Research Of Rolling Mill Vibration Control Based On The Roll Gap Coupling Characteristics

The rolling mill exists vibration problems generally. The thinner strip rolled, the higherspeed and the more vibration problems have. The vibration problems of rolling mill have twotypes: the vertical vibration of Screw-down system and the torsional vibration of Drivingsystem. The torsional vibration of main drive system and vertical vibration of mill stand werestudied separately in the past, because the torsional vibration frequency is much lower thanthe vertical vibration frequency. However, the rolling speed improved, and thevertical-torsional vibration will inevitably. Reveal the interplay between the vertical vibrationand torsional vibration will be a new task in the rolling mill vibration study.In this paper, a type rolling mill be chose for the study object. The dynamics analysis ofmain driving system and Screw-down system were carried out. The main contents are asfollows:(1) Vertical vibration mechanism of the rolling mill was analyzed, the dynamics model ofstand and roller have been established to provide a basis for obtaining a vertical-torsionalcoupling dynamic model.(2) Torsional vibration generating mechanism of the mill drive system was analyzed, andthe concentration parameters system mathematical model of the mill which are the type ofmultiple grade branch and the type of single branch direct string have been established byusing mechanical dynamics. And torsional vibration system model is solved, results wassimulated and analyzed.(3) The system of Vertical vibration and torsional vibration as well as the mechanism ofrolling interface were explored, and rolling force model based on the roll gap lubricationunsteady dynamic including the roll gap geometry and stress distribution has been researched.vertical-torsional coupling mathematical model described by the equation of state was established. Vibration system of the transfer function matrix was derived under thelinearization hypothesis of rolling mill, and transformed into state space model describingvertical and torsional vibrations coupled systems. Secondly, The establishment of the stateequation is analyzed to optimize the system structure. Designing the State FeedbackDecoupling Controller to decouple mathematical model within the linear range, and usingMatlab/Simulink analysis software to verify the effect of decoupling.Results of this study revealed the relationship between vertical vibration and torsionalvibration, the vertical-torsional coupling model has been established, and decoupling themodel by designing controller design, dynamic characteristics of coupled model obtained toprovide a theoretical basis for the mill dynamics design.