CN107328502B - Anchor rod tray load visualization digital imaging method - Google Patents
Anchor rod tray load visualization digital imaging method Download PDFInfo
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- CN107328502B CN107328502B CN201710535284.8A CN201710535284A CN107328502B CN 107328502 B CN107328502 B CN 107328502B CN 201710535284 A CN201710535284 A CN 201710535284A CN 107328502 B CN107328502 B CN 107328502B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
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Abstract
The invention relates to a visual digital imaging method for anchor rod tray load, which is suitable for a non-contact measuring method for underground anchor rod stress, and particularly adopts a CCD (charge coupled device) camera to shoot a plurality of images before and after the tray is deformed, adopts a digital speckle correlation technique to carry out space identification on the plurality of images before and after the surface of a measured tray is deformed, calculates to obtain a three-dimensional coordinate, and fits and establishes a three-dimensional model before and after the surface of the tray is deformed to obtain data before and after the surface of the tray is deformed; obtaining a strain field by rapid three-dimensional deformation analysis and comparison of three-dimensional space data before and after deformation of the tray, obtaining a stress field by combining bending rigidity of the tray, and obtaining real-time load of the anchor rod by back-calculating integral of the stress field; compared with the traditional strain gauge, a displacement sensor, an anchor rod puller and a hydraulic pillow, the digital imaging technology for visualizing the tray load is simple and convenient to use, and the three-dimensional deformation and strain measurement can be quickly realized.
Description
Technical Field
The invention relates to a visual digital imaging method for anchor rod tray load, which is suitable for a non-contact measurement method for underground and tunnel anchor rod stress.
Background
The anchor rod is the most widely applied support reinforcement mode in mining engineering, and the purpose of anchor rod load observation is the load change condition of the anchor rod during the service period of the roadway, monitors the working state of the anchor rod and can provide actual measurement basis for adjusting and modifying support parameters. The anchor rod is arranged in the drill hole and is in a closed state, so that the stress strain of the anchor rod cannot be directly observed, and the traditional contact type measuring method, such as a strain gauge, an optical fiber sensor, a displacement sensor and the like, has the defects of single function, few measuring points, limited data and larger theoretical calculation error; the non-contact vision measurement method is rapidly developed due to the rapidness and convenience of the non-contact vision measurement method, and is gradually developed from the traditional marking point coordinate vision measurement to the three-dimensional full-field vision measurement.
The dynamic performance of the anchor rod can be accurately disclosed only by measuring the dynamic deformation and the strain data of the anchor rod in the three-dimensional whole field, so that the deformation of the anchor rod is urgently required to be accurately measured in the three-dimensional whole field under complex working conditions, scientific data is provided for related research of the anchor rod, and the problem cannot be well solved due to the problems of the traditional contact-based detection method.
Disclosure of Invention
The invention provides a visual digital imaging method for anchor rod tray load, which can quickly realize three-dimensional deformation and strain measurement, can obtain full-field displacement, is suitable for wide test object range and has no special requirement on the measurement environment.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a visual digital imaging method for anchor rod tray load comprises the following steps:
the first step is as follows: installing a tray on the wall surface of the roadway, fixing the anchor rod at the central position of the tray, defining the tray before deformation when no pretightening force is applied, and defining the tray after deformation after the pretightening force is applied;
the second step is that: a first camera and a second camera are respectively arranged on two sides of a central shaft of the anchor rod tray, a first light source is arranged between the tray and the first camera, and a second light source is arranged between the tray and the second camera;
the third step: calibrating system coordinates by adopting a binocular stereo vision principle and a Zhang Zhengyou plane calibration method;
the fourth step: the first light source and the second light source are emitted to the tray before deformation, speckle images are formed on the surface of the tray, the tray on which the speckle images are formed is observed by using the first camera and the second camera, and the plane coordinate of the image of a certain light spot in the speckle images is calculated to obtain the three-dimensional coordinate of the light spot before deformation;
