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Robot With Broken Leg Learns To Walk Again In Under 2 Minutes

KentuckyFC (1144503) writes When animals lose a limb, they learn to hobble remarkably quickly. And yet when robots damage a leg, they become completely incapacitated. That now looks set to the change thanks to a group of robotics engineers who have worked out how to dramatically accelerate the process of learning to walk again when a limb has become damaged. They've tested it on a hexapod robot which finds an efficient new gait in under two minutes (with video), and often faster, when a leg becomes damaged. The problem for robots is that the parameter space of potential gaits is vast. For a robot with six legs and 18 motors, the task of finding an efficient new gait boils down to a search through 36-dimensional space. That's why it usually takes so long. The new approach gets around this by doing much of this calculation in advance, before the robot gets injured. The solutions are then ordered according to the amount of time each leg remains in contact with the ground. That reduces the dimension of the problem from 36 to 6 and so makes it much easier for the robot to search. When a leg becomes damaged, the robot selects new gaits from those that minimize contact with the ground for the damaged limb. It compares several and then chooses the fastest. Voila! The resulting gaits are often innovative, for example, with the robot moving by springing forward. The new approach even found a solution should all the legs become damaged. In that case, the robot flips onto its back and inches forward on its "shoulders."

15 of 69 comments (clear)

  1. Great by Sockatume · · Score: 5, Funny

    Crowbars won't save you now.

    --
    No kidding!!! What do you say at this point?
  2. Re:Another step to the T-800 Terminator by JaredOfEuropa · · Score: 2

    I for one welcome our self-compensating robotic overlords. Break a leg!

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    If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
  3. Just Testing Code by Anonymous Coward · · Score: 5, Insightful

    The "new" walking patterns are all pre-programmed. It's not learning, it's just running a few presets and seeing which results in the greatest forward speed. This has use, but I wouldn't throw around "learning" for this experiment. If a novel break comes along that the programmers have not planned for, the machine won't have a working behavior is it's data banks.

    1. Re:Just Testing Code by fahrbot-bot · · Score: 3, Insightful

      Well... It's leaning in the same sense that I did when I accidentally hit my thumb with a hammer and my grandfather said that I should try and not do that again - and that he had learned that solution himself in his younger days. Grandfathers are often helpful like that.

      --
      It must have been something you assimilated. . . .
    2. Re:Just Testing Code by Dutchmaan · · Score: 3, Insightful

      If a novel break comes along that the programmers have not planned for, the machine won't have a working behavior is it's data banks.

      Just presenting an oversimplified argument, but how would that differ from what our DNA has programmed for us. When I see robots using code for whatever specific reason, what's really going through my mind are that these are just micro components of what will eventually be incorporated into a much larger more complex "organism" Think of robots these days as simple organisms, where the primary concerns are mostly locomotion and simple functionality.

  4. It is even faster when injured... by earthman · · Score: 5, Insightful

    So the forward speed with all legs functioning is 0.25m/s, and with one leg broken it is 0.27m/s.

    Therefore, if a robot chases you, do NOT break its leg, because that only makes it chase you even faster!

    1. Re:It is even faster when injured... by Abstrackt · · Score: 2, Funny

      I picture breaking five legs and having it hop around on the sixth like a pogo stick.

      --
      They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance. - Terry Pratchett
    2. Re:It is even faster when injured... by wonkey_monkey · · Score: 5, Funny

      You clearly know nothing about extrapolation. The more legs you break, the faster it goes!

      Obviously the solution is to break one of your own legs to level the playing field.

      --
      systemd is Roko's Basilisk.
  5. the possibilities are endless. by nimbius · · Score: 4, Funny

    finally, a roomba with the possibility to give a cat PTSD.

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    Good people go to bed earlier.
  6. Fast Forward by retech · · Score: 4, Interesting

    There was a show in the 1980's from the CBC in Canada called "Fast Forward". Every week it focused on different tech innovations and where they'd go. One week they had learning robots. For the most part these were all simplistic things. But they had an "ant" that was about 2 feet long that was autonomous. The MIT crew that had created it realized that a centralized brain was just too big and power draining to build into the robot. So they had a system of sensors with rudimentary data and needs (leg=up, down, forward, backward, touching, not, moving or not, etc). If they shut it down it lost the memory of how to do anything it learned that day. They turned it on for the camera and it was a flailing ball of legs. Within 5 minutes it not only learned how to walk but circumvent objects, falls, danger. It still sticks out as amazing. Watching this video, I wonder what ever happened to that bot from nearly 30 yrs ago and wonder why does this spider seem to have actually gone back in time?

  7. Under two minutes of bullshit by Wrath0fb0b · · Score: 4, Insightful

    Hey, I can make all kinds of tasks faster by precomputing much of the work and then looking it up in a table. Congratulations, you've (re)discovered another instance of a Space/Time tradeoff.

    Now, in particular what they've done is still wicked cool -- it's a great idea to perform may millions of simulations ahead of time so that at runtime (heh) you can quickly draw on that data to adapt. It would be perfectly good research even without the over-the-top claim that they've somehow made the work faster as opposed to cleverly pre-computing much of it.

    But that's research -- you do something neat and then you make a ridiculous overstatement to generate buzz ...

  8. Controlling Damaged Aircraft by Anonymous Coward · · Score: 5, Informative

    I recall about a decade ago the Department of Defense or NASA working on this sort of adaptability for controlling damaged aircraft.

    An aircraft that suddenly loses use of a part of a wing or a flight control surface may still have sufficient flight control capability to fly home. The problem generally is that the pilot's control inputs won't produce the same motion responses, and the pilot generally has only seconds to map the inputs to control outputs.

    The idea was for the computer to do this mapping for the pilot, so the pilot would continue to apply the appropriate inputs (to roll the plane for example). The computer would determine which of the remaining flight surfaces to employ in order to best achieve the desired motion.

    One example that I recall was when the aircraft rudder was lost, yaw motion was compensated by dropping the landing gear and speed brakes on only one side of the aircraft to cause more drag on only one side, yawing the aircraft.

  9. Is this really a breakthrough? by iONiUM · · Score: 3, Insightful

    Against the Slashdot rules, I read TFA and watched the entire video.

    Unless I'm mistaken, all they did was create a giant array of possible motor combinations for movement, and then the robot just randomly tries them until it finds one which lets it more-or-less go in the same direction. It may not be the best one, but one that mostly works (it just stops at the first one that mostly works).

    Is that really a super big breakthrough? If the robot dynamically adapted to the broken leg, and figured out how to move using some semi-intelligent algorithm, I would say that is really awesome. But this is literally just trial and error through pre-created movement specs, randomly, then just selecting one that is mostly okay.

    Not trying to downplay other's achievements or research or anything, but it just doesn't seem like a big break through, unless "brute force" is something novel.

  10. As the Black Knight says... by alexhs · · Score: 2

    When animals lose a limb, they learn to hobble remarkably quickly.

    Right, I'll do you for that!
    It's just a flesh wound.

    --
    I have discovered a truly marvelous proof of killer sig, which this margin is too narrow to contain.
  11. How long to prevent it? by T.E.D. · · Score: 3, Funny

    How long will it take that robot to figure out how to stop the researchers from breaking its legs in the first place?