Structure specified robust H∞ loop shaping control of a MIMO electro-hydraulic servo system using particle swarm optimization

A fixed-structure controller based on robust H∞ loop shaping control is proposed in this paper. It can be used to guarantee the robust performance under a structure-specified controller. In this proposed technique, Particle Swarm Optimization (PSO) is applied in the design controller, and the inverse of infinity norm from disturbances to states is formulated as the objective function in searching the optimal controller. Simulation results of MIMO electro-hydraulic servo system show that the proposed controller has simpler structure than that of the conventional H∞ loop shaping controller and its stability margin is near the H∞ loop shaping controllers.