A micro-vibration trajectory measuring device and a measuring method thereof

Abstract

The application discloses a kind of for micro vibration trajectory measuring device and its measuring method, belong to the measurement field of vibration trajectory.The application utilizes beam splitter to divide laser into two mutually perpendicular ways, respectively through two mutually perpendicular pinhole plates fixed on the same vibration support and irradiate CCD sensor and photoelectric sensor QPD on QPD output quadrant position signal and according to its change period generation pulse sequence signal and trigger signal by single-chip microcomputer, power supply receives pulse sequence signal for driving laser to emit laser pulse, and CCD sensor receives trigger signal sent by single-chip microcomputer and then records image information.The application can complete a cycle of vibration trajectory synthesis by the single image pair formed by two synchronous CCD sensors, without inertia vibration measuring element and avoids the repeated superposition of multi-cycle measurement results, improves the real-time performance and accuracy of measurement.

Description

Technical Field

[0001] This invention relates to a device and method for measuring minute vibration trajectories, and more particularly to a system for measuring the trajectory of low-to-medium frequency mechanical vibrations. Background Technology

[0002] In engineering applications such as conveying, cleaning, grinding, and screening of mechanical parts or material particles, specific modes of mechanical vibration are often required to improve work efficiency. In other engineering fields, it is necessary to suppress vibration to prevent it from adversely affecting instruments and equipment. Therefore, it is usually necessary to conduct experimental measurements to obtain modal data such as vibration amplitude, frequency, and phase, providing a basis for equipment monitoring, theoretical analysis, and system optimization.

[0003] Currently, indirect, inertial sensors are commonly used to measure parameters such as displacement in mechanical vibrations. Sensors are installed in orthogonal directions to detect vibration parameters, and then the vibration parameters of the vibrating body are obtained through signal synthesis and analysis. However, the accuracy and reliability of the measurement results are affected by the mutual coupling between different motion directions of the inertial sensing elements, differences in sensor linearity, and signal gain. Furthermore, the overlapping of multiple period measurement results makes it difficult to distinguish the motion state of characteristic points on the vibrating body within a single vibration cycle. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide a non-contact, high-precision measuring device and method for measuring displacement and vibration trajectory of moderate-intensity mechanical vibration.

[0005] To achieve the above objectives, the present invention employs the following technical solution.

[0006] A device for measuring the trajectory of minute vibrations includes a laser 1, a power supply 2, a first planar beam splitter 3 and a second planar beam splitter 4, a first pinhole plate 5 and a second pinhole plate 6, an L-shaped vibration transmission bracket 7, a photoelectric sensor QPD 8, a first CCD sensor 9 and a second CCD sensor 10, a microcontroller 11, an image acquisition and processing system 12, and a computer 13.

[0007] The laser 1, power supply 2, planar beam splitter 3, planar beam splitter 4, photoelectric sensor QPD8, CCD sensor 9, and CCD sensor 10 are all mounted on the same working plane. Planar beam splitter 3, with an isolation distance A, is positioned behind the output port of laser 1 and forms a 45° angle with the laser beam. The emitted beam from laser 1 is split into two mutually perpendicular laser beams, I and II, by planar beam splitter 3. Pinhole plates 5 and 6 are perpendicular and located in the paths of laser beams I and II, respectively. The pinhole of pinhole plate 5 faces laser beam I, and the pinhole of pinhole plate 6 faces laser beam II. The isolation distance B between pinhole plates 5 and 6 is fixed. The L-shaped vibration transmission bracket 7 is symmetrically distributed on both sides of the planar beam splitter 3 on its two mutually perpendicular arms, and is placed on the vibrating body to be tested. The CCD sensor 9 is positioned at an isolation distance C in the path of the pinhole plate 5. The target surface of the CCD sensor 9 is perpendicular to the laser beam I, and it images the pinhole plate 5 within the imaging range of the CCD. Its output is connected to the image acquisition and processing system 12 via a signal line. The planar beam splitter 4 is positioned at an isolation distance D behind the pinhole plate 6 and is at a 45° angle to the laser beam. In the path of laser beam II at an angle of °, laser beam II passes through the small hole of the small aperture plate II 6 and is split into laser beam III and laser beam IV by the planar beam splitter II 4. Laser beam III is in the same direction as laser beam II, and laser beam IV is perpendicular to laser beam II. The isolation distance E of CCD sensor II 10 is located behind the planar beam splitter II 4 in the path of laser beam III. Its target surface is perpendicular to laser beam III. It images the small aperture plate II 6 within the imaging range of the CCD sensor. CCD sensor II 10 is connected to the image acquisition and processing system 12 through a signal line. The isolation distance F of photoelectric sensor QPD8 is set in the path of laser beam IV of planar beam splitter II 4 and its photosensitive surface is perpendicular to laser beam IV. Its output is connected to the microcontroller 11 through a signal line. The image acquisition and processing system 12 is connected to the trajectory synthesis computer 13 through a signal line. CCD sensor I 9 and CCD sensor II 10 are respectively connected to the microcontroller 11 through signal lines. Laser 1 and microcontroller 11 are connected to power supply 2 through signal lines.

