Non-contact three-dimensional displacement measurement method and system based on thunder-vision fusion

Abstract

The invention discloses a non-contact three-dimensional displacement measurement method and system based on Leiyu fusion, and relates to the technical field of structural displacement measurement. Based on structure three-dimensional displacement measurement fusing an LFMCW millimeter wave radar technology and a computer vision technology, a radar and a camera are adopted to carry out data acquisition on structure measuring points, and radar DAC original data of out-plane movement of a structure and image data of in-plane movement of the structure are obtained; radar original data are analyzed through a frequency modulation ranging method and a phase method to obtain the radial distance and radial displacement of a measuring point, and meanwhile, camera image data are analyzed through a DIC sub-pixel matching technology to obtain the in-plane position and displacement of the measuring point. And based on the spatial relationship of the data acquisition results of the two devices and the influence relationship between the data of each dimension of the target point, the rapid acquisition of the three-dimensional displacement at the structural target point is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of structural displacement measurement, and in particular to a non-contact three-dimensional displacement measurement method and system based on radar-vision fusion. Background Art

[0002] As the most intuitive physical quantity to characterize the state of a structure, displacement response is the basis for structural health monitoring and subsequent damage identification, safety warning and other work. In the three-dimensional world, the movement of objects belongs to three-dimensional space movement. Therefore, in order to ensure the safety of the structure, it is very necessary to realize non-contact three-dimensional displacement vibration monitoring and early warning of engineering structures. However, during the operation of bridges, buildings, transmission towers, wind turbine towers and other structural facilities, they will be affected by various external loads (wind, seismic loads, etc.) and the aging of their own materials. They will be gradually damaged during the service period and will swing to a certain extent, affecting the comfort and safety of the structure. At present, non-contact displacement measurement of engineering structures can be achieved through technologies such as total stations, laser vibrometers, GNSS, visual measurement and microwave radar. Total stations and GNSS can realize three-dimensional displacement measurement of structures, but their measurement acquisition frequency is low. Laser vibrometers have extremely high measurement accuracy, but are easily affected by the surface properties of the measured structure (damage, contamination, roughness). Total stations and laser vibrometers face challenges in achieving long-term and real-time multi-point synchronous acquisition, while GNSS measurement point layout is cumbersome and requires attachment to the structure being measured and independent power supply, making it difficult to use in a lightweight manner.

[0003] Both monocular and binocular vision technologies can achieve 3D displacement measurement of target points, but each has its limitations. Monocular vision has low out-of-plane measurement accuracy. Although binocular vision technology can estimate depth through parallax information obtained by two cameras and obtain higher displacement measurement accuracy, the stereo correlation between the left and right camera images is sometimes difficult to guarantee (the optimal angle of the stereo optical system is about 30°). In addition, when measuring 3D vibration at long distances, for large outdoor settings, it may be necessary to compromise between the stereo angle and the baseline (the distance between cameras), which is not conducive to the layout of the equipment. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of monocular camera measurement accuracy, stereo matching and baseline distance of binocular cameras, mutual interference between multiple radars and spatial layout during long-distance measurement, and to provide a non-contact three-dimensional displacement measurement method and system based on radar-vision fusion.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A non-contact three-dimensional displacement measurement method based on radar and vision fusion, the method steps comprising:

[0007] S1. Data acquisition: synchronously obtain the first frame of radar DAC raw data and the first frame of camera image data;

[0008] S2. Establish a coordinate system: Take the center of the camera imaging surface as the origin, the two axes of the imaging surface as the X and Y directions, and the optical axis as the Z axis to establish a three-dimensional coordinate system for radar-visual fusion measurement, and obtain the radar position and the deviation from the camera's spatial position;

[0009] The radar-visual fusion is based on radar and computer vision processing;

[0010] S3. Preliminary data processing: The first frame of raw data collected by the millimeter wave radar is analyzed using the frequency modulation ranging method and the phase method to obtain the straight-line distance and micro-vibration between the measuring point and the target point;

[0011] For the image data collected by the camera, DIC sub-pixel matching is used to realize the recognition of the pixel position and displacement in the X and Y directions at the sub-pixel level within the target point plane, and the corresponding pixel scale is identified according to the physical size of the marker at the target point in the image data;

[0012] S4. Scale factor calculation: Calculate the scale factor of the first frame of image data according to the physical length and pixel scale of the reference object;

