Synthesis of fixed-architecture, robustH2andH∞controllers

Abstract

This paper discusses and compares the synthesis of fixed-architecture controllers that guarantee either robustH2orH∞performance. The synthesis is accomplished by solving a Riccati equation feasibility problem resulting from mixed structured singular value theory with Popov multipliers. Whereas the algorithm for robustH2performance had been previously implemented, a major contribution described in this paper is the implementation of the much more complex algorithm for robustH∞performance. Both robustH2andH∞, controllers are designed for a benchmark problem and a comparison is made between the resulting controllers and control algorithms. It is found that the numerical algorithm for robustH∞performance is much more computationally intensive than that for robustH2performance. Both controllers are found to have smaller bandwidth, lower control authority and to be less conservative than controllers obtained using complex structured singular value synthesis.