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Article
Adaptive Control of Freeze-Form Extrusion Fabrication Processes
ASME Dynamic Systems and Control Conference
  • Xiyue Zhao
  • Robert G. Landers, Missouri University of Science and Technology
  • Ming-Chuan Leu, Missouri University of Science and Technology
Abstract

Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing process that extrudes high solids loading aqueous ceramic pastes in a layer-by-layer fashion below the paste freezing temperature for component fabrication. Due to effects such as the air bubble release, agglomerate breakdown, change in paste properties during extrusion as a result of liquid phase migration, etc., the extrusion force is difficult to control. In this paper, an adaptive controller is proposed to regulate the extrusion force. Recursive Least Squares is used to estimate extrusion force model parameters during fabrication and a low-order control scheme capable of tracking general reference trajectories is designed and implemented to regulate the extrusion process. The controller is implemented to regulate the extrusion process. The controller is implemented fro sinusoidal, triangular, and square reference trajectories and the results demonstrate excellent tracking performance of the adaptive extrusion force controller. Several parts were fabricated with the adaptive extrusion force controller. These results illustrate the need for extrusion force control and that variable reference extrusion.

Department(s)
Mechanical and Aerospace Engineering
Sponsor(s)
Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio)
Keywords and Phrases
  • Adaptive Extrusion Force Control,
  • Ceramic Paste Extrusion,
  • Solid Freeform Fabrication
Document Type
Article - Conference proceedings
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2008 Defense Technical Information Center (DTIC), All rights reserved.
Publication Date
10-1-2008
Publication Date
01 Oct 2008
Citation Information
Xiyue Zhao, Robert G. Landers and Ming-Chuan Leu. "Adaptive Control of Freeze-Form Extrusion Fabrication Processes" ASME Dynamic Systems and Control Conference (2008)
Available at: http://works.bepress.com/robert-landers/13/