Robotized multi-pass Tungsten Inner Gas welding of Francis hydro power turbines

Using robots for heavy welding application is a growing field of automation; numerous development project carried out for the ship manufacturing or the offshore industry. However, most of the largest size Francis hydro power turbine are still welded manually due to their unique and complex design, and the high-quality requirements. This paper presents an application of a Tungsten Inner Gas robot welding system for heavy multi-pass welding, what emphasizes the synergy of advanced CAD — CAM programming and human-in-the-loop control. The concept consists three separated phase: the off-line planning of the whole process, the plan update based on the previous activities, and the on-line welding operation. The proposed system was verified through experiments.