Uncertain nonlinear time delay systems fast and large disturbance rejection based on adaptive interval type-2 fuzzy PI control

In this paper, adaptive interval type-2 fuzzy proportional integral (PI) control scheme to attenuate fast and large disturbance for a class of uncertain nonlinear time delay systems is proposed. By incorporating adaptive interval type-2 time delay fuzzy logic controller (AT2DFLC) with PI controller, not only the typical switching law chattering can be significantly attenuated but also the instability resulting from system time delay can be overcome. Based on the Lyapunov theory of stability, the free parameters of the AT2DFLC and PI controller coefficients can be tuned on-line by output feedback adaptive laws derived from Lyapunov function with time delays. Simulation results show that the chattering phenomena can be attenuated and the prescribed tracking performance can be preserved simultaneously by the advocated control scheme.