The paper deals with the synthesis of a non-fragile state controller with reduced design complexity for a class of continuous-time nonlinear delayed symmetric composite systems. Additive controller gain perturbations are considered. Both subsystems and interconnections include time-delays. A low-order control design system is first constructed. Then, stabilizing controllers with norm bounded gain uncertainties are designed for the control design system using linear matrix inequalities (LMIs) for both delay-independent and delay-dependent stability approaches. The main result shows that when such a non-fragile low-order controllers are implemented into each local controller of the decentralized controller for the global system, the global closed-loop systems are globally asymptotically stable.
This papers extends the Inclusion Principle to a class of linear continuous-time uncertain systems with state as well as control delays. The derived expansion-contraction relations include norm bounded arbitrarily time-varying real uncertainties and a point delay. They are easily applicable also to polytopic uncertainties. These structural conditions are further specialized on closed-loop systems with arbitrarily time-varying parameters, a point delay, and guaranteed quadratic costs. A linear matrix inequality (LMI) delay independent procedure is used for control design in the expanded space. The results are specialized on the overlapping decentralized control design. A numerical illustrative example is supplied.