TigBot - A Wall Climbing Robot for TIG Welding of Stainless Steel Tanks

The University of Canterbury research team takes on the challenge to develop a wall climbing robot which automates tungsten inert gas (TIG) welding of stainless steel tanks. The robot, coded "TigBot" is designed to carry a 4kg payload including a welding torch, camera and associated hardware. The device is required to be steerable by an operator and move independently at variable, controlled speeds. Novel locomotion has been developed to produce a smooth motion so as to satisfy continuous welding. This paper firstly examines the feasibility of various techniques for vertical welding, which leads to our conceptual design. It then discusses an adhesion mechanism and locomotion in detail. Experiments are conducted to validate the design and calculations. Optical tracking systems to enable autonomous welder tip positioning are discussed. Finally a prototype TigBot robot is developed by integrating the adhesion mechanism, locomotion, TIG welding system, sensors, and controller.