Adaptive robust control for nonlinear systems with mismatched uncertainties

In this paper, the adaptive robust output tracking problem for a class of n onlinear systems which have both mismatched uncertainties and matched uncer tainties has been addressed. The nominal system is input-output linearizabl e. Based on the input-output linearization technique and Lyapunov approach, an adaptive control law is developed to track the bounds on the plant unce rtainties so that no prior knowledge of the bounds is required. It is shown that the output of the closed-loop systems ultimately track the desired ou tput with a bounded tracking error despite the system uncertainties. An exa mple is performed to illustrate the effectiveness of the proposed control s cheme.