Single-shot three-dimensional shape measurement of specular surfaces by orthogonal color fringe pattern reflection technique

摘要

A convenient method based on fringe reflection technique with a single color fringe pattern is presented in this paper for dynamic measurements. A color screen and a color CCD camera are required in the system. The orthogonal color fringe pattern, which is composed with a horizontal fringe pattern in the red channel and a vertical fringe pattern in the blue channel, is displayed by the screen. The CCD camera captures the distorted color fringe pattern via the tested specular surface. The horizontal and vertical fringe patterns will be distinguished directly once the composite color fringe pattern is read by the software like MATLAB. After we get the phase of the horizontal and vertical fringe patterns by Fourier transform profilometry, the two directions' slope distributions of the tested specular surface can be acquired by the slope-phase relation of fringe reflection technique, and the shape can be reconstructed by intergral of the slope. The whole shape measurement can be completed by a single fringe pattern. The experiment of measuring a plane mirror shows the phase error of the presented method is several times smaller than the existing method, and a vibrating wafer measuring experiment proves the ability of the proposed method to reach dynamic measurement.