WO2020118483A1 - Coherent light-based vibration source positioning device and method - Google Patents

Abstract

Disclosed in the present application are a coherent light-based vibration source positioning device and method. The method comprises: obtaining n different positions of a surface of a vibration object, the n different positions being arranged at a first interval; collecting a plurality of speckle images for each position of n different positions of the surface of the vibration object, the speckle image being formed by reflecting coherent light onto the surface of the vibration object, and then by diffusing the reflected light; obtaining vibration oscillograms of n different positions of the surface of the vibration object according to the plurality of speckle images, and determining a vibration source position of the vibration object. By using the embodiments of the present application, an environment limitation of vibration source positioning can be reduced, and the efficiency and precision of vibration source positioning are improved.

Description

Vibration source positioning device and method based on coherent light Technical field

The present application relates to the field of electronic technology, and in particular to a device and method for positioning a vibration source based on coherent light.

Background technique

The vibration signal of the mechanical system in operation contains a wealth of information on the operating state of the mechanical system, and the vibration characteristics have a strong correspondence with the fault. The mechanical system has a complex structure and many components. The collected dynamic signals are a comprehensive reflection of each component, and the influence of the propagation path increases the complexity of the signal. In addition, the early faults of many mechanical systems are weak, and the vibration sources and interference signals are overlapped, which makes it difficult to effectively identify and separate weak vibration signals such as early faults. Therefore, the location and recognition of weak vibration signal sources has important theoretical significance and engineering value. These information It is very useful for equipment operation status monitoring and fault diagnosis.

The weak fault signal amplitude or energy is often submerged in the interference characteristics, which is difficult to identify well. A fast and highly sensitive weak vibration signal detection and processing method is needed to effectively extract the weak vibration signal and rationally detect the weak fault signal Feature recognition and analysis. Piezoelectric acceleration sensors can be used to measure fine displacement vibrations of equipment parts, but they require contact measurement. They cannot be used at high temperatures, high speeds, or extremely small object sizes. Another problem that is difficult to solve is When the sensor moves with the measured object at high speed, there are problems with power supply and data transmission. Another measurement method is the use of laser triangulation, but this sensor uses imaging measurement technology to obtain a very small bright spot image through a complex design imaging lens, so for some highly reflective material surfaces, or black materials, It will cause the spot image to be missing and the object displacement cannot be calculated. In addition, because each machine has many components, each component may vibrate. These vibrations affect, superimpose, and hybridize with each other. Finally, the entire device experiences a "composite" vibration.

Based on the above reasons, it is urgent to propose a new vibration source positioning method, which can overcome the above-mentioned defects, and at the same time quickly and effectively locate the vibration source, and then find the fault in the mechanical system according to the vibration source.

Summary of the invention

An embodiment of the present application provides a device and method for positioning a vibration source based on coherent light. With the embodiment of the present application, a speckle image of a vibrating object can be acquired, and then a vibration waveform diagram can be obtained from the speckle image, and then the vibration can be determined according to the vibration waveform diagram. Intensity, fitting the extreme point of vibration intensity, positioning the vibration source, can reduce the environmental limitations of vibration source positioning, improve the efficiency and accuracy of vibration source positioning.

In a first aspect, an embodiment of the present application provides a device for positioning a vibration source based on coherent light, including:

A coherent light generator, a lens, a mirror, a MEMS two-dimensional scanning mirror, a high-speed camera, and a processing device connected to the high-speed camera;

The coherent light generator is used to generate coherent light;

The lens is used to focus the coherent light generated by the coherent light generator, and irradiate the focused coherent light to the reflector;

The reflecting mirror is used to reflect the focused coherent light onto the MEMS two-dimensional scanning mirror;

The MEMS two-dimensional scanning mirror is configured to irradiate the coherent light reflected by the mirror to n different positions on the surface of the vibrating object according to instructions of the processing device, and the n different positions are distributed at a first interval, wherein n is an integer greater than 1;

The high-speed camera is configured to acquire a plurality of speckle images for each of n different positions on the surface of the vibrating object, and send the plurality of speckle images to the processing device, wherein, the The speckle image is formed by irradiating the reflected coherent light onto the surface of the vibrating object, and is formed after the surface of the vibrating object is reflected;

The processing device is configured to acquire vibration waveforms of n different positions on the surface of the vibrating object according to the received multiple speckle images; and determine the vibration source of the vibration object according to the vibration waveforms position.

In a possible embodiment, the multiple speckle images collected for each of the n different positions on the surface of the vibrating object include:

The processing device controls the kth position among the n different positions to control the high-speed camera to acquire Rk speckle images corresponding to the period T, where k is an integer greater than 0 and less than or equal to n, and Rk is a positive integer;

The acquiring vibration waveforms at n different positions on the surface of the vibrating object according to the received multiple speckle images includes:

The processing device determines the kth position among the n different positions according to the received Rk speckle images, and determines the change of the position of the Rk speckle images according to time changes to obtain the kth position Vibration waveform diagram of location;

According to the vibration waveforms of n different k-th positions, determine the vibration waveforms of n different positions on the surface of the vibrating object.

