Adaptive and Switching Internal Model Design

This article addresses the output regulation problem for linear systems whose model is not known a priori but are internally stable or have achieved internal stability through feedback. The article provides a perspective that complements classical internal model-based methodologies. The paradigm we follow emphasizes adaptive feedforward control, signifying all those design methodologies that position a model of the signal to be tracked or rejected by a controlled system outside the primary feedback loop responsible for system stabilization.