the fifth step: applying pretightening force to the tray to deform the tray, irradiating the first light source and the second light source to the deformed anchor rod tray to form speckle images on the surface of the tray, matching the speckle images before deformation with the deformed speckle images, and determining the point-to-point relation of the two speckle images according to the maximum correlation coefficient so as to find out the position of a light spot after the deformation of the tray in the fourth step;
and a sixth step: after matching is finished, calculating the plane coordinates of the image of the light spot in the deformed speckle image to obtain the three-dimensional coordinates of the deformed light spot;
the seventh step: the difference value between the three-dimensional coordinate before deformation and the three-dimensional coordinate after deformation is the full-field three-dimensional displacement of the tray;
eighth step: setting a reference sub-area on a reference image obtained after the tray is deformed by taking a point to be measured as the center, and searching a corresponding target sub-area on the reference image by means of sub-area matching, wherein the center position of the target sub-area is the corresponding position of the point to be measured in the target image; obtaining a displacement function by utilizing least square fitting on the displacement of each point in the target sub-area, taking the function as a function value at the central point of the target sub-area, and obtaining a strain value by derivation of the function;
the ninth step: selecting another target subarea, calculating according to the process to obtain a strain value after the deformation of the tray, and repeating the steps to obtain a full-field strain value of the tray;
the tenth step: obtaining a strain field by rapid three-dimensional deformation analysis and comparison of three-dimensional space data before and after deformation of the tray, obtaining a stress field by combining bending rigidity of the tray, and obtaining real-time load of the anchor rod by back-calculating integral of the stress field; the specific calculation method is as follows:
omega-deflection;
k is the ground coefficient;
d, bending rigidity of the anchor rod tray;
e-modulus of elasticity;
mu-poisson's ratio;
h, the thickness of the anchor rod tray;
r is the distance from the center of the pallet to the point sought;
q is a concentrated load;
a-radius of anchor tray
As a further preferred aspect of the present invention, a first camera and a second camera are respectively arranged on two sides of a central shaft of the tray, wherein the first camera and the second camera are respectively arranged at an angle of 45 degrees with respect to the central shaft;
as a further preferred embodiment of the present invention, a first light source is disposed between the tray and the first camera, and a second light source is disposed between the tray and the second camera, wherein the first light source and the second light source are respectively disposed at an angle of 60 degrees with respect to the central axis, the first light source is disposed approximately 15cm away from the middle position between the tray and the first camera, and the second light source is disposed approximately 15cm away from the middle position between the tray and the second camera;
as a further preferred aspect of the present invention, the first camera and the second camera both employ CCD cameras;
as a further preferred embodiment of the present invention, the reference picture is processed by sub-pixel processing, and the denoising thereof is processed by wavelet transform.
Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:
compared with the traditional strain gauge, a displacement sensor, an anchor rod puller and a hydraulic pillow, the digital imaging technology for visualizing the tray load is simple and convenient to use, and the technology is applied to the anchor rod and the tray for the first time, so that the three-dimensional deformation and strain measurement can be quickly realized; meanwhile, the invention does not need optical interference fringe processing, and has the advantages of relatively simple optical path, non-contact, high precision, capability of obtaining full-field displacement, wide range of applicable test objects, no special requirement on the measurement environment and the like.
Drawings
The invention is further illustrated with reference to the following figures and examples.
FIG. 1 is a schematic overall structure of a preferred embodiment of the present invention;
in the figure: the camera system comprises a first camera 1, a second camera 2, a first light source 3, a second light source 4, an anchor rod 5, a tray 6 and a control computer 7.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.
As shown in fig. 1, the present invention includes the following technical features: a first camera 1, a second camera 2, a first light source 3, a second light source 4, an anchor rod 5, a tray 6 and a control computer 7.
