阅读说明：本技术 手持式微波测振系统 (Hand-held microwave vibration measuring system ) 是由 熊玉勇 彭志科 李松旭 孟光 于 2020-05-13 设计创作，主要内容包括：本发明提供了一种手持式微波测振系统,包括指示与定位模块、微波雷达收发模块、控制模块、信号采集与处理模块、防抖模块、显示与数据保存模块以及电源模块,电源模块用于供电；微波雷达收发模块用于产生并发射单频连续波微波信号,并接收目标散射的电磁回波,得到零中频基带信号；信号采集与处理模块用于采集微波雷达收发模块输出的零中频基带信号,并进行振动信息提取与分析；控制模块用于控制系统的启动与停止、设置参数、控制各模块工作运行和数据传输；防抖模块用于消除手持等抖动对测量结果的影响；指示与定位模块用于辅助指示与定位振动测试目标和/或测点。本发明解决现有振动测量仪器便携性差、体积和功耗大、成本高、测试环境要求高及适用范围受限等技术问题。(The invention provides a handheld microwave vibration measurement system which comprises an indication and positioning module, a microwave radar transceiver module, a control module, a signal acquisition and processing module, an anti-shake module, a display and data storage module and a power supply module, wherein the power supply module is used for supplying power; the microwave radar transceiver module is used for generating and transmitting a single-frequency continuous wave microwave signal and receiving an electromagnetic echo scattered by a target to obtain a zero intermediate frequency baseband signal; the signal acquisition and processing module is used for acquiring zero intermediate frequency baseband signals output by the microwave radar transceiver module and extracting and analyzing vibration information; the control module is used for controlling the starting and stopping of the system, setting parameters, controlling the working operation and data transmission of each module; the anti-shake module is used for eliminating the influence of hand-held shake and the like on the measurement result; and the indicating and positioning module is used for assisting in indicating and positioning the vibration test target and/or the measuring point. The invention solves the technical problems of poor portability, large volume and power consumption, high cost, high requirement on test environment, limited application range and the like of the existing vibration measuring instrument.)

1. The utility model provides a hand-held type microwave vibration measurement system which characterized in that, is including instructing and orientation module, microwave radar transceiver module, control module, signal acquisition and processing module, demonstration and data storage module and power module, wherein:

the power supply module supplies power to the indicating and positioning module, the microwave radar transceiver module, the control module, the signal acquisition and processing module and the display and data storage module;

the microwave radar transceiver module is used for generating and transmitting a single-frequency continuous wave microwave signal and receiving an electromagnetic echo scattered by a target to obtain a zero intermediate frequency baseband signal;

the signal acquisition and processing module is used for acquiring two-channel zero intermediate frequency baseband signals output by the microwave radar transceiver module and extracting and analyzing vibration information;

the control module is used for controlling the starting and stopping of the system, setting parameters, controlling the working operation and data transmission of each module;

the indication and positioning module is used for assisting in indicating and positioning the vibration test target and/or the measuring point;

and the display and data storage module is used for displaying and storing information including vibration measurement time domain waveforms and vibration characteristic analysis results.

2. The system of claim 1, wherein the setting parameters comprise setting baseband signal sampling parameters, signal processing and analysis parameters, and display and data storage parameters.

3. The handheld microwave vibration measuring system according to claim 1, wherein the indicating and positioning module is a laser or visible light device, and the direction indicated by the indicating and positioning module is the same as or close to the central direction of the beam emitted by the microwave radar transceiver module.

4. The system according to claim 1, further comprising an anti-shake module for eliminating the effect of shake on the measurement results, including hand-held or head-mounted.

5. The handheld microwave vibration measuring system according to claim 4, wherein the anti-shake module comprises a software anti-shake sub-module and/or a physical anti-shake sub-module.

6. The hand-held microwave vibration measurement system according to claim 5, wherein the physical anti-shake sub-module comprises an active shake isolation device or a passive shake isolation device for isolating or attenuating hand-held or head-mounted shake from being conducted to the microwave radar transceiver; the software anti-shake sub-module comprises a band-pass filter, and the band-pass filter is used for filtering the extracted vibration displacement time-domain waveform of the measured target and/or the measured point.

7. The hand-held microwave vibration measuring system according to claim 1, further comprising a housing, wherein the indication and positioning module, the microwave radar transceiver module, the control module, the signal acquisition and processing module, the display and data storage module and the power supply module are all packaged in the housing.

