An approach to design fuzzy PI supervisor for a nonlinear system

Presents an approach to the design of a fuzzy supervisor for PID controllers that are used for controlling nonlinear systems. In this approach, the design is based on an output performance criterion, namely a response with a minimum settling time and without overshoot, whatever the operating conditions may be. The application used for a demonstration is a three-tank system where the connections between the tanks and the leakage in each tank are simultaneously taken into account (a MIMO system). According to the proposed approach, two fuzzy PI supervisors are designed in order to modify the parameters of two PI controllers online. The implementation of this type of control in the simulator of the three-tank system model confirms, through the simulation results, that the output performances are reached whatever the set-points, the configuration and the initial water levels in the three tanks may be