基于条纹中心线的载波散斑条纹解调方法

针对传统傅里叶变换法在处理含有多突起的载波散斑条纹图时,由于存在频谱展宽会出现严重的解调相位失真,提出了一种基于条纹中心线的载波散斑条纹解调方法.根据载波调制时所采用平行调制方式和倾斜调制方式,分别从理论上对相关的中心线解调法进行数学推导,并进一步采用最小二乘三次曲面拟合法获得被测物面全场的离面位移信息.实验结果表明:利用上述中心线解调法和曲面拟合法能解调出复杂的载波条纹图,并获得具有亚像素定位准确度、连续光滑的全场离面位移信息.

A Method to Modulate Carrier-wave Speckle Pattern Fringe Based on Fringe Center

There are noticeable demodulation phase errors for spectrum expanding when the traditional Fourier transform method is used to evaluate the carrier-wave interfergram fringe pattern including multi-protuberances. A new method to modulate carrier-wave speckle pattern fringe based on finge center was proposed. According to the parallel modulation method and gradient modulation method, the corresponding mathematical reasoning of fringe center modulation method was carried out in theory respectively. Then least-square cubic surface fitting algorithm was adopted to evaluate the whole out-of-plane displacement of object surface. Experimental results show that the above-mentioned modulation method and surface fitting method could not only modulate complex carrier-wave fringe pattern, but also obtain alabastrine whole out-of-plane displacement information with sub-pixel location precision and continuum.