by David Geer
Contact the author at geercom@windstream.net
Draganflyer X6 UAV
Soars In Any Direction, Holds Position,
Takes Video, Snaps Stills
The Draganflyer X6 UAV is the lightest, most maneuverable unmanned
miniature helicopter for its price, specially produced for the rigors of commercial
applications inside and outside the military. With a weight of one kilogram,
near limitless flight orientations, and a price tag — and this is news — of only
$15,000, it surpasses any other commercially available, UAV copter.
The Copter
The Draganflyer X6 UAV is a six-rotor, unmanned
miniature helicopter for police, commercial, and military,
as well as numerous other applications (we will list them
shortly). The relatively inexpensive UAV (US$15,000) flies in
any direction without circling to face its new headings; it
does not have to turn to take a new course head on — it
simply starts moving in that direction. The copter operates
autonomously or manually.
This VTOL (Vertical Take-Off and Landing) craft is
shown lifting straight up and maneuvering at varied angles
in the video at
www.draganfly.com/uav-helicopter/
draganflyer-x6/features. The six-rotor configuration that
enables these feats includes three pairs of dual blades that
each move in counter motion to the other. Three arms
The UAV in flight with CCD camera and LED sensors visible.
10 SERVO 09.2009
extend the rotors to an equal distance from each other.
The arms collapse for easy folding and transportation at a
fraction of the X6’s operational dimensions.
By applying varying (differential) thrust (similar to thrust
vectoring) to each rotor pair independent of the other two,
the craft changes directions quickly and acutely when
desired. By splitting up the thrust among three rotor blade
pairs, the craft increases thrust capacity by 100 percent
while maintaining the same footprint.
Six brushless motors direct drive each rotor for
increased power, efficiency, and low noise. Brushless motors
offer greater efficiency and precision because the computer
controlled motors calculate the speed of the motor, and
use that input in equations for adjusting the speed to the
specific rate required. A brushless configuration also
enables the user to build a motor with many
electromagnets on the stator, affording greater control over
speed and acceleration.
Motors that include brushes create more electrical
noise than the brushless kind. Other advantages include
longer wear (brushes tend to wear out) and greater ease of
temperature management (stator-based electromagnets are
easier to cool).
The Draganflyer X6 houses 11 sensors that enable
heading, stabilization, and roll, pitch, yaw, and attitude
response/control. These include a GPS receiver, barometric
sensor, three MEMS (micro electromechanical systems)
gyros, three magnetoresistive sensors, and three MEMS
accelerometers.
GPS enables the Draganflyer to hover in one place
while the operator manipulates camera controls to take
video or stills. The GPS also enables the operator to read
current positioning errors, longitude, latitude, and altitude,
as well as information about the accuracy of the GPS data
