Study On Characteristic Analysis And Control Measures Of Rolling Mill Vertical-torsion Coupling Vibration

The rolling mill is one of the key and core equipment in modern iron and steel industry. In recent years, as the development of modern steel industry towards to largescale, high load, high-speed direction, various nonlinear vibration which caused by parameters of rolling mill frequently occurred. In-depth studying on nonlinear vibration problems of rolling mill and putting forward corresponding control strategies is an important topic which is urgently solved in strip rolling fields. But previous studies usually tend to ignore the hydraulic screw down system and separate vertical vibration system and main drive system, while practice shows that the complex nonlinear verticaltorsion coupling factors exist in rolling mill system. Therefore, the topic will study on the vibration characteristics and control methods of the hydraulic screw down vertical system and vertical-torsion coupling system.In the rolling process, two and three degrees of freedom hydraulic screw down vertical vibration system model was established based on nonlinear stiffness between the rolling interface, viscous damping between the hydraulic cylinder and the frame. The impact of viscous damping and excitation frequency on non-linear vertical vibration were analyzed by the phase plane method, the Poincare mapping method and the maximum Lyapunov exponent. Especially, by means of a multiple scales method, the existence and stability of periodic solutions in a first order approximation close to the main parametric resonance were investigated by the frequency–response equation.Variable friction vertical-torsion coupling vibration model was established based on the variable friction, then two and three degrees of freedom dynamic rolling force vertical-torsion coupling vibration model was established based on dynamic rolling force. In view of the former, the impact of rolling force on coupling system vibration characteristics are studied by MATLAB simulation.In view of the latter, the impact of linear damping, extraneous force, damping of main drive system and viscous damping of hydraulic cylinder on coupling system vibration characteristics are studied by MATLAB simulationThe ADRC technique is applied in vertical vibration system, the vertical vibration ADRC system is designed. The vibration phenomenons of rolling mill are controlled. The simulation shows that ADRC technique has a good rapidity, accuracy, stronger robustness and anti-jamming ability, which can easily control the stable operation of the whole system. It has high application value and provides a new way for vibration control of the vertical system for rolling mill.