Fuzzy Self-Tuning PID Control of the Main Drive System for Four-High Hot Rolling Mill

Abstract

The main drive system used for four-high mill is usually a double closed-loop DC motor speed regulating system. Generally, the speed controller and current controller are proportional-integral-derivative (PID) controllers. The parameters of these controllers are usually determined by the engineering design method and are constant in the whole process. So the controllers can give good control effect in the rated operating condition. Once disturbance occurs, the control effects are often just passable. In this paper, fuzzy logic is used to adjust the parameters of the speed PID controller to improve the disturbance rejection ability. Simulation results show that the fuzzy tuning PID controller can give better control effect than the regular designed PID control.