ROBOTS: FastRunner: A Robotic Bird Designed to Run Instead of Fly?

9 January 2014

In a DARPA-funded project, MIT was contracted to design and build a robot that runs fast and can walk through rough terrain.  So, they’re designing a robot to imitate . . . a bird? 

Yes, a bird. 

The world’s fastest running animal is a bird.  A flightless bird.   The ostrich.  In fact, the ostrich can run so fast, it’s probably never felt the need to fly.

DARPA has funded the joint effort of MIT and the Florida Institute of Human and Machine Cognition (IHMC) in a project to develop a robot that walks and runs.  Past DARPA-funded projects have resulted in the quadrupedal robots, BigDog, Robo-Cheetah and the Wildcat.  But the end result of this latest effort will be the first robotic biped in the DARPA arsenal.

Robo-Ostrich or FastRunner

 

Robo-Ostrich is designed not just to walk, but to run and run fast.  Although the first full prototype has yet to be designed, the working computer simulation has legs and is hitting speeds of 27 mph.  Impressive considering this is about the speed of the fastest human runner – in a hundred yard dash.  But this robot could sustain that speed indefinitely.

The designers, however, aren’t satisfied with a mere 27 mph and are hoping to, eventually, develop a ‘bot that will reach a speed of 50 mph.  And the 50 mph mark would be another milestone on two counts.  First, real ostriches clock no higher than about 43 mph. And, second, real ostriches are the fastest land animals on earth.  So, the 50 mph Robo-Ostrich would not only beat the real bird, but would also beat every other land-based animal on the planet.

Although this ‘bot is formally named “FastRunner,” it has come to be known, informally, as Robo-Ostrich.  Why?  Because the only way to develop a robot that could run as fast as an ostrich was to build its legs to as closely imitate the legs of a real ostrich as possible.  And if your ostrich robot is really going to perform like an ostrich, it needs the legs and, more or less, the rest of the ostrich body to go with it. 

By the way, this is called biomimicry – designing a technology to imitate nature in order to solve a complex human problem.

Indeed, everyone is so excited about the Robo-Ostrich’s performance that it’s easy to forget that this robot doesn’t really exist.  Right now, the ‘bot is a computer simulation, which is only about 40% complete.

Robo-Ostrich / FastRunner Simulation

However, this isn’t the “damper” it once was because modern computer simulations are remarkably good.  In fact, modern computer simulations are so good that they quite precisely predict the performance of the real things they simulate.  So, if you can “get it right” on the computer, you can break out your hammer and wrench (figuratively speaking) and start building.  But the building phase for Robo-Ostrich is still “a ways off.”

The development of Robo-Ostrich is particularly significant because this robot’s working legs will incorporate advanced technologies to maintain the robot’s balance.  In the past, designers attempted to build complex systems into robotic legs that would monitor and respond to every variation in movement on every type of terrain.  This required large, on-board computers, complex programs, and equally complex mechanics to control every aspect of simulated walking and running.

However, a new non-linear approach is being used in the development of Robo-Ostrich.  Although complicated to develop, the new system will be of a much simpler design.

To oversimplify, imagine your automobile with computers in each wheel monitoring every bump and, then, commanding the suspension system to precisely respond in order to compensate for each disruption. 

Readers familiar with automotive suspension will furrow their brow and ask, “Why?”  For almost a century, automobiles have used a spring that flexes when the wheel rolls over that speed bump (for example) and, then, returns the chassis to its original position – no computers required.

Very, very roughly, a similar set of principles are being used to develop the mechanics of Robo-Ostrich’s legs.  Though much more complex than an automobile suspension system, the goal is a relatively simple, self regulating balance mechanism that allows the ‘bot to maintain its balance as it walks over uneven surfaces.

The real ostrich can grow to a height in excess of 9 feet and weigh as much as 250 pounds.  In other words, you wouldn’t want to meet the real bird – in a bad mood — in an ally — at night.

Robo-Ostrich, however, will only measure about half the height and weight of the real bird.  This relatively “petite” size and weight produce an intended advantage. The lighter weight makes the robot faster and lowers its power requirements extending its range.

