微型零件中圆孔的高精度定位方法  

High Precision Algorithm for Center Positioning of Circle Hole in Micro-parts

作　　者：张进[1] 王仲[1] 李霞[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《电子测量与仪器学报》2008年第3期47-50,共4页Journal of Electronic Measurement and Instrumentation

基　　金：天津市自然科学基金资助项目(编号:043612111)

摘　　要：根据微型零件中圆孔的成像特点,为了实现其高精度定位,提出了基于双三次样条插值的圆孔定位方法。首先使用Canny算子得到被测圆孔图像的单像素边缘,然后在此基础上利用双三次样条函数在边缘法线方向上对图像进行插值,对插值的结果进行差分,从而得到边缘的亚像素位置,再通过椭圆最小二乘拟合计算出亚像素精度的圆心坐标,精度优于0.025个像素。实验结果证明,此方法可以有效的提高圆孔的定位精度。According to the imaging characteristics, in order to achieve high precision in positioning center of holes in micro-parts, a high precision algorithm is proposed in this paper, which is based on bicubic spline interpolation. Firstly, Canny edge detector is used to obtain the pixel-level edge of the circle hole. After that, bicubic spline interpolation is operated along the normal direction of the edge. And then, the result of interpolation is differenced to get the subpixel location of the edge. Finally, the subpixel-level circle center is calculated by ellipse least-square fitting, and the error is less than 0. 025 pixel. Experimental results show that the proposed algorithm may significantly improve the precision in center positioning of circle holes in micro-parts.

关 键 词：图像处理 亚像素 双三次样条 差分 最小二乘拟合 

分 类 号：TP751.1[自动化与计算机技术—检测技术与自动化装置]