Nathaniel Durbin
COM 309
Prof. Barid
28-Sep-97
Innovations in Aircraft Construction
Do you remember assembling your first bicycle, and becoming convinced the instructions
you received were really written in an ancient Egyptian sandscript. For decades
construction workers at Boeing have had similar feelings while trying to assemble
aircraft of parts and wires. Than in 1994, with the emergence and growth of virtual reality,
engineers at the Boeing corporation began to develop ideas which would allow their
workers to wear head mounted displays while assembling an airplane. This technology would provide all the information needed for assembly without having to constantly
shift back to the volumes of bewildering manuals for instruction, saving time and
resources.
The concept behind this idea is simple enough, although the implementation requires
the use of an emerging technology as augmented reality. Augmented reality (AR) uses
similar head mounted displays (HMD's) and visual trackers as virtual reality, although instead of completely emerging oneself into an artificial world, it overlays the
information onto the real world, allowing the user to view both simultaneously.
Instructions and diagrams appear superimposed onto the real world providing real-time
visual instructions for assembling particular portions of the aircraft. In particular AR
can overlay information showing intended drilling locations or providing instructions
about a particular part or how to assemble it.
This technology in still in the prototype stage, and is still under development by
Boeing, Silicon Graphics, and the McDonnell Douglas Aerospace Incorporation. One
prototype system includes a mounted camera attached to a Silicon Graphics workstation
placed on a mobile cart. When the camera is placed and aimed at certain sections of the
airplane the computer uses pattern recognition on a series of dots and crosses depending
on their length and width to associate it with a specific location on the plane.
The computer than calls up the appropriate data on the planes section and overlays
that onto the HMD of the user; as each step in the procedure is completed the user
hits a key and the system outputs the instructions for the next step. A more advanced
version of this technology is a wearable system that allows the user to be mobile by
placing the camera on the head mounted display, and a small three pound computer
on a waist belt (which uplinks to the mainframe via a wireless network).
One of Boeings first real needs for this technology was in its wire shop, where workers
construct about 1,000 bundles of wires, each bundle can have up to a few hundred
wires and range from 2 to 120 feet in length. Rather than having to built hundreds
of three by eight foot plywood boards with each possible layout diagrammed on it, workers
have every wire layout overlaid to them wire by wire onto any blank board. This
not only saves a huge amount of space in pre-assembled boards, but also greatly enhances productivity and efficiency in a bundles assembly. Previously, bundles built on
the plywood boards would often require one worker to assemble one wire at a time
with all the schematics glued to the board, and any improperly wired board would
have to be completely rebuilt.
This technology has been working quite successfully so far, it seems that its biggest
limitation is the positional tracking system. David Mizell, Boeing's virtual systems
manager, says "the hardest technical issue is the position/orientation tracker.
It has to be small, accurate, long-range, fast, and cheap. Those attributes do not
often show up at the same party." For instance if the worker briefly blocks the
camera's view and moves his head slightly (and thus the camera) than the tracker
will be slightly off line (of either the wire bundle or another section of the aircraft in the
computer). Boeing has also been working on a two-part redundant system where it
would use both the tracker, and a magnetic field system which works similarly to
seismology. In each work area three large electrical magnets are placed perpendicular to the
aircraft, and a sensor on the worker measures the relative strength of these magnets
and outputs the camera's precise location and orientation to the workpiece. With
both of these systems running simultaneously, one can tracker can briefly fail while the
other holds position.
This technology is still clearly in the development phase. The AR project at Boeing
only consists of ten workers along with support staff and management, and has not
yet proven cost effective. It's most successful advantage is in time savings. A
1995 test showed a group using AR technology to be 20 to 50 percent faster wiring the same
material as traditional methods, namely because workers did not have to constantly
refer back to their manuals. However, the current price for a single AR unit is
from $8,000 to $16,000, making any large scale implementation very costly. Officials at Boeing
are convinced that this technology will pay off in the long run because of it's enormous
savings in time resources.
The Boeing AR project has also paved the way for other projects to begin to emerge.
AR technology is currently being planned for aircraft maintenance, general construction,
military uses, as well as medical and surgical applications. Potentially a surgeon could pull up information while diagrams were overlain onto the patient during
surgery, and a aircraft or auto-mechanics could access specifications on a particular
part just by looking at it. Given a little more development time to smooth over
some of the complications of tracking the users orientation, augmented reality could have
a profound impact on numerous professions. Whether or not your bicycle ever comes
with a AR outfit is an entirely other story, but for a manufactures at the Boeing
Aircraft Corporation life is going to become significantly less cumbersome.
Works Cited
Krumenaker, Larry. "Trends," Technology Review
. Feb/Mar 1997. p.18.
Nash, Jim. "Wiring the Jet Set," Wired
. Oct. 1997. p.129.
Sprout, Allison L. "Reality Boost," Fortune
. Mar. 21, 1994. p. 93.