A novel 3D vision-based robotic welding path extraction method for complex intersection curves

With the rapid development of robot technology, robotic welding technology has gradually been applied in the complex co-main intersection pipeline welding field. However, due to the existence of clamping errors and processing dimensional errors in intersecting pipes of the same specification, the actual welding path deviates from the taught path and cannot meet the accuracy requirements of robot welding, which further hinders the development and application of robotic welding in this field. To solve these problems, we propose a 3D vision-based robotic welding path extraction method for complex intersecting curves without programming and teaching. We begin by selecting the complex co-main intersection pipeline as the research object and building a robotic welding system based on 3D vision. Through mathematical analysis of the complex intersecting pipe model and an analysis of the internal coordinate transformation relationship within the welding system, we establish a mathematical model of the complex intersection curves at any clamping position in the manipulator coordinate system. On this basis, We propose a multi-view point cloud stitching method using Eye-in-Hand calibration and the ICP algorithm to obtain a complete co-main intersection pipeline point cloud. Subsequently, we propose a mathematical model parameter-solving algorithm based on the co-main intersection pipeline point cloud. Finally, the obtained actual parameters of the workpiece are combined with the established mathematical model to extract the welding path of the robot's current position. Experimental results demonstrate that the proposed method can automatically extract welding seams for complex intersection curves without the need for programming and teaching.