Some results on robust output feedback stabilization of nonlinear systems

This paper aims at extending the results about the design of output feedback stabilizers for systems in normal form starting from Uniformly Completely Observable (UCO) state feedback control laws in two main directions: first, we show how output feedback {em asymptotic} stabilization can be achieved even without requiring local exponential stability of the state feedback UCO-based loop and without designing an explicit local nonlinear observer. Second, we show how to design the output feedback stabilizer starting from an UCO state feedback control law which is not vanishing on the desired asymptotic attractor which, as a consequence, may be not invariant for the original controlled system. Key tools in achieving this goal are the ones developed in the theory of output regulation.