The invention discloses a visual digital imaging method for anchor rod tray load, which comprises the following steps:
the first step is as follows: installing a tray on the wall surface of the roadway, fixing the anchor rod at the central position of the tray, defining the tray before deformation when no pretightening force is applied, and defining the tray after deformation after the pretightening force is applied;
the second step is that: a first camera and a second camera are respectively arranged on two sides of a central shaft of the anchor rod tray, a first light source is arranged between the tray and the first camera, and a second light source is arranged between the tray and the second camera;
the third step: calibrating system coordinates by adopting a binocular stereo vision principle and a Zhang Zhengyou plane calibration method;
the fourth step: the first light source and the second light source are emitted to the tray before deformation, speckle images are formed on the surface of the tray, the tray on which the speckle images are formed is observed by using the first camera and the second camera, and the plane coordinate of the image of a certain light spot in the speckle images is calculated to obtain the three-dimensional coordinate of the light spot before deformation;
the fifth step: applying pretightening force to the tray to deform the tray, irradiating the first light source and the second light source to the deformed anchor rod tray to form speckle images on the surface of the tray, matching the speckle images before deformation with the deformed speckle images, and determining the point-to-point relation of the two speckle images according to the maximum correlation coefficient so as to find out the position of a light spot after the deformation of the tray in the fourth step; wherein, the first camera and the second camera system are used for recording an image I before the deformation of the object1And the deformed image I2By means of a digital image correlation algorithm, measure I1And I2Determining the corresponding geometric points of the object before and after deformation, and comparing, matching and calculating. The correlation coefficient formula is commonly used as:
in the formula: i is1(xi,yj) Representing a point (x) in the subregion A before deformationi,yj) The gray value of (d); i is2(xi *,yj *) Representing a point (x) in the sub-zone B after deformationi *,yj *) The gray value of (a);
and
average gray values of the sub-area A and the sub-area B respectively; x is the number ofi *＝xi+xdef，yj*＝yj+ydefWherein (x)def,+ydef) Is the displacement of point P in the x and y directions; when the correlation coefficient is 1, the two sub-regions are completely correlated; when the correlation coefficient is 0, it means that the two sub-regions are completely uncorrelated. Changing xdefAnd + ydefI.e. moving the sub-region over the deformed image, different values of C can be obtained, so that C takes the maximum values xdef and + ydefI.e. in the sub-regionA displacement component of the heart;
and a sixth step: after matching is finished, calculating the plane coordinates of the image of the light spot in the deformed speckle image to obtain the three-dimensional coordinates of the deformed light spot;
the seventh step: the difference value between the three-dimensional coordinate before deformation and the three-dimensional coordinate after deformation is the full-field three-dimensional displacement of the tray;
eighth step: setting a reference sub-area on a reference image obtained after the tray is deformed by taking a point to be measured as the center, and searching a corresponding target sub-area on the reference image by means of sub-area matching, wherein the center position of the target sub-area is the corresponding position of the point to be measured in the target image; obtaining a displacement function by utilizing least square fitting on the displacement of each point in the target sub-area, taking the function as a function value at the central point of the target sub-area, and obtaining a strain value by derivation of the function; the method of sub-region matching and a correlation coefficient formula is adopted, so that the matching speed and precision are improved;
the ninth step: selecting another target subarea, calculating according to the process to obtain a strain value after the deformation of the tray, and repeating the steps to obtain a full-field strain value of the tray;
the tenth step: obtaining a strain field by rapid three-dimensional deformation analysis and comparison of three-dimensional space data before and after deformation of the tray, obtaining a stress field by combining bending rigidity of the tray, and obtaining real-time load of the anchor rod by back-calculating integral of the stress field;
as a further preferred aspect of the present invention, a first camera and a second camera are respectively arranged on two sides of a central shaft of the tray, wherein the first camera and the second camera are respectively arranged at an angle of 45 degrees with respect to the central shaft;
as a further preferred embodiment of the present invention, a first light source is disposed between the tray and the first camera, and a second light source is disposed between the tray and the second camera, wherein the first light source and the second light source are respectively disposed at an angle of 60 degrees with respect to the central axis, the first light source is disposed approximately 15cm away from the middle position between the tray and the first camera, and the second light source is disposed approximately 15cm away from the middle position between the tray and the second camera;
