One of the more fascinating Juenger books is the (I think untranslated)
Glaeserne Bienen (1960). The main figure of the book, Richard, visits
the home of the owner of a media empire (Zapparoni) who also owns
a number of industries. Waiting for Zapparoni in his garden Richard
can hear what he thinks are bees flying around. He finds them odd
and catches one:
"An diesen Bienen fiel zunächst die groesse auf...Sie hatten etwa
den Umfang einer Walnuss, die noch in den gruenen Schale steckt.
Die Fluegel waren nicht beweglich wie Vogel- oder Insektenfluegel,
sondern sie waren als starrer Saum um den koerper herumgefuehrt,
also eher Stabilisierungs- und Tragflaechen.
Die Groesse war weniger auffaellig, als man denken sollte, da das Tier
vollkommen durchsichtig war...So ging es mir, nachdem ich begriffen
haette, dass es sich hier nicht um eine neue Tierart, sondern um
Mechanismen handelte. Zapparoni, dieser Teufelskerl, hatte wieder
einmal der Natur ins Handwerk gepfuscht..."
I could not avoid thinking of Juenge's bees when reading the conference
report underneath.
Micro Air Vehicles Conference
Below is a summary of the Micro Air Vehicle Conference held last month
at
Georgia Tech. Information on the availability of Proceedings will be
forthcoming once arrangements have been finalized.
LEARNING FROM THE BIRDS AND BEES: ENGINEERS LOOK TO INSECTS FOR IDEAS IN
DESIGNING TINY "MICRO AIR VEHICLES"
Imagine an aircraft small enough to fit in the palm of your hand,
yet able to fly into damaged buildings to search for survivors or
onto battlefields to detect toxic chemicals.
"Micro Air Vehicles" capable of these and other tasks are the
goals for a new program proposed by the Defense Advanced Research
Projects Agency (DARPA). The technical challenges of building such
air vehicles was the focus for a two-day conference held at the
Georgia Institute of Technology February 19-20.
The agenda for the "First International Conference on Emerging
Technologies for Micro Air Vehicles" included 17 technical
presentations from more than a dozen organizations studying the
rapidly-expanding area, as well as presentations from officials of
DARPA and the Defense Airborne Reconnaissance Office (DARO).
"When you approach technical people with this idea, their first
response is that you cannot build an aircraft this small and make
it useful," said Dr. Sam Blankenship, conference co- chair and
coordinator of the "MicroFlyer" program, the Georgia Institute of
Technology's micro air vehicle effort. "But many people, including
us, think you can do this."
Designers of micro air vehicles face formidable challenges and a
host of unknowns.
No flying vehicles of this size currently exist, meaning designers
must look to birds and insects for information about flight
principles on a scale this small. Researchers believe aerodynamic
principles governing aircraft with six-inch wings may be
significantly different from those that have guided aircraft
design since the Wright Brothers' 1903 airplane.
"There may be something about very small sizes that changes the
aerodynamics," Blankenship explained. "The Wright Flyer made
smaller and smaller and smaller ultimately won't work, and we'll
probably have to use some other method to get efficient motion in
an aircraft this small. We may have to learn from insects and
birds."
Beyond basic aerodynamic techniques, severe weight restrictions
demand new types of flight controls, power sources, propulsion
systems and avionics to fit within the 50 grams (two ounces)
allowed for the vehicle and its payload.
Full-sized aircraft use motors and hydraulic actuators to move
wing and tail structures that provide directional control, for
instance. Because of the weight associated with those devices,
however, MicroFlyers must use radically different control
techniques.
Georgia Tech engineers are developing innovative control concepts.
Research Engineer Robert Roglin in the Georgia Tech Research
Institute (GTRI) is investigating electrically-actuated
piezoelectric structures that differentially alter lift. Robert J.
Englar, a principal research engineer in GTRI, is applying
techniques for directing engine thrust across the wings.
Researchers at several institutions are studying tiny jet turbine
engines, pulsejets, ducted fans and other concepts for propulsion.
But since the MicroFlyers could contact humans during their search
missions, whirring rotor blades or exposed propellers may be too
dangerous to use.
Batteries or other electrical sources offer another challenge, as
do guidance and navigation systems -- and the tiny payloads that
will transmit television images or sniff the air for contaminants.
Recent advances in micro electro-mechanical systems (MEMS) and
microelectronics technology give engineers confidence that systems
that tiny could one day be practical.
At Georgia Tech, for instance, researchers have been working to
integrate multiple functions into single chips. Progress to date
has demonstrated integrated image acquisition, processing and data
compression, including demonstration of optical-through- wafer
interconnects. Drs. Joy Laskar, Nan Marie Jokerst, Martin Brooke,
April Brown and Scott Wills in the School of Electrical and
Computer Engineering make up this project team developing the
chips.
Researchers including Nile Hartman and Bob Schwerzel in GTRI are
working on the area of miniaturized integrated-optic chemical and
biological sensor systems.
Though flown under human control, the MicroFlyers must be
independent enough to avoid obstacles and maintain stable flight
by themselves.
"Flying a remote-controlled helicopter is extremely difficult, and
even experienced people crash them all the time," Blankenship
said. "These aircraft will need autonomy so we don't have to spend
a lot of time training people to operate them."
Since they may search environments containing toxic chemicals or
biological hazards, the MicroFlyers must also be inexpensive
enough to be thrown away. Designers are aiming at a $1,000
per-unit cost for the expendable vehicles.
The effort to design MicroFlyers involves many different technical
challenges, so Blankenship believes only organizations with broad
interdisciplinary expertise will be successful in building them.
"We're not really sure what will turn out to be the most difficult
challenge," he added. "Nobody has ventured into this realm
before."
Speakers at the conference included Dr. James McMichael,
Director of the micro Air Vehicle (microAV) program in the Defense
Advanced Research Projects Agency, and Col. Michael Francis,
former director of the microAV program.
Information about the conference is on the World Wide Web at:
<http://spbtrc.gtri.gatech.edu/MicroVehicle>
Program for the Conference is at:
<http://spbtrc.gtri.gatech.edu:80/MicroVehicle/register.htm>
Bertil Haggman
bertil.haggman@helsingborg.se
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