Sensor guided robot welding in shipbuilding

This paper presents the design and validation of a novel and universal 6D seam track-ing system that reduces the need of accurate robot trajectory programming. Such sensor driven motion control together with adaptive control of the welding process is the foundation for increased flexibility and autonomous behavior of robotic and man-ufacturing systems. The system is able to follow any 3D spline seam in space with moderate radius of curvature by the real-time correction of the position and orienta-tion of the welding torch, using the through-arc sensing method. The 6D seam tracking system was developed from results of the ROWER-2 aiming at advancing the automatic welding and assembly of ship sections. The validation ex-periments showed that this system was both robust and reliable and is able to manage curvatures and abrupt changes in the weld joint in a stable way.