Proceedings of COBEM 2005 18th International Congress of Mechanical Engineering
Copyright © 2005 by ABCM November 6-11, 2005, Ouro Preto, MG
AUTOMATIC MONITORING OF POLYMERS FLUX USING IMAGE
PROCESSING
André Borin Soares
LAPSI – DELET – UFRGS, Av. Osvaldo Aranha 103, 206B
borin@eletro.ufrgs.br
Juan Carlos Sandoval Ortiz
LABMECFRAC / GPFAI – DEMEC – UFRGS, Rua Sarmento Leite, 425
juanca@mecanica.ufrgs.br
Thiago Rosa Figueiró
LAPSI – DELET – UFRGS, Av. Osvaldo Aranha 103, 206B
figueiro@eletro.ufrgs.br
Leticia Vieira Guimarães
LAPSI – DELET – UFRGS, Av. Osvaldo Aranha 103, 206B
leticia@eletro.ufrgs.br
Altamiro Amadeu Susin
LAPSI – DELET – UFRGS, Av. Osvaldo Aranha 103, 206B
susin@eletro.ufrgs.br
Abstract. A polymer drying system requires constant monitoring due to the possible system fails, specially related to
the material particles flux when they leave the conveyor belt to pass throw the funnel and arrive at the fuse. The
problem consists on the natural tendency of the particles to aggregate to the fuse, obstructing the conduction duct.
Nowadays, the monitoring is made by an operator that constantly observes the images deriving from a camera
installed at the top of the funnel, which acquire images of transportation fuse. The problems of this method are the
tiredness of the operators and the many attributions they have, observing many factory spots, which makes it difficult
to quickly response at the beginning of the duct obstruction. The proposed system uses the camera signal already
installed at the top of the funnel to make image processing in order to monitor the flux. In the image acquired is
selected a Region of Interest (R.O.I.) and on it the system verify the variation of luminance due to the polymer pass. If
the variation became smaller than a threshold and the quantity of polymer on the R.O.I. became greater then a second
threshold, then is defined and obstruction. The system performs an automatic estimate the quantity of polymer that may
characterize a obstruction and then generate an alarm sound to an operator fast enough to be able to control the flux.
Keywords: Flux monitoring, automatic supervision, industrial automation, image processing and motion detection.
1. Introduction
Generally, industrial process control needs monitoring several sensors in order to take decisions to control several
points of the process.
Lately, image sensors have been used for surveillance with manual monitoring and/or manual alarm. Also, in
automatic security systems applying image processing as face, finger print or car plate recognition and identification,
for example. Generally, industrial environment is very noisy for usual sensors as temperature, pressure that generate
low energy signals that are very sensitive to noise. The usages of image sensors in industry have been encouraged by
the improvement of their technology, that permit to use cameras in noisy environment as so as the decreasing of their
size and cost allow to spread their application even in small places. Moreover, the image processing tasks already used
in security systems can be adapted to industrial application successfully.
This work proposes an image processing technique to monitoring a material transport line of a polymers industry.
Polymers particles are heated and pressed in order to take de water of dry the particle, after the washing process. The
transport line is located between the heating and pressing process. The critical points of the material transport line to be
monitored are the funnel that conducts the polymer particles from the heating location to the pressing location. The
pressing is performed by a fuse that rotates inside of a pipe while the particles are located between the fuse and the pipe
wall, so the particles ate pressed and transported to the next point of the process, at the same time. The pipe is often
obstructing by the increasing of the number of particles transported by the line. Therefore, the flux of polymers must be
controlled.
Nowadays, the flux of polymers is controlled manually. A technician monitors the transport line and the funnel state
by images transmitted to the control section of the industry. The manual monitoring is not a trustworthy method because