Study On Tiantie Mill Shaft Torsional Vibration Characteristics And Its Restraining Method

Due to the higher product quality in the modern rolling industry, there are more technical requirements for the dynamic performance and steady-state accuracy of the mill main transmission system. Torsional vibration often arises in the main transmission system, because the load disturbance and the elastic connection between the motor and the roller hinder the performance improvement in the speed control system, especially biting, throwing and the strong impact of load changing. Mill torsional vibration phenomenon not only affects the normal production and reduces the quality of the work piece, but also reduces the fatigue life of transmission and affects the safe production. In the severe case, there will be accidents of broken roller and broken shaft, etc, which would cause the mill destruction.In this paper, the mechanical segment and the electrical segment is studied as a whole to solve the Tiantie mill torsional vibration issue. The Matlab/Simulink is used to model the mill main transmission model and the electrical control system model, which will be tested by the simulation results.In the paper, the inherent frequencies with the corresponding vibration mode of Tiantie F1 mill are calculated on the basis of empirical formula. And the high torsional vibration shaft will be found based on the analysis of the modes. Then, the model is used to take typical rolling process test, the results of which are analyzed. Lastly, simulation tests are made in different rolling condition, and an important conclusion is made: the damping characteristics of the system are the key point to suppress torsional vibration, there will be different impact with different damping.According to the viewpoint of changing the system damping to suppress torsional vibration, fuzzy-single neuron PI mixed control method is proposed. According to many typical rolling process simulations, we can conclude from the results: after adopting the hybrid control method, the system have faster dynamic response, smaller overshoot and shorter dynamic time, and higher precision in the steady state, thus the system robustness is strengthened significantly, and the vibration phenomenon is improved. So, the fuzzy-single neuron mixed control method is an effective way to suppress torsional vibration.