In a possible embodiment, the determining the location of the vibration source of the vibrating object according to the vibration waveform includes:

The processing device determines the vibration signal of the k-th position according to the vibration waveform of the k-th position among the n different positions;

The processing device calculates and obtains the mean square value of the vibration signal of the kth position within the period T according to the vibration signal of the kth position, and determines the vibration intensity of the kth position;

The processing device performs three-dimensional curve fitting on the vibration intensity of n different positions, determines the extreme point of the vibration intensity, and locates the vibration source position of the vibration object.

In a possible embodiment, after determining the extreme point of the vibration intensity, the method further includes:

The processing device takes the vibration intensity extreme point as a center and obtains m different second positions at a second interval, the second interval is smaller than the first interval, and m is an integer greater than 1;

The processing device instructs the MEMS two-dimensional scanning mirror to irradiate the coherent light reflected by the mirror to the m different second positions, and instructs the high-speed camera to collect the m different second positions Speckle image

The processing device obtains vibration waveform diagrams of m different second positions according to the received speckle images of m different second positions; and determines the second vibration object according to the vibration waveform diagrams Extreme point of vibration intensity.

In a possible embodiment, the positioning of the vibration source of the vibrating object includes:

Using the vibration intensity extreme point or the j-th vibration intensity extreme point as the vibration source position of the vibrating object; or

Three-dimensional fitting is performed according to the acquired extreme value point of the vibration intensity and the second extreme value point of the vibration intensity, a center point is obtained, and the center point is used as the vibration source position of the vibrating object.

In a second aspect, an embodiment of the present application provides a method for locating a vibration source based on coherent light, including:

Acquiring n different positions on the surface of the vibrating object, the n different positions are distributed according to the first interval, where n is an integer greater than 1;

Acquiring a plurality of speckle images for each of n different positions on the surface of the vibrating object, the speckle image being irradiated to the surface of the vibrating object by coherent light, and formed after being reflected by the surface of the vibrating object;

Acquiring vibration waveform diagrams of n different positions on the surface of the vibrating object according to the plurality of speckle images, and determining the vibration source position of the vibration object according to the vibration waveform diagrams.

In a possible embodiment, the multiple speckle images collected for each of the n different positions on the surface of the vibrating object include:

For the k-th position among n different positions, Rk pieces of speckle images are acquired corresponding to the period T, where k is an integer greater than 0 and less than or equal to n, and Rk is a positive integer;

The acquiring vibration waveforms at n different positions on the surface of the vibrating object according to the received multiple speckle images includes:

For the kth position among the n different positions, according to the received Rk speckle images, determine the change of the position of the Rk speckle images according to time changes, and obtain the vibration waveform of the kth position Figure;

According to the vibration waveforms of n different k-th positions, determine the vibration waveforms of n different positions on the surface of the vibrating object.

In a possible embodiment, the determining the location of the vibration source of the vibrating object according to the vibration waveform includes:

Determine the average value of the vibration signal of the kth position according to the vibration waveform of the kth position among the n different positions, and obtain the square value of the average value of the vibration signal;

Determine the vibration intensity of the k-th position by integrating the square of the average value of the vibration signal of the k-th position in the period T;

Perform three-dimensional curve fitting on the vibration intensity of n different positions, determine the extreme point of the vibration intensity, and locate the vibration source position of the vibration object.

In a possible embodiment, after determining the extreme point of vibration intensity, the method further includes:

Taking the vibration intensity extreme point as the center, obtaining m different second positions at a second interval, the second interval is smaller than the first interval, and m is an integer greater than 1;

Acquiring multiple speckle images for each of m different second positions on the surface of the vibrating object, and acquiring the speckle images of the m different second positions;

Acquiring vibration waveform diagrams of m different second positions according to the speckle images of m different second positions; and determining a second vibration intensity extreme point of the vibrating object according to the vibration waveform diagrams;

The above steps are passed through j-2 iterations to obtain the jth vibration intensity extreme point, where j is an integer greater than or equal to 2.

In a possible embodiment, the location of the vibration source of the vibrating object includes:

Using the vibration intensity extreme point or the j-th vibration intensity extreme point as the vibration source position of the vibrating object; or

Three-dimensional fitting is performed according to the obtained plurality of extreme points of vibration intensity, a center point is obtained, and the center point is used as the vibration source position of the vibrating object.

