Design of a PID controller based on H∞ loop shaping method using frequency responses

Robust control is used for a system with perturbations of a plant and disturbances. Above all, H_∞ loop shaping method is known as a method showing a good control performance. However, this method takes designing cost because it needs a mathematical model of the actual plant. In order to reduce the identification cost, we propose a fixed-order controller design method which only uses frequency responses. The proposed method can derive a controller satisfying the better control performance with non-linear optimization.