Feasibility Preserving Constraint-Handling Strategies for Real Parameter Evolutionary Optimization
This work addresses constraint-handling for evolutionary algorithms in optimization, offering incremental improvements with new methods that enhance robustness and scalability for applications like structural design.
The paper tackled the problem of handling constraints in real-parameter evolutionary optimization by proposing two new feasibility-preserving strategies based on parent-centric and inverse parabolic probability distributions, which achieved robust performance and located optima within an error of 10^{-10} on problems with up to 500 variables.
Evolutionary Algorithms (EAs) are being routinely applied for a variety of optimization tasks, and real-parameter optimization in the presence of constraints is one such important area. During constrained optimization EAs often create solutions that fall outside the feasible region; hence a viable constraint- handling strategy is needed. This paper focuses on the class of constraint-handling strategies that repair infeasible solutions by bringing them back into the search space and explicitly preserve feasibility of the solutions. Several existing constraint-handling strategies are studied, and two new single parameter constraint-handling methodologies based on parent-centric and inverse parabolic probability (IP) distribution are proposed. The existing and newly proposed constraint-handling methods are first studied with PSO, DE, GAs, and simulation results on four scalable test-problems under different location settings of the optimum are presented. The newly proposed constraint-handling methods exhibit robustness in terms of performance and also succeed on search spaces comprising up-to 500 variables while locating the optimum within an error of 10$^{-10}$. The working principle of the IP based methods is also demonstrated on (i) some generic constrained optimization problems, and (ii) a classic `Weld' problem from structural design and mechanics. The successful performance of the proposed methods clearly exhibits their efficacy as a generic constrained-handling strategy for a wide range of applications.