The Study Of Large-format Film Thickness On-line Detection And Control System

With the development of society and people’s living standards improve, more and more plastic film was widely used to industry, agriculture, construction, medical, and other industries in everyday life, people are increasing demands on the quality of film. The thickness of film is one of the key indicators to judge the quality of the film, the article is based on an existing woven bag production enterprise, for the "unique" recycling of waste plastic as raw material, through the film drawing then weaving woven bags under background of regeneration film drawing. Existing renewable drawing film production, there is no corresponding film thickness measurement and control system, the paper is under the background to design and explore the large format film thickness of on-line detection and control system.This paper describes the background, origin and significance of the subject, combined with actual production by the abroad and domestic company’s existing research status, introduce the development of thickness measurement technology through the detection, investigation and ultimately determine the large-format film thickness online testing program, complete the design of film thickness line detection system hardware, software platform and the corresponding interface. Film thickness control is a nonlinear, time-varying complex control system, we build the mathematical model of film production system through experimental method, through the traditional PID control system and fuzzy PID control system simulation analysis, it conclude the fuzzy PID control system is better than the traditional PID control system in regulation time, overshoot, etc. The Kp, Ki, Kd of fuzzy PID control parameters is calculated by MATLAB offline program and directly is stored in S7-224xpPLC, instead of complex fuzzy control algorithms and improve the efficiency of the PLC.In summary, it achieve the online detection and control system for large-format film by writing PLC programs, basically solved the film thickness of existing enterprises online detection and control, while also providing a reference of certain film thickness of the detection and control for other enterprises.