DocumentCode :
2160353
Title :
A Soft Sensor for viscosity control of polymer extrusion
Author :
McAfee, Marion ; Thompson, Stephen
Author_Institution :
Sch. of Mech. & Aerosp. Eng., Queen´s Univ. Belfast, Belfast, UK
fYear :
2007
fDate :
2-5 July 2007
Firstpage :
5671
Lastpage :
5678
Abstract :
Viscosity represents a key indicator of product quality in polymer extrusion but has traditionally been difficult to measure in-process in real-time. An innovative, yet simple, solution to this problem is proposed by a Prediction-Feedback observer mechanism. A `Prediction´ model based on the operating conditions generates an open-loop estimate of the melt viscosity; this estimate is used as an input to a second, `Feedback´ model to predict the pressure of the system. The pressure value is compared to the actual measured melt pressure and the error used to correct the viscosity estimate. The Prediction model captures the relationship between the operating conditions and the resulting melt viscosity and as such describes the specific material behavior. The Feedback model on the other hand describes the fundamental physical relationship between viscosity and extruder pressure and is a function of the machine geometry. The resulting system yields viscosity estimates within 1% error, shows excellent disturbance rejection properties and can be directly applied to model-based control. This is of major significance to achieving higher quality and reducing waste and set-up times in the polymer extrusion industry.
Keywords :
extrusion; feedback; geometry; observers; polymers; product quality; viscosity; machine geometry; melt viscosity; model-based control; open-loop estimate; polymer extrusion; prediction-feedback observer mechanism; product quality; soft sensor; viscosity control; Data models; Fasteners; Polymers; Predictive models; Pressure measurement; Viscosity;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Control Conference (ECC), 2007 European
Conference_Location :
Kos
Print_ISBN :
978-3-9524173-8-6
Type :
conf
Filename :
7068524
Link To Document :
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