Grey relational analysis coupled with firefly algorithm for multiobjective optimization of wire electric discharge machining

Abstract

Complex engineering problems are often required to be addressed for multiobjective optimization. Wire electric discharge machining is one such multiobjective optimization problem. Conflicting objectives such as material removal rate, surface roughness and kerf have always been research interest for optimization. In this article, a novel optimization strategy has been formulated by coupling grey relational analysis with firefly algorithm to optimize the responses. Process parameters such as pulse-on time, pulse-off time, peak current and servo voltage are studied. Response parameters such as material removal rate, surface roughness and kerf are considered. Firefly algorithm is the main technique and grey relational analysis is used to generate a grey relational grade. This grade is further used in firefly algorithm for movement of firefly to the neighboring brighter and attractive firefly. In this process of self-organization, simultaneous optimal solution for material removal rate, surface roughness and kerf is obtained. Peak current is found to be the most influencing factor affecting all the three responses. Pareto surface plot is also plotted to recommend alternate solutions for various responses based on the priorities. As the proposed strategy is generalized, it can be customized and applied for any multiobjective optimization problem.