Robust Adaptive Control for a Class of Uncertain Nonlinear Systems

The problem of robust adaptive control is studied for a class of nonlinear systems subject to unmodeled dynamics,nonlinear uncertainties and parameter uncertainties.The more extensive unmodeled dynamics introduced is input-to-state practical stable(ISpS),and unknown nonlinearities satisfy triangular bound conditions.In the framework of Lyapunov second method and applying tuning function adaptive backstepping theory,a smooth partial state feedback controller is explicitly constructed,which guarantees global uniform ultimate boundness for all states of closed-loop systems,and renders the output converge to a small neighborhood of the origin for all admissible uncertainties.Eventually a numerical example is given to illustrate the viability of the conclusion.