Robust Stabilization of Multivariable Systems with Both Parameter Variation and Unstructured Uncertainty.

The paper considers the problem of finding a single compensator which stabilizes a multi-input multi-output (MIMO) plant having both parameter variation and high-frequency unstructured uncertainty. An uncertain system model proposed in Wei and Yedavalli (1989) is used to characterize plants containing those two different uncertainties. Closed loop stability criteria corresponding to the factorized uncertain system is derived