Design considerations for remotely operated welding in space: task definition and visual weld monitoring experiment.

500 Pages·3.5 MB·en_US

by  Renyerson, Charles Martin.

DESIGN CONSIDERATIONS FOR REMOTELY OPERATED WELDING
IN
SPACE: TASK DEFINITION AND VISUAL WELD MONITORING EXPERIMENT
by
Charles Martin Reynerson
B.S. Naval Architecture, University of California, Berkeley (1987)
SUBMITTED TO THE DEPARTMENT OF OCEAN ENGINEERING AND THE
DEPARTMENT OF AERONAUTICS AND ASTRONAUTICS IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREES OF
ENGINEER AERONAUTICS AND ASTRONAUTICS
IN
and
NAVAL ENGINEER
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
May, 1993
©
Charles Martin Reynerson, 1993. All rights reserved
The author hereby grants to MIT permission to reproduce and to
distribute copies of this thesis document in whole or in part.
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DESIGN CONSIDERATIONS FOR REMOTELY OPERATED WELDING
IN
SPACE: TASK DEFINITION AND VISUAL WELD MONITORING EXPERIMENT
by
Charles Martin Reynerson
SUBMITTED TO THE DEPARTMENT OF OCEAN ENGINEERING AND THE
DEPARTMENT OF AERONAUTICS AND ASTRONAUTICS IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREES OF
ENGINEER AERONAUTICS AND ASTRONAUTICS
IN
AND
NAVAL ENGINEER
Abstract
This thesis explores the concept of welding in a space environment with
the use of automation. Since the amount of time astronauts can work outside a
spacecraft is limited, future construction and repair tasks will likely be assisted
by automation. It is also likely that remote space welding will be needed for the
construction of large-scale space structures in earth orbit as well as for lunar
and martian ground-based structures. Due to the complex nature of the tasks
to be accomplished, the equipment will probably not be fully autonomous but
instead supervised by a human operator.
The welding fabrication problem in space is examined in a broad sense,
including some of the considerations for designing a human supervisory remote
welding system. The history of space welding processes is examined, as well
as current research in the field. A task definition and functional analysis is
provided to assist future designers in outlining typical operational sequences for
such a remote welding system. Such analysis is important when deciding
whether the human operator should perform certain tasks or if the operator
should supervise the automated system while performs the tasks.
it
An experiment was performed to test the ability of a remote operator to
recognize surface weld defects using a video image from a CCTV camera
located at the inspection site. Variables studied include camera field of view,
lighting conditions, and video viewing vs. direct viewing. Several defect types
were used to determine how the variables affected recognition success rates.
Thesis Supervisor: Koichi Masubuchi
Professor of Ocean Engineering and Material Science

Acknowledgements
would like to thank my thesis advisor, Koichi Masubuchi, for the
I
constant guidance and support he has offered me since the first time set foot
I
in his office. Without him, may not have been able to achieve MIT's first dual
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engineer degrees in NE and EAA. also thank him for sending me to
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Huntsville, Alabama for a week-long workshop entitled "Space Welding", held in
August 1992. also wish to thank my thesis reader, Greg Zacharias, for
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agreeing to this duty when my original thesis reader elected to leave MIT. His
help and inspiration was invaluable during the experimental portion of this
thesis.
would also like to thank my wife, Valerie, for her patient support during
I
the writing of this thesis. Her editorial skills helped tremendously to transform
my worst sentences into something more concise. As the first experimental
subject to view the videotape, her suggestions helped to make the other
viewing sessions go more smoothly.
give special thanks to the other experimental subjects: Gokhan Gotug,
I
Pat Keenan, Shinji Koga, Koichi Masubuchi, and Jeff McGlothin.