Adaptive fuzzy regulation of strip tension and looper angle in hot finishing mill

Abstract

This paper presents an adaptive fuzzy controller with feedback linearization and switching control technique that is used to regulate the tension of steel strip and the angle of looper system that exist between stands of the hot finishing mill. Each control loop in the proposed controller adopted an adaptive fuzzy logic structure which is reported to be superior in performance to the neural network techniques. The adaptive fuzzy controller is robust due to its fuzzy representation of the controller and is adaptive due to its training capability. The feedback linearizing control term improves control performance particularly in the transient behavior, whereas the switching control term compensates for the inevitable model approximation error incurred by the fuzzy logic representation. Combining all these terms, the proposed controller is asymptotically stable with robustness in the adaptive fuzzy controller.