光载波条纹图的计算机辅助分析——阶梯形虚拟光栅解调法

COMPUTER AIDED ANALYSIS OF FRINGE PATTERN USING STAIRCASE VIRTUAL GRATING DEMODULATION TECHNIQUE

本文提出一种两维光测条纹图的相位测量技术——阶梯形虚光栅解调算法．此法只需要获取一幅光载波条纹图，由计算机产生两个由Ｎ（整数）个象素构成、透射函数呈阶梯形分布、彼此间有一定相位差的两个虚光栅（参考信号），通过在整数域的运算实现对条纹图和虚光栅的相乘型叠加，低通滤波后得到两个相位差已知的叠栅函数，然后从两个相差为已知值的正弦信号中提取相位信息．理论分析和计算机模拟表明，具有相当高的测量精度，计算简便快捷．文中还给出了阶梯虚光栅解调法在投影光栅法三维形貌测量中的应用实例．

A fast demodulation technique for automatic analysis of fringe pattern is proposed using staircase virtual grating.Applying a low pass filter to product of computer generated virtual gratings and the demodutated fringe pattern generates Moire functions for extracting phase values from a single interferogram.In contrast to the Fourier Transform technique and Quadrature Multiplicative Moire method,the technique processes a fringe pattern in the integer signal domain instead of the frequency domain and real signal domaim.The theoretic analysis and computer simulation and an example of application to demodulate a deformed grating pattern for 3 D profilmetry are given in this paper.