Indirect adaptive interval type-2 fuzzy output feedback controller for MIMO nonlinear systems

This paper proposes an adaptive robust fuzzy controller for the tracking problem of a class of uncertain nonlinear MIMO systems. The control signal is comprised of two parts. One part is an adaptive fuzzy controller which approximates the system unknown functions using an interval type-2 fuzzy approximator. The other part is an H
_∞
based controller that is applied to attenuate the effect of disturbance and approximation error. Moreover, it is assumed that only output variables are measurable. Therefore, a state observer is carried out to estimate the system states. To illustrate the effectiveness and resilience behavior of the proposed controller, simulation results for a two DOF robotic manipulator are presented.