The two legged design has distinct advantages over the past quadrupedal models.  Not only is a two-legged robot lighter, but its movements are more flexible allowing it to, among other things, “get through narrower spaces” and maneuver more easily around obstacles.  With such a flexible build, this robot, like other “be-footed” robots, is designed to negotiate rough terrain that would defy a wheeled-vehicle like a jeep.  Even on irregular surfaces, the finished ‘bot is expected to run (or walk) at a speed of 10 mph.

Although still in the design phase, everything about the development of Robo-Ostrich seems to be on track.  Still, it will be a while before we’ll see the actual two-legged bird ‘bot walking and running . . . but not flying.

Thursday 9 January 2014

GCLM5444HOxenia

ROBOTS: Fast On Their Feet -- Robo-Cheetah & The Wildcat

6 February 2014



            Creating a “legged” robot is one thing.  Making it run instead of walk is another.  But, then, there’s yet another challenge.  Can you make it run fast?

            Developed for DARPA by Boston Dynamics, the robo-cheetah’s claim to fame is its speed.  Modeled after the real-life cheetah, this robot boasts a “cat-like spine,” which “flexes and extends” with the robot’s galloping stride. And it gallops -- “constantly tipping forward, falling, and regaining equilibrium with every step.”  After the development of the first prototype, in 2011, it was showcased running at speeds of up to 18 mph by March of 2012.  By September, it clocked 28.3 mph – faster than the fastest human runner in a hundred-yard dash.

            Of course, with all the excitement, Robo-Cheetah still had a couple issues that needed to be ironed-out before it could go bounding across a battlefield.  It was running at high speeds, but it was only running on a treadmill.  Still, it was about ready to jump off the treadmill and, at least, onto flat ground. 

            Robo-Cheetah's biggest issue was that it was still “tethered” by a power cord.  In other words, it had to be plugged into a wall socket to get the juice it needed to move.   There’s no portable power pack for this ‘bot that can store enough power to let it run free.  Portable power supplies are a big issue in robotics and one of the biggest challenges to maximum performance. 

            There’s a tradeoff.  You need enough power to allow the ‘bot to operate for long stretches of time.  You, also, need a power pack light-weight enough for the ‘bot to carry.  But, when you make the power pack light enough, there’s not enough power to run the ‘bot.  And, when you make a power pack with enough power, the pack (and ‘bot) become so heavy that, now, . . . the 'bot's short on power -- again.  It's like running in a circle. 

Robo-Cheetah 

            But, soon, there were more than technical challenges – there were challengers.   The first competitor was MIT. The Biomimetic Robotics Lab at MIT, also under the sponsorship of DARPA, was, and is, working on its own version of the robo-cheetah.  MIT is trying to recreate the running movement of the real cheetah.  They’re more public with their work.  The MIT website shows their version of Robo-Cheetah.  Their robot can’t run as fast as the Boston Dynamics model, but MIT’s model boasts a “highly efficient leg motor, imitation tendons, and a responsive tail.”  With these improvements MIT’s Robo-Cheetah has a rhythm and movement completely different from other four-legged ‘bots. 

MIT's Version of Robo-Cheetah 

            MIT's Robo-Cheetah, also, “will” run on a battery (but it, too, is still plugged into a wall-socket).  Unlike the other Robo-Cheetah, MIT’s uses a surprisingly simple and more effective way of regulating its leg motion – one without the usual sensors and complicated computer feedback-loops that were, and are, still a common part of robotic technology.

            But what’s so important about imitating a real cheetah?  The robo-cheetah is one of a group of DARPA-funded projects applying the concepts of biorobotics.  To meet DARPA’s requirements, drones must be built to perform more like . . . wildlife.  The term “biomimetics” or “biomimicry” is used to describe the development of technology designed to imitate and replicate the activities of biological systems and organisms.   But, why imitate nature?  Well, “if you want drones 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.”

            The need for walking (rather than rolling) robots is a prime example.  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 limited.  Human beings, horses, mules, and dogs can all travel over terrain that would be impossible for any wheeled vehicle to handle. 