[0008] More preferably, the laser 1 is a semiconductor laser whose beam is expanded and collimated, or a helium-neon laser, or a solid-state laser.

[0009] Further preferably, the power supply 2 is a linear constant current drive power supply, or a modulation power supply containing a signal generator.

[0010] Further preferably, the photoelectric sensor QPD8 is a four-quadrant photoelectric sensor QPD.

[0011] Further preferably, the CCD sensor 9 and the CCD sensor 10 are CCD image sensors.

[0012] Further preferably, the image acquisition and processing system 12 is a dual-channel image acquisition and processing system.

[0013] Further preferably, distance A is 1-2 cm, which is the closest distance from the edge of the planar beam splitter to the light exit port; distance B is the radius of the light passage of the planar beam splitter plus the maximum amplitude. The distance D is limited to being greater than the maximum amplitude of the pinhole plate in the direction of the laser beam II; distances C and E are the imaging distances of the CCD sensor, and distance F is the imaging distance of the QPD photoelectric sensor.

[0014] To achieve the above objectives, the present invention employs the following other technical solution.

[0015] A measurement method for a device for measuring minute vibration trajectories includes the following steps:

[0016] S1. Under static conditions, change the position of the small aperture plate 5 multiple times, and record the position of the light spot on the image plane of CCD sensor 9 and CCD sensor 10 and the corresponding quadrant information of photoelectric sensor QPD8 each time, thereby finding the position of each quadrant on the image plane of CCD sensor 9 and CCD sensor 10 and its boundary line.

[0017] S2. Select the measurement orientation, correct the images P1 and P2 obtained under dynamic conditions, then perform ROI extraction, segmentation, and boundary smoothing, and calculate the center coordinates of the sequence of light spots on the image;

[0018] S3. According to the quadrant change order of the photoelectric sensor QPD8, find the order of each point on images P1 and P2 and number them respectively. Based on the spatial perpendicular relationship between the image P1 plane and the image P2 plane, use the image coordinates of points with the same number to determine the three-dimensional coordinates of the spatial points.

[0019] S4. Fit the spatial curves according to the order of each spatial point and calculate the vibration parameters.

[0020] The specific content and method of step S1 described above are as follows:

[0021] S11. Under static conditions, the position of the small aperture plate is changed multiple times, and the position of the light spot on the image plane of CCD sensor 19 and CCD sensor 20 and the corresponding quadrant information of photoelectric sensor QPD8 are recorded each time.

[0022] S12. Based on the position of the light spot on the image plane of CCD sensor 19 and CCD sensor 20 and the corresponding quadrant information of photoelectric sensor QPD8, find the position of each quadrant on the image plane of CCD sensor 19 and CCD sensor 20 and its boundary line.

