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case. A typical police robot might stay
locked in a mobile trailer for many
months with the battery on trickle
charge, until it is suddenly needed for
a particular scenario. The police robot
must be constructed in a way to
withstand rough terrain, rough
treatment by a suspect, and possibly
have some sort of manipulator to
handle a suspected bomb or unknown
object. It is usually remotely operated
by a trained person, and should
possess a superior high definition
vision system. A security robot is quite
often used on a daily or nightly basis,
and needs to be continually operable.
The robot can look like the IAI
Guardium shown in Figure 5 — a golf
cart sized autonomous vehicle
patrolling a typical airport.
It can also look like the small
Avatar III security robot shown in
Figure 6 that weighs 25 pounds and
is made by Robotex.
It must contain high density/long
life batteries as it cannot be tethered
to a power or control source. It is
rarely remotely operated and its
sphere of operation is within a known
environment. A significant degree of
autonomy is important such as
following a line on the floor or a preprogrammed path. The robot’s
working terrain is usually within a
building or within an enclosed
outdoor yard with a fence, and simple
steerable tires or differential steering
is sufficient in most cases. It would
rarely be ‘attacked’ by anyone and
damages most likely would be
minimal. The robot might be used to
continually send back a video signal of
its surroundings to a manned central
control station.
It should also be noted that
security and police robots need not
take a passive ‘look and see’ role in
their operations. I am not implying
using weapons. A security robot
might use an ear-splitting siren, a
brilliant xenon strobe, or even emit a
cloud of tear gas in the presence of
an unwanted intruder. A police robot
might use the same techniques and
maybe even a flash/bang stun
grenade to disorientate an intruder,
but these devices have also been
known to start a fire, so use is not
always appropriate.
In contrast, a military robot must
be designed for both of the above
roles, with the possibility of damage
(or destruction) most likely. I
personally examined an iRobot
PackBot that had been returned from
the Middle East military conflicts and
IED. What I saw was a mangled pile
of robot scrap that was strapped atop
a pallet. These robots can take a lot of
damage and still come up ‘ticking.’
A military robot could be
continually operated throughout a
theater of battle and might be
autonomous or remotely operated.
Modern military operations are
frequently within city environments
with many buildings and structures.
Early Security Robot
Back in the early ‘80s when I was
attending the annual robot shows
presented by Robotics International of
the Society of Manufacturing Engineers
(RI-SME), I first saw a very unique robot
designed for security applications. The
Denning Sentry shown in Figure 7 was
manufactured by Denning Mobile
Robots of Woburn, MA and was very
well designed and built.
Standing about four feet tall and
28 inches in diameter, it was a fairly
large and heavy robot. The omnidirectional wheels allowed the robot
to revolve on its axis, or immediately
move in any direction (without the
body of the robot revolving) and then
head in a new direction. Figure 8 (a
photo of the Denning Branch research
robot platform) shows how the three
wheel assemblies were steered by the
motor in the forefront of the
photograph. Figure 9 shows a view of
the interior. The robot was
preprogrammed for a specific path
within a building’s structured
environment. Navigation was
accomplished by sensing strategically
placed IR beacons along an intended
path to guide the robot in conjunction
with the programming. It had a series
of 24 Polaroid electrostatic ultrasonic
range finder transducers around the
robot’s circumference to detect
stationary objects and walls, as well as
moving objects of interest in a security
situation.
According to their literature,
“These range finders improved the
navigational solution by allowing the
robot to measure its offset as it
approached a wall structure, while
Figure 5. Guardium UGV security robot
patrolling an airport.
Figure 6. Avatar III by Robotex in
Sunnyvale, CA.
Figure 7.
Denning
Mobile
Robot's
security
robot.
