Reduced-order H? controllers based on improved genetic algorithm

Abstract

An approach of reduced-order H? controller for a class of linear continuous dynamic systems is presented based on Genetic Algorithm. Necessary and sufficient conditions are given, in terms of linear matrix inequality, for the existence of controller. A rank condition is changed to object function of genetic algorithm(GA). The minimum order nk of the controller and a corresponding parameter pair (X; y ) of positive definite matrix are obtained by means of searching the object function. and then the reduced-order H? controllers are constructed. in this paper, the code is °oat, the selection operator is rank- based fitness assignment and elitist model, the crossover operator is improved real cross, the mutation operator is real mutation. The simulation results show that the controller has the same control effect as all-order H? controllers based on MATLAB. Copyright © 2005 IFAC.