[0023] The specific content and method of step S2 described above include the following sub-steps:

[0024] S21. Select a suitable measurement direction to ensure that the light spots do not appear in a straight line or overlap on the imaging plane of CCD sensor 9 and CCD sensor 10, so as to determine the order of the light spots;

[0025] S22. Set the trigger signal trigger edge generated by the microcontroller 11 and the first pulse in the pulse sequence to be aligned with a certain change edge of the quadrant signal of the photoelectric sensor QPD8. Set the length of the pulse sequence to the quadrant change period of the photoelectric sensor QPD8. Set the exposure time of CCD sensor 19 and CCD sensor 20 to be greater than the quadrant period of the photoelectric sensor QPD8, so that the CCD sensor can record the light spot sequence of one vibration cycle completely.

[0026] S23. At the start of a vibration cycle, after CCD sensor 19 and CCD sensor 20 receive the trigger signal, they respectively acquire a digital image P1 and P2 of a sequence of light spots. First, the images are processed to remove distortion and noise, and the coordinates of each pixel in the image are corrected to obtain the corrected image.

[0027] S24. Perform adaptive ROI extraction on the denoised image;

[0028] S25. Use the improved minimum error method to segment the laser spot image;

[0029] S26. Use the opening operation in morphological processing to process the light spot image after threshold segmentation, and smooth its boundary without significantly changing the light spot area.

[0030] S27. The geometric center coordinates (a, b) of the light spot can be calculated by traversing the pixels of the light spot outline using a circle fitting algorithm. The sum of squares function of the residuals:

[0031] Q = ∑ i∈E ε i 2 =∑ i∈E ε i 2 [(x i -a) 2 +(y i -b) 2 -r 2 ] 2 (1)

[0032] In the formula, (x i y i) represents the pixel coordinates of the image boundary, and r is the radius. Assuming the center coordinates are (a, b), we can apply the least squares principle to obtain equation (2), and approximate the circle using least squares.

[0033]

[0034] Substituting and simplifying the above equations yields the formula for calculating circle fitting:

[0035]

[0036] The specific content and method of step S3 described above include the following sub-steps:

[0037] S31. Computer 13 receives the quadrant change sequence determined by QPD photoelectric sensor 8, thereby determining whether the light spots on images P1 and P2 move clockwise or counterclockwise, and judging the position sequence of the light spots on the two images.

[0038] S32. Based on the quadrant positions on the image determined by S12, number the center coordinates of the light spots on images P1 and P2 in sequence, thereby achieving a one-to-one correspondence between the positions of the light spots on images P1 and P2.

[0039] S33. Using the perpendicular relationship between the planes where images P1 and P2 are located, determine the three-dimensional coordinates of the spatial points based on the coordinates of the two sets of images with the same center point number.

[0040] The specific content and method of step S4 described above include the following sub-steps:

[0041] S41. The image is transmitted to computer 13. First, the program is initialized and the thread loop is opened. When a cycle measurement begins, the image is acquired and the OpenCV library function is used to process the image. After performing distortion correction, noise reduction, adaptive ROI extraction, segmentation, boundary smoothing and center detection, the geometric center coordinates of the light spot are obtained.

[0042] S42. Fit a spatial curve according to the order of each spatial point and analyze the vibration parameters;

[0043] S43. Determine if the thread has ended. If it has not ended, return to the thread to perform the next cycle measurement. If it has ended, save the vibration parameter data, reclaim the thread resources, and terminate the program.

[0044] The beneficial effects of this invention are as follows: It provides a device and method for real-time measurement of minute vibration trajectories. Using the QPD signal from a photoelectric sensor as the trigger signal for a CCD sensor and the signal for determining the direction of light spot movement in the image, two CCD sensors record the vibration trajectories of light spots on two orthogonal planes in real time, determine the direction of light spot movement in the two images, establish a one-to-one correspondence between the light spots in the two images, and thus determine the coordinates and trajectory of the spatial vibration point. This invention can control the period of the measurement pulse sequence according to the vibration period and measurement needs. A single image pair formed by two synchronous CCD sensors can complete the synthesis of a vibration trajectory for one cycle, enabling real-time recording of mechanical vibration trajectories and modes, thus improving the speed and accuracy of measurement. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of the device for measuring minute vibration trajectories according to the present invention.

