A single-camera three-dimensional video extensometer and measurement method
A three-dimensional video and measurement method technology, applied in measurement devices, instruments, optical devices, etc., can solve the problems of complex dual-camera calibration process, affecting test accuracy, large measurement errors, etc., and achieve the effect of overcoming the inability to measure off-plane displacement.
Active Publication Date: 2021-09-03
NANJING UNIV OF SCI & TECH
View PDF6 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0002] As a commonly used testing tool, video extensometers are widely used in the testing of mechanical properties of materials. Conventional single-camera video extensometers can only measure two-dimensional in-plane deformation, and small out-of-plane displacements will cause large measurement errors, thereby affecting test accuracy.
The 3D video extensometer based on dual cameras requires a camera synchronization device, which increases the hardware cost
And the calibration process of dual cameras is very complicated, which limits its use in 3D video extensometers
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0017] The following description will be further described below with reference to the accompanying drawings and specific embodiments.
[0018] like figure 1 As shown, a single camera three-dimensional video extensometer includes an industrial camera 8, a high resolution lens 7, a tripod 9, a computer 10, a front coated mirror 5 having at least two identification point 6. In the figure, 1, 2, 3, and 4 are universal testing machines: 1 is the column, 2 is the beam, 3 and 4 of the upper and lower chucks.
[0019] The industrial camera 8 is disposed on the tripod 9, and the high resolution lens 7 is disposed in front of the industrial camera 8, and the high resolution lens 7 is positive to the front coating mirror 5; the front coating mirror 5 is disposed next to the object to be tested. And the lens can clearly observe the object to be tested and its virtual images in the mirror. The spotted spots were prepared on the surface of the object to be tested.
[0020] In the unloaded and ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a single-camera three-dimensional video extensometer and a measurement method. The measurement method includes the following steps: before the test, a plane calibration plate is used to calibrate the internal parameters of the camera; speckles are prepared on the surface of the object to be measured, and a mark is fixed and pasted beside it The mirror at the point, the camera collects the speckle real image of the object to be tested in the initial state and the speckle virtual image in the mirror; the object to be tested is loaded during the test, and the loading process is solved by using the internal parameters of the camera and the corresponding image coordinates of the real image and the virtual image The rotation matrix and normalized translation vector of the camera coordinate system and mirror coordinate system in any state in the mirror, using the actual distance between any two points in the mirror to calculate the translation vector coefficient; calculate the three-dimensional space coordinates of two points to be measured on the surface of the object , the displacement and strain calculation between the two points to be measured can be realized. The invention can realize three-dimensional displacement and strain calculation by using a single camera, and has the advantages of non-contact, high measurement precision, simple equipment, convenience and practicality, and the like.
Description
Technical field [0001] The present invention relates to the field of light test experimental mechanics, and more particularly to a single camera three-dimensional video lead meter and measurement method. Background technique [0002] The video extensometer is widely used in the mechanical performance test of the material, and the conventional single camera video leads can only measure the differential deformation in the two-dimensional surface, and the micro-displacement position will cause a large measurement error, which affects the test accuracy. . The three-dimensional video extensometer based on the two-camera needs the camera synchronization device, and the hardware cost is added. And the calibration process of the double camera is very complicated, which limits its use in a three-dimensional video extensometer. Inventive content [0003] It is an object of the present invention to provide a single camera three-dimensional video leading meter and measurement method, and th...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01B11/16
CPCG01B11/162
Inventor 刘聪刘晓鹏徐志洪康新
Owner NANJING UNIV OF SCI & TECH