In a third aspect, an embodiment of the present application further provides a computer storage medium, where the computer storage medium may store a program, and when the program is executed, it includes some or all steps of the method described in the second aspect above

It can be seen that in the solution of the embodiment of the present application, by acquiring n different positions on the surface of the vibrating object; then multiple speckle images are collected for each of the n different positions on the surface of the vibrating object; finally according to The multiple speckle images acquire vibration waveforms of n different positions on the surface of the vibrating object, and determine the vibration source position of the vibration object according to the vibration waveforms. Adopting the embodiments of the present application can reduce the environmental limitation of vibration source positioning, improve the efficiency and accuracy of acquiring vibration intensity extreme points, and thereby improve the efficiency and accuracy of positioning the vibration source.

These or other aspects of the present application will be more concise and understandable in the description of the following embodiments.

BRIEF DESCRIPTION

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, without paying any creative work, other drawings can be obtained based on these drawings.

1 is a schematic diagram of an application scenario of a vibration source positioning device based on coherent light provided by an embodiment of the present application;

Figure 2 is a schematic diagram of selecting different positions of a vibrating object;

Figure 3 is the vibration speckle image obtained by the high-speed camera;

4 is a schematic diagram of vibration waveforms obtained from speckle images at different positions of a vibrating object;

Figure 5 is a schematic diagram of three-dimensional surface fitting of the vibration source center;

6 is a schematic diagram of selecting the surface positions of vibrating objects with different degrees of density;

7 is a schematic flowchart of a method for positioning a vibration source based on coherent light according to an embodiment of the present application.

detailed description

The embodiments of the present application will be described below with reference to the drawings.

Referring to FIG. 1, FIG. 1 is a schematic diagram of an application scenario of a device for positioning a vibration source based on coherent light according to an embodiment of the present application. As shown in FIG. 1, the application scenario includes: a vibrating object 10 and a vibration source positioning device 20.

Wherein, the above-mentioned vibrating object 10 including the vibrating source 11 may be the corresponding automated production equipment in the fields of automobile manufacturing, household appliances, transportation, or food, wear-resistant parts in numerically controlled machine tools, or other objects such as manipulators.

The vibration source positioning device 20 includes a coherent light generator 201, a lens 202, a reflection mirror 203, a MEMS two-dimensional scanning mirror 204, a high-speed camera 205, and a processing device 206 connected to the high-speed camera 205, of which MEMS two Dimensional scanning mirror represents a two-dimensional scanning mirror of Micro-Electro-Mechanical System. Its internal structure is generally in the order of micrometers or even nanometers. It is an independent intelligent system.

The aforementioned coherent light generator 201 is used to generate coherent light; the lens 202 is used to focus the coherent light generated by the coherent light generator 201 and irradiate the focused coherent light to the reflecting mirror 203; the reflecting mirror 203 is used to The focused coherent light is reflected onto the MEMS two-dimensional scanning mirror 204. The MEMS two-dimensional scanning mirror 204 is used to irradiate the coherent light reflected by the reflecting mirror 203 to n different positions on the surface of the vibrating object 10 according to the instruction of the processing device 206, and the n different positions are distributed according to the first interval. The above-mentioned high-speed camera 205 is used to acquire multiple speckle images for each of n different positions on the surface of the vibrating object 10, and send the multiple speckle images to the processing device 206, wherein the speckle image is The reflected coherent light is irradiated on the surface of the vibrating object, and is formed after the surface of the vibrating object is reflected; the processing device 206 is used to acquire vibrations at n different positions on the surface of the vibrating object according to the received multiple speckle images Waveform diagram; and determine the location of the vibration source of the vibrating object according to the vibration waveform diagram.

Specifically, the coherent light may be an ultraviolet or near infrared laser, and the coherent light generator may be various types of laser generators. The MEMS two-dimensional scanning mirror can rotate the mirror surface in two directions of X and Y, can quickly deflect the coherent light reflected by the mirror, and complete the high-speed scanning in the XY directions of the surface of the vibrating object 10 without moving the vibrating object. The MEMS two-dimensional scanning mirror 204 can adjust the scanning angle, and the scanning angle of the MEMS two-dimensional scanning mirror 204 can be preset according to the coherent light angle incident on the reflecting mirror 203 and the specific position of the surface of the vibrating object 10 to be located. During the scanning process, the MEMS two-dimensional scanning mirror 204 can complete the scanning in the X-axis direction from left to right, and the scanning in the Y-axis direction from the forward direction. Alternatively, it is possible to scan clockwise or counterclockwise. You can also pre-set the angle that the MEMS two-dimensional scanning mirror needs to be adjusted, and then select the scanning direction every time according to the minimum rotation angle.

Since there are vibration sources 11 for the vibrating object, and during vibration propagation, the farther away from the vibration source, the more the vibration signal is attenuated, then n points at different positions can be selected on the surface of the vibrating object 10, according to the n points on the surface of the vibrating object 10 The size of the vibration signal at different locations determines the point closest to the vibration source. Optionally, the n different positions may be points on the same surface of the vibrating object that are evenly distributed at the first interval. The same surface is convenient for scanning by the MEMS two-dimensional scanning mirror, and at the same time is convenient for high-speed cameras to collect images. n is a positive integer greater than 1, such as the three positions A, B, and C in FIG.

