Development of Fuzzy Controller for Stabilizing the Arc State in Gas Metal Arc Welding

GMA 용접에 있어서 아크 안정화를 위한 퍼지제어기 개발에 관한 연구

  • 강문진 (포항산업과학연구원 설비용접연구팀) ;
  • 이세헌 (한양대학교 정밀기계공학과)
  • Published : 1999.12.01

Abstract

The weld quality of $CO_2$ arc welding is closely related to the arc stability. As the characteristics of the arc are excessively complex and nonlinear, it is not easy to make the arc model as mathematical form and to control the arc state to be stabilized. This paper was aimed to estimate the arc stability and to control for stabilizing the arc state in short circuit metal transfer mode of $CO_2$ arc welding. For these purposes, the behaviors of arc stability was investigated at different welding conditions using Mita's arc stability index, and the fuzzy control algorithm which uses the arc stability index as control imput and the arc voltage as control output was developed. In the control of the arc stability, the experiments of two cases were performed; the case of setting an initial welding voltage arbitrarily, the case of the step change in workpiece shape. Obtained results were as follows; Mita's arc stability index was able to be estimated qualitatively in the case of using the inverter type welding power source and the control performance for stabilizing the arc status was excellent in the case of existing step change disturbance.