Real Coded Genetic Algorithm for Design of IIR Digital Filter with Conflicting Objectives

A solution methodology for the design of digital infinite impulse response (IIR) filter considering multiple conflicting objectives has been proposed. The nucleus of the method is that multiple objectives can be attuned suitably, to optimize the performance in pass bands, stop bands and transition bands of IIR digital filters. The proposed method uses multiobjective optimization approach for designing stable IIR filter using real-coded genetic algorithm (RCGA). Digital IIR filters are designed by minimizing magnitude response and phase response simultaneously, using weighted sum approach. The value of weights are searched using RCGA along with filter coefficients thus assigning different weight vector to each individual population thereby finding multiple pareto-optimal solutions in one simulation run. The order of the filter is controlled by a control gene whose value is also optimized along with the filter coefficients to obtain optimum order of designed IIR filter. The computational experiments show that the proposed approach gives better digital IIR filters than the existing genetic algorithm based methods.