[0046] In the diagram: 1 is the laser, 2 is the power supply, 3 is the first plane beam splitter, 4 is the second plane beam splitter, 5 is the first pinhole plate, 6 is the second pinhole plate, 7 is the L-shaped vibration transmission bracket, 8 is the QPD photoelectric sensor, 9 is the first CCD sensor, 10 is the second CCD sensor, 11 is the microcontroller, 12 is the image acquisition and processing system, and 13 is the computer.

[0047] Figure 2 This is a flowchart of the measurement method for the device for measuring minute vibration trajectories of the present invention. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0049] The following will combine Figure 1 , Figure 2 This invention provides a detailed description of a device and method for measuring the trajectory of minute vibrations.

[0050] The present invention provides a device for measuring the trajectory of minute vibrations, comprising a laser 1 and a power supply 2, a first planar beam splitter 3 and a second planar beam splitter 4, a first pinhole plate 5 and a second pinhole plate 6, an L-shaped vibration transmission bracket 7, a photoelectric sensor QPD 8, a first CCD sensor 9 and a second CCD sensor 10, a microcontroller 11, an image acquisition and processing system 12, and a computer 13.

[0051] The laser 1, power supply 2, planar beam splitter 3, planar beam splitter 4, photoelectric sensor QPD8, CCD sensor 9, and CCD sensor 10 are all mounted on the same working plane. Planar beam splitter 3, with an isolation distance A, is positioned behind the output port of laser 1 and forms a 45° angle with the laser beam. The emitted beam from laser 1 is split into two mutually perpendicular laser beams, I and II, by planar beam splitter 3. Pinhole plates 5 and 6 are perpendicular and located in the paths of laser beams I and II, respectively. The pinhole of pinhole plate 5 faces laser beam I, and the pinhole of pinhole plate 6 faces laser beam II. The isolation distance B between pinhole plates 5 and 6 is fixed. The L-shaped vibration transmission support 7 is symmetrically distributed on both sides of the planar beam splitter 3 on its two mutually perpendicular arms, and is placed on the vibrating body to be tested. The CCD sensor 9 is positioned at an isolation distance C in the path of the pinhole plate 5. The target surface of the CCD sensor 9 is perpendicular to the laser beam I, and it images the pinhole plate 5 within the imaging range of the CCD. Its output is connected to the image acquisition system 12 via a signal line. The planar beam splitter 4 is positioned at an isolation distance D behind the pinhole plate 6 and is at a 45° angle to the laser beam. In the path of the angled laser beam II, after passing through the small hole of the small aperture plate II 6, the laser beam II is split into laser beam III and laser beam IV by the planar beam splitter II 4. Laser beam III is in the same direction as laser beam II, and laser beam IV is perpendicular to laser beam II. The isolation distance E of the CCD sensor II 10 is located behind the planar beam splitter II 4 in the path of laser beam III. Its target surface is perpendicular to laser beam III. It images the small aperture plate II 6 within the imaging range of the CCD sensor. The CCD sensor II 10 is connected to the image acquisition and processing system 12 through a signal line. The isolation distance F of the photoelectric sensor QPD8 is set in the path of laser beam IV of the planar beam splitter II 4, and its photosensitive surface is perpendicular to laser beam IV. Its output is connected to the microcontroller 11 through a signal line. The image acquisition and processing system 12 is connected to the trajectory synthesis computer 13 through a signal line. The CCD sensor I 9 and CCD sensor II 10 are respectively connected to the microcontroller 11 through signal lines. The laser 1 and the microcontroller 11 are connected to the power supply 2 through a signal line.

[0052] The laser 1 mentioned above is a semiconductor laser, a helium-neon laser, or a solid-state laser whose beam has been expanded and collimated.