8. The system of claim 1, wherein the microwave radar transceiver module comprises a microwave signal source, a power divider, a power amplifier, a quadrature phase shifter, a low noise amplifier, a quadrature mixer, a low pass filter, a transmitting antenna, and a receiving antenna, wherein:

the microwave signal source is connected with the power divider, the power divider is connected with the power amplifier and the quadrature phase shifter, the power amplifier is connected with the transmitting antenna, the receiving antenna is connected with the low-noise amplifier, the low-noise amplifier and the quadrature phase shifter are connected with the input end of the quadrature frequency mixer, and the output end of the quadrature frequency mixer is connected with the low-pass filter.

9. The hand-held microwave vibration measuring system according to claim 1, wherein the vibration information extraction comprises the steps of:

step S1: carrying out sliding window interception on the acquired two-channel zero intermediate frequency baseband signals;

step S2: performing arc fitting and circle center estimation on the signal in the sliding window by using a circle fitting algorithm;

step S3: judging whether the proportion of the fitting circular arc to the circumference is larger than a threshold value or not, if so, extracting a phase evolution time sequence corresponding to the vibration of the detected target and/or the measured point by using an arc tangent demodulation algorithm, and if not, selecting the phase evolution time sequence corresponding to the vibration of the detected target and/or the measured point, wherein the standard deviation of the two-channel baseband signals is larger;

step S4: and extracting the vibration displacement time sequence of the measured target and/or the measured point.

10. The system of claim 9, wherein the threshold value is set at a constant value between 0 and 1/2.

Technical Field

The invention relates to the technical field of vibration measuring instruments, in particular to a handheld microwave vibration measuring system.

Background

Vibration measurement is an important way and an essential link for realizing structural mechanical property testing, health monitoring and equipment fault diagnosis and other micro-motion characteristic extraction. The two types of vibration measurement can be classified into a contact type and a non-contact type according to the sensing type, wherein the contact type sensor is mainly an acceleration sensor and is most widely applied, but the non-contact type measurement has obvious advantages in terms of the easiness of mounting the sensor, the measurement of a light structure and the like, such as a laser displacement sensor. In practical application, a vibration measuring instrument (abbreviated as a "vibration meter") which is convenient and quick and has a wide application range has important application value and engineering application requirements, and is particularly suitable for point inspection tests of mechanical equipment and structures, hammering mode tests, vibration measurement in severe environments such as high voltage and the like.

However, for the existing vibration meter, the contact-type installation is complicated, the application in vibration measurement in special environments such as light flexible structure and high pressure is limited, and the portability is poor. The non-contact laser vibration measuring instrument has large volume and power consumption, high cost and high requirement on measuring environment. Therefore, a convenient, quick, low-cost and high-precision handheld non-contact vibration measuring instrument is lacked at present.

The invention patent of patent document 201910434648.2 discloses a laser vibrometer, in which: laser emitted by the laser device is divided into two beams of light after passing through the isolator and the first coupler, the first beam of light enters the fourth coupler after being modulated by the two acousto-optic frequency shifters, and the second beam of light is divided into a correction beam and a signal beam after passing through the third coupler; the correction light beam enters the second coupler after passing through the intensity phase modulator; the signal light beam irradiates the surface of the target to be measured through the optical transceiving system and enters the second coupler after passing through the circulator; the signal light beam and the correction light beam are mixed in the second coupler, and the mixed light beam enters the fourth coupler to interfere with the reference light and then enters the balance detection system; and obtaining the Doppler vibration condition of the target to be detected through a demodulation algorithm, and finally obtaining the vibration information of the target to be detected. The vibration meter can eliminate stray light of the emission system, so that the detection capability and the precision of the system are improved. However, the above scheme has large power consumption and high requirement on the measurement environment.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a handheld microwave vibration measuring system.

The invention provides a handheld microwave vibration measurement system, which comprises an indication and positioning module, a microwave radar transceiver module, a control module, a signal acquisition and processing module, a display and data storage module and a power supply module, wherein:

the power supply module supplies power to the indicating and positioning module, the microwave radar transceiver module, the control module, the signal acquisition and processing module and the display and data storage module;

the microwave radar transceiver module is used for generating and transmitting a single-frequency continuous wave microwave signal and receiving an electromagnetic echo scattered by a target to obtain a zero intermediate frequency baseband signal;

the signal acquisition and processing module is used for acquiring two-channel zero intermediate frequency baseband signals output by the microwave radar transceiver module and extracting and analyzing vibration information;

the control module is used for controlling the starting and stopping of the system, setting parameters, controlling the working operation and data transmission of each module;

the indication and positioning module is used for assisting in indicating and positioning the vibration test target and/or the measuring point;

and the display and data storage module is used for displaying and storing information including vibration measurement time domain waveforms and vibration characteristic analysis results.

