Method for positioning circle center of thin-wall circular tube part by using improved least square fitting

• Main Authors: LI LE, LIU TENGYUAN, TANG XINKAI, LI YONG, TANG YONGXIA, HAN HAOTING
• Format: Patent
• Language: Chinese; English
• Published: 26.08.2022
• Subjects: CALCULATING; COMPUTING; COUNTING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS

The invention provides a method for positioning the circle center of a thin-wall circular tube part by using improved least square fitting. The method comprises the steps of image preprocessing, boundary pixel obtaining, contour detection, minimum enclosing rectangle fitting, side length calculation, tangency point obtaining, circle center initial positioning, boundary fitting point screening and least square fitting. Compared with a traditional least square fitting method, the method has the advantages that fitting can be well carried out on the conditions of single-edge inward concave, outward turning, inner burrs, outer burrs, out-of-round and the like of the thin-wall circular pipe part, accurate positioning of the circle center is achieved, and good robustness is achieved. And the positioning detection of the irregular circular thin-wall circular tube part is realized. 本发明提供一种利用改进最小二乘拟合对薄壁圆管类零件圆心定位的方法，包括：图像预处理、获取边界像素、轮廓检测、最小外接矩形拟合、边长计算、获取切点、圆心初定位、筛选边界拟合点、最小二乘拟合。与传统最小二乘拟合方法相比，本方法在对于薄壁圆管类零件出现单边内凹、外翻、内毛刺、外毛