[0053] The power supply 2 mentioned above is a linear constant current drive power supply, or a high voltage power supply, or a modulation power supply containing a signal generator.

[0054] The aforementioned photoelectric sensor QPD8 is a four-quadrant photoelectric sensor QPD.

[0055] The aforementioned CCD sensor 9 and CCD sensor 10 are CCD image sensors.

[0056] The image acquisition and processing system 12 described above is a dual-channel image acquisition and processing system.

[0057] The distance A mentioned above is 1-2 cm, which is the closest distance from the edge of the planar beam splitter to the light exit port; the distance B is the radius of the light aperture of the planar beam splitter plus the maximum amplitude. The distance D is limited to being greater than the maximum amplitude of the pinhole plate in the direction of the laser beam II; distances C and E are the imaging distances of the CCD sensor, and distance F is the imaging distance of the QPD photoelectric sensor.

[0058] A measurement method for a micro-vibration trajectory measuring device according to the present invention includes the following steps:

[0059] S1. Under static conditions, the position of the aperture plate 5 is changed multiple times. Each time, the position of the light spot on the image plane of CCD sensor 9 and CCD sensor 10, as well as the corresponding quadrant information of the photoelectric sensor QPD8, are recorded. In this way, the positions of each quadrant on the image plane of CCD sensor 9 and CCD sensor 10 and their boundaries are found. The specific content and steps are as follows:

[0060] S11. Under static conditions, change the position of the small aperture plate 5 multiple times, and record the position of the light spot on the image plane of CCD sensor 9 and CCD sensor 10 and the corresponding quadrant information of photoelectric sensor QPD8 each time.

[0061] S12. Based on the position of the light spot on the image plane of CCD sensor 19 and CCD sensor 20 and the corresponding quadrant information of photoelectric sensor QPD8, find the position of each quadrant on the image plane of CCD sensor 19 and CCD sensor 20 and its boundary line.

[0062] S2. Select the measurement orientation, correct the images P1 and P2 obtained under dynamic conditions, then perform ROI extraction, segmentation, and boundary smoothing, and calculate the center coordinates of the sequence of light spots on the image. The specific content and steps are as follows:

[0063] S21. Select a suitable measurement direction to ensure that the light spots do not appear in a straight line or overlap on the imaging plane of CCD sensor 9 and CCD sensor 10, so as to determine the order of the light spots;

[0064] S22. Set the trigger signal trigger edge generated by the microcontroller 11 and the first pulse in the pulse sequence to be aligned with a certain change edge of the quadrant signal of the photoelectric sensor QPD8. Set the length of the pulse sequence to the quadrant change period of the photoelectric sensor QPD8. Set the exposure time of CCD sensor 19 and CCD sensor 20 to be greater than the quadrant period of the photoelectric sensor QPD8, so that the CCD sensor can record the light spot sequence of one vibration cycle completely.

[0065] S23. At the start of a vibration cycle, after CCD sensor 19 and CCD sensor 20 receive the trigger signal, they respectively acquire a digital image P1 and P2 of a sequence of light spots. First, the images are processed to remove distortion and noise, and the coordinates of each pixel in the image are corrected to obtain the corrected image.

[0066] S24. Perform adaptive ROI extraction on the denoised image;

[0067] S25. Use the improved minimum error method to segment the laser spot image;

[0068] S26. Use the opening operation in morphological processing to process the light spot image after threshold segmentation, and smooth its boundary without significantly changing the light spot area.

[0069] S27. The geometric center coordinates (α, b) of the light spot can be calculated by traversing the pixels of the light spot outline using a circle fitting algorithm. The sum of squares function of the residuals:

[0070] Q = ∑ I∈E ε i 2 =∑ i∈E ε i 2 [(x i -a) 2 +(y i -b) 2 -r 2 ] 2 (1)

[0071] In the formula, (x i y i ) represents the pixel coordinates of the image boundary, and r is the radius. Assuming the center coordinates are (a, b), we can apply the least squares principle to obtain equation (2), and approximate the circle using least squares.

