wave antenna 1, the omnidirectional white noise measurement antenna 2, the Yagi directional antenna 4 and the directional antenna receiver 8 are respectively connected to the signal coupler 12 through the coaxial cable 13. The signal coupler 12, the filter amplifier 11, the software defined radio receiver 10 and the background processing terminal 9 are connected in sequence. The background processing terminal can be a PC, a tablet computer or a smart phone.

[0023] See also Figure 2 In actual use, the electromagnetic wave remote detection device of the motor cluster 6 based on SDR technology can be arranged in the center of the motor array according to the test layout diagram. Care should be taken to avoid the antenna sweep plane coinciding with the plane where the motor is located, to prevent the motor close to the system from blocking the electromagnetic wave signal of the motor farther away, thereby producing a situation similar to the "transit effect", so as to enhance the global coverage capability of the system.

[0024] See also Figure 3 , which is a typical embodiment of a motor cluster electromagnetic wave remote detection device based on SDR technology, an omnidirectional standing wave antenna 1, an omnidirectional white noise measurement antenna 2, a Yagi directional antenna 4, a directional antenna receiver 8, a signal coupler 12, a filter amplifier 11, and a software defined radio receiver are integrated on a mobile platform body 14, which is convenient for the device to be set up. It has the following structural features:

[0025] 1. The axis of the Yagi directional antenna 4 must be strictly parallel to the axis of the electromagnetic wave reflecting plate 3, and a laser positioning device 5 is added to the Yagi directional antenna 4, and its laser emission direction is also strictly parallel to the axis of the electromagnetic wave reflecting plate 3, forming a precise aiming system for the directional antenna array. The antenna insulating bracket 7 adopts a single-arm cantilever beam mechanism and is located directly above the electromagnetic wave reflecting plate 3. Since the motor is generally installed relatively low, this structure can prevent the antenna insulating bracket from appearing in the sweep angle θ, avoiding the shielding of the motor electromagnetic wave signal causing signal attenuation and distortion.

[0026] 2. An equatorial horizontal rotation axis 17 and an equatorial pitch rotation axis 18 are added to the rear of the electromagnetic wave reflector 3. They are electrically driven and can realize controllable rotation in two degrees of freedom, horizontal and pitch. The structure is similar to that of a gimbal, and can realize automatic periodic radar scanning of the motor cluster 6 and precise tracking scanning of key motors.

[0027] 3. The entire detection system is installed on the mobile platform body 14. Through the combination of two universal wheels and two ordinary wheels, convenient hand-pushing movement can be achieved. If conditions permit, it can also be replaced with an electric mobile platform, a rail mobile platform or an AGV autonomous mobile vehicle, etc., to achieve inspections at different angles or between different factory buildings.

[0028] 4. Since the detection system requires a better antenna receiving height, the overall center of gravity is relatively high, so an anti-dumping counterweight 19 is provided.

[0029] 5. The antenna insulating bracket 7, antenna base 15 and antenna bracket 16 and other brackets should all be made of insulating materials to prevent common mode interference of the antenna.

[0030] The present invention can be used movably on the ground, or installed on the roof or buried underground, etc. The detection object can be a device or component that emits electromagnetic waves other than a motor, and a radio spectrum receiving device similar to SDR such as FPGA, STM32 single-chip computer system, etc. can also be used. The system can also use its extended frequency range (30MHz-1.7GHz) and be applied to shortwave, very high frequency and microwave bands, which has a certain positive effect on long-distance directional communication and civilian-grade astronomical radio.

[0031] The main principle of the present invention is based on SDR software defined radio technology. Through a reasonably designed antenna array, the radio wave remote sensing signals leaked during the operation of the motor are collected, and artificial intelligence data analysis and comparison are performed, thereby realizing a single system overall remote detection of multiple motor clusters, without the need to arrange various sensors, single-chip microcomputers and signal transmitters for each motor.

[0032] During the operation of the motor cluster, electromagnetic wave radiation will be generated due to the contact of the brushes, the variable frequency and industrial frequency power supply excitation coils, the electromagnetic vibration of the stator and rotor air gap, etc. Although the outer cover is grounded for shielding, a small part of the electromagnetic wave will still leak out. The industrial EMC standard and EN60034-1 stipulate the radiation limit of the frequency range of 30MHz-1GHz, and 20Hz-20KHz is the audible noise area. Therefore, these two parts of the spectrum will be evaluated before the motor leaves the factory. The frequency below 20Hz is the infrasound area, which is quite different from the motor rotation frequency and is not considered. The frequency of 20KHz-30MHz is not evaluated and is the main frequency range of the object detected by this method.

