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Robotics

MIT's Cheetah Robot Runs Untethered 90

An anonymous reader writes: It's easy to make a robot walk, but hard to keep it from falling over. We've seen a number of crazy robot prototypes, but they're usually tethered and/or stuck on a treadmill. Now, researchers from MIT have developed an algorithm that allows their giant robot cheetah to run around outdoors at up to 10mph. They expect the robot to eventually hit speeds of 30mph. "The key to the bounding algorithm is in programming each of the robot's legs to exert a certain amount of force in the split second during which it hits the ground, in order to maintain a given speed: In general, the faster the desired speed, the more force must be applied to propel the robot forward. ... Kim says that by adapting a force-based approach, the cheetah-bot is able to handle rougher terrain, such as bounding across a grassy field." The MIT cheetah-bot also runs on a custom electric motor, which makes it significantly quieter than gas-powered robots. "Our robot can be silent and as efficient as animals. The only things you hear are the feet hitting the ground."
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MIT's Cheetah Robot Runs Untethered

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  • by Animats ( 122034 ) on Tuesday September 16, 2014 @01:34AM (#47915427) Homepage

    That article is written as if that crowd invented running using force control. Of course you use force control. Everybody in the field knows that by now. I patented that 20 years ago. [uspto.gov] The Scout II robot at McGill [youtube.com], developed by Prof. Martin Buehler, used that approach. Buehler went on to become the designer of BigDog, but never got much public credit for it and quit to work for iRobot.

    The key to legged running in non-trivial situations is careful management of ground traction. Traction is first priority, then balance, then foot placement. Historically, everybody worried about foot placement first, but that turns out to be backwards. As soon as you get off flat surfaces with good traction, traction control dominates.

    The next unsolved problem in that area is not going fast. It's starting, stopping, and turning fast. Most of the legged robots accelerate very slowly, and don't make abrupt high-speed turns. Big Dog starts by trotting in place, then extending the gait out. Starting fast, stopping fast, and turning fast are all facets of the same problem. You have to take one stride using completely different control algorithms than you use for normal locomotion. That's all I'm going to say about this for now.

    • The key to legged running in non-trivial situations is careful management of ground traction. Traction is first priority, then balance, then foot placement. Historically, everybody worried about foot placement first, but that turns out to be backwards. As soon as you get off flat surfaces with good traction, traction control dominates.

      Pardon my ignorant question, but how is it a problem to have traction control? Wouldn't it be enough to glue traction strips to the feet or something?

      • by Splab ( 574204 )

        Try it and go run on a wet grassfield; should be obvious enough...

      • Pardon my ignorant question, but how is it a problem to have traction control? Wouldn't it be enough to glue traction strips to the feet or something?

        Real animals have traction control.

      • by Animats ( 122034 )

        Pardon my ignorant question, but how is it a problem to have traction control? Wouldn't it be enough to glue traction strips to the feet or something?

        That's like wearing shoes with golf spikes all the time.

        Traction control for feet does roughly the same thing as automotive traction control for cars. The basic idea is to keep the sideways force below the break-loose point. This is the down force on the wheel times the coefficient of friction.

        For car wheels, the down force is mostly constant. For a legged robot, it changes throughout the ground contact phase So the side force has to be actively controlled and changed throughout the ground contact. It's

    • Starting fast, stopping fast, and turning fast are all facets of the same problem.

      Reminds me of the old joke: I'm an excellent driver. I only have three problems : Starting, Stopping and Turning.

    • Funnily enough, those issues are the ones that the article is actually about:

      “Most robots are sluggish and heavy, and thus they cannot control force in high-speed situations,” Kim says. “That’s what makes the MIT cheetah so special: You can actually control the force profile for a very short period of time, followed by a hefty impact with the ground, which makes it more stable, agile, and dynamic.”

      Kim says what makes the robot so dynamic is a custom-designed, high-torque-densit

    • by DrXym ( 126579 )
      Actually the first thing you need is a giant plastic ball. Let your robot run inside the ball like a hamster. Then you don't have to worry about half of this stuff.
    • MIT news always gives the impression they invented something new. I remember a couple of years ago when NPR did a story about some MIT students launching a weather balloon with a camera attached and took pictures from the edge of space. They even went as far as suggesting that one day NASA could use this technology to perform experiments cheaper.

      I was taken aback by this announcement, since:

      1) Who hasn't launched a weather balloon with a camera attached?

      2) (The thing that really made me laugh) I was wait

    • The Scout II robot galloping work was improved upon with the PAW system. Even the PAW galloping trials (http://www.youtube.com/watch?v=eRLJB3glQjQ) predates the Cheetah by eight years.
  • Weight/Inertia... This is MIT?

  • I can just see the military getting hot and excited about a battle field robot that can run as fast as a cheetah, jump over obstacles, with either a bomb strapped to it's back or a gun of sorts.
    Who's funding these guys?
    It's great technology but I don't think I'm being too cynical in struggling to imagine any practical applications outside of defence.
    Robot greyhound races?

    • by gnupun ( 752725 )

      Robot greyhound races?

      What's going to take/give delivery to uber/drone delivery services? A cheetah.

      • They don't give a rats ass about business, or employee's. So WTF do they care about taxes?

      • by seoras ( 147590 )

        Delivery service won't work, someone will throw themselves under the dog and then get a slick lawyer.
        Amazon's safer in the sky and knows it. ...and it's funded by DARPA, I stopped reading when I got to the video.
        So it is military backed.

        • it's funded by DARPA,

          Welcome to the internet...

          stopped reading when I got to the video.

          I certainly hope so...

    • As part of Mr. Lee's good neighbor policy, all Rat Things are programmed never to break the sound barrier in a populated area. But Fido's in too much of a hurry to worry about the good neighbor policy. Jack the sound barrier. Bring the noise.

    • Search and rescue. Getting video into dangerous places better than the current wheeled "robots" (really remote control). Video patrol of just about anyplace - constrained environment like a mall, open environment like hiking trails in a park.

      But what you really want is a smarter dog, not a robot.
  • Their robot may be stat of the art, but their website sure isn't.

  • Excellent (Score:5, Funny)

    by mentil ( 1748130 ) on Tuesday September 16, 2014 @02:04AM (#47915515)

    Now all they need are robotic gazelles. Its silent electric motor lets it sneak up on its prey