Robustness of perturbed large-scale systems with local constant state feedback

The robustness problem of perturbed large-scale systems is considered. The nominal large-scale system is stabilized by a local constant state feedback ui(t) = kixi (t) and the local optimal control law ui (t) = − R i −1 Bi TPixi (t), respectively. In the above two cases, bounds are obtained for an allowable non-linear time-invariant (or time-varying) perturbation such that the resulting closed-loop large-scale system remains stable. The special case of a linear perturbation is also treated here.