            How do you design a ‘bot that travels over rough terrain like a mule?  Well, you design it . . . like a mule.  And Boston Dynamics' “Robo-Mule” (later, renamed “BigDog”) was the first in a new line of bio-inspired “walking” robots.  But, again, why a cheetah?  Is it just a cool sounding name or is it the sleek look of the moving animal?  Neither. There’s something special about cheetahs that DARPA wants to capture in robotic performance.

            Robo-Cheetah is being designed to move, quite specifically, like a cheetah.  Unlike Robo-Mule (“BigDog”), Robo-Cheetah is meant to be ultra-speedy and agile, able to “chase and evade” like the actual animal.  Designers are working on getting it to run at cheetah speed, but their ultimate ambition goes much farther than that.  They hope to design a ‘bot that can run faster than any animal on earth -- as fast as 70 mph.

            Robo-Cheetah will have many military applications, including emergency and disaster response.  But DARPA has hinted at performance that might improve on nature.  At least, humans might be able to do things with Robo-Cheetah you’d never try with the real thing – including uses in “advanced agriculture and vehicular travel.”  Just think.  Riding a Robo-Cheetah!

            Of course, the pressure rose with two Robo-Cheetahs in development: The speedy one by Boston Dynamics and the graceful one by MIT.  But, the race got even tighter when another competitor came out of left field -- the Robo-Ostrich.  Ostrich?  What’s an ostrich got to offer in this race?  An ostrich is a bird, and it can’t even fly.  Well, fly it can’t, but maybe it doesn’t need to because the ostrich is the fastest land animal on earth.

            DARPA has funded the joint effort of MIT and the Florida Institute of Human and Machine Cognition (IHMC) in a project to develop a robot that walks and runs.  But the end result of this latest effort will be the first robotic biped in the DARPA arsenal -- a robotic ostrich.

            Robo-Ostrich is designed not just to walk, but to run and run fast.  Although the first full prototype has yet to be designed, the working computer simulation has legs and is hitting speeds of 27 mph.  Impressive, again, because this is about the speed of the fastest human runner in a hundred yard dash.

Robo-Ostrich 

            Robo-Ostrich’s designers are only hoping for a maximum speed of 50 miles an hour – faster than the fastest ostrich -- clocked at 43 mph.  On the other hand, this is a bit slower than the 70 mph Boston Dynamics is hoping for Robo-Cheetah.   But there’s “a whole ‘lot of hoping going on” here.  Robo-Cheetah isn’t off the treadmill, and Robo-Ostrich is a computer simulation.  We’ll just wait and see.

            What’s the secret of Robo-Ostrich’s speed?  Two legs.  What’s so special about a two-legged robot?  Not only is a two-legged robot lighter than a robot with twice the number of legs, but its movements are more flexible allowing it to, among other things, “get through narrower spaces” and maneuver more easily around obstacles.  With such a flexible build, this robot, like other “be-footed” robots, is designed to negotiate rough terrain that would defy a wheeled-vehicle like a jeep.  Even on the most irregular surfaces, the finished ‘bot is expected to run (or walk) at a speed of 10 mph, more than twice as fast as a walking human being.

            Well, with MIT pushing hard to the goal with both their robots, Robo-Cheetah and Robo-Ostrich, Boston Dynamics had to do something.  They announced their plan to take the lead in the race, by unleashing Robo-Cheetah from its treadmill.  They promised their Robo-Cheetah, unteathered, would hit the road in 2013.   And it did, but with a twist.

            In 2013, the cordless “Wildcat” was shown galloping and running (and even running backward) on flat terrain.  But, wait, what happened to Robo-Cheetah?  Why the Wildcat?  Why Robo-Cheetah's little sister?

            To speed up development, Robo-Cheetah was . . . modified.  To get rid of its power cord and, then, to get it off the treadmill and onto the ground, Robo-Cheetah had to lose some of its bulk and weight.   It, also, lost its electric motor and gained an internal combustion (gasoline powered) engine.   Even with these reductions, it lost some of its treadmill speed -- slowing from 28 to about 16 mph. 

            The Wildcat may be slower than the fastest human in a hundred yard dash but, if its chasing you, you’d better get to safety within that hundred yards.  Why?  Because the Wildcat will still be going strong and fast long after you, I, or any human runner, would have worn out and fallen to the ground.  The Wildcat still only performs on flat terrain, but the plan is to have it walking on the same rough ground that its distant cousin the Robo-Mule/BigDog handles with ease.

