Optimal robust adaptive fuzzy H∞ tracking control without reaching phase for nonlinear system

An optimal h∞ tracking-based indirect adaptive fuzzy controller for a class of perturbed uncertain affine nonlinear systems without reaching phase is being developed in this paper. first a practical interval type-2 (it2) fuzzy system is used in an adaptive scheme to approximate the system using a nonlinear model and to determine the optimal value of the h∞ gain control. secondly,to eliminate the trade-off between h∞ tracking performance and high gain at the control input,a modified output tracking error has been used. the stability is ensured through lyapunov synthesis and the effectiveness of the proposed method is proved and the simulation is also given to illustrate the superiority of the proposed approach. © 2013 el mehdi mellouli et al.