Disturbance rejection using Takagi-Sugeno fuzzy model applied to an interconnected tank system

This paper presents control and stabilization of an interconnected tank system that can be used in irrigation systems and chemical processes for mixing liquids. We propose a nonlinear controller with a state space representation based on Takagi-Sugeno fuzzy models [Takagi, T. and Sugeno, M., 1985]. This controller is based on an affine PDC (parallel distributed and compensation) control law and an augmented fuzzy observer to reject disturbances. Stability and stabilization of the closed loop is proved by a Lyapunov approach using a quadratic function. The whole conditions of stabilization can be put in the form of a LMI problem that can be conveniently solved.