[0033] This method uses a motor cluster electromagnetic wave remote detection device based on SDR technology to perform remote detection. The antenna array detects the frequency change of the electromagnetic wave emitted by the motor, transmits the signal to the signal coupler without distortion through a coaxial cable, fits the time domain signal curve of the full frequency range of 0Hz-50MHz, and then passes through a pre-filter amplifier to filter the signals outside the frequency range of 20KHz-30MHz, amplifies the signals within the frequency range of 20KHz-30MHz by 30-50db, and then enters the software defined radio receiver for analog-to-digital conversion, and then enters the background processing terminal to perform fast Fourier transform FFT of the time domain signal to generate a frequency spectrum of the motor abnormal signal. The difference between it and the white noise measured by the omnidirectional white noise measurement antenna is made at each frequency, so that the frequency distribution and corresponding amplitude parameters of the abnormal signal can be found, and the motor abnormality can be found.

[0034] Before using this method for remote motor detection, multiple comparative measurements are performed first, common motor faults are artificially generated to obtain the spectrum diagrams of the corresponding faults, which are stored in the database for classification and preservation to form an expert comparative diagnosis system. After that, the on-site motor is detected, and the spectrum diagram obtained by monitoring is automatically matched and screened with the expert system, and a self-diagnosis report is intelligently generated to provide motor fault alarms and early warnings to users and service personnel, and feedback adjustment of motor operating parameters is performed for motor systems with DCS systems.

[0035] The detection system was used to scan the full frequency, the software was rtlpan, and the frequency was scanned at 20KHz-30MHz to obtain the spectrum diagram. The simulation test was carried out using test motors and other equipment, and the motor spectrum line was found near 580KHz, proving that the system can be used to detect the electromagnetic parameters of AC motors. DC motors and variable frequency motors can also be tested, and can be used at frequencies of 0-1.7GHz. Moreover, due to their structure and response characteristics, the electromagnetic wave radiation of the latter has more obvious characteristics and is easier to form a fault corresponding spectrum.

[0036] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A motor cluster electromagnetic wave remote detection device based on SDR technology, used for remote detection of the operation status of a motor cluster, wherein the motor cluster array is arranged, characterized in that: It includes a detection antenna array, a signal coupler, a pre-filter amplifier, a software defined radio receiver and a background processing terminal; The detection antenna comprises an omnidirectional standing wave antenna, an omnidirectional white noise measurement antenna, a Yagi directional antenna and a directional antenna receiver, wherein the omnidirectional standing wave antenna and the omnidirectional white noise measurement antenna face the motor array, and the Yagi directional antenna and the directional antenna receiver thereof face a specific direction of the motor array and can be adjusted in angle within the range of the motor array; The omnidirectional standing wave antenna, the omnidirectional white noise measurement antenna, the Yagi directional antenna and the directional antenna receiver are respectively connected to the signal coupler through coaxial cables, and the signal coupler, the filter amplifier, the software defined radio receiver and the background processing terminal are connected in sequence.

2. According to claim 1, a motor cluster electromagnetic wave remote detection device based on SDR technology is characterized in that: The directional antenna receiver is connected to an arc-shaped electromagnetic wave reflecting plate through a group of antenna insulating brackets and is located at the focus of the electromagnetic wave reflecting plate.

3. According to the SDR technology-based motor cluster electromagnetic wave remote detection device of claim 1, it is characterized in that: The omnidirectional standing wave antenna, the omnidirectional white noise measurement antenna, the Yagi directional antenna, the directional antenna receiver, the signal coupler, the filter amplifier, and the software defined radio receiver are integrated on a mobile cart, and the mobile cart is arranged in the center of the motor array.

4. A remote detection method for a motor cluster electromagnetic wave remote detection device based on SDR technology as claimed in claim 1, characterized in that: The detection antenna array receives the frequency change of the electromagnetic wave emitted by the motor, and transmits the signal to the signal coupler without distortion through the coaxial cable, fitting the time domain signal curve of the full frequency range of 0Hz-50MHz, and then passes through the pre-filter amplifier to filter the signals outside the frequency of 20KHz-30MHz, and amplify the signals within the frequency of 20KHz-30MHz by 30-50db, and then enters the software defined radio receiver for analog-to-digital conversion, and then enters the background processing terminal to perform fast Fourier transform FFT of the time domain signal to generate a frequency spectrum of the abnormal signal of the motor. The difference between it and the white noise measured by the omnidirectional white noise measurement antenna is made at each frequency, and the frequency distribution and corresponding amplitude parameters of the abnormal signal can be found, and the motor abnormality can be found.

5. A remote detection method according to claim 4, characterized in that: Before using this method for remote motor detection, multiple comparative measurements are performed first, common motor faults are artificially generated to obtain the spectrum diagrams of the corresponding faults, which are stored in the database for classification and preservation to form an expert comparative diagnosis system. After that, the on-site motor is detected, and the spectrum diagram obtained by monitoring is automatically matched and screened with the expert system, and a self-diagnosis report is intelligently generated to provide motor fault alarms and early warnings to users and service personnel, and feedback adjustment of motor operating parameters is performed for motor systems with DCS systems.

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