Simplified H_∞ Mixed Sensitivity Algorithm

Inspired by the loop shaping theory, a kind of simplified H ∞ mixed sensitivity algorithm is presented. This is based on the observation on the characteristics of the singular value curves of H ∞ S/T mixed sensitivity function as well as on the correlativity between S and T. The core of the algorithm is to shape T that is the transfer function of the closed loop system according to the knowledge a priori, then the controller K is designed directly without selecting any weighting functions. It is obvious that if the shape of T is fixed, the shape of S is also fixed because of the correlativity of S and T. Therefore it guarantees fundamentally that the designed control system will have fine control performance and robustness.