Multivariable fixed-structural controller design for H∞ loop shaping method by iterative LMI optimization using frequency response data

Robust control is used for a system with uncertainties and disturbances. Above all, the H_∞ loop shaping method is known as the method achieving good control performance. However, this method takes much time to build the mathematical model of an actual plant and its uncertainty. This paper proposes the multivariable fixed-structural controller design method which only uses frequency response data of the plant. In this method, the controller is designed by iterative LMI optimization. Since the controller is designed without the modeling using frequency response data, identification cost is expected to be reduced compared with the model-based approach. Moreover, the fixed-structural controller is readily designed. The effectiveness of the proposed method is verified through the experiment for a tension-and-velocity control apparatus, then comparison with the other method in the last of this paper is given.