无衍射光莫尔条纹的中心定位方法

无衍射光莫尔条纹被广泛应用在精密测量领域中,实现无衍射光莫尔条纹中心的精确定位是高精度测量的关键。通过对无衍射光莫尔条纹图像特征进行分析,提出了一种无衍射光莫尔条纹的中心定位方法。该方法首先根据光强分布特征,提取莫尔条纹图像中两光斑中心局部同心圆区域;然后进行局部同心圆环检测,确定初始圆心集;再对初始圆心集进行聚类分析确定两光斑中心的初始位置;最后删除异常点并迭代求取两光斑中心较精确的位置,实现无衍射光莫尔条纹两光斑中心的定位目的。理论和实验结果表明该方法能快速、准确地同时确定两光斑中心位置,且误差小于1 pixel。

Central positioning method of non-diffracting moire fringes

Non-diffracting moire fringes are widely used in the field of precision measurement, and the accuracy of finding the central positions of the fringes is the key to realize high-precision measurement. By analyzing the characteristics of the non-diffracting moire fringe images, a method to seek the central positions of the fringes was proposed. Firstly, two local concentric circle regions, including the central spots, were extracted through the feature of intensity distribution. Secondly, the local concentric ring detection was performed to determine the initial center set. Thirdly, the initial center set was clustered to determine the initial positions of the two spot centers. Finally, the abnormal points were deleted and the more precise positions of the center of the two central spots were obtained by iterative algorithm, realizing the positioning purpose of the two central spots of the non-diffracting moire fringes. Theoretical and experimental results show that the method can determine the center position of two spots at the same time quickly and accurately, and the error is less than 1 pixel.