Robust output regulation for a class of nonlinear systems in output feedback form

The robust output regulation problem was analyzed for a class of nonlinear systems in output feedback form with unknown nonlinearities.Compared with the classic internal model design,besides information of the exosystem and the plant,stabilizing functions generated from the stabilization process are also used to construct the internal model in the presence of system unknown nonlinearities.The presented backstepping algorithm can regulate the output to any prescribed accuracy while maintaining uniform ultimate boundedness of overall signals.The simulation shows the effectiveness of the proposed control algorithm.