How ROBOCOPTER works:
ROBOCOPTER uses
a hall effect magnetic field sensor to rescue
victims. The sensor detects a change in polarity as
it passes over the north and south poles of a
magnet. It behaves like an on/off switch: the
values it sends to the Cricket Board flip between 0
and 255.
ROBOCOPTER's
crew are two small cricket boards, one mounted in
the base of the mountain and on mounted on the
swing-arm boom. These cricket boards have two motor
ports, two sensor ports and an infrared signal
transmitter and receptor which allow crickets to
communicate wirelessly.
The base-cricket controls the swing-arm boom
by operating a motor connect by a simple series of
gears meshed to a large gear on the boom. The base
cricket responds to messages sent to it by the
helicopter cricket, which tells the base cricket to
turn the motor on and off depending on whether it
has detected and rescued the victim.
The helicopter cricket controls the rotor of
ROBOCOPTER making it
spin when it is in flight. It also controls the
winch which raises and lowers the life ring. But
most importantly it is connected to the magnetic
field sensor and reacts when the sensor detects a
magnet by executing a series of procedures. The
helicopter cricket communicates with the base
cricket, telling it when to stop the boom and when
to resume forward motion, allowing ROBOCOPTER to hover in place
above the victim while the life ring is lowered and
reeled up again (hopefully with the vicitim
attached), and then to fly away to safety.
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ROBOCOPTER
