Robust non-fragile LQ controllers: the static state feedback case

This paper describes the synthesis of non-fragile or resilient regulators f or linear systems. A general framework for fragility is described using sta te-space methodologies, and the LQ/H-2 static state-feedback problem is exa mined in detail. We discuss the multiplicative structured uncertainties cas e, and propose remedies of the fragility problem using an optimization prog ramming framework via matrix inequalities. A special case that leads to a c onvex optimization framework via linear matrix inequalities (LMIs) will be considered. The benchmark problem is taken as an example to show how specia l controller gain variations can affect the performance of the closed-loop system.