Abstract: An application of an adaptive fuzzy system for compensating the effects induced by the nonlinear and parameter uncertainty existed in the electro-hydraulic servo system is presented. Firstly, the system is divided into two parts, one is known linear part and the other is unknown nonlinear part. A feedback controller is designed for the known part to assure it stable. Secondly a fuzzy basic function is used only to study the upper bound of the unknown part and the output is used as the parameter of compensating controller. Finally an adaptive fuzzy controller and its adaptive parameters are designed based on Lyapunov function to insure the closed system’s robustness and the convergence to zero is speeded up. The proposed scheme is implemented and tested on the electro-hydraulic position servo system of vertical roller of hot strip mill. The results show the proposed controller can achieve better performance than conven- tional PID one.

Key words: Adaptive fuzzy controller, Edger rolling mill, Electro-hydraulic servo system