Adaptive control on wire feeding in robot arc welding system

Abstract

The quality of aluminum alloy welds is determined by the weld formation and penetration. Usually, the quality of traditional TIG welding almost depends on the skilled welder?s experience rather than theoretical and analytical techniques. At the same time, an industry robot welding system with insufficient feedback control always leads to poor welding quality, especially in manufacturing aluminum structure with mismatching deformation and butt joint gap. In order to enhance welds quality with full penetration, an intelligent control system was developed with a robot system in this paper. A welding pool imaging and processing system, as well as an identification model of the geometrical information of the weld pool, which supplies dynamic response in robotic arc welding process, have been set up. An adaptive controller was also installed, hence, the welding parameters, such as welding peak current and wire feeding rate, can be adjusted in real time with varying welding conditions to obtain sound weld joint. The experimental results show that the real-time and precision requirements for monitoring and control of weld quality could be satisfied by using this on-line control system.