In fully automatic robot welding cells, it is necessary to determine the exact position of joints before the welding process. For this purpose, a 2D/3D profile sensor is mounted directly in front of the welding torch on the robot. The special design created especially for the application is particularly compact in order to minimize the occurrence of interference contours on the welding torch. The sensor now detects the joint via laser triangulation. The guide point is determined via uniVision software and sent to the control system. A web correction is now carried out using this information and the weld seam is placed.