Adaptive fuzzy control for MIMO nonlinear systems

This paper presents an adaptive fuzzy control scheme for a class of uncertain multi-input multi-output(MIMO) nonlinear systems with unknown control direction and nonsymmetric control gain matrix. In this scheme, fuzzy systems are used to approximate unknown nonlinear functions, a controller is developed to avoid the calculation of the matrix inverse. A robust controller is employed to compensate for the lumped errors and a Nussbaum gain function is incorporated in the robust controller to estimate the unknown control direction. It is proved that all the signals in the resulting closed-loop system are bounded and that the tracking errors converge asymptotically to zero. A simulation example is used to demonstrate the effectiveness of the proposed scheme.