[0013] S5. Z-direction displacement verification: Based on the principle of radar vibration measurement, the Z-direction displacement verification is realized according to the influence of the inward and outward movement of the target point on the radar radial displacement;

[0014] Convert the pixel position of the target point to the real physical position, obtain the spatial position angle of the target point, calculate the impact of the in-plane movement on the radar radial displacement, and the change in the radar radial displacement and the Z-direction displacement value caused by the in-plane movement;

[0015] S6. X and Y displacement verification: Use the verified Z displacement value to verify the in-plane X and Y position and displacement obtained by DIC, and calculate the verified in-plane position and displacement value;

[0016] Use the verified Z-direction displacement value to verify the X and Y-direction position and displacement, and calculate the verified in-plane position and displacement value

[0017] S7. Real-time calibration of scale factor: Calculate the projection of the marker on the XZ plane, the angle between the imaging optical path and the Z direction, and the compensation length, and calculate the new scale factor value after real-time calibration under specific conditions;

[0018] S8. Data calculation and update: Bring the verified parameters into the next frame of data, repeat steps S5 to S7, complete the displacement verification and scale factor verification, complete the calculation of all acquisition frames, and obtain the real-time three-dimensional displacement value of the target point.

[0019] Further, in step S2, a three-dimensional coordinate system of the radar-visual fusion measurement system is established with the center of the imaging surface where the camera is located as the origin, the two axes of the camera imaging surface as the X and Y directions, and the camera optical axis as the Z axis. The origin of the coordinate system is , the radar position is set to point, Point and Camera The spatial position deviation between .

[0020] Further, in step S3, the first frame of raw data collected by the radar is analyzed to obtain the straight-line distance between the measuring point and the target point. And the micro-vibration of the target point is obtained based on the phase method ; At the same time, DIC sub-pixel matching is used to achieve the pixel position in the X and Y directions of the target point surface at the sub-pixel level for the image data collected by the camera , and displacement , The corresponding pixel scale is identified based on the actual physical size of the marker at the target point in the image data.

[0021] Furthermore, in step S4, the scale factor calculation is expressed as:

[0022] ;

[0023] in, is the physical length of the reference object, is the pixel scale, is the scale factor.

[0024] Furthermore, in step S5, the displacement of the radar It can be composed of two parts. One part is the change in the radial displacement of the radar caused by the movement of the target point in the plane. The other part is the change in the radial displacement of the radar caused by the out-of-plane movement, which is recorded as , the displacement of the target point measured by the radar in the direction of the line connecting the target point and the measuring point , the calculation formula is ; According to the position data in step S3 and the influence of the in-plane and out-of-plane movement of the target point on the radial displacement of the radar, the displacement verification in the Z direction is realized;

[0025] Convert the pixel position of the target point in the X and Y directions to the actual physical position and , expressed as:

[0026] ;

[0027] ;

[0028] in, and is the actual physical position coordinate value, and are the pixel position coordinate values ​​in the X and Y directions, and is the pixel displacement value in the X and Y directions;

[0029] Among them, the spatial position angles of the target points that need to be obtained include: origin Its perpendicular projection point on the target point plane The distance between , the horizontal angle between the radar and the target point is , the vertical angle between the radar and the target point is , the horizontal angle between the camera and the target point is , the vertical angle between the camera and the target point is , expressed as:

[0030] ;

[0031] ;

[0032] ;

[0033] ;

[0034] ;

[0035] in, is the radial distance, is the displacement in the direction of the line connecting the target point and the measuring point measured by the radar, , is the spatial position deviation coordinate value in X and Y directions;

[0036] The influence of the target point moving in the X and Y directions on the radar radial displacement can be expressed as , , expressed as:

[0037] ;

[0038] ;

[0039] in, , is the impact of the target point moving in the X and Y directions on the radar radial displacement, and is the pixel displacement value in the X and Y directions;

[0040] The superposition component obtains the radial displacement measured by the radar caused by the movement of the target surface for:

[0041] ;

[0042] Radar radial displacement change caused by target point movement and Z displacement , expressed as:

[0043] ;

[0044] ;

[0045] in, The change in radar radial displacement caused by in-plane movement, is the Z-direction displacement value.

