Alpha Dog
As short a
time as 15 years ago, it seemed almost impossible to imagine a walking
robot. At least, a walking robot that wasn’t an
entertainment device. Sure, you could
design a device that went through all the motions of walking. But it would walk on an ideally flat surface
with no external physical interference or interaction of any kind. In other words, most walking robots were not
so different from those animatronic devices displayed in Disneyland shows.
As long as
the environment was carefully adjusted to the limitations of a walking robot,
everything would be fine. But that’s not
what DARPA wanted. The DARPA program
required a robot that could . . . really
walk. This robot’s purpose was to
accompany soldiers, potentially in combat situations, as they walked through
rough terrain. Just as humans and
animals adjust their walking to the terrain, so would the robot envisioned by
the DARPA project.
In other
words, DARPA wanted a robot that could, and would, walk in every sense of the
word.
Big Dog
The initial
project, undertaken by Boston Dynamics, resulted in the unveiling of quadruped
(four-legged) “Big Dog” in 2005. It’s
funny, but there’s something almost creepy looking about Big Dog in every still shot. But when you see it move, the creepiness
disappears as the viewer clearly recognizes something “familiar” and “natural”
in walking motion of the robot. Just
watching Big Dog in motion wordlessly defines the term “biomimickry” – a technology
copied from (imitating) nature.
Big Dog (at the Beach?)
What
complex problem was this new “legged” technology designed to solve? The Army identified “physical overburden” as
major problem in warfare. The modern
soldier carries a substantial load of gear -- weighing as much as 100
pounds. Both soldiers’ performance and readiness
are impaired by the physical weight of their gear.
Well, “in
the old days,” this problem was solved with a mule. Accompanying soldiers, in the field, was a
load bearing animal, a mule, which carried a lot of heavy gear leaving the
soldiers less fatigued and more responsive to expected and unexpected
challenges.
In 2012,
Boston Dynamics unveiled the LS3 -- “Alpha Dog” – Big Dog taken to the next
level.
Alpha Dog
Alpha Dog
can carry a bigger load – increased from 340 to 400 pounds. This new version is quieter making a sound
considerably quieter than the “swarm of bees sound” made by its
predecessor. While Big Dog was
vulnerable to “cow tippers,” Alpha Dog and can “right” itself if tipped
over.
Alpha Dog
is also faster than its predecessor. The
robot manages a 1 to 3 mph walk over rough terrain and a 5 mph jog over
relatively level surfaces. On a flat
surface, such as a roadway, Alpha Dog can reach a speed of 7 mph.
Alpha Dogs
Put in
practical terms, the goal is to develop a robot that can travel with a squad of
soldiers as they complete their mission – without hindering that mission in any
way. In order to do this, Alpha Dog will
have to be able to follow the squad, but with a degree of independence or
autonomy.
While Alpha
Dog will respond to voice commands, the commander cannot command Alpha Dog in
its every action without the robot becoming more of a burden and less of a help
to its handler. So, Alpha Dog’s design
is must incorporate certain “autonomy settings.” These settings will include: (1) “leader-follower tight,” (2) “leader-follower
corridor,” and (3) “go-to-waypoint.”
(1) Leader-follower tight: Requires
the Alpha Dog to follow the leader’s path as closely as possible.
(2) Leader-follower corridor:
Requires Alpha Dog to “follow” the leader, but with the “freedom to make local
path decisions.” So, the leader will not
have to worry or account for Alpha Dog’s mobility capabilities. The robot can vary its path slightly to avoid
obstacles or obstructions without any special intervention from the leader.
(3)
Go-to-waypoint: Requires Alpha Dog to proceed to particular set of GPS coordinates
without a leader – avoiding obstacles on its own.
A reasonable question: How can it do
these things unless it can see?
Well, for its own purposes, it can see.
Alpha Dog has a “stereo” vision
system. First, it has a pair of cameras
mounted into its “head.” Second, each
camera focuses on the same object or location from a slightly different angle –
like human vision. The angle to which
each camera must adjust to focus on a distant object or location, discloses the
depth, or distance, of that object or point.
But Alpha Dog also has a LIDAR
detecting and ranging system. LIDAR is a
just a combination of the words “light” and “radar,” but is often assumed to be
an acronym for “LIght Detection And Ranging.” (A useful factoid when you are
trying to locate resources about this technology.) Not only does the LIDAR system help Alpha Dog
follow a human lead, but also records intelligence data directly from its
environment.
This type of sophisticated, simulated
vision is necessary to allow Alpha Dog to meet another basic DARPA project
requirement. Without the “perception”
capability to detect and judge both distance and grade, this robot wouldn’t be
able to “walk” up and down hills.
In terms of communication, Alpha Dog
can’t give orders, but will be able to take orders. Voice recognition technologies allow squad
members direct spoken commands to which this robot responds.
There will be “more.” DARPA’s final goals for the perfected ‘bot
will include a much larger load-carrying capacity. The current 400 pound maximum will need to
increase to 1,000 pounds – the weight of the gear required by a nine-man
infantry squad on a 3 day mission.
Although Alpha Dog’s walking speed is about to par, its range will have
to increase to allow the ‘bot to walk at about two-and-a-half mph for 8 hours. Also, the ‘bot must be able to “burst” into
220 yard sprints at a speed of about 24 mph.
See also: Big Dog -- Terrestrial Support Robotics
Thursday 15 May 2014
GCLM5444HOxenia
See also: Big Dog -- Terrestrial Support Robotics
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