基于分区背景估计的两步相移干涉相位盲解调算法

Phase Blind Demodulation Algorithm for Two-Step Phase-Shifting Interferometry Based on Zoned Background Estimation

为了提高两步相移干涉测量术的相位重建精度,提出了一种基于分区背景估计的相位盲解调算法。该算法选取干涉图中的一系列零值点作为种子,围绕种子生成Voronoi图,并将干涉图划分为若干区域,将区域内全部点背景设置为种子点背景,最后拼接为完整背景。对该算法进行了数值模拟和实验分析。数值模拟结果表明,理想情况下该算法解调相位的均方根误差(RMSE)接近实际背景法。实验结果表明,相比传统低通滤波方法,该算法解调相位的RMSE降低了16%。

To improve the phase reconstruction accuracy of two-step phase-shifting interferometry measurement method, a phase blind demodulation algorithm based on zoned background estimation is proposed. In the algorithm, a sequence of zero value points in interferograms are picked out as seeds. A Voronoi figure surrounding these seeds is created, and the Voronoi figure segments each interferogram into several zones. The background of all points in these zones is set as the seed background, and a whole background is obtained when we combine these seed backgrounds. Numerical simulation and experimental analysis are conducted. Numerical simulation results show that the root-mean-square error （RMSE） of demodulation phase of the proposed algorithm is close to that of the method with real background. Experimental results show that the demodulation phase RMSE is reduced by 16% compared with the traditional low-pass filtering method.