Preferably, the setting parameters include setting baseband signal sampling parameters, signal processing and analysis parameters, and display and data storage parameters.

Preferably, the indication and positioning module is a laser or visible light device, and the direction indicated by the indication and positioning module is the same as or close to the transmitting beam direction of the microwave radar transceiver module.

Preferably, the measurement device further comprises an anti-shake module, wherein the anti-shake module is used for eliminating the influence of shake including hand holding or head wearing on the measurement result.

Preferably, the anti-shake module comprises a software anti-shake sub-module and/or a physical anti-shake sub-module.

Preferably, the physical anti-shake sub-module comprises an active shake isolation device or a passive shake isolation device for isolating or weakening the conduction of hand-held or head-worn shake to the microwave radar transceiver; the software anti-shake sub-module comprises a band-pass filter, and the band-pass filter is used for filtering the extracted vibration displacement time-domain waveform of the measured target and/or the measured point.

Preferably, the microwave radar device further comprises a shell, and the indication and positioning module, the microwave radar transceiver module, the control module, the signal acquisition and processing module, the display and data storage module and the power supply module are all packaged in the shell.

Preferably, the microwave radar transceiver module includes a microwave signal source, a power divider, a power amplifier, a quadrature phase shifter, a low noise amplifier, a quadrature mixer, a low pass filter, a transmitting antenna, and a receiving antenna, wherein:

the microwave signal source is connected with the power divider, the power divider is connected with the power amplifier and the quadrature phase shifter, the power amplifier is connected with the transmitting antenna, the receiving antenna is connected with the low-noise amplifier, the low-noise amplifier and the quadrature phase shifter are connected with the input end of the quadrature frequency mixer, and the output end of the quadrature frequency mixer is connected with the low-pass filter.

Preferably, the vibration information extraction includes the steps of:

step S1: carrying out sliding window interception on the acquired two-channel zero intermediate frequency baseband signals;

step S2: performing arc fitting and circle center estimation on the signal in the sliding window by using a circle fitting algorithm;

step S3: judging whether the proportion of the fitting circular arc to the circumference is larger than a threshold value or not, if so, extracting a phase evolution time sequence corresponding to the vibration of the detected target and/or the measured point by using an arc tangent demodulation algorithm, and if not, selecting the phase evolution time sequence corresponding to the vibration of the detected target and/or the measured point, wherein the standard deviation of the two-channel baseband signals is larger;

step S4: and extracting the vibration displacement time sequence of the measured target and/or the measured point.

Preferably, the threshold is set at a constant between 0 and 1/2.

Compared with the prior art, the invention has the following beneficial effects:

1. the handheld microwave vibration meter provided by the invention can solve the problems that the contact vibration meter is complex and tedious to install, cannot be suitable for light and flexible structure vibration measurement, is limited in use in high-voltage and other special environments and the like; the problems of strict requirements on installation and environmental conditions of non-contact vibration measuring instruments, large volume and power consumption, high cost, poor portability and the like are solved; according to the invention, the microwave vibration sensing and measurement are realized through the microwave radar transceiver module, the problems of limited range of vibration measurement amplitude value range, narrow frequency response range and low measurement precision are solved, and the miniaturization and low power consumption of the system are easy to realize; the vibration information extraction method in the signal acquisition and processing module can effectively solve the problems of micro-amplitude, large-amplitude and the like of multi-scale vibration measurement and information extraction.

2. The invention can realize multi-scale (large or micro amplitude), broadband and high-precision vibration measurement, and provides the non-contact vibration measuring instrument and device with low cost, good portability, easy operation and wide application range.