as a further preferred aspect of the present invention, the first camera and the second camera both employ CCD cameras;
as further optimization of the invention, the reference picture is processed by sub-pixel, and the denoising is processed by a wavelet transform method, so that the precision is improved;
as a further preferred aspect of the present invention, in step three, system coordinate calibration is performed by using a binocular stereo vision principle and a Zhang Zhengyou plane calibration method, and the specific calibration includes the following steps:
the first step is as follows: establishing a planar latticed calibration template, adopting a planar circle center calibration plate or a planar black and white chessboard calibration plate, wherein circle center positions on the calibration template or intersection points of black and white chessboard grids are calibration control points, and defining coordinate values of known calibration control points as coordinate values of a world coordinate system;
the second step is that: after the calibration template is established, shooting the calibration template from different angles to obtain a plurality of calibration template images from different angles;
the third step: carrying out image processing on the calibration template to obtain coordinates of calibration control points on each calibration image;
the fourth step: substituting the coordinates and the image coordinates of the calibration control points on the calibration template into the first camera model and the second camera model to obtain the analytic solutions of the parameters of the first camera and the second camera;
the fifth step: solving the deflection coefficient through the minimum variance;
and a sixth step: and solving a final iteration result according to the nonlinear programming, wherein the final iteration result comprises internal and external parameters of the first camera and the second camera.
The digital speckle correlation method measuring system consists of two parts, namely hardware and software, wherein the hardware part consists of a first camera, a second camera and a control computer and is responsible for the collection, storage and other work of a test piece deformation image; the software part is used for processing the acquired scattered images to obtain required deformation information.
During the image acquisition process, it should be noted that,
regarding the erection of the camera: an image acquisition system of a three-dimensional digital image correlation method focuses and images a measured object from different angles by using two CCD cameras, namely a first camera and a second camera, and obtains digital images of the surface of the measured object before and after deformation; in practical operation, the detected area must be ensured to be always within the visual field and depth of field range of the two cameras during the deformation motion.
Calibration of the camera: the calibration process of the three-dimensional digital image correlation method comprises the following steps of firstly using two CCD cameras to shoot a calibration template at the same time, imaging the calibration template at different postures, then respectively carrying out single-camera calibration on a first camera and a second camera, and finally carrying out double-camera calibration.
In the image processing process, it should be noted that,
firstly, performing sub-pixel processing on a picture, wherein digital images acquired by a first camera and a second camera are discrete pixel points, and each pixel point has a quantization error of as many as +/-1/2 pixels under an image coordinate system, wherein the error is determined by hardware configuration of a CCD camera; in addition, the pixel size and the number of pixels of an image collected by the CCD are limited, and the accuracy of gray information obtained by measurement is greatly limited due to the determination of the corresponding scale of the pixels; second, reconstructing an image using the processed coefficients by processing the coefficients transformed with the wavelet; thirdly, the wavelet coefficients are processed using the correlation between the multi-scale wavelet coefficients before being subjected to reconstruction filtering.
The main idea of denoising based on wavelet transform is to utilize the multi-scale characteristics of wavelet analysis, firstly perform wavelet transform on an image polluted by noise, and then perform unified processing on the obtained wavelet coefficients by thresholding to obtain a new wavelet coefficient; then, carrying out inverse transformation to obtain an image with noise removed; finally, image matching, wherein the task of the image matching is to find corresponding points in the two digital images, and the precision of the image matching is directly related to the shape of the measured object and the precision of deformation measurement; the basic process of matching is as follows: firstly, determining a region to be detected on a reference image in a manually specified mode; then, in the region to be measured, grids are uniformly divided, and grid points are points to be measured; and finally, calculating to obtain the corresponding positions of all points to be measured in the target by using a correlation coefficient image matching method, and completing an image matching task.
