Research And Software Implementation Of Binocular Vision Measurement Algorithm Based On Digital Image Correlation

Digital Image Correlation(DIC)method is an optical measurement technology.Due to its high precision,non-contact,full-field measurement and other characteristics,it has been paid more and more attention,and its application range has been extended from the measurement of mechanical properties of materials to Biological,medical,civil machinery,defense and military industries and other fields.However,there are still many problems in the DIC technology that need further research and improvement.For example,the measurable area of the object with large curvature is small,and there are many mismatches in the stereo matching process.The measurement speed and accuracy still cannot meet some actual measurement needs.In view of the above problems,this paper has carried out related research on DIC-based binocular vision measurement technology and algorithms.The specific research work is as follows:(1)Researched binocular stereo vision measurement technology and camera imaging model,researched and analyzed several commonly used camera calibration methods,and wrote algorithm software for experimental verification,providing a theoretical basis for subsequent 3D measurement algorithms.(2)Research and analysis of the commonly used sub-pixel matching algorithm,improved sub-pixel matching algorithm,and compared with the traditional sub-pixel matching algorithm in accuracy and iterative efficiency;an automatic speckle area extraction algorithm is proposed to replace the current method of manually selecting the speckle area,combined with the speckle quality evaluation function,to provide a reference basis for the quality of the speckle spraying effect,and to facilitate subsequent related calculations.(3)A stereo matching method based on a variable circle matching template is proposed,which improves the robustness of stereo matching and is suitable for the 3D measurement of objects with large curved surfaces,so that it can better meet the requirements of actual engineering measurement.(4)Based on Visual Studio 2010 compilation environment and Emgu CV image library,DIC measurement software was written in C# language,based on this,a DIC measurement system was built,three-dimensional measurement and material deformation measurement experiments were carried out to verify the accuracy and effectiveness of the software algorithm.