3. The module is integrated in the shell, so that the portable operation such as handheld or head-wearing is facilitated, and the problems that the microwave is invisible and whether the microwave is aligned with a target or a measuring point is difficult to judge are solved by using the indicating and positioning module;

4. according to the invention, the anti-shake module is arranged in the handheld microwave vibration measurement system, so that the influence of shake including handheld or head-mounted shake on the vibration measurement result is effectively eliminated.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a block diagram of a handheld microwave vibration measurement system according to an embodiment of the present invention;

fig. 2 is a block diagram of a microwave radar transceiver module according to an embodiment of the present invention;

fig. 3 is a flowchart of a method for extracting vibration information in a signal acquisition and processing module according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

As shown in fig. 1 to 3, the handheld microwave vibration measuring system provided by the present invention includes a microwave radar transceiver, a signal collecting and processing module, a controller, a display and data storage module, a power supply module, an indication and positioning module, an anti-vibration module and a housing, wherein the indication and positioning module and the microwave radar transceiver are matched in position to achieve fast and accurate indication and positioning of a test target and/or a measurement point of the handheld microwave vibration measuring instrument, the microwave radar transceiver is connected with the signal collecting and processing module, the output end of the signal collecting and processing module is connected with the display and data storage module, and the software anti-vibration sub-module is connected with a vibration information extracting and analyzing sub-module in the signal collecting and processing module. The controller is connected with the microwave radar transceiver, the signal acquisition and processing module, the anti-shaking module and the display and data storage module, the power supply module supplies power for other modules except the shell, and the shell provides packaging support for other modules and is convenient for handheld or head-mounted portable operation.

The following further develops the individual modules: the shell encapsulates the microwave radar transceiver, the signal acquisition and processing module, the controller, the display and data storage module, the power module, the indication and positioning module and the anti-shaking module in a shell, and is convenient for portable operations such as handholding or head wearing. The microwave radar transceiver is used for generating and transmitting single-frequency continuous wave microwave signals and receiving electromagnetic echoes scattered by a target to obtain zero intermediate frequency baseband signals. The invention senses and measures the vibration of a target and/or a measuring point based on the phase modulation and the interference measurement of the single-frequency continuous wave microwave radar, and can realize high-precision and multi-scale vibration measurement. As shown in fig. 2, the microwave radar transceiver includes a microwave signal source, a power divider, a power amplifier, a quadrature phase shifter, a low noise amplifier, a quadrature mixer, a low pass filter, a transmitting antenna, and a receiving antenna, wherein: the microwave signal source is connected with the power divider, the power divider is connected with the power amplifier and the quadrature phase shifter, the power amplifier is connected with the transmitting antenna, the receiving antenna is connected with the low-noise amplifier, the low-noise amplifier and the quadrature phase shifter are connected with the input end of the quadrature frequency mixer, and the output end of the quadrature frequency mixer is connected with the low-pass filter. The signal of the microwave signal source is divided into two paths through a power divider, one path is connected with a transmitting antenna through a power amplifier, and the other path is connected with a quadrature mixer through a quadrature phase shifter; the low-pass filter outputs two-channel zero intermediate frequency baseband signals. In the microwave radar transceiver, the local oscillation signal adopts the same signal source as the transmitting signal, and is mixed with the receiving signal through the orthogonal frequency mixer through the orthogonal phase shifter, so that a zero intermediate frequency baseband signal of an orthogonal channel can be obtained, and meanwhile, the phase noise is effectively reduced. In order to reduce the volume and the power consumption, a chip type microwave radar transceiver is adopted. The signal acquisition and processing module is used for acquiring two-channel zero intermediate frequency baseband signals output by the microwave radar transceiver and extracting and analyzing vibration information. As shown in fig. 3, the vibration information extraction method includes:

step 1, carrying out sliding window interception on the two-channel zero intermediate frequency baseband signal.

And 2, performing arc fitting and circle center estimation on the signal in the sliding window by using a circle fitting algorithm.

And 3, judging whether the ratio of the fitting circular arc to the circumference is larger than a threshold value, if so, extracting a phase evolution time sequence corresponding to the vibration of the detected target and/or the measuring point by using an arc tangent demodulation algorithm, and if not, selecting the signal with the larger standard deviation in the two-channel baseband signals as the phase evolution time sequence corresponding to the vibration of the detected target and/or the measuring point. The threshold may be set at a constant between 0 and 1/2, as desired. For convenience of explanation, assume a dual channel baseband signal S within a window₁(t) and S₂(t) are respectively expressed as:

