Research On Synchronous Control Systems Of Medium Plate Dividing Shear’s Pinch Roll

The research on this thesis is based on the phenomenon of dividing shear’s pinch roll transporting plate deviation which is at NO.1cold rolling area during the internship of author in Baosteel Branch Luo Jing4200mm Medium Plate Factory.The steel industry still has an important position in the national economy in21century. As important production materials, medium plates are widely used in shipbuilding, construction, petroleum chemical industry, machinery manufacturing, and other industries. In the medium plate production process, as a last procedure in the cold rolling line, roll-cut dividing shear plays a vital role in the yield of medium plate. In the actual production, it often appears curved sickle, edge wave, S type and so on, which makes unqualified products increased. The yield and steel production operation efficiency is limited and solving the problem is imminent. One main reason for this problem is that the motors of pinch roll are not synchronous, therefore this thesis is aimed at controlling the pinch roll synchronization.The novelty is mainly reflected in the master-slave synchronization control method and control algorithm. At the aspect of control method, this thesis puts forward an improved synchronization one based on the speed and the torque of one master and three slaves. That is to say, the torque’s set value of the lower roll goes after the main motor, while the speeds’set values of two motors at upper roll follow the actual values of lower roll respectively. This way can solve the deficiency of the speed or the torque synchronization control method based on one master and three slaves. In the control algorithm, variable universe fuzzy control is adopted. The fuzzy controller can change their quantized factor and proportional factor, and then it can moderate their input and output basic domain, which is equal to moderate control rules according to the real situation for maximizing a good fuzzy control performance. This way can settle the shortcoming of the traditional PID that is not suitable for nonlinear, time-varying, lag of the system and the drawback of choosing input, output variable domain in the conventional fuzzy control system for its rules of human subjectivity. At first, this thesis introduces the background and significance of the research, and then the process flows of pinch roll, working principle, and the reason of plate wandering. After that, it introduces the ways of multi-motor synchronous control and control algorithm, besides that, this thesis puts forward an improved synchronous control strategy. Ultimately, it takes the synchronous control methodology with variable universe self-adaptive fuzzy PID after its feasibility analysis. According to the principle of asynchronous motor vector control, it builds simulation platform in the Simulink, and puts the designed variable universe self-adaptive fuzzy controller into the simulating model, and then compares the results of control method between traditional PID and parameter self-tuning fuzzy PID, which is used to state the validity and practicability of pinch roll control system.