Output feedback synthesis via the circle criterion for linear systems subject to saturating inputs

A method is presented for synthesizing output feedback controllers for linear systems subject to input saturations. An observer-based controller and an output dynamic feedback type are both considered. The procedure is based upon the use of the absolute stability, through the circle criterion, and an LMI formulation. In the dynamic output feedback case, a linearizing change of variables allows one to state the LMI conditions. The method provides both the stabilizing controller and the set of admissible initial conditions which is maximal with respect to some criteria