A continuous asymptotic tracking control strategy for a class of uncertain MIMO nonlinear systems

In this paper, a Lyapunov-based continuous tracking control strategy is developed that compensates for uncertainty in a class of high-order highly coupled multi-input multi-output (MIMO) nonlinear systems with up to three degrees of freedom. Based on mild assumptions on the structure of the system nonlinearities and the high frequency gain matrix, the controller is shown to be semi-globally asymptotically stable under full-state feedback. The control design, which is robust and adaptive, does not rely on bounds for the estimated parameters.