|An Evolutionary Approach to Design Practical µ Synthesis Controllers
Ali Lari and Alireza Khosravi*
International Journal of Control, Automation, and Systems, vol. 11, no. 1, pp.167-174, 2013
Abstract : This paper proposes an evolutionary approach to solve µ synthesis problem. The goal is to achieve low order, practical µ synthesis controllers without any order reduction. In the proposed approach µ synthesis problem is solved as a constraint optimization problem in which robust stability and robust performance based on µ analysis are considered as the constraint and the cost function respectively. In order to solve the optimization problem an improved particle swarm optimization (PSO) is chosen to find the required coefficients of a structure-specified controller. The performance and robustness of the proposed controller are investigated by an uncertain mass-damper-spring system and is compared with the D-K iteration controller (the conventional solution to µ synthesis problem). Simulation results demonstrate the advantages of the proposed controller in terms of simple structure and robustness against plant perturbations and disturbances in comparison with D-K iteration controller.
Keyword : µ synthesis problem, D-K iteration method, particle swarm optimiazation, robust control.