Output Regulation of General Linear Systems with Saturating Actuators

This paper studies the classical problem of output regulation for linear systems subject to actuator saturation. The asymptotically regulatable region, the set of all initial conditions of the plant and the exosystem for which output regulation is possible, is characterized in terms of the null controllable region of the anti-stable subsystem of the plant. Feedback laws are constructed that achieve regulation on the asymptotically regulatable region. These feedback laws are constructed from the stabilizing feedback laws in such a way that a stabilizing feedback law that achieves a larger domain of attraction leads to a feedback law that achieves output regulation on a larger subset of the asymptotically regulatable region and, a stabilizing feedback law on the entire asymptotically null controllable region leads to a feedback law that achieves output regulation on the entire asymptotically regulatable region.