Piping and Pressure Vessel Welding Automation through Adaptive Planning and Control

Welding automation is a pathway to reducing costs in the energy sector and dependence on certified welders, who are in short supply. Recent research into system-level automation of multibead/layer Tungsten Inert Gas welding for stainless-steel components is presented. Automation is pursued for weld planning, execution, and defect detection. Planning utilizes active seam/groove sensing and intuitive weld bead positioning. Bead and layer geometries are estimated using weld bead shape prediction that takes into account process parameters. After the first weld layer, subsequent trajectory plans are adapted to compensate for differences between the planned and actual weld surface. Sensor-based, closed-loop control of the process is being pursued to compensate for gravitational effects. Continuous monitoring of the real-time process to predict/detect the occurrence of welding defects is in development. Near-real-time defect detection provides the opportunity for immediate evaluation and correction, reducing costly repairs. Preliminary experimental results are presented.