Fringe-scanning method using a general function for shadow moiré

Abstract

We describe a new high-resolution three-dimensional measurement method for shadow moiré. The method is based on the principle of using shadow moiré to produce moiré fringes and a fringe-scanning technique. In this method, a general function, instead of an arctangent function, is used for detecting the shape of an object. One can subsequently analyze the general function using numerical analysis with a digital computer. Two systems for static and dynamic measurements are proposed. Experimental results show that measurement accuracies in static and dynamic measurement systems are obtainable to greater than 1/50 and 1/40 fringes, respectively.