Application Research Of Electro-Hydraulic Proportional Tension Control Of Lead Cathode Uncoiler

Lead sheet uncoiler plays an important role in the lead cathode preparation unit, and the production quality and efficiency of cathode plate is mainly affected by the unwinding tension of lead sheet uncoiler.Based on the analysis of actual working conditions of the new lead sheet uncoiler,the technology of electro-hydraulic proportional control and indirect tension control to the object is applied in the paper.And it also considers the related technical principles deeply.At first,the technology of electro-hydraulic proportional and tension control is summarized in the paper.Besides,the feature and application of electro-hydraulic proportional control system is also described.While the focal point is that the dissertation of the application of tension control system and the developing status of the electro-hydraulic proportional control tension.Secondly.after analyzing the lead sheet tension,control theory and working process,the conclusions that the main factor affecting the tension of lead sheet uncoiler,the stress analysis of floating tension roller,and the method of moment of inertia compensation and roll diameter calculation and correction is made in the paper.So the accuracy of tension control can be improved.By separating the speed control of electro-hydraulic proportional valve controlled hydraulic motor from the tension control of electro-hydraulic proportional relief valve controlled hydraulic motor, the tension electro-hydraulic proportional control system which is due to the constant speed and constant tension is designed in the paper.Then,according to model all hydraulic components, the method of segmentation modeling to analyze the system is used in the paper,and the system of speed,force and torque is established separately.The mathematical model of lead sheet uncoiler production line system is built based on the coupling of speed and tension.And the simulation can be made by Matlab.Last but not least,the control strategy called Sliding Mode Variable Structure(SMC) based on index approaching rate to control tension is applied in the paper.Because the system exists many problems,such as:time-varying parameters,coupling,multiple interference.And the electro-hydraulic control model of speed,torque and force are established by Matlab/Simulink.Comparing the simulation results which are controlled by PID and SMC,the conclusion that PID control can make the system unstable and slow.In contrast,SMC control has ability to resist interference,and whose performance is better than PID control.In addition, in order to detect whether the performance of electro-hydraulic valve is in keeping with factory index,electro-hydraulic servo units to test static and dynamic characteristic is applied in the paper.Such as:load flow characteristics,pressure characteristics,pressure-flow characteristics, Amplitude and phase frequency.The result show that the electro-hydraulic valve meets the system requirements.So it can lay the the foundation of electro-hydraulic proportional tension control system.