In the data processing process, it should be noted that,
carrying out space identification on a plurality of images before and after deformation of the surface of the tested tray by adopting a digital speckle correlation technique, calculating to obtain a three-dimensional coordinate, fitting and establishing a three-dimensional model before and after deformation of the surface of the tray, and obtaining data before and after deformation of the surface of the tray; and (3) obtaining a strain field by rapid three-dimensional deformation analysis and comparison of three-dimensional space data before and after the deformation of the tray, obtaining a stress field by combining the bending rigidity of the tray, and obtaining the real-time load of the anchor rod by performing back-calculation integration on the stress field.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The meaning of "and/or" as used herein is intended to include both the individual components or both.
The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components via other components.
In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.
Claims (5)
1. A visual digital imaging method for anchor rod tray load is characterized in that: the method comprises the following steps:
the first step is as follows: installing a tray on the wall surface of the roadway, fixing the anchor rod at the central position of the tray, defining the tray before deformation when no pretightening force is applied, and defining the tray after deformation after the pretightening force is applied;
the second step is that: a first camera and a second camera are respectively arranged on two sides of a central shaft of the anchor rod tray, a first light source is arranged between the tray and the first camera, and a second light source is arranged between the tray and the second camera;
the third step: calibrating system coordinates by adopting a binocular stereo vision principle and a Zhang Zhengyou plane calibration method;
the fourth step: the first light source and the second light source are emitted to the tray before deformation, speckle images are formed on the surface of the tray, the tray on which the speckle images are formed is observed by using the first camera and the second camera, and the plane coordinate of the image of a certain light spot in the speckle images is calculated to obtain the three-dimensional coordinate of the light spot before deformation;
the fifth step: applying pretightening force to the tray to deform the tray, irradiating the first light source and the second light source to the deformed anchor rod tray to form speckle images on the surface of the tray, matching the speckle images before deformation with the deformed speckle images, and determining the point-to-point relation of the two speckle images according to the maximum correlation coefficient so as to find out the position of a light spot after the deformation of the tray in the fourth step; wherein, the first camera and the second camera system are used for recording an image I1 before the deformation of the object and an image I2 after the deformation, and I is measured by a digital image correlation algorithm1And I2Determining the corresponding geometric points of the object before and after deformation, and comparing, matching and calculating; the correlation coefficient formula is commonly used as:
in the formula: i is1(xi,yj) Representing a point (x) in the subregion A before deformationi,yj) The gray value of (d); i is2(xi *,yj *) Representing a point (x) in the sub-zone B after deformationi *,yj *) The gray value of (a);
and
average gray values of the sub-area A and the sub-area B respectively; x is the number ofi *＝xi+xdef，yj*＝yj+ydefWherein (x)def,+ydef) Is the displacement of point P in the x and y directions; when the correlation coefficient is 1, the two sub-regions are completely correlated; when the correlation coefficient is 0, it means that the two sub-regions are completely uncorrelated; changing xdefAnd + ydefI.e. moving the sub-region over the deformed image, different values of C may be obtained such that C takes the x of the maximum valuedefAnd + ydefI.e. the displacement component of the center of the sub-region;
and a sixth step: after matching is finished, calculating the plane coordinates of the image of the light spot in the deformed speckle image to obtain the three-dimensional coordinates of the deformed light spot;
the seventh step: the difference value between the three-dimensional coordinate before deformation and the three-dimensional coordinate after deformation is the full-field three-dimensional displacement of the tray;
eighth step: setting a reference sub-area on a reference image obtained after the tray is deformed by taking a point to be measured as the center, and searching a corresponding target sub-area on the reference image by means of sub-area matching, wherein the center position of the target sub-area is the corresponding position of the point to be measured in the target image; obtaining a displacement function by utilizing least square fitting on the displacement of each point in the target sub-area, taking the function as a function value at the central point of the target sub-area, and obtaining a strain value by derivation of the function;
