任意相移阴影叠栅相位解调技术的研究

Demodulating the Phase of Phase-Shifting Shadow Moiré Using Arbitrary Phase Shift

结合时域和频域干涉图分析方法,提出一种任意相移阴影叠栅条纹图相位解调技术,降低了干涉图在采样过程中对相移量的严格标定要求,补偿了相移阴影叠栅技术固有的相移不匀误差。使用空域技术确定采样干涉图的正交信号,进而得到了采样干涉图的相移量,然后运用任意相移相位提取算法搜索测量相位信息。实验证明此方法简单方便、求解迅速,且优于典型的相移算法,其测量误差的标准差不超过3×10-3 mm,该方法为提高相移阴影叠栅技术的测量精度提供了有效手段。

Combined with the temporal and frequency domain fringe analysis methods, a new phase shifting shadow Moire technique to relax the restriction on the phase shift between frames is proposed. The proposed algorithm can extract the precise phase using three or more interferograms in an arbitrary sequence. The first stage of the algorithm is to estimate the heights and determines the frame differences based on the spiral phase transform technique. The second stage uses the generalized least-squares method to extract the temporal phase. Experimental results show that high accuracy phase estimates are obtained by the proposed algorithm. It is shown the standard deviation of the proposed method is less than 3× 10-3 ram. The proposed algorithm gives an effective solution to improve measurement accuracy of shadow Moire.