Adaptive output regulation of nonlinear systems based on output feedback and NN feedforward control

This paper proposes a new design method of an adaptive regulator based on output feedback control for nonlin- ear systems with higher order relative degree and disturbances. The proposed method is an adaptive output feedback control based on the OFEP (Output Feedback Exponentially Passive) properties of the controlled system. To realize a stable adaptive output feedback control system, we introduce a PFC for a nonlinear system which does not satisfy OFEP conditions and design an adaptive feedforward input with a structure of neural networks in order to attain output regulation and remove the steady-state bias error from the PFC output. This method can design the robust adaptive controller with higher accuracy on output regulation.