Preferably, n may be a square of positive numbers, such as 4, 9, 16, etc., and the arrangement order of n points is a square arrangement, as shown in FIG. 2, for vibrating object 101, 9 different positions A1 on the upper surface are selected ~A9, and evenly distributed at the first preset interval. In this way, the vibration intensity of the surface of the object can be obtained with equal probability, so as to avoid the result deviation due to the different density of the selected positions.

The high-speed camera 205 is used to acquire speckle images stably and at high speed, and may be an image controller (Charge-coupled Device, CCD) or a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor (CMOS) sensor). The vibration of the object will cause the displacement of the speckle projected on the surface of the object. The frequency and amplitude of the displacement are related to the vibration of the measured object. Therefore, the continuous speckle image can be taken by using the high-speed camera 205 to calculate the speckle The offset, in turn, obtains object characteristics such as vibration frequency and amplitude in the frequency space. For n different positions on the surface of the selected vibrating object 10, the high-speed camera 205 collects multiple speckle images for each of the n different positions. The speckle image is shown in FIG. 3, and then the collected multiple speckles The spot image is sent to the processing device 206.

Optionally, the multiple speckle images collected for each of the n different positions on the surface of the vibrating object include: the processing device controls the high-speed camera to collect Rk corresponding to the period T for the kth position among the n different positions A speckle image, where k is an integer greater than 0 and less than or equal to n, and Rk is a positive integer.

The MEMS 2D scanning mirror can quickly change the speckle projection position. For the first position among n different positions, the high-speed camera continuously collects R1 speckle images in the period T, and then quickly switches to the second position, high speed The camera continuously collects R2 speckle images in the same period T, and so on, to complete the image acquisition of n different positions. When a high-speed camera collects speckle images at n different positions, for the same high-speed camera, under the same resolution, the image Rk acquired in each period T is the same. However, when the resolution is switched or the high-speed camera is replaced, the images Rk acquired in different periods T are different. In both cases, the acquisition of Rk speckle images corresponding to the period T satisfies the condition, so Rk may be the same value or a different value.

The processing device 206 is the computing core and the control core of the coherent light vibration source positioning device of this embodiment, is connected to the high-speed camera 205, receives multiple speckle images collected by the high-speed camera 205, and obtains the surface of the vibrating object 10 according to the acquired speckle images Vibration waveforms at n different locations of the system, and determine the location of the vibration source of the vibrating object according to the vibration waveforms. In addition, the processor 206 can also be connected to the coherent light generator 201 and the MEMS two-dimensional scanning mirror 204 to control whether the coherent light emits coherent light, and automatically adjust the MEMS two-dimensional scanning mirror according to the angle of the coherent light reflected by the reflecting mirror 203 The angle of 204.

Optionally, obtaining vibration waveforms of n different positions on the surface of the vibrating object according to the received multiple speckle images, including: the processing device for the kth position among the n different positions, according to the received Rk sheets Speckle image, determine the change of the position of the Rk speckle image according to time changes, obtain the vibration waveform of the kth position; according to the vibration waveform of the n different kth positions, determine the n of the surface of the vibrating object Vibration waveforms at different locations.

Specifically, assuming that n is 3, n different positions are the three points A, B, and C in FIG. 1. For the first position in n different positions, such as point A in FIG. 1, the processor receives To the R1 speckle images, these speckle images are positionally shifted with time due to the vibration of the object surface, as shown in a1 in FIG. 4, the R1 speckle images are acquired at a time interval Δt, from left to right The acquisition times of the four speckle images are t, t+Δt, t+2Δt, and t+3Δt, until the image acquisition in the period T is completed. According to the speckle image change of a1 in FIG. 4, a vibration waveform diagram at point A as shown in b1 of FIG. 4 can be obtained, the horizontal axis is time, and the vertical axis is amplitude, and the amplitude changes according to the displacement of the speckle image. Similarly, R2 speckle images corresponding to point B in FIG. 1 can be obtained as shown in a2 in FIG. 4, and the corresponding vibration waveform diagram is b2 in FIG. 4, and R3 speckles corresponding to point C in FIG. 1 The image is shown as a3 in FIG. 4, and the corresponding vibration waveform is b3 in FIG.

After obtaining vibration waveforms corresponding to n different positions on the surface of a vibrating object, it is necessary to perform feature extraction on the waveforms. The vibration feature extraction is the key to determining the location of the vibration source. The features that can be extracted include time-domain features such as mean, mean square, and variance , Singularity index, waveform factor, peak factor; frequency domain characteristic amplitude spectrum, phase spectrum, power spectrum, power spectrum density, etc.; and time-frequency domain characteristics, such as wavelet transform. Then the vibration source position is obtained according to the extracted feature analysis.

