Saturday, May 24, 2014

ROBOTS: BigDog – Terrestrial Support Robotics

15 May 2014

            Recently unmanned underwater drone technology seems have taken center stage among DARPA Programs.  For a while, proposals seemed to focus on UAV’s, unmanned aerial vehicles, but now include new, ambitious, underwater projects like the Hydra and UFP, which have recently appeared on the horizon.   

 Hydra UUV for the ocean's shallow waters
            On the other hand, Lockheed’s SSMS may be one of the first in new wave of terrestrial unmanned logistical and support vehicles.  The SSMS, Squad Mission Support System, vehicle sports the familiar wheels of most terrestrial vehicles.   But wheeled vehicles are of limited utility in many contexts.  I can’t help wondering when a new class of large terrestrial unmanned vehicles, with legs, will become the order of the day or, in terms of development proposals, the order to tomorrow.


            If the goal is high speed, accessibility, and maneuverability, terrestrial robots such as FastRunner (robo-ostrich) are prototypes intended to exploit to the maximum many of the advantages of bipedal locomotion. 

 FastRunner or "Robo-Ostrich"

            On the other hand, (or maybe on many other feet), there is a new generation of many-legged robots, most notably a group of hexapodal robots.  Most of these six-legged robots are designed more for the purposes of entertainment or amusement than military application.  But the multi-legged robot has distinct advantages over a two-legged or even four legged counterpart in terms of stability in motion over extremely difficult terrain.

            Looking back, from a mechanical standpoint, the business of walking was so complex that it seemed almost impossible to imagine a practical robot design incorporating motion – on foot – as short a time as 15 years ago.  But that changed with Big Dog.

 BigDog

            In 2002, Boston Dynamics [2] began work on a four-legged robot for military use.  Funded by the DARPA (Defense Advanced Research Projects Agency), the first prototype of this robotic quadruped was unveiled in 2005.  What had first been called, "Robo-Mule," but now renamed "Big Dog," had been developed by Boston Dynamics with Foster-Miller (a division of Qinetiq North America), Jet Propulsion Laboratory, and the Harvard University Concord Field Station. 

            Big Dog is about three feet long, two and a half feet high with a weight of 240 pounds.  In terms of size, it is roughly comparable to its inspiring model, the mule.  The DARPA program required a robotic pack animal, like the army mule, to travel "on foot" with soldiers through terrain too rough for wheeled vehicles.

            The latest prototype is capable of walking through terrain rough enough to stop a jeep.  Big Dog can run at about 4 mph with a 340 pound load and can climb a 35 degree grade. This robot carries a computer that receives feedback from the robot's sensors and controls its direction, movement, and balance.

            Powered by an “impressive” two-stroke, one-cylinder, 15-HP go-kart engine, Big Dog had a few bugs.  It could be tipped like a cow.  But unlike a cow, it couldn’t get back up.  Also, it was anything but silent -- making a sound often compared to a swarm of bees.  But since the 2005 unveiling, there has been a lot of work and refinements as well as the addition of a robotic arm that not only can pick things up, but throw them as well.  With the first unveiling, Big Dog's capabilties may have seemed modest, but this was the beginning of a new generation of walking robots inspired by biological organisms:  What's called biomimickry.

            In the 1950’s, the sci-fi vision of robotic technology was both exotic and strange.  The technology of the future was envisioned and presented as something completely different and contrary to our natural biological surroundings.  However, when technology confronted reality, we biological organisms seem to have had the last laugh because we could (and still can) do a whole lot of extremely useful things that our most sophisticated robotic technology cannot.

            The jeep took a basic automobile and raised the center of gravity, increased the size and scale of the automotive suspension system and produced spectacular off-road performance -- for a machine with wheels.  But the wheel, itself, was limiting.  Every Rover we’ve landed on Mars ended its life when it got stuck.  Human beings aren’t the strongest animal in the forest, but if just two of us were on Mars with those Rovers, we’d have extended their useful lives by getting them “un-stuck” in short order.  Why?  Because we have a repertoire of movements and leverage that we can use to apply force in almost any direction.  The best of those early sci-fi ’bots looked high-tech but, in fact, were functionally stunted.

            When sci-fi was still dominated by those inhuman and unnatural versions of mechanistic technology, a new methodology of approach to technological design was, quietly, born.  “Biomimetics” was a term used to describe the development of technology designed to imitate and replicate the activities of biological systems and organisms.  Then, the term “bionic” was coined to describe a technology incorporating a “function copied from nature.”  When Hollywood got a hold of the term “bionic,” the “Six Million Dollar Man” hit the small screen.  Maybe Hollywood’s version of the term “bionic” was just too interesting to be seriously “scientific,” and the term “bionic” fell into scientific oblivion.

            The gap was finally filled with the introduction of the term “biomimicry,” which has been widely adopted to describe any technology imitating (copied from) nature.  But, in some contexts, biomimicry is more of a necessity than a choice.  If you want robots or drone vehicles that work in a particular way, and the only known example of such performance is a biological organism, you’ll either have to imitate the organism or forget the project altogether.

            I am still amazed and entertained by the videos of Big Dog’s performance.  The movements are, in some ways, so “life-like” – so reminiscent of the movements of an animal.
 

BigDog (in Winter?)
 
Thursday 15 May 2014
GCLM5444HOxenia

See also: "Alpha Dog" -- "Big Dog" Taken to the Next Level

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