Logic-based switching adaptive stabilization of feedforward nonlinear systems

For a class of feedforward nonlinear systems, we systematically solve the g lobal adaptive stabilization problem. The proposed adaptive stabilizer cons ists of a nested saturation feedback and a tuning mechanism, which is const ituted by a set of switching logics and is used to adaptively tune the satu ration levels in a switching manner. It is proved that under the proposed c ontrol, global asymptotic regulation of states is achieved. The class of sy stems can be of arbitrary dynamic order, the contained uncertain nonlineari ties need not be explicitly bounded, and even the form of nonlinearities ca n also be unknown.