基于改进最小二乘法的焊缝特征直线提取方法

Algorithm of extracting feature lines in welding seam image based on improved least-square method

关键词:  图像处理  焊缝跟踪  中心线  线性度  最小二乘法

Key words:  image processing  seam tracking  centerline  linearity  the least-square method

摘要:

提出了一种基于线性度的改进最小二乘法,用于提取焊缝特征直线.该方法提出直线线性度L,点到直线的距离范围R以及一次性剔除数据点数N三个参量,并以L为准则,结合R和N,通过循环利用最小二乘法,逐步将中心线数据点划分为满足L要求的若干点集.以含有数据点最多的点集拟合的直线作为该算法求得的焊缝特征直线.最后,讨论了三个参量的取值对拟合直线的影响.结果表明,该算法能够有效地检测V形焊缝特征直线,满足焊缝跟踪图像处理算法的要求.

Abstract:

For extracting the feature lines in welding seam images,the improved least-square method based on linearity is proposed.This improved least-square method defines three parameters:linearity L;the limit of distance between points and the fitted lines R,the number of the data points eliminated at one time N.Taking L as principle,with R and N,the data points of the centerline are divided into several point sets by using the least-square method iteratively.The feature line is included in the point set which contains most of the points,and then,least-square method is applied to fit this point set until the linearity of the fitted line is not less than the expected one.This fitted line is taken as the feature line.Finally,the influence of three parameters on the fitting lines is discussed.The results indicate that this method can efficiently extract the feature lines in V-groove welding seam image and meet the requirement of image processing methods applied in seam tracking.