Decoupling and robust optimisation of multivariable feedback systems

A design criterion for achieving the input-output decoupling of multivariable feedback systems and the robust stabilization of systems with time-varying nonlinear uncertainties is outlined. Moreover, by applying the minimum H^∞-norm and the optimal interpolation technique, an effective design algorithm is presented to achieve the robust optimization of multivariable feedback systems subjected to time-varying nonlinear uncertainties. Since the requirements of internal stability are satisfied, the proposed design algorithm performs appropriately, even if the plant is unstable and/or nonminimum phase. From the result of the robust optimization, one can predict the maximum sector bounds of nonlinear uncertainties that can be tolerated in the feedback system