Optical 3-D shape and deformation measurement of rotating blades using stroboscopic structured illumination

Abstract

An optical method for shape and deformation measurement of a rotating blade, which is based on Fourier transform profilometry FTP and the stroboscopic effect, is proposed and has been verified by experiments. The integrated principles of the method, the process of 3-D phase unwrapping, and the detailed design of the synchronization con- trol unit are discussed. Experimental results on a commercial electric fan prove that FTP can reconstruct the shape of a rotating blade efficiently and reveal its deformation different times clearly by using stroboscopic structured illumination. This method can be used for studying high-speed motion with rapid periodic signals. © 2005 Society of Photo-Optical Instrumentation Engineers. DOI: 10.1117/1.2127927 Subject terms: Fourier transform profilometry; 3-D shape measurement; stroboscope; dynamic 3-D visualization; structured illumination; phase unwrapping; rotating blade.