[0072]

[0073] Substituting and simplifying the above equations yields the formula for calculating circle fitting:

[0074]

[0075] S3. According to the quadrant change sequence of the photoelectric sensor QPD8, find the order of points on images P1 and P2 and number them respectively. Based on the spatial perpendicular relationship between the plane of image P1 and the plane of image P2, use the image coordinates of points with the same number to determine the three-dimensional coordinates of the spatial points. The specific content and steps are as follows:

[0076] S31. Computer 13 receives the quadrant change sequence determined by photoelectric sensor QPD8, thereby determining whether the light spots on images P1 and P2 move clockwise or counterclockwise, and judging the position sequence of the light spots on the two images.

[0077] S32. Based on the quadrant positions on the image determined by S12, number the center coordinates of the light spots on images P1 and P2 in sequence, thereby achieving a one-to-one correspondence between the positions of the light spots on images P1 and P2.

[0078] S33. Using the perpendicular relationship between the planes where images P1 and P2 are located, determine the three-dimensional coordinates of the spatial points based on the coordinates of the two sets of images with the same center point number.

[0079] S4. Fit the spatial curves according to the order of each spatial point, and calculate the vibration parameters. The specific content and steps are as follows:

[0080] S41. The image is transmitted to computer 13. First, the program is initialized and the thread loop is opened. When a cycle measurement begins, the image is acquired and the OpenCV library function is used to process the image. After performing distortion correction, noise reduction, adaptive ROI extraction, segmentation, boundary smoothing and center detection, the geometric center coordinates of the light spot are obtained.

[0081] S42. Fit a spatial curve according to the order of each spatial point and analyze the vibration parameters;

[0082] S43. Determine if the thread has ended. If not, return to the thread to perform the next cycle measurement; if it has ended, save the vibration parameter data, reclaim thread resources, and terminate the program. Vibration curves can also be plotted using MATLAB software.

[0083] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A device for measuring the trajectory of minute vibrations, characterized in that: It includes a laser (1) and power supply (2), a first planar beam splitter (3) and a second planar beam splitter (4), a first small hole plate (5) and a second small hole plate (6), an L-shaped vibration transmission bracket (7), a photoelectric sensor QPD (8), a first CCD sensor (9) and a second CCD sensor (10), a microcontroller (11), an image acquisition and processing system (12) and a computer (13); The laser (1), power supply (2), planar beam splitter one (3), planar beam splitter two (4), photoelectric sensor QPD (8), CCD sensor one (9) and CCD sensor two (10) are arranged on the same working plane; the isolation distance A of the planar beam splitter one (3) is set behind the light outlet of the laser (1) and forms a 45° angle with the laser beam of the laser (1); the emitted beam of the laser (1) is split into two mutually perpendicular laser beams I and II by the planar beam splitter one (3); the pinhole plate one (5) and pinhole plate two (6) are perpendicular to each other and are located in the paths of laser beam I and laser beam II, respectively. Above, the small hole of the first small hole plate (5) faces the laser beam I, and the small hole of the second small hole plate (6) faces the laser beam II. The isolation distance B between the first small hole plate (5) and the second small hole plate (6) is fixed on the two mutually perpendicular arms of the L-shaped vibration transmission bracket (7), symmetrically distributed on both sides of the planar beam splitter (3). The L-shaped vibration transmission bracket (7) is placed on the vibrating body to be tested. The isolation distance C of the first CCD sensor (9) is set in the path of the first small hole plate (5). The target surface of the first CCD sensor (9) is perpendicular to the laser beam I. The first small hole plate (5) is imaged within the imaging range of the CCD sensor. Its output is connected to the image acquisition and processing system (1). 2) Connected by signal lines; the isolation distance D of the planar beam splitter two (4) is located on the laser beam II path behind the aperture plate two (6), and forms a 45° angle with the laser beam II. After passing through the aperture of the aperture plate two (6), the laser beam II is split into laser beam III and laser beam IV by the planar beam splitter two (4). Among them, the laser beam III is in the same direction as the laser beam II, and the laser beam IV is perpendicular to the laser beam II; the isolation distance E of the CCD sensor two (10) is located on the laser beam III path behind the planar beam splitter two (4), and its target surface is perpendicular to the laser beam III. Within the shooting range of the CCD, it forms an image of the aperture plate two (6). For example, CCD sensor 2 (10) is connected to image acquisition and processing system (12) via signal lines; photoelectric sensor QPD (8) is isolated at a distance F on the path of laser beam IV of planar beam splitter 2 (4) and its photosensitive surface is perpendicular to laser beam IV, and its output is connected to microcontroller (11) via signal lines; the image acquisition and processing system (12) is connected to trajectory synthesis computer (13) via signal lines; CCD sensor 1 (9) and CCD sensor 2 (10) are respectively connected to microcontroller (11) via signal lines; laser (1) and microcontroller (11) are connected to power supply (2) via signal lines.

