— This paper proposes a strategy referred to as Stability Overlay (SO) for linear and nonlinear time-varying plants, that provides input/output stability guarantees for a wide set of adaptive control schemes. We use this methodology to endow Multiple-Model Adaptive Control (MMAC) architectures with robust stability properties when the plant to be controlled is uncertain and time-varying. We emphasize that adaptive control strategies should be able to handle timevarying plants, since these methodologies are usually applied to plants with drifting parameters. The results presented herein clearly indicate that multiple-model strategies augmented with the SO for time-varying plants ensure stability of the closedloop for a wide class of disturbances and model uncertainty, while providing high performance capabilities whenever the stabilizing controllers have been designed for performancerobustness.
Paulo Andre Nobre Rosa, Jeff S. Shamma, Carlos Sil