Real-time Display System for Contour Lines and Equal-displacement Lines by Scanning Moire Method Using Phase-shifting

用栅格投影法得到的栅格图形进行相位分析来测量三维物体的精确形状，用干涉仪得到的条纹的位相分析来测量平板的精确平面度。为了分析栅格和条纹的相位分布，我们提出了傅里叶变换、Gabol变换和小波变换的方法。我们将这些方法应用于形状和条纹图案的分析。然而，物相分析通常耗费大量的时间。在这项研究中，我们提出了四种实时测量三维物体形状或板材平面度的方法。第一种是相移扫描云纹法。第二种是相位差扫描云纹法。第三种是利用投影网格和两个矩形函数的矩形亮度的相关性进行相移的方法。最后是积分移相法。这些方法可以实时提供准确的相位分布。给出了用于形状、应变和应力分析的原理和应用。

Phase analysis of grid patterns obtained by grid projection methods is used to measure accurate shapes for 3-D objects, and also phase analysis of fringes obtained by interferometer is used to measure accurate flatness of plates. The accuracy of the phase analysis methods is 1110-1/1000 of a grid pitch or a wavelength of light.To analyze phase distributions of grids and fringe patterns, we proposed the Fourier transform method, the Gabol transform method and the wavelet transform method previously. We applied these methods to analysis of shapes and fringe patterns. However, phase analysis usually consumes much time. In this study, we propose four methods to measure shapes of 3-D objects or flatness of plates in real-time. The first is a phase-shifting scanning moire method. The second is a phase difference scanning moire method. The third is a phase-shifting method using the correlation of the rectangular brightness of a projected grid and two rectangular functions. The last is the integrated phase shifting method. These methods can provide accurate phase distributions in real-time.The principle and application applied to shape, strain and stress analysis are shown.