线结构光管道焊缝表面形貌重建与质量评估  

Surface Morphology Reconstruction and Quality Evaluation of Pipeline Weld Based on Line Structured Light

作　　者：韩家杰 周建平[1] 薛瑞雷 许燕[1] 刘宏胜[1] Han Jiajie;Zhou Jianping;Xue Ruilei;Xu Yan;Liu Hongsheng(College of Mechanical Engineering,Xinjiang University,Urumqi,Xinjiang 830047,China)

机构地区：[1]新疆大学机械工程学院,新疆乌鲁木齐830047

出　　处：《中国激光》2021年第14期99-108,共10页Chinese Journal of Lasers

基　　金：自治区高校科研计划自然科学重点项目(XJEDU20181006);2018新疆维吾尔自治区天山雪松计划(2018xs01);大型油气输送管道全位置自动焊接技术研究(2017D01C038)。

摘　　要：为了检测管道焊缝表面质量,建立了基于线结构光的检测系统。首先通过图像处理提取中心线与特征点,测量出轮廓仪回转中心与待测管道的轴线偏差。然后对平台空间位姿进行校正,获取了焊缝表面形貌信息,通过数值运算和点云处理,重建了管道焊缝表面的三维形貌。再通过最小二乘改进算法拟合母材平面,提取焊缝的边缘轮廓。最后根据测量出的余高和焊缝宽度等参数,建立理想焊缝模型,设定空间阈值,识别焊缝缺陷,检测焊缝成形质量。实验结果表明,与直接在每一帧轮廓线上进行检测的方法相比,所提方法的效果优良。Objective At present, pipeline automatic welding is generally equipped with a structural light sensor for seam tracking. And the detection of welding quality is one of the key points in robotic welding. Therefore, it has great practical value for the research on the detection of welding quality monitored by a linear structured light sensor. However, the existing weld forming quality detection based on structured light is mostly carried out on each contour line, and the change of adjacent contour lines is not properly utilized. For pipeline welds, it is difficult to guarantee the interval of adjacent contour lines when reconstructing the three-dimensional(3 D) morphology of the weld surface by line structured light scanning. The weld edge, width and reinforcement extracted from each single contour also exist deviations due to the positioning error of the detection platform. Aiming at these problems, this paper presents a weld forming quality inspection method based on 3D reconstruction. And we hope that our findings can be helpful for pipeline automatic welding production.Methods In order to improve the speed of extracting central-lines from structured light,the region of interest(ROI)should be extracted from the first and the last frames of the original N-frame images.Then the ROI is corrected by random sampling to ensure that the feature region is always within the ROI in the acquisition process.After Gaussian filtering,median filtering,image binarization,and morphological processing,the edge of structured light is extracted by the Laplace operator,and the sub-pixel centerline of structured light is obtained by the gray centroid method.Then the average value of each column is taken as the actual centerline position(Fig.3).To calculate the deviation between the axis of the pipeline to be measured and the rotation center of the profiler,the feature points of each central-line are extracted by calculating the changing rate and piecewise fitting,according to the measured results of the profilometer in both the horiz

关 键 词：激光技术 结构光 图像处理 三维重建 焊缝质量检测 

分 类 号：TP242.26[自动化与计算机技术—检测技术与自动化装置]