VSD-MOEA: A Dominance-Based Multi-Objective Evolutionary Algorithm with Explicit Variable Space Diversity Management

Abstract

Abstract Most state-of-the-art Multi-Objective Evolutionary Algorithms (MOEAs) promote the preservation of diversity of objective function space but neglect the diversity of decision variable space. The aim of this paper is to show that explicitly managing the amount of diversity maintained in the decision variable space is useful to increase the quality of MOEAs when taking into account metrics of the objective space. Our novel Variable Space Diversity based MOEA (VSD-MOEA) explicitly considers the diversity of both decision variable and objective function space. This information is used with the aim of properly adapting the balance between exploration and intensification during the optimization process. Particularly, at the initial stages, decisions made by the approach are more biased by the information on the diversity of the variable space, whereas it gradually grants more importance to the diversity of objective function space as the evolution progresses. The latter is achieved through a novel density estimator. The new method is compared with state-of-art MOEAs using several benchmarks with two and three objectives. This novel proposal yields much better results than state-of-the-art schemes when considering metrics applied on objective function space, exhibiting a more stable and robust behavior.