基于点云的马鞍形焊缝提取和轨迹生成方法

A method for saddle shaped welds extraction and trajectories generation based on point cloud

马鞍形焊缝自动焊接存在焊缝难以识别定位以及焊枪姿态难以规划的问题,为了实现马鞍形焊缝的自动焊接,选取实际装配的管类交叉结构件作为研究对象,提出一种基于点云的马鞍形焊缝识别与规划方法。根据马鞍形焊缝的空间语义特征,提出基于法向量和空间距离的紧耦合约束的方法提取焊缝关键点,之后用三次B样条曲线对关键点进行近似拟合,得到最终的空间焊接曲线。实验表明,提取出的焊缝轨迹与真实轨迹相比,最大误差为0.68mm,最大均方根误差为0.29。该方法具有较高的精度和鲁棒性,可满足实际焊接的需求。此方法的实用性不仅局限于马鞍形焊缝,也能处理其他具有曲线变化的焊缝。

Automatic welding of saddle shaped welds has the problems of difficult identification and localization of the weld seam,and difficult planning of welding torch posture.In order to realize the automatic welding of saddle shaped welds,a saddle weld identification and planning method based on point cloudis proposed using the actual assembly of pipe cross structures as the research object.This method utilizes tight coupling constraints between the normal vector and spatial distance to extract the key pointsaccording to the spatial semantic features.And the key points are approximated by three times cubic B spline curvesto obtain the final spatial welding curve.Experiments show that the maximum error of the extracted weld trajectory compared with the real trajectory is 0.68mm,and the maximum root mean square error is 0.29.The method has high accuracy and robustness,which can meet the needs of practical welding.The practicality of this method is not only limited to saddle shaped weld seams,but also can deal with other weld seams with curvilinear variations.