Optionally, determining the vibration source position of the vibrating object according to the vibration waveform diagram includes: the processing device determines the vibration signal of the kth position according to the vibration waveform diagram of the kth position among the n different positions; the processing device according to the kth position The vibration signal of the position is calculated to obtain the mean square value of the vibration signal of the kth position in the period T, and the vibration intensity of the kth position is determined; the processing device performs three-dimensional curve fitting on the vibration intensity of the n different positions to determine the vibration intensity Extreme point, locate the vibration source position of the vibrating object.

In the embodiment of the present application, since the vibration signal attenuates the farther away from the vibration source during vibration propagation, and the vibration has positive and negative values of peaks and troughs, the mean square value of the vibration signal can effectively reflect the strength of the signal. The positive square root value is an expression of average energy. Therefore, if the vibration intensity is defined as E(x, y), then the formula for calculating the vibration intensity is:

Where x represents the amplitude in Figure 4 and t represents time.

For different measurement positions, the vibration intensity is calculated respectively, and then the vibration intensity is fitted with a three-dimensional curve to determine the extreme point of vibration intensity (x-max, y-max), and then the location of the vibration source is located. As shown in Figure 5, where XY is the coordinate of the measured object position, the Z direction is the vibration intensity, where "·" indicates n different positions, and "+" indicates the location of the vibration source estimate point.

It can be seen that in the embodiments of the present application, by using MEMS two-dimensional scanning mirrors to receive coherent light and reflect it to the surface of the vibrating object, and then scanning the vibrating object, the deflection of the light-sensing beam can be quickly achieved in all directions on the surface of the vibrating object Perform a full-speed and comprehensive scan; then use a high-speed camera to collect the speckle image, and calculate the displacement of the speckle according to the speckle image sequence to calculate the displacement of the object, and calculate the waveform of the displacement with time in real time. A waveform diagram reflecting the vibration of an object is obtained. This process collects images by a high-speed camera, which realizes non-contact vibration measurement, reduces the environmental constraints of vibration measurement, and removes the real image reconstruction of the speckle image by processing the speckle image. The process of obtaining vibration waveforms directly from the image improves the efficiency of obtaining vibration waveforms.

In a possible embodiment, after the vibration source positioning device 20 for coherent light determines the vibration intensity extreme point according to the vibration intensity of n different positions, the processing device is also used for: the processing device is centered on the vibration intensity extreme point, Acquire m different second positions at the second interval, the second interval is smaller than the first interval, m is an integer greater than 1; the processing device instructs the MEMS two-dimensional scanning mirror to irradiate the coherent light reflected by the mirror to m different second positions Two positions, and instructs the high-speed camera to collect speckle images of m different second positions; the processing device acquires vibration waveforms of m different second positions according to the received speckle images of m different second positions ; And determine the second extreme point of vibration intensity of the vibrating object according to the vibration waveform diagram.

After determining the extreme points of vibration intensity based on the n speckle images collected at the first time, only a preliminary positioning of the vibration source can be performed, and the vibration source can also be positioned more accurately. As shown in FIG. 6, the n positions selected by c1 in FIG. 6 are the positions selected in FIG. 5, and the vibration extreme point has been determined to be the position marked with “+” according to the foregoing embodiment. Under this premise, m different second positions are reselected at the second interval, such as the position "+" marked with c2 in FIG. 6. Among the m different second positions selected by c2 in FIG. 6, the vibration extreme point 601 determined by c1 in FIG. 6 can be used as the center position, and m-1 second positions can be selected at the second interval. The interval is s times the first interval, and s is a decimal between 0 and 1. The vibration extreme point 601 determined by c1 in FIG. 6 can also be used as the center, and m second positions are additionally selected at the second interval, and the second interval is determined according to the distance between the original n different positions and the vibration extreme point 601 For example, the distance between the kth position in n different positions and 601 is L1, then the distance between the kth second position in m different second positions and 601 is s*L1, or L1-1, where 1 is a positive number.

After acquiring m different second positions, you can collect the speckle image at the second position according to the same process as above, obtain the vibration waveform diagram based on the speckle image, determine the vibration intensity according to the vibration waveform diagram, and then perform three-dimensional vibration intensity Fitting, the second extreme point of vibration intensity is determined.

Optionally, locating the vibration source location of the vibration object includes: using the vibration intensity extreme point or the jth vibration intensity extreme point as the vibration source location of the vibration object; or performing three-dimensional simulation based on the obtained multiple vibration intensity extreme points Combine, find the center point, and use the center point as the vibration source position of the vibrating object.