2. The device for measuring minute vibration trajectories according to claim 1, characterized in that: The laser (1) is a semiconductor laser whose beam is expanded and collimated, or a helium-neon laser, or a solid-state laser.

3. The device for measuring minute vibration trajectories according to claim 1, characterized in that: The power supply (2) is a linear constant current drive power supply or a modulation power supply containing a signal generator.

4. The device for measuring minute vibration trajectories according to claim 1, characterized in that: The aforementioned photoelectric sensor QPD(8) is a four-quadrant photoelectric sensor QPD.

5. The device for measuring minute vibration trajectories according to claim 1, characterized in that: Both CCD sensor one (9) and CCD sensor two (10) are CCD image sensors.

6. The device for measuring minute vibration trajectories according to claim 1, characterized in that: The image acquisition and processing system (12) is a dual-channel image acquisition and processing system.

7. The device for measuring minute vibration trajectories according to claim 1, characterized in that: The distance A is 1cm-2cm from the edge of the planar beam splitter to the nearest light outlet; the distance B is the radius of the light-transmitting aperture of the planar beam splitter plus a multiple of the maximum amplitude; the distance D is limited to being greater than the maximum amplitude of the small aperture plate in the direction of laser beam II; the distances C and E are the imaging distances of the CCD sensor, and the distance F is the imaging distance of the photoelectric sensor QPD.

8. A measurement method for a micro-vibration trajectory measuring device according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Under static conditions, change the position of the small hole plate (5) multiple times, and record the position of the light spot on the image plane of CCD sensor (9) and CCD sensor (10) and the corresponding quadrant information of photoelectric sensor QPD (8) each time, so as to find the position of each quadrant on the image plane of CCD sensor (9) and CCD sensor (10) and its boundary line. S2. Select the measurement orientation, correct the images P1 and P2 obtained under dynamic conditions, then perform ROI extraction, segmentation, and boundary smoothing, and calculate the center coordinates of the sequence of light spots on the image; S3. According to the quadrant change order of the photoelectric sensor QPD(8), find the order of each point on image P1 and P2 and number them respectively. Based on the spatial perpendicular relationship between the image P1 plane and the image P2 plane, use the image coordinates of the points with the same number to determine the three-dimensional coordinates of the spatial points. S4. Fit the spatial curves according to the order of each spatial point and calculate the vibration parameters.

9. The measurement method for a micro-vibration trajectory measuring device according to claim 8, characterized in that: The specific content and method of step S4 include the following steps: S41. The image is transmitted to the computer (13). First, the program is initialized and the thread loop is opened. When a cycle measurement begins, the image is acquired and the OpenCV library function is used to process the image. After performing distortion correction, noise reduction, adaptive ROI extraction, segmentation, smoothing of boundaries and center detection, the geometric center coordinates of the light spot are obtained. S42. Fit a spatial curve according to the order of each spatial point and analyze the vibration parameters; S43. Determine if the thread has ended. If it has not ended, return to the thread to perform the next cycle measurement. If it has ended, save the vibration parameter data, reclaim the thread resources, and terminate the program.

Images