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Identification and control of a multizone crystal growth furnaceThis paper presents an intelligent adaptive control system for the control of a solid-liquid interface of a crystal while it is growing via directional solidification inside a multizone transparent furnace. The task of the process controller is to establish a user-specified axial temperature profile and to maintain a desirable interface shape. Both single-input-single-output and multi-input-multi-output adaptive pole placement algorithms have been used to control the temperature. Also described is an intelligent measurement system to assess the shape of the crystal while it is growing. A color video imaging system observes the crystal in real time and determines the position and the shape of the interface. This information is used to evaluate the crystal growth rate, and to analyze the effects of translational velocity and temperature profiles on the shape of the interface. Creation of this knowledge base is the first step to incorporate image processing into furnace control.
Document ID
19920057075
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Batur, C.
(NASA Lewis Research Center Cleveland, OH, United States)
Sharpless, R. B.
(Akron, University OH, United States)
Duval, W. M. B.
(NASA Lewis Research Center Cleveland, OH, United States)
Rosenthal, B. N.
(NASA Lewis Research Center Cleveland, OH, United States)
Singh, N. B.
(Westinghouse Science and Technology Center Pittsburgh, PA, United States)
Date Acquired
August 15, 2013
Publication Date
May 1, 1992
Publication Information
Publication: Journal of Crystal Growth
Volume: 119
Issue: 3-4,
ISSN: 0022-0248
Subject Category
Instrumentation And Photography
Accession Number
92A39699
Distribution Limits
Public
Copyright
Other

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