Title: Output-feedback control of arc length for manual gas metal arc welding with higher order sliding modes

Authors: Manas Kumar Bera; Bijnan Bandyopadhyay; Arun Kumar Paul

Addresses: Interdisciplinary Programme in Systems and Control Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India ' Interdisciplinary Programme in Systems and Control Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India ' Fiona 1602, Hiranandani Estate, Thane (W), 400607, Maharastra, India

Abstract: This paper explores the design of a non-linear output-feedback control technique based on the higher order sliding mode approach for an uncertain manual gas metal arc welding (GMAW) system. To cope with the large uncertainties affecting the dynamics of the system and the rapid changes in contact tip to workpiece distance (CT) caused by the uneven movement of the welding gun by the operator, an output-feedback control system has been developed with an observer-controller that combines the second order sliding mode (SOSM) controllers and an SOSM differentiator. A non-linear single input single output (SISO) system model has been considered here for the design. Thus, the robust output feedback controller with observer is proposed here, which has been compared with an earlier proposed classical feedback linearisation approach. Simulation results are presented and discussed in order to establish a framework for comparison.

Keywords: gas metal arc welding; GMAW; higher order sliding mode; HOSM; second order sliding mode; SOSM; feedback linearisation; feedback control; arc length; SMC; sliding mode control; nonlinear modelling; SISO system models; controller design; simulation; observer.

DOI: 10.1504/IJMIC.2014.062029

International Journal of Modelling, Identification and Control, 2014 Vol.21 No.4, pp.418 - 428

Published online: 23 Aug 2014 *

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