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Robotics Build

Robot With Broken Leg Learns To Walk Again In Under 2 Minutes 69 69

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

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  • Just Testing Code (Score:5, Insightful)

    by Anonymous Coward on Wednesday July 23, 2014 @10:38AM (#47515399)

    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.

  • by earthman (12244) on Wednesday July 23, 2014 @10:51AM (#47515495)

    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!

  • by Wrath0fb0b (302444) on Wednesday July 23, 2014 @11:26AM (#47515771)

    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 [wikipedia.org].

    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 ...

  • by iONiUM (530420) on Wednesday July 23, 2014 @11:29AM (#47515805) Homepage Journal

    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.

  • by fahrbot-bot (874524) on Wednesday July 23, 2014 @12:58PM (#47516471)

    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.

  • by Dutchmaan (442553) on Wednesday July 23, 2014 @03:02PM (#47517391) Homepage

    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.

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