3D sampling moire measurement for shape and deformation based on the binocular vision

The sampling moire' method enables digitization and automation of moire' generation and phase analysis by recording single specimen grating image processed by sampling and interpolation approach. With its high efficiency and robustness, it has been extensively utilized for real-time deformation field measurements in multiscale structures. However, current methods focus primarily on 2D deformation, and the measurement technology of 3D deformation field is still in shortage. This paper introduces a universal 3D sampling moire' method based on binocular vision principles for surface topography and 3D displacement component measurements. The method simplifies two-dimensional phase matching to one-dimensional matching using epipolar rectification, significantly enhancing stereo matching speed. And a fixed-point iterative method addresses large deformations caused by non-uniform grating distribution in 3D measurements. Simulations and experiments are carried out to demonstrate the feasibility and precision of the proposed method. When being compared with the traditional 3DDIC methods, the 3D sampling moire & PRIME; method offers comparable accuracy, faster computation, and improved noise resistance. The obtained results verify that the 3D sampling moire & PRIME; has a good potential for real-time 3D deformation measurement in further application.