 



The Wildcat

 

Thursday 6 February 2014

GCLM5444HOxenia

ROBOTS: “Legged” Robots – LittleDog Does It First

5 June 2014

            In 2005, Boston Dynamics unveiled BigDog (also search “Big Dog”) a four-legged (quadrupedal) robot.  The project, funded by DARPA, was intended to develop the robotic equivalent of a pack mule to work directly with soldiers in the field.  As a “legged” robot, BigDog was expected to go where wheeled vehicles couldn’t. 

ROBOTS: Big Dog – Terrestrial Support Robotics

 

 

          Then came “Alpha Dog,” the LS3, an advanced version of BigDog.

 

 

Alpha Dog

ROBOTS: “Alpha Dog” – “Big Dog” Taken to the Next Level

             Boston Dynamics has continued with the on-going development of a faster quadruped, Robo-Cheetah.  Even as Robo-Cheetah took the speed record for “legged” ‘bots, topping 28 mph on an in-lab treadmill, developers remain optimistic that this ‘bot will, someday, reach even higher speeds. 
 

Robo-Cheetah



            While Robo-Cheetah stayed tethered to its treadmill, last October, a slightly smaller and slower spin-off, the Wildcat, jumped off the treadmill.   The Wildcat left its “power cord” behind running at speeds of just over 15 mph.

 

WildCat



            But that’s not all.  A bipedal robo-ostrich, “FastRunner,” has been modeled (computer simulated prototype) as, yet another, more advanced battle ‘bot.  FastRunner’s two legs will allow it to gain more speed and move with more agility than any four-legged robot ever could.

FastRunner / "Robo-Ostrich"

            But let’s take a few steps back.  There’s a smaller less celebrated robot that has had a significant place in the development process of all this robotic technology.  I can’t call this an “unsung” robot, but it’s certainly “less-sung” than the full sized robots we’ve been talking about.  To many, this small robot seems almost like a detail on the R & D trail to the ever-growing family of ever more amazing legged robotic achievements.  But, sometimes, there's more than you'd suspect "in the details."  

LittleDog

            LittleDog was developed by Boston Dynamics with DARPA funding.  Unlike other robotic prototypes, Little Dog was never intended as a stand-alone “field” robot.  LittleDog was, and is, a “testbed.”

            A testbed is a sort of a standard “model” of a device of a certain type -- such as an automobile, airplane, computer, or computer operating system.  This model is used to test new components.  So, let’s say an automobile manufacturer develops the prototype of an innovative new automobile engine or chassis.  The manufacturer’s research division will maintain a sort of “standard” or “model” vehicle into which the newly developed component and be installed and tested. 

            So, LittleDog, “The Legged Locomotion Learning Robot,” is not, and never will be, a robot for use in the field.  Instead, it is a model used to test components being developed for other projects.  And there is more perfected technology stuffed into this small ‘bot than you'd ever guess. 

            Each of LittleDog’s four legs is powered by three electric motors.  At a length of about 12 inches, a width of about 7 inches, and a height of about 5 and a half inches, this small ‘bot can move over obstacles much larger than the length of its legs and body.



LittleDog

            Several separate teams are working at the development of LittleDog’s speed and agility of movement.  All are confident that, if they can make LittleDog do it, the same capacities and abilities can be built into its bigger “field” counterparts.   LittleDog already has such a good “sense of it's surroundings” that it can avoid obstacles that, sometimes, trip-up its comparatively giant “field” counterparts.

            Among other things, LittleDog is trying out new software, which is intended to allow this little ‘bot to read maps and navigate through the corresponding terrain.  Other teams have "taught" this 'bot new walking techniques that allow LittleDog to negotiate obstacles the robot could neither see nor predict.



            While LittleDog may not actually “run with the big dogs,” those bigger dogs can't do anything that LittleDog hasn’t done first.

 

Thursday 5 June 2014

GCLM5444HOxenia

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.

Army, Lockheed to test drones-only mission, by air and land

            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