Modeling Of Tension System Of Film Blowing Machine And Control Strategy Research

Tension control is a very important part in plastic production industry, tension controlaccuracy directly affect the quality of products and production efficiency. Tension controlsystem is a typical nonlinear, time-varying, strong coupling control system, and peoplealways pay much attention to how to achieve precise control to this system.Based on the project of“design electrical control system of film blowing machinewhich comes from Heng Qi packing new material limited company of Qin Huang Dao”,this paper begin to design and research winding tension control system of film blowingmachine, content is as follows:First, this paper establish the mathematical models of winding tension, load cells andAC motor under vector control, design the double loop speed regulate system of AC motor,and set up the mathematical model of tension control system’s controlled object based onunderstanding the structure and molding process of film blowing machine. Windingtension of film blowing machine belongs to micro-tension, so use direct tension controlmethod to control it, detective device adopts load cells, actuators are AC motor and itsdriving mechanism, take PLC as controller.Second, aiming at the defect that conventional PID controller can not adjust controlparameters promptly, design the PID controller based on fuzzy self-adaptive tuning. Dueto time-varying of tension control system, using conventional PID controller with fixedparameters to control it, the control effect is not ideal. The PID controller based on fuzzyself-adaptive tuning adjusts PID parameters timely according to system’s error and errorrate, and realize the function of control parameters’on-line adjustment. The simulationresults show that winding tension is still stable under the control of fuzzy self-adaptivetuning PID controller when the parameters of the controlled object change.The last, put winding tension control system which has been designed into filmblowing machine’s actual production, the winding quality of film blowing machine underthe tension control system is good, and meet manufacturer requirements. The experimentalresults show that the winding tension control system of film blowing machine which is designed based on direct tension control method is reasonable and effective.