[0046] Further, in step S6, by The in-plane X and Y positions obtained by DIC sub-pixel matching and displacement , Check the influence of the target point Z-direction movement on the displacement within the plane. and , expressed as:

[0047] ;

[0048] ;

[0049] The in-plane position of the target point after verification , expressed as:

[0050] ;

[0051] ;

[0052] in, and for and The coordinate value of the target point’s in-plane position after verification;

[0053] Calculate the displacement values ​​after calibration in X and Y directions and , expressed as:

[0054] ;

[0055] .

[0056] Furthermore, in step S7, a new scale factor value after real-time verification is calculated, specifically:

[0057] calculate Projection on the XZ plane :

[0058] ;

[0059] Calculate the angle between the optical path and the Z direction during the imaging of the marker and :

[0060] ;

[0061] ;

[0062] Calculate the offset length of the marker and :

[0063] ;

[0064] ;

[0065] The new scale factor after real-time verification is calculated based on the condition that the physical length after Z-direction movement is converted to the same pixel length before movement. The value is calculated as:

[0066] .

[0067] Further, after completing steps S1 to S7, the three-dimensional displacement value of the first frame data is obtained, and the three-dimensional displacement value of the first frame data is updated according to the calculation result of the first frame. , , Parameters, repeat steps S5 to S7, complete the verification of the second frame data, and so on to complete the data calculation of all acquisition frames, and finally obtain the real-time three-dimensional displacement of the target point.

[0068] A non-contact three-dimensional displacement measurement system based on radar and vision fusion is provided for rapid acquisition of three-dimensional displacement at a structural target point.

[0069] The beneficial effects of the present invention are:

[0070] (1) The data obtained by radar and vision are fused and processed, making full use of the complementary advantages of the two displacement measurement technologies to realize the recognition of three-dimensional displacement information of structural vibration; the displacement data of the structure can be obtained globally from multiple directions, so as to fully understand the operating status of the structure;

[0071] (2) Solve the problems of target point spatial positioning, radar Z-direction displacement measurement deviation, DIC two-dimensional displacement measurement error and scale factor uncertainty that are difficult to achieve with a single technology;

[0072] (3) The data information obtained by radar and camera can be fully utilized. Through the spatial relationship between data and the influence relationship between data of each dimension, the three-dimensional data of the target point can be quickly acquired based on the existing data. It has the characteristics of fast calculation speed, no need for additional data storage, and easy computer programming implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 This is a flow chart of a non-contact three-dimensional displacement measurement method based on radar-visual fusion in an embodiment of the present invention;

[0074] Figure 2 It is a schematic diagram of the measurement and use of the non-contact three-dimensional displacement measurement method based on radar and vision fusion in an embodiment of the present invention;

[0075] Figure 3 Schematic diagram of the target point spatial position calculation principle in an embodiment of the present invention;

[0076] Figure 4 Schematic diagram of the Z-direction displacement verification principle in an embodiment of the present invention;

[0077] Figure 5 Schematic diagram of the X and Y direction displacement verification principle in an embodiment of the present invention;

[0078] Figure 6 Schematic diagram of the scale factor verification principle in an embodiment of the present invention;

[0079] Figure 7 It is an algorithm flow chart of the non-contact three-dimensional displacement measurement method based on radar and vision fusion in an embodiment of the present invention;

[0080] Figure 8 It is the three-dimensional displacement data measured in the embodiment of the present invention. DETAILED DESCRIPTION

[0081] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0082] like Figure 1As shown, a non-contact three-dimensional displacement measurement method based on radar-vision fusion is provided, which is used to solve the problems of low measurement accuracy of monocular cameras, difficult setting of stereo matching and baseline distance of binocular cameras in existing non-contact three-dimensional displacement measurement, and solve the problems of mutual interference between multiple radars and spatial layout during long-distance measurement, so as to realize a non-contact three-dimensional displacement measurement technology that can be carried out in real time and with high precision. In this embodiment, radar and camera are used to collect data on structural measuring points, and radar DAC raw data of structural out-of-plane movement and image data of in-plane movement are obtained. Radar raw data is analyzed by frequency modulation ranging method and phase method to obtain radial distance and radial displacement of measuring points, and DIC sub-pixel matching technology is used to analyze camera image data to obtain in-plane position and displacement of measuring points, and based on the spatial relationship of the data acquisition results of the above two devices and the influence relationship between each dimensional data of the target point, the three-dimensional displacement at the structural target point is quickly acquired. The method includes the following steps:

[0083] S1. Figure 2 As shown in the figure, the three-dimensional coordinate system of the radar-visual fusion measurement system is established with the center of the imaging surface where the camera is located as the origin, the two axes of the camera imaging surface as the X and Y directions, and the direction of the camera optical axis as the Z axis. The origin of the coordinate system is , the radar position is set to point, Point and Camera The spatial position deviation between .

