A Variable Universe fuzzy controller for decoupling control of MIMO nonlinear systems

This paper describes the design of the variable universe(VUFC) fuzzy controller for uncertain multiple-input multiple-output coupling nonlinear dynamical systems with unknown nonlinearities. These unknown nonlinearities are approximated by the fuzzy system with a set of fuzzy rules whose parameters are adjusted on-line according to some adaptive laws for the purpose of controlling the output of the nonlinear system to track a given trajectory. The overall control system guarantees that the tracking error converges in the small neighborhood of zero and that all signals involved are uniformly bounded. Simulations are performed and a comparison between the proposed VUFC decoupling control and a conventional PI decoupling control for doubly fed wound motor(DFWM) is presented to demonstrate the effectiveness of the proposed design method.