Arc stability estimation and fuzzy control for arc stabilisation in short circuit transfer mode of CO2 arc welding

The purpose of the present work is to evaluate and control the arc stability in the short circuit transfer mode of CO, are welding. The arc stability was investigated under different gelding conditions, using the arc stability index developed by Mia et al., and a fizzy control algorithm ws developed. The correct parameters for the subset of fuzz input/output variables were determined front the experimental results using a regression model. Simulations using the fuzzy controller with the selected parameters were performed. Application of the arc stability control in real welding showed convergent performance, similar to the result of the simulations. Also, when a step change in contact tip to work distance (CTWD) was introduced, the arc was initially unstable; however, it became stable within 6 s. Furthermore, when the CTWD was varied continuously, a stable arc yeas maintained even under conditions ii-here the MID increased.