Exploring scope of practical implementation of variable structure systems using sliding mode control to arc welding process

Abstract

A practical arc welding controller should be able to make, within its power range, all arc welding joints effectively and efficiently. Existence of large diversity at input and process, positional welding, polarity etc, and need to meet wide range quality engineering parameters of joints along with creating a favorable impact of process on energy efficiency and environment have made arc welding complex. Representative dynamical systems for starting, stopping and normal welding are different. Complexity of the process needs close control of multiple dynamical modes with widely different time range. They are molten pool oscillations, dynamics of metal transfer, spatter generation and arc stability. This article explores the scope of practical implementation of SMC to complete arc welding process. In manual welding arc is extinguished by increasing the arc length much beyond the controller can sustain. In that process, it produces large unusable heat particularly with 6013 (rutile) electrodes causing discomfort to the welder and co-workers. The present article, as well, discusses implementation mechanism of SMC to optimize arc light intensity and reduce heat generation in arc column in order to convert mechanism of manual arc extinction of SMAW welder friendly. Chattering issue is not important.