in the formula, DC₁And DC₂The direct current offset of the baseband signals of the first channel and the second channel respectively, x (t) is the vibration displacement of a measured target and/or a measured point, theta is the sum of fixed phase shift generated by the distance between the measured target and/or the measured point and the radar, fixed phase shift generated by microwave surface reflection and the like, delta theta (t) is phase noise, and lambda is the wavelength of the single-frequency continuous wave microwave signal. It can be seen that using the arctangent demodulation algorithm requires accurate estimation and compensation of the DC offset, i.e. accurate estimation of the DC offset is required₁And DC₂Otherwise, the extracted phase evolution time sequence has a large error, when the circle fitting algorithm is used for performing direct current offset estimation on the dual-channel baseband signal in the sliding window, if the proportion of the fitted circular arc to the circumference is very small, the fitting error is large, particularly when the ratio is smaller than 1/12, the estimation error of the direct current offset is very large, and at the moment, the inverse tangent demodulation algorithm is used for extracting the phase evolution time sequence corresponding to the vibration of the measured target and/or the measured point, so that a large measurement error is generated. When the ratio of the fitted circular arc to the circumference is large, more accurate direct current offset estimation can be realized, and thus higher-precision vibration measurement can be obtained by utilizing an arc tangent demodulation algorithm. For the case that the fitted circular arc occupies a relatively small circumference, it can be concluded that the vibration amplitude of the measured target and/or measured point is relatively small, i.e. much smaller than λ/2. Neglecting the DC offset, S₁(t) and S₂(t) is orthogonal, where the mean value, S, is ignored, based on the magnitude of θ, and is known from the Taylor series expansion of the trigonometric function₁(t) or S₂One of (t) may be approximately equal to 4 π x (t)/λ. In order to obtain the best approximation and adapt to the situation of different theta, the two-channel baseband signal S can be selected according to the Taylor series expansion knowledge of the trigonometric function₁(t) and S₂The larger standard deviation in the step (t) is used as a phase evolution time sequence corresponding to the vibration of the measured target and/or the measured point, so that the large standard deviation is realizedMulti-scale, high precision vibration measurement of amplitude and micro-amplitude.

Step 4, extracting the vibration displacement time sequence x (nT) of the measured target and/or the measured point_s) N is 1,2, …, and the extraction method comprises:

in the formula, T_sIn order to sample the time interval between the samples,

for the phase evolution time sequence corresponding to the vibration of the measured target and/or the measured point extracted in the step 3,and 3, averaging the phase evolution time sequence corresponding to the vibration of the measured target and/or the measured point extracted in the step 3, wherein lambda is the wavelength of the single-frequency continuous wave microwave signal emitted by the microwave radar transceiver. The vibration information analysis is used for carrying out time domain, frequency domain and time-frequency domain characteristic analysis on the extracted vibration displacement time sequence, and comprises vibration frequency, vibration amplitude and the like. The time domain analysis can analyze the characteristics such as the maximum value, the average value and the evolution of the vibration amplitude of the measured target and/or the measured point based on a statistical method, the frequency analysis can obtain the characteristics such as the vibration frequency by adopting fast Fourier transform and autocorrelation analysis, and the time frequency domain analysis can obtain the time frequency distribution characteristics of the measured target and/or the measured point by adopting short-time Fourier transform and other methods.

The controller of the hand-held microwave vibration measuring system is used for controlling the start and stop of the test, setting parameters, controlling the operation of each module and transmitting data. Setting parameters includes setting sampling parameters of baseband signals, signal processing and analyzing parameters and displaying and data storing parameters. And the display and data storage module of the handheld microwave vibration measurement system is used for displaying and storing information including vibration measurement time domain waveforms and vibration information characteristic analysis results. The power module is used for supplying power to each module of the instrument and is a direct current power supply. And the indicating and positioning module is used for assisting in indicating and positioning a vibration test target and/or a measuring point of the measuring instrument. The laser or visible light device can be selected, and the indication direction is the same as or close to the central direction of the transmitting beam of the microwave radar transceiver. The anti-shake module is used for eliminating the influence of shake such as handheld or head-mounted shake on the measurement result. Comprises one or a combination of a software anti-shake sub-module and a physical anti-shake sub-module. The vibration measurement of the target and/or the measuring point is influenced due to inevitable shaking of the hand or the head of the human body, so that the measurement deviation is caused. Considering that the hand or head of a human body shakes in a certain frequency range, generally about 4-9Hz, the vibration waveform measuring deviation caused by shaking can be eliminated by adopting a band-pass filter to filter the extracted vibration displacement time-domain waveform of the measured target and/or the measured point based on software anti-shaking. The in-band cut-off frequency of the band-pass filter can be determined by the jitter frequency measured by an accelerometer arranged in the shell, and can also be directly determined according to empirical values; the physical anti-shake sub-module adopts an active or passive shake isolation device to isolate or weaken the conduction of hand-held or head-worn shake to the microwave radar transceiver. An active or passive jitter isolation device may be mounted in the middle of the hand-held or head-mounted portion and the microwave radar transceiver, as desired.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.