Iterative design of the reduced-order weight and controller for the H∞ loop-shaping method under open-loop magnitude constraints

The H_∞ loop-shaping method is known to be an effective control method, however, it has two drawbacks. The first is that it is difficult to select appropriate loop-shaping weights, and the second is that the resulting controller is very complex. Lanzon has proposed a suboptimal loop-shaping weight design method. It is formulated as a generalized eigenvalue minimization problem. This suboptimal loop-shaping weight design method provides high order weights, emphasizing the second drawback. To resolve these two drawbacks, a reduced-order loop-shaping weight and stabilizing controller design method is proposed in this paper. The effectiveness of the proposed method is verified experimentally by velocity control of a belt-driven two-mass system.