Reverse engineering by fringe projection

Abstract

We report on the development of a versatile and portable optical profilometer and show its applicability for quick and accurate digitization of 3-D objects. The profilometer is an advanced fringe-projection system that uses a calibrated LCD matrix for fringe-pattern generation, a hierarchical sequence of fringe patterns to demodulate the measured phase, and a photogrammetric calibration technique to obtain accurate 3-D data in the measurement volume. The setup in itself is mechanically stable and allows for a measurement volume of about 1x1x0.5 m<SUP>3</SUP>. We discuss the calibration of the sensor and demonstrate the process of recording phase data for several sub-views, generating 3-D point clouds from them, and synthesizing the CAD representation of an entire 3-D object by merging the data sets.