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.

Development of the method for joint operation of neural-network tuners for current and speed

“…The subject of present study is the system of control over motion speed of a two-high reversing rolling mill. Roughing rolling stands belong to sophisticated non-linear metallurgical aggregates whose parameters can change during operation [1,2]. The systems of control over given units widely employ direct current electric drives and Pand PI-controllers with constant parameters.…”

“…Such systems are built using the principles of subordinate regulation [3,4], according to which the two control circuits are synthesized: an external circuit to control rotation frequency of the electric motor and the internal circuit to control current of the anchor. Applying the specified linear controllers leads to the deterioration in quality of transition processes under conditions of changing modes of operation [1,2]. Specifically, parameters of the armature winding and mechanical part can change in the examined drive.…”

DC Drive Adaptive Speed Controller Based on Hyperstability Theory

“…In [5,6], the neural network and fuzzy tuners of the speed PI-controller parameters are proposed, respectively. The advantages of these tuners include the rules of the PI-controller parameters adjustment, which are understandable by the process automation engineers.…”

Neural Network Dynamic Surface Backstepping Control for the Speed and Tension System of Reversible Cold Strip Rolling Mill

“…In [5], the active disturbance rejection control method was used to observe the system states and total uncertainty, which realized effective dynamic decoupling and approximate linearization for the speed and tension system, however, the control parameters of the designed controller are relatively difficult to adjust. In [7], the PID control parameters were adjusted online by using the fuzzy logic method, which improved the tracking control precision of the rolling mill speed system effectively, but this control method has an obvious deficiency, that is, the online adjustment time is relatively long. In [7], the PID control parameters were adjusted online by using the fuzzy logic method, which improved the tracking control precision of the rolling mill speed system effectively, but this control method has an obvious deficiency, that is, the online adjustment time is relatively long.…”

“…In , a dynamic decoupling controller was designed based on the pole assignment method, which weakened the coupling and improved the dynamic and static performance of the system effectively, while having relatively high requirements on the system model precision. In , the PID control parameters were adjusted online by using the fuzzy logic method, which improved the tracking control precision of the rolling mill speed system effectively, but this control method has an obvious deficiency, that is, the online adjustment time is relatively long. In , a decentralized overlapping control method was proposed based on the inclusion principles, which realized decoupling and coordinated control among the left coiler tension, the main rolling mill speed, and the right coiler tension, but the calculation process of the controller design method is relatively complicated.…”