[0084] After placing the radar and camera in a certain spatial position according to the measurement requirements, use a ruler to roughly measure the offset distance between the radar and camera imaging center points. , and set up special targets for radar and visual fusion at the measuring points of the structure to obtain accurate detection data. Figure 3 It can be seen that the displacement measured by the radar is the radial displacement on the line connecting the target point and the position of the radar. There is a real-time deviation between the directly measured data and the Z direction of the three-dimensional coordinate system of the radar-vision fusion system, and the true Z-direction displacement of the structural vibration cannot be obtained. DIC technology is generally used to measure the two-dimensional displacement of a target point in a plane. When the target point moves out of the plane, the imaging position and scale factor of the target point on the camera will change in real time, resulting in a deviation in the in-plane displacement measurement of the DIC technology, causing distortion of the X and Y displacement measurements in the radar-vision fusion system, and failing to reflect the true displacement of the target point in the X and Y directions. Therefore, this embodiment solves the above-mentioned problems by integrating LFMCW millimeter-wave radar technology with computer vision technology.

[0085] The spatial position and scale factor of the target point are obtained by using the first frame data of the radar and the camera, and the displacement value directly analyzed in the second frame data is mutually verified by the known spatial position to obtain the real spatial displacement in the visual fusion system coordinate system; specifically, the following steps are included:

[0086] S2. Synchronize the acquired first frame of raw data of the millimeter wave radar and the first frame of image data collected by the camera, such as Figure 3 As shown, the original spatial position and scale factor of the target point are calculated;

[0087] S3. The first frame of raw data collected by the LFMCW millimeter wave radar is analyzed using the frequency modulation ranging method and the phase method to obtain the straight-line distance between the measuring point and the target point and micro vibration ; For the image data collected by the camera, DIC technology is used to achieve the pixel position in the X and Y directions of the target point at the sub-pixel level within the surface , and displacement , The corresponding pixel scale is identified based on the actual physical size of the marker at the target point in the image data.

[0088] S4. Based on the physical length of the reference object obtained in step S3 and pixel scale , solve the scale factor in the first frame of image data :

[0089] ;

[0090] S5. According to the LFMCW millimeter wave radar vibration measurement principle, when the target point moves within the surface, it will cause the radar measurement value to change, so the radar displacement It can be composed of two parts. One part is the change in the radial displacement of the radar caused by the movement of the target surface. The other part is the change in the radial displacement of the radar caused by the out-of-plane movement, which is recorded as , the displacement of the target point measured by the radar in the direction of the line connecting the target point and the measuring point , the calculation formula is According to the position data in S3 and the relationship between the in-plane and out-of-plane movement of the target point and the influence on the radial displacement of the radar, the displacement verification in the Z direction can be realized. Step S5 specifically includes the following sub-steps:

[0091] S5.1. Convert the pixel position of the target point in the X and Y directions to the actual physical position and , the calculation formula is:

[0092] ;

[0093] ;

[0094] in, and is the actual physical position coordinate value, and are the pixel position coordinate values ​​in the X and Y directions, and is the pixel displacement value in the X and Y directions;

[0095] S5.2. Figure 4 As shown, solve the spatial position of the target point, the origin Its perpendicular projection point on the target point plane The distance between , the horizontal angle between the radar and the target point , the vertical angle between the radar and the target point , the horizontal angle between the camera and the target point , the vertical angle between the camera and the target point . Use the following formulas to solve , , , , :

[0096] ;

[0097] ;

[0098] ;

[0099] ;

[0100] ;

[0101] in, is the radial distance, is the displacement in the direction of the line connecting the target point and the measuring point measured by the radar, , It is the spatial position deviation coordinate value in X and Y directions.

