An adaptive fuzzy approach to control the plate width in rough mills

摘要

The control system adopts an adaptive fuzzy system to account for the complicated process dynamics characterized by nonlinear, time-varying parameters, uncertain and load disturbances properties. Firstly, the system is divided into two parts, one is known linear part and the other is unknown nonlinear part. And a feedback controller is designed for the known part to assure its stability. Secondly, a fuzzy basic function is used only to study the upper bound of the unknown part and it is used as the parameter of the compensating controller. Finally, an adaptive fuzzy controller and its adaptive law is designed based on Lyapunov function to guarantee robustness of closed-loop system and the convergence to zero is speeded up. A series of simulation works have been conducted to evaluate the performance of the proposed control system. The control performance is analyzed in detailed in terms of the system response speed and robustness under varieties of conditions. The conclusion shows the controller is valid.