Specifically, after performing three-dimensional curve fitting on the vibration intensity of n different positions and locating the vibration intensity extreme point of the vibrating object, the vibration intensity extreme point may be directly used as the vibration source position, or the second vibration intensity The extreme point is directly used as the vibration source position of the vibrating object. After performing three-dimensional curve fitting on the vibration intensity at the m second positions and locating to the second vibration intensity extreme point of the vibrating object, performing three-dimensional curve fitting on the vibration intensity extreme point and the second vibration intensity extreme point, Find the center point, and use the center point as the vibration source position.

Alternatively, as indicated by c3 in FIG. 6, iteratively repeat the previous vibration intensity extreme point as the center, select different positions of the vibration surface at decreasing intervals, and determine different vibration extreme points. Because the sampling points near the vibration source are getting denser and denser, the vibration source center determined by the method embodiment is more and more accurate, and it is closer to the real vibration source center. After j-2 iterations, the j-th vibration intensity extreme point is obtained, and j is a positive integer greater than 1. The j-th vibration intensity extreme point can be used as the vibration source position of the vibrating object, or the vibration intensity extreme point obtained previously and the second to j-th vibration intensity extreme points can be three-dimensionally fitted to obtain the center point, And use the central store as the location of the vibration source.

In a possible embodiment, the above-mentioned vibration positioning device 20 based on coherent light is used for the detection of equipment vibration faults in the production automation process. During the detection process, the device is in a highly operational state, then the vibration positioning device 20 based on coherent light The MEMS two-dimensional scanning mirror in can be in a static state, and only needs the coherent light generator to emit coherent light intermittently, which can achieve multi-point irradiation of the surface of the vibrating object. The high-speed camera should be exposed at a speed higher than the operation of the device to obtain Accurate speckle image.

In an alternative embodiment, the above-mentioned vibration positioning device 20 based on coherent light can also be used for real-time online measurement of the assembly accuracy of the entire mechanical system and wear-resistant parts when the CNC machining machine tool is cutting the product at high speed. At the same time of determining the vibration source of the machine tool, the trend and distribution of vibration intensity attenuation are determined according to the three-dimensional curve fitting of the vibration intensity, and then the cause of the vibration is determined. It is determined that the vibration caused by the material selection or assembly process is large, which reduces the machine tool vibration. Provide basis for vibration.

It can be seen that in the solution of the embodiment of the present application, the coherent light is generated by the coherent light generator; the lens focuses the coherent light generated by the coherent light generator, and irradiates the focused coherent light to the mirror; the mirror will The focused coherent light is reflected on the MEMS two-dimensional scanning mirror, and the MEMS two-dimensional scanning mirror irradiates the coherent light reflected by the mirror to n different positions on the surface of the vibrating object according to the instructions of the processing device, and the n different positions follow the first interval Distribution; the high-speed camera collects multiple speckle images for each of n different positions on the surface of the vibrating object, and sends the multiple speckle images to the processing device, where the speckle image is reflected by the reflected coherent light to the vibrating object The surface is formed after scattering; the processing device obtains vibration waveforms of n different positions on the surface of the vibrating object according to the received speckle images; and determines the vibration source position of the vibration object according to the vibration waveforms. The embodiments of the present application have the following advantages: 1. Irradiate coherent light to different positions on the surface of the object through the MEMS two-dimensional scanning mirror, which can quickly realize multi-point measurement on the surface of the object without moving the object or rotating with the object at high speed , Reduce the environmental limitation of vibration source positioning; At the same time, the MEMS two-dimensional scanning mirror locates the vibration source on the vibrating object from coarse to fine, which improves the accuracy of vibration source positioning. 2. The coherent light projection and image acquisition in the process are both non-contact, capable of wiring and collecting data. 3. The surface and internal structure of the measured object are subjected to coherent light irradiation due to deformation and vibration, and then imaged by the optical sensor, so that the object displacement and deformation information are also included in the speckle image, the present invention does not require speckle image Phase solution is used to reconstruct the real image of the original object. Instead, the speckle sequence image is taken multiple times through a high-speed sensor, and the displacement of the speckle is quickly solved to calculate the displacement of the object. Real-time calculation of the waveform diagram of the change of displacement with time to solve the spectrogram reflecting the vibration of the object. Finally, locate the vibration extreme point and the location of the vibration source according to the vibration spectrogram. This process reduces the steps of image reconstruction. Improve the accuracy of the vibration source. The vibration source positioning device can be widely used in various fields such as automobile manufacturing, home appliances, transportation and food.

In short, the embodiment of the present application can quickly switch the projection position of the coherent light to the surface of the vibrating object through the MEMS two-dimensional scanning mirror, collect the speckle image of the projection position, and then obtain the vibration waveform diagram based on the speckle image, and then determine the vibration waveform diagram Vibration intensity, fitting the extreme point of vibration intensity, and repeatedly performing the extreme point positioning process to achieve the location of the vibration source from coarse to fine, reducing the environmental limitations of vibration source positioning, and improving the efficiency and accuracy of vibration source positioning .

