A general H/sub infinity //LTR design problem

Abstract

An alternative approach to the loop transfer recovery (LTR) design problem based on H/sub infinity / optimization is considered. An H/sub infinity //LTR design problem is formulated as an H/sub infinity / optimization of the weighted recovery matrix (RM). This general recovery formulation includes the indirect H/sub infinity //LTR design problem (equivalent to LQG/LTR), the H/sub infinity //LTR sensitivity, and the input-output recovery problem as special cases. The weight matrix is also used for obtaining robustness in the final design. The control problem corresponding to the general H/sub infinity //LTR design problem is formulated as a standard H/sub infinity / state-space problem. The state-space solution to the H/sub infinity / problem is derived and the corresponding H/sub infinity //LTR controller is implemented as a Luenberger observer of order at most n+n/sub w/ (n/sub w/ is the order of the weight on the RM). The proposed H/sub infinity //LTR method handles both minimum phase and nonminimum phase systems in the same framework. >