Due to ever increasing precision and automation demands in robotic welding, the automatic and robust 3D seam extraction has become a research hot-spot of the welding robots. At present, most of the research work about seam extraction is aimed at butt joints. Nevertheless,too little work has been devoted to fillet joints and lap joints. Consequently,to achieve robust 3D seam extraction of different weld seams, a novel seam extraction system is proposed according to the 3D structures of welding work pieces. Firstly, a fringe projection system based on Digital Light Processing(DLP) projector is designed to measure the appearance of welding work pieces. Secondly, fusion of the shape information of welding work piece, a 3D seam extraction algorithm is proposed based on point cloud segmentation. Finally, according to the space structure of weld seams, the 3D seam path model and pose estimation are solved based on the established mathematical model of weld seams. Experiments show that the proposed algorithm could well solve different weld seams, such as fillet joints, butt joints and lap joints. Meanwhile, it could well overcome the influence of the materials of welding work pieces, scratch and rust.

由于机器人焊接中精度和自动化要求的不断提高，因此自动而强大的3D焊缝提取已成为焊接机器人的研究热点。目前，有关接缝抽取的大部分研究工作都是针对对接接头的。但是，对于圆角接合和搭接接合的工作很少。因此，为了实现不同焊缝的鲁棒3D焊缝提取，根据焊接工件的3D结构提出了一种新颖的焊缝提取系统。首先，设计了一种基于数字光处理（DLP）投影仪的条纹投影系统，以测量焊接工件的外观。其次，融合焊接工件的形状信息，提出了一种基于点云分割的3D焊缝提取算法。最后，根据焊缝的空间结构，在建立的焊缝数学模型的基础上，求解了3D焊缝路径模型和姿态估计。实验表明，该算法能够很好地解决角焊缝，对接缝和搭接缝等不同焊缝。同时，可以很好地克服焊接材料，划伤，生锈的影响。