Method for error compensation of phase-shifting projection moire system

摘要

PURPOSE: A method for compensating measurement error in phase-shifting project moire is provided to improve the accuracy of the three dimensional shape measurement of the whole system by compensating phase distortion error of the phase-shifting project moire. CONSTITUTION: A method for compensating measurement error in phase-shifting project moire includes the steps of obtaining a wavelength become longer than the original wavelength by generating beat phenomenon of the two wavelengths having similar characteristic value, calculating order of moire pattern by using the long wavelength generated by the beat, obtaining two equivalent wavelengths by using two grids having different pitch, extracting order of moire pattern phase about height of a measuring point(28) based on the short equivalent wavelength, and calculating the height of the measuring point from the extracted order.