Adaptive output feedback control for a class of MIMO nonlinear systems

In this paper, we consider a general class of MIMO nonlinear systems with parametric uncertainty where the matrix pre-multiplying the control input is a matrix with nonzero leading principle minors. Under the mild assumption that the sign of the leading minors of the control input gain matrix are known, a Lyapunov based singularity free controller is designed that yields a uniformly ultimately bounded (UUB) tracking result under output feedback while compensating for uncertain parameters in both the drift vector and the input matrix. The output feedback result is facilitated via the use of a high gain observer