A new and simple robust control design for linear systems with structured time varying real parameter uncertainty

Abstract

In this paper, a new methodology for robust control design of linear systems with structured real parameter uncertainty is presented. The distinctive feature of this method is that it explicitly offers robustness guarantees for real parameter uncertainty. This provides a much needed alternative design method compared to existing robust control design methods such as H ∞ and μ -synthesis which tend to be conservative when specialized to real parameter uncertainty. The proposed robust control design method is inspired by the concept of sign (qualitative) stability in ecology, leading to a specific structure of the desired closed loop system matrix involving pseudosymmetry. Thus, this design method focuses on achieving a specific closed loop system structure that promises the desired robustness measure as opposed to building a controller as a function of the uncertainty. This design procedure is simple and straightforward without requiring intensive computation. The proposed algorithm is promising with considerable scope for extensions and improvements adding to the bank of available control design methods for linear state space systems.