Analysis On Torsional Vibration Of Rolling Mill Main Drive And Research On Torsional Vibration Suppression Of Multi-Mass-Spring Body

Various phenomena of torsional vibration appear in the main drive system of rolling mill in the process of rolling, which deteriorates the rolling precision and the quality of production, even damages mechanical equipments severely. Finally, leads to a tremendous loss and threats the safety in production.In order to analyze the causes in-depth of torsional vibration and put forward corresponding countermeasures to solve the problem, the mechanical part and electrical part are considered as a whole to research in this paper. First of all, consider a rolling mill system composed of main motor, intermediate shafts, reducing gear box, joint shafts, work rollers, support rollers, as an equivalent "Multi-mass-spring system" with several inertial and elastic components, and predigest it into a two-mass system. Then, mathematical model of the multi-mass-spring torsion system in the laboratory is established. Through the research on experimental system in the laboratory, the mechanism of the torsion vibration has been analyzed.The suppression of the torsional vibration of multi-mass-spring torsion system is considered as an issue of controller design of a class of uncertain system with structured uncertainties and load perturbation. The issue is considered as a Hx standard control problem by constructing a suitable augmented plant. Then robust μ controller and H∞, controller are designed separately through robust control theory. The results of simulation show that desirable results are achieved for robust control strategy to suppress the torsional vibration, and the robust μ control strategy shows more superiority than robust H∞ control strategy to deal with the problem of structured uncertainties. Finally, the robust μ control algorithm is proved on the multi-mass-spring torsion system model and as an effective control method to suppress the vibration of multi-mass-spring experimental system.