Study Of Plastic Film Thickness On-line Monitoring System Based On Virtual Instrument

With the improvement of people’s living standards, the consumption of plastic film is growing, which products are widely used in many industry fields, such as agricultural production, package of daily product, chemical industry.architecture and so on.According to the different application environment and use, the requirements for the thickness of plastic film are not the same, however, there are generally certain requirements for its uniformity.Therefore, in plastic film production, in order to ensure its quality and improve economic efficiency, the uniformity of its thickness monitoring has great significance.This paper mainly researches on the methods of constructing the virtual instrument system, which is based on the development platform of LabVIEW,then combines with the practice, developes the online monitoring of plastic film thickness.The main work this paper studied is as follows.In first chapter,according to the current situation of plastic film thickness monitoring technology,combined with the developments and advantages of virtual instrument, we can clearly sure that the monitoring system of plastic film thickness is of great significance for industrial production.Then,in the second section,starting from the feasibility and system’s demand analysis, we try to constructing an overall scheme of on-line monitoring system of the plastic film’s thickness based on virtual instrument.In the third chapter, according to the function of the system needed, we choose the hardware that virtual instrument’s hardware platform is needed. That is an integrated measurement system of non-contact method,which consists of one capacitance sensor and two eddy current senors in each measure point.and using PCL816 data acquisition card of Advantech company for signal acquisition.which has 16 channels and high-resolution.In the forth section, we finally build the on-line monitoring system of plastic film’s thickness using the construction method of instrument based on LabVIEW.which has a friendly man-machine interface login so that it can fully guarantee the security of the system. After a successful login to the system.it can be visual monitored the changes of thickness on live,and give a timely warning when the deviation of thickness is ultra, at the same time set up a standard database management and preservation for the thickness data obtained from monitoring, which can be convenient for the later’s retrieval,playback and call, so that it can be more effectively to the management of production. The system can meet the requirements of the thickness on-line monitoring in the plastic film production, and has the advantage of modularize structure and well-expanding function. Further more, the system developing based on LabVIEW software can be generated to specification so that its application program and installing software allow the user who do not need to install the LabVIEW software also can operate the system, which will greatly facilitate the users.