Modeling and decoupling control analysis for consumable DE-GMAW

Abstract

Aiming at the instability of dynamic welding arc and strong coupling among welding parameters, a mathematical model for consumable double-electrode gas metal arc welding (DE-GMAW) was established by the method of equivalent path and then dynamical analysis was carried out. On this basis, an approach was proposed to control the stability of the welding arc using the wire extensions of main and bypass torch as a control object. And then a comparative analysis of two different decoupling control schemes was made respectively using the bypass wire feed speed and the bypass current as input and using the wire feed speed of main and bypass as input. The results show that the mathematical model can reflect the process of consumable DE-GMAW well and the decoupling control scheme using the wire feed speed of main and bypass as inputs has better dynamic performance and robustness. © 2011 Springer-Verlag Berlin Heidelberg.