Design And Development Of Paper Positioning System For Die-cutting Machine Based On Machine Vision

In order to improve the precision of vertical platen die-cutting machine with electronic or mechanical gauge,taking the vertical platen and trash-cleaning die-cutting machine 1450ER made by ChangRong in TianJin as the research project,the paper develops the paper positioning system based on machine vision.The system is able to locate the edge or color block of the paper for die cutting with the precision at 0.02 millimeter.Just as important,it works with the real-time data transmission function.This paper has mainly carried on the following research:Firstly,the overall system design.It established the system organization,the necessary equipment and the software and hardware design demands.Secondly,imaging optical path design and hardware equipment selection.This section was to introduce a new type of mini industrial camera packaged with the light sources which can be installed at the front lay and side lay of die-cutting machine.Moreover,the focal length and working distance of the camera was determined.Thirdly,design of I/O control board.The I/O control board was designed to realize the isolated input and output drive control for cameras and light sources,also,featured the de-twitter and filter of input signal and delay shaping for pulse,which can bring the cameras and light sources synchronous exposure.Next,also the most important,research on image processing algorithms and data communication.By using the traditional edge detection operator,the edge of paper can be positioned roughly.Then,Sub pixel level processing to edge points is necessary to improve positioning accuracy.After that,a line can be fitted with the least square method,which may be considered as the edge of paper.According to the line,paper's angle and distance relative to standard position is obtained by mathematical geometry operation.In order to ensure the real-time data transmission,it selected the Ethernet Modbus/TCP protocol for writing the data to the PLC register or memory address.Lastly,system testing and man-machine interface design.The calibration principle of industrial camera and calibration procedure are studied.Besides,it introduced the man-machine operation interface designed by QT Designer,with which make it easy to set the parameters of the hardware device and image processing tools to meet the requirements of operational stability.