the ninth step: selecting another target subarea, calculating according to the process to obtain a strain value after the deformation of the tray, and repeating the steps to obtain a full-field strain value of the tray;
the tenth step: obtaining a strain field by rapid three-dimensional deformation analysis and comparison of three-dimensional space data before and after deformation of the tray, obtaining a stress field by combining bending rigidity of the tray, and obtaining real-time load of the anchor rod by back-calculating integral of the stress field; the specific calculation method is as follows:
k is the ground coefficient;
d, bending rigidity of the anchor rod tray;
e-modulus of elasticity;
mu-poisson's ratio;
h, the thickness of the anchor rod tray;
r is the distance from the center of the pallet to the point sought;
q is a concentrated load;
a-anchor tray radius;
and in the third step, system coordinate calibration is carried out by adopting a binocular stereo vision principle and a Zhang Zhengyou plane calibration method, and the specific calibration comprises the following steps:
the first step is as follows: establishing a planar latticed calibration template, adopting a planar circle center calibration plate or a planar black and white chessboard calibration plate, wherein circle center positions on the calibration template or intersection points of black and white chessboard grids are calibration control points, and defining coordinate values of known calibration control points as coordinate values of a world coordinate system;
the second step is that: after the calibration template is established, shooting the calibration template from different angles to obtain a plurality of calibration template images from different angles;
the third step: carrying out image processing on the calibration template to obtain coordinates of calibration control points on each calibration image;
the fourth step: substituting the coordinates and the image coordinates of the calibration control points on the calibration template into the first camera model and the second camera model to obtain the analytic solutions of the parameters of the first camera and the second camera;
the fifth step: solving the deflection coefficient through the minimum variance;
and a sixth step: solving a final iteration result according to the nonlinear programming, wherein the final iteration result comprises internal and external parameters of the first camera and the second camera;
in the image processing process, firstly, performing sub-pixel processing on an image, improving the measurement precision by adopting a sub-pixel matching algorithm based on space domain iteration, then performing image denoising, wherein the image denoising adopts wavelet transformation, and the main process is firstly, reconstructing the image by detecting the singularity of a wavelet mode maximum point of the image; second, reconstructing an image using the processed coefficients by processing the coefficients transformed with the wavelet; thirdly, the wavelet coefficients are processed using the correlation between the multi-scale wavelet coefficients before being subjected to reconstruction filtering.
2. The anchor rod tray load visualization digital imaging method of claim 1, wherein: and a first camera and a second camera are respectively arranged on two sides of the central shaft of the tray, wherein the first camera and the second camera are respectively arranged at an angle of 45 degrees with the central shaft.
3. The anchor rod tray load visualization digital imaging method of claim 1, wherein: a first light source is arranged between the tray and the first camera, and a second light source is arranged between the tray and the second camera, wherein the first light source and the second light source are respectively arranged at an angle of 60 degrees with the central axis, the first light source is arranged at a position 15cm away from the middle position of the tray and the first camera, and the second light source is arranged at a position 15cm away from the middle position of the tray and the second camera.
4. The anchor rod tray load visualization digital imaging method of claim 1, wherein: the first video camera and the second video camera both adopt CCD cameras.
5. The anchor rod tray load visualization digital imaging method of claim 1, wherein: the reference picture is processed by sub-pixel processing, and the denoising of the reference picture is processed by a wavelet transform method.
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| CN109029279B (en) * | 2018-07-23 | 2020-01-10 | 清华大学 | Deformation measuring method and device |
| CN109493329A (en) * | 2018-11-02 | 2019-03-19 | 河北工业大学 | Digital Image Correlation Method based on local mesh reflnement |
| CN109470116A (en) * | 2018-12-29 | 2019-03-15 | 贵州省质安交通工程监控检测中心有限责任公司 | A kind of anchor pole, which is drawn, dials experiment displacement measurement system and its measurement method |
| CN112504523B (en) * | 2020-11-05 | 2022-05-06 | 郑州大学 | Method for measuring stress field through two-dimensional non-contact computer vision |
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| CN112924197B (en) * | 2021-03-25 | 2023-05-12 | 中国重汽集团济南动力有限公司 | Suspension deformation motion monitoring device and method |
| CN113280750B (en) * | 2021-06-09 | 2022-08-30 | 武汉大学 | Three-dimensional deformation monitoring method and device |
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