噪声干扰的相位误差与相位展开可靠性研究OA北大核心CSTPCD

In order to compare the advantages and disadvantages of several 3-D reconstruction methods,an evaluation method was adoped for theoretical analysis and experimental verification.The wrapped phase error model of fringe noise interference was established,and the maximum variance of the wrapped phase error was obtained.Then the reliability of three classical dual-frequency phase unwrapping algorithms was analyzed and compared.The results show that the dual-frequency four-step phase-shifting algorithm 4fh+4fl has the strongest anti-interference ability,and its reconstructed object surface is smooth and wrinkle-free.The second is the 3fh+3f algorithm,whose phase errors are 169.7％and 126.9％of those of 4fh+4fl.Finally,the 3fh+2f algorithm has a large number of folds on the reconstructed shapes,and the measurement accuracy is the worst.The phase errors of the 3fh+2f algorithm are 442.6％and 388.8％of those of the 4fh+4fl algorithm.However,compared with the 4fh+4fl algorithm and the 3fh+3fl algorithm,the measurement efficiency is improved by 37.5％and 16.6％.This study provides a method to evaluate the advantages and disadvantages of each dual-frequency phase shift method and provides a reference for the selection of the above three methods.