[0102] S5.3. The effect of the target point moving in the X and Y directions on the radar radial displacement can be expressed as , , can be calculated as follows:

[0103] ;

[0104] ;

[0105] in, , is the impact of the target point moving in the X and Y directions on the radar radial displacement, and is the pixel displacement value in the X and Y directions;

[0106] The superposition component obtains the radial displacement measured by the radar caused by the movement of the target surface for:

[0107] ;

[0108] S5.4. Figure 5 As shown in the figure, the change in the radar radial displacement caused by the movement of the target surface and Z displacement Can be calculated as follows:

[0109] ;

[0110] ;

[0111] in, is the change in radar radial displacement caused by in-plane movement, is the Z-direction displacement value.

[0112] S6, such as Figure 6 As shown in the figure, when the target point moves in the Z direction (out of plane), its position and scale factor on the camera imaging surface will change. The calibrated Z displacement value is used. Check the position and displacement of the target point in X and Y directions;

[0113] S6.1. The X and Y positions in the plane obtained by DIC and displacement , Check the influence of the target point Z-direction movement on the displacement within the plane. and , expressed as:

[0114] ;

[0115] ;

[0116] The in-plane position of the target point after verification , expressed as:

[0117] ;

[0118] ;

[0119] in, and for and The coordinate value of the target point’s in-plane position after verification;

[0120] S6.2. Displacement values ​​after calibration in X and Y directions and It can be calculated as follows:

[0121] ;

[0122] ;

[0123] S7. When the target point moves in the Z direction (out of the plane), a scale factor will be caused. For the calculation of this part of the influence, step S7 specifically includes the following sub-steps:

[0124] S7.1. Calculate Projection on the XZ plane , the calculation formula is:

[0125] ;

[0126] S7.2. Calculate the angle between the upper / lower optical path and the Z direction during the imaging of the marker according to the following formula and ,have:

[0127] ;

[0128] ;

[0129] S7.3. Calculate the compensation length of the marker and ,have:

[0130] ;

[0131] ;

[0132] S7.3. Calculate the new scale factor after real-time verification based on the condition that the physical length after Z-direction movement is converted to the same pixel length before movement. The value is calculated as:

[0133] ;

[0134] S8. After the above steps are completed, , , Bring in the next frame of data, repeat steps S5 to S7, complete the verification of the next frame of data, and so on to complete the data calculation of all the acquired frames, and finally obtain the real-time three-dimensional displacement of the target point. The algorithm calculation process is as follows Figure 7 shown.

[0135] like Figure 8 As shown, the data collected separately using the LFMCW millimeter wave radar technology and the computer vision technology can be fused and processed by the algorithm of this embodiment to accurately measure the three-dimensional displacement information of the target point.

[0136] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A non-contact three-dimensional displacement measurement method based on radar and vision fusion, characterized in that: The method steps include: S1. Data acquisition: synchronously obtain the first frame of radar DAC raw data and the first frame of camera image data; S2. Establish a coordinate system: Take the center of the camera imaging surface as the origin, the two axes of the imaging surface as the X and Y directions, and the optical axis as the Z axis to establish a three-dimensional coordinate system for radar-visual fusion measurement, and obtain the radar position and the deviation from the camera's spatial position; The radar-visual fusion is based on radar and computer vision processing; S3. Preliminary data processing: Analyze the first frame of raw data collected by the millimeter-wave radar to obtain the straight-line distance and micro-vibration between the measuring point and the target point; For the image data collected by the camera, DIC sub-pixel matching is used to realize the recognition of the pixel position and displacement in the X and Y directions at the sub-pixel level within the target point plane, and the corresponding pixel scale is identified according to the physical size of the marker at the target point in the image data; S4. Scale factor calculation: Calculate the scale factor of the first frame of image data according to the physical length and pixel scale of the reference object; S5. Z-direction displacement verification: According to the influence of the target point's in-plane and out-plane movement on the radar's radial displacement, the Z-direction displacement verification is realized; Convert the pixel position of the target point to the real physical position, obtain the spatial position angle of the target point, and calculate the change in the radar radial displacement caused by the in-plane movement to verify the Z-direction displacement value; S6. X and Y displacement verification: Use the verified Z displacement value to verify the in-plane X and Y position and displacement obtained by DIC, and calculate the verified in-plane position and displacement value; Use the verified Z-direction displacement value to verify the X and Y-direction position and displacement, and calculate the verified in-plane position and displacement value S7. Real-time calibration of scale factor: Calculate the projection of the marker on the XZ plane, the angle between the imaging optical path and the Z direction, and the compensation length, and calculate the new scale factor value after real-time calibration under specific conditions; S8. Data calculation and update: Bring the verified parameters into the next frame of data, repeat steps S5 to S7, complete the calculation of all acquisition frames, and obtain the real-time three-dimensional displacement value of the target point.

2. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 1 is characterized in that: In step S2, a three-dimensional coordinate system of the radar-visual fusion measurement system is established with the center of the imaging surface where the camera is located as the origin, the two axes of the camera imaging surface as the X and Y directions, and the camera optical axis as the Z axis. The origin of the coordinate system is , the radar position is set to point, Point and Camera The spatial position deviation between .

3. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 2 is characterized in that: In step S3, the first frame of raw data collected by the radar is analyzed to obtain the straight-line distance between the measuring point and the target point. And the micro-vibration of the target point is obtained based on the phase method ; At the same time, DIC sub-pixel matching is used to achieve the pixel position in the X and Y directions of the target point surface at the sub-pixel level for the image data collected by the camera , and displacement , The corresponding pixel scale is identified based on the actual physical size of the marker at the target point in the image data.

4. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 3 is characterized in that: In step S4, the scale factor calculation is expressed as: ； in, is the physical length of the reference object, is the pixel scale, is the scale factor.

5. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 4 is characterized in that: In step S5, the displacement of the radar It can be composed of two parts. One part is the change in the radial displacement of the radar caused by the movement of the target point in the plane. The other part is the change in the radial displacement of the radar caused by the out-of-plane movement, which is recorded as , the displacement of the target point measured by the radar in the direction of the line connecting the target point and the measuring point , the calculation formula is ; According to the position data in step S3 and the influence of the in-plane and out-of-plane movement of the target point on the radial displacement of the radar, the displacement verification in the Z direction is realized; Convert the pixel position of the target point in the X and Y directions to the actual physical position and , expressed as: ； ； in, and is the actual physical position coordinate value, and are the pixel position coordinate values ​​in the X and Y directions, and is the pixel displacement value in the X and Y directions; Among them, the spatial position angles of the target points that need to be obtained include: origin Its perpendicular projection point on the target point plane The distance between , the horizontal angle between the radar and the target point is , the vertical angle between the radar and the target point is , the horizontal angle between the camera and the target point is , the vertical angle between the camera and the target point is , expressed as: ； ； ； ； ； in, is the radial distance, is the displacement in the direction of the line connecting the target point and the measuring point measured by the radar, , is the spatial position deviation coordinate value in X and Y directions; The influence of the target point moving in the X and Y directions on the radar radial displacement can be expressed as , , expressed as: ； ； in, , The influence of the target point moving in the X and Y directions on the radar radial displacement; The superposition component obtains the radial displacement measured by the radar caused by the movement of the target surface for: ； Radar radial displacement change caused by target point movement and Z displacement , expressed as: ； ； in, is the change in radar radial displacement caused by in-plane movement, is the Z-direction displacement value.

6. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 5 is characterized in that: In step S6, by The in-plane X and Y positions obtained by DIC sub-pixel matching and displacement , Check the influence of the target point Z-direction movement on the displacement within the plane. and , expressed as: ； ； The in-plane position of the target point after verification , expressed as: ； ； in, and for and The coordinate value of the target point’s in-plane position after verification; Calculate the displacement values ​​after calibration in X and Y directions and , expressed as: ； 。 7. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 6 is characterized in that: In step S7, a new scale factor value after real-time verification is calculated, specifically: calculate Projection on the XZ plane : ； Calculate the angle between the optical path and the Z direction during the imaging of the marker and : ； ； Calculate the offset length of the marker and : ； ； The new scale factor after real-time verification is calculated based on the condition that the physical length after Z-direction movement is converted to the same pixel length before movement. The value is calculated as: 。 8. The non-contact three-dimensional displacement measurement method based on radar and visual fusion according to claim 7 is characterized in that: After completing steps S1 to S7, the three-dimensional displacement value of the first frame data is obtained, and the three-dimensional displacement value of the first frame data is updated according to the calculation result of the first frame. , , Parameters, repeat steps S5 to S7, complete the verification of the second frame data, and so on to complete the data calculation of all acquisition frames, and finally obtain the real-time three-dimensional displacement of the target point.

9. A non-contact three-dimensional displacement measurement system based on radar and visual fusion, characterized in that: Used to execute the non-contact three-dimensional displacement measurement method based on radar and vision fusion as described in claims 1 to 8.

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