Contour measurement by fibre optic fringe projection and Fourier transform analysis

Abstract

This paper describes an optical technique for contour measurement based on the fibre optic fringe projection and Fourier transform analysis. Sinusoidal fringes are produced by the interference of two spherical wavefronts emitted from the output fibre of a directional coupler. The fringe pattern is projected on an object surface and the deformed grating image is captured by a CCD camera for subsequent analysis by a microcomputer. In contrast to the conventional moiré method, this method is relatively simple and accurate, and is capable of conducting fully automatic measurement. © 1995.