Hydraulic gap control of rolling mill based on self-tuning fuzzy PID
A closed-loop control system for the hydraulic gap control (HGC) that is driven by electrohydraulic servo valves is developed for practical application. Based on the mathematical model estimated by a system identification technique, the control algorithm is designed, and the fuzzy inference rules are established. The simulation and field test results of the step response and the position tracking that is carried out on the HGC system of a cold rolling mill show that when compared with the conventional PID control system, the self-tuning fuzzy PID system has the characteristics of fast response, short rise time, no lag, small overshoot, and strong anti-interference ability. At the same time, the self-tuning fuzzy PID control algorithm can not only improve the position tracking ability of the HGC system, but can also tune the servo valve to overcome the nonlinearity of the HGC system.