Interpretation of static-weighting H-infinity design approaches for interval plants

This paper takes advantage of the critical direction theory to select a meaningful static weight for the H_∞ design of robust controller for parametrically uncertain plants. The mechanisms leading to conservatism in an earlier approach utilizing a constant overbounding uncertainty bound are analyzed first; then, an alternative less conservative uncertainty bound is presented. Finally, an example is used to illustrate that the proposed approach can substantially increase the stabilizable uncertainty level.