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FINAL APPROACH
BY WILLIAM SIURU
The next-generation UAV
The Predator and Global Hawk unmanned aerial vehicles
(UAVs) are playing key roles in the war on terrorism.
Predators equipped with Hellfire missiles can seek out and
destroy enemy targets. Other Predators fly reconnaissance
missions over Iraq. UAVs are great for high-risk missions because
they don't endanger human pilots, but they fly slow and, thus,
are vulnerable to hostile antiaircraft fire. They also must be flown
by highly
skilled pilots
on the ground. Last, they are
expensive; Predators cost about
$2 million each.
Here, Me
X-Cell 60
RC hellcopter
Is In
flight with
the technologically
advanced
control
system
on board.
With Navy funding, researchers at the Massachusetts Institute
of Technology (MIT) are developing the technology to produce
more maneuverable, more intelligent and less expensive UAVs.
Researchers equipped an X-Cell 60 RC helicopter with a
7-pound instrumentation box containing inertial sensors, a
global positioning (GPS) receiver, an altimeter and a computer.
Flown manually by a trained UAV pilot, the robot helicopter
performed a 360-degree aileron roll at high speed. The maneuver
was recorded, and the information was used to create a
computer simulation from which the researchers developed the
autonomous control software for the helicopter's onboard computer.
The maneuver was then repeated robotically to achieve
the first-ever autonomous acrobatic maneuver with a helicopter.
Researchers are currently working on a split-S—a basic
combat maneuver used by pilots to reverse direction quickly.
The control system works by memorizing the maneuvers
performed by an experienced human pilot and breaking down
the complex pilot inputs into basic mathematical algorithms.
In "building-block" fashion, the computer can then create new,
complex maneuvers just by recombining the various sets of
algorithms. This development makes it possible to program and
fly aggressive maneuvers that may have been previously
unheard of, giving UAVs a decided advantage in a hostile environment.
On a typical mission, a human pilot on the ground
would manually control the UAV through basic maneuvers
such as takeoff and landing, though autonomous takeoff and
landing have already been demonstrated. With a flip of a
switch on the control box, the helicopter would then fly
autonomously.
This new technology presents many possibilities. Small,
agile, robotic helicopters could perform military reconnaissance
154 MODEL AIRPLANE NEWS
Graduate student Loannls Martlnos and
Professor Eric Feron of the Department of
Aeronautics and Astronautics at MIT hold
the robotic helicopter they helped develop.
This Is a block diagram of the
system used to simulate actual
flight maneuvers and develop
computer algorithms.
or carry weapons. They would be particularly attractive for use
in mountainous, urban and other challenging areas that are
currently too dangerous for larger, manned aircraft. They could
fly at low altitude and in tight spaces to locate terrorists in
caves and record live images that could be transmitted to the
ground or to manned aircraft in flight. Civilian versions could
survey disaster sites that are too dangerous for manned operations.
According to the researchers, the technology could, in
the future, yield a 6-inch version able to fly robotically through
an air-conditioning duct, land inside a room and covertly listen
in on a conversation.
The robot helicopter is equipped with vibration-isolation
gear to protect the electronic equipment; this gear could also
keep a camera still, which would give filmmakers a more economical
way to shoot blur-free aerial footage.
The researchers estimate that a military robotic helicopter
with a range of at least several hundred miles would cost
around $500,000. A non-militarized version for filming aerial
imagery would cost significantly less. Though the military is
currently testing unmanned helicopter drones, these would
probably not be in service until after 2006. +