Referring to FIG. 7, FIG. 7 is a schematic flowchart of a method for positioning a vibration source based on coherent light according to an embodiment of the present application. As shown in Figure 7,

S701. Acquire n different positions on the surface of the vibrating object, where the n different positions are distributed according to the first interval.

S702. Collect a plurality of speckle images for each of n different positions on the surface of the vibrating object. The speckle image is formed by coherent light reflected on the surface of the vibrating object and scattered.

S703. Acquire vibration waveform diagrams of n different positions on the surface of the vibrating object according to the plurality of speckle images, and determine a vibration source position of the vibration object according to the vibration waveform diagrams.

In a possible embodiment, the multiple speckle images collected for each of the n different positions on the surface of the vibrating object include:

For the kth position out of n different positions, Rk pieces of speckle images are acquired corresponding to the period T, and mk may be the same or different;

The acquiring vibration waveforms at n different positions on the surface of the vibrating object according to the received multiple speckle images includes:

For the kth position among the n different positions, according to the received Rk speckle images, determine the change of the position of the Rk speckle images according to time changes, and obtain the vibration waveform of the kth position Figure;

According to the vibration waveforms of n different k-th positions, determine the vibration waveforms of n different positions on the surface of the vibrating object.

In a possible embodiment, the determining the location of the vibration source of the vibrating object according to the vibration waveform includes:

Determine the vibration signal of the k-th position according to the vibration waveform of the k-th position among the n different positions;

Calculating the mean square value of the vibration signal of the k-th position in the period T according to the vibration signal of the k-th position, and determining the vibration intensity of the k-th position;

Perform three-dimensional curve fitting on the vibration intensity of n different positions, determine the extreme point of the vibration intensity, and locate the vibration source position of the vibration object.

In a possible embodiment, after determining the extreme point of the vibration intensity, the method further includes:

Taking the vibration intensity extreme point as the center, acquiring m different second positions at a second interval, the second interval being smaller than the first interval;

Acquiring multiple speckle images for each of m different second positions on the surface of the vibrating object, and acquiring the speckle images of the m different second positions;

Acquiring vibration waveform diagrams of m different second positions according to the speckle images of the m different second positions; and determining a second vibration intensity extreme point of the vibrating object according to the vibration waveform diagrams;

The above steps are passed through j-2 iterations to obtain the jth vibration intensity extreme point, where j is an integer greater than or equal to 2.

In a possible embodiment, the location of the vibration source of the vibrating object includes:

Using the vibration intensity extreme point or the j-th vibration intensity extreme point as the vibration source position of the vibrating object; or

Three-dimensional fitting is performed according to the obtained plurality of extreme points of vibration intensity, a center point is obtained, and the center point is used as the vibration source position of the vibrating object.

It should be noted here that for the specific description of the above steps S701-S703, reference may be made to the related description of the embodiments shown in FIG. 1 to FIG. 6, which will not be described here.

An embodiment of the present application further provides a computer storage medium, where the computer storage medium may store a program, and when the program is executed, it includes some or all steps of any one of the obstacle avoidance methods described in the foregoing method embodiments.

The embodiments of the present application are described in detail above, and specific examples are used to explain the principle and implementation of the present application. The descriptions of the above embodiments are only used to help understand the method and core idea of the present application; at the same time, Those of ordinary skill in the art, based on the ideas of the present application, will have changes in the specific implementation and application scope. In summary, the content of this specification should not be construed as limiting the present application.

Claims (10)

