Vision extensometer implementation method based on digital speckles

A technology of digital speckle and realization method, which is applied in the direction of measuring devices, instruments, and optical devices, etc., can solve the problems of difficulty in making different marks, and achieve the effects of wide application range, high measurement efficiency, and simple spraying work

Active Publication Date: 2014-02-12
新拓三维技术(西安)有限公司
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Problems solved by technology

However, some aspects still need to be further improved. First, the core of the extensometer to measure the strain is the light intensity contrast between the sample and the mark. The greater the contrast, the better the tracking effect of the extensometer. Due to the diversity of sample materials and colors, It brings great difficulty to the production of different marks

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  • Vision extensometer implementation method based on digital speckles
  • Vision extensometer implementation method based on digital speckles
  • Vision extensometer implementation method based on digital speckles

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Embodiment Construction

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0025] The present invention proposes a digital speckle-based visual extensometer implementation method, the specific operation steps are as follows figure 1 shown. The hardware device structure adopted is as follows: figure 2 As shown, it is mainly composed of 2 CCD cameras, 2 LED lights, 1 controller and 1 computer.

[0026] The first step, speckle and mark preparation: make speckle on the measurement area on the surface of the sample to be tested, and mark two calculation points (that is, the measured points) on the surface of the sample with black cross lines. Preferably, the preparation requirements: (a) the speckle particles sprayed on the surface of the sample should be randomly distributed; (b) the speckle contrast is obvious and should be greater than a predetermined threshold; (c) the speckle preparation range should be larger than the measured d...

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Abstract

The invention discloses a vision extensometer implementation method based on digital speckles. The method includes the first step of speckle and mark making, the second step of binocular camera calibration, the third step of speckle image acquisition, the fourth step of image subarea specifying, the fifth step of image correlation matching, the sixth step of three-dimensional coordinate reconstruction and the seventh step of deformation calculation. Through the operating steps, the vision extensometer implementation method based on the digital speckles can be used for accurately measuring the deformation of materials in the tensile experiment process and has the advantages of being convenient to operate, capable of achieving non-contact measurement, accurate and reliable in measuring result and the like.

Description

technical field [0001] The invention belongs to the technical field of machining measurement, and relates to a method for realizing a visual extensometer, in particular to a method for realizing a visual extensometer based on digital speckle. Background technique [0002] With the continuous development of the processing and manufacturing industry, the performance requirements of the processed materials are getting higher and higher, and correspondingly, the detection methods of the material performance are becoming more and more advanced. The measurement of deformation has developed from the past mechanical measurement to optical non-contact measurement. When the mechanical contact knife-edge extensometer measures the deformation of the material during stretching, the friction between the knife-edge and the measured piece will produce relative motion (slip), which affects the accuracy of the measurement results. The non-contact video extensometer is produced on the basis o...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01B11/16
Inventor 唐正宗李磊刚卢岗
Owner 新拓三维技术(西安)有限公司
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