Adaptive fuzzy multivariable controller design based on the Lyapunov scheme

In this paper a new approach to the design of multivariable adaptive-fuzzy controllers is proposed. The approach is based on fuzzy Lyapunov synthesis, that is an extension of the classical Lyapunov synthesis in the domain of computing with words. The closed-loop system is monitored and the parameters of the controller are adapted in order to minimizing the error between the actual and the desired states of the system. Stability of the closed-loop system is shown by the Lyapunov function which is used in the design stage. The performance of the proposed method is evaluated by applying it to a quadruple-tank process as a case study.