A vibration source positioning device based on coherent light, characterized in that it includes: A coherent light generator, a lens, a mirror, a MEMS two-dimensional scanning mirror, a high-speed camera, and a processing device connected to the high-speed camera; The coherent light generator is used to generate coherent light; The lens is used to focus the coherent light generated by the coherent light generator, and irradiate the focused coherent light to the reflector; The reflecting mirror is used to reflect the focused coherent light onto the MEMS two-dimensional scanning mirror; The MEMS two-dimensional scanning mirror is configured to irradiate the coherent light reflected by the mirror to n different positions on the surface of the vibrating object according to instructions of the processing device, and the n different positions are distributed at a first interval, wherein n is an integer greater than 1; The high-speed camera is configured to acquire a plurality of speckle images for each of n different positions on the surface of the vibrating object, and send the plurality of speckle images to the processing device, wherein, the The speckle image is formed by irradiating the surface of the vibrating object with the coherent light and reflecting after the surface of the vibrating object is reflected; The processing device is configured to acquire vibration waveforms of n different positions on the surface of the vibrating object according to the received multiple speckle images; and determine the vibration source of the vibration object according to the vibration waveforms position. The device according to claim 1, wherein the plurality of speckle images collected for each of n different positions on the surface of the vibrating object comprises: The processing device controls the kth position among the n different positions to control the high-speed camera to acquire Rk speckle images corresponding to the period T, where k is an integer greater than 0 and less than or equal to n, and Rk is a positive integer; The acquiring vibration waveforms at n different positions on the surface of the vibrating object according to the received multiple speckle images includes: The processing device determines the kth position among the n different positions according to the received Rk speckle images, and determines the change of the position of the Rk speckle images according to time changes to obtain the kth position Vibration waveform diagram of location; According to the vibration waveforms of n different k-th positions, determine the vibration waveforms of n different positions on the surface of the vibrating object. The device according to claim 1 or 2, wherein the determining the vibration source position of the vibrating object according to the vibration waveform diagram comprises: The processing device determines the vibration signal of the k-th position according to the vibration waveform of the k-th position among the n different positions; The processing device calculates and obtains the mean square value of the vibration signal of the kth position within the period T according to the vibration signal of the kth position, and determines the vibration intensity of the kth position; The processing device performs three-dimensional curve fitting on the vibration intensity of n different positions, determines the extreme point of the vibration intensity, and locates the vibration source position of the vibration object. The device according to claim 3, wherein after determining the extreme point of the vibration intensity, the method further comprises: The processing device takes the vibration intensity extreme point as a center and obtains m different second positions at a second interval, the second interval is smaller than the first interval, and m is an integer greater than 1; The processing device instructs the MEMS two-dimensional scanning mirror to irradiate the coherent light reflected by the mirror to the m different second positions, and instructs the high-speed camera to collect the m different second positions Speckle image The processing device obtains vibration waveform diagrams of m different second positions according to the received speckle images of m different second positions; and determines the second vibration object according to the vibration waveform diagrams Extreme point of vibration intensity; The above steps are passed through j-2 iterations to obtain the jth vibration intensity extreme point, where j is an integer greater than or equal to 2. The device according to claim 3, wherein the location of the vibration source for positioning the vibrating object comprises: The extreme point of the vibration intensity is taken as the location of the vibration source of the vibrating object. The device according to claim 4, wherein the location of the vibration source for positioning the vibrating object comprises: Using the j-th vibration intensity extreme point as the vibration source position of the vibrating object; or Three-dimensional fitting is performed according to the obtained plurality of extreme points of vibration intensity, a center point is obtained, and the center point is used as the vibration source position of the vibrating object. A method of locating a vibration source based on coherent light is characterized by including: Acquiring n different positions on the surface of the vibrating object, the n different positions being distributed according to the first interval, where n is an integer greater than 1; Acquiring a plurality of speckle images for each of n different positions on the surface of the vibrating object, the speckle image being irradiated to the surface of the vibrating object by coherent light, and formed after being reflected by the surface of the vibrating object; Acquiring vibration waveform diagrams of n different positions on the surface of the vibrating object according to the plurality of speckle images, and determining the vibration source position of the vibration object according to the vibration waveform diagrams. The method according to claim 7, wherein the plurality of speckle images collected for each of n different positions on the surface of the vibrating object includes: For the k-th position among n different positions, Rk pieces of speckle images are acquired corresponding to the period T, where k is an integer greater than 0 and less than or equal to n, and Rk is a positive integer; The acquiring vibration waveforms at n different positions on the surface of the vibrating object according to the received multiple speckle images includes: For the kth position among the n different positions, according to the received Rk speckle images, determine the change of the position of the Rk speckle images according to time changes, and obtain the vibration waveform of the kth position Figure; According to the vibration waveforms of n different k-th positions, determine the vibration waveforms of n different positions on the surface of the vibrating object. The method according to claim 7 or 8, wherein the determining the vibration source position of the vibrating object according to the vibration waveform diagram comprises: Determine the vibration signal of the k-th position according to the vibration waveform of the k-th position among the n different positions; Calculating the mean square value of the vibration signal of the k-th position in the period T according to the vibration signal of the k-th position, and determining the vibration intensity of the k-th position; Three-dimensional curve fitting is performed on the vibration intensity of n different positions, the extreme point of the vibration intensity is determined, and the vibration source position of the vibration object is located. The method according to claim 9, wherein after determining the extreme point of vibration intensity, the method further comprises: Taking the vibration intensity extreme point as the center, obtaining m different second positions at a second interval, the second interval is smaller than the first interval, and m is an integer greater than 1; Acquiring multiple speckle images for each of m different second positions on the surface of the vibrating object, and acquiring the speckle images of the m different second positions; Acquiring vibration waveform diagrams of m different second positions according to the speckle images of the m different second positions; and determining a second vibration intensity extreme point of the vibrating object according to the vibration waveform diagrams; The above steps are passed through j-2 iterations to obtain the jth vibration intensity extreme point, where j is an integer greater than or equal to 2.

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