Research Of Full-field Vibration Measurement Based On High-Speed Binocular Imaging And Digital Speckles Correlation Method

Dynamic displacement and frequency are the basic parameters of the system dynamics, which are important monitoring amounts to ensure the normal operation of the machinery. This paper will use optical measurement technology-3D digital speckle correlation method to achieve the three-dimensional vibration measurements of the object. Digital speckle correlation method(DSCM) has the advantages of full-field measurement, non-contact, high-precision, simple optical path, the field of measurement can be adjusted, without special requirements of measurement environment,etc. Three-dimensional digital speckle correlation method(3D-DSCM) composed the binocular stereo vision theory and digital speckle correlation method has the ability to measure three-dimensional topography and three-dimensional deformation of flat or curved surface of the object than the two-dimensional digital speckle correlation method.Firstly,based on the theoretical study of 3D-DSCM, conducted vibration experimental tests under sinusoidal excitation to study various factors(light intensity changes, the size of the sub-region, the correlation function and shape functions, etc.) influence on the surface vibration measurement results, and give the methods to improve the precision of measurement.In the study of three-dimensional digital speckle correlation method, for the distribution between the left gray speckle images and right gray speckle images will affect the accuracy of the stereo-matching problem, combined with regularization algorithm of robust motion estimation, put forward a robust three-dimensional digital speckle correlation stereo matching methods that suitable for stereo-matching.Developed a robust three-dimensional digital speckle correlation methods based on a small plane reverse projection reconstruction,established points corresponding relationship of the set of left gray speckle images and right gray speckle images by a small plane assumptions and camera model, and then use the robust three-dimensional digital speckle correlation method for correlation operation to achieve the object three-dimensional deformation measurements.Achieve the above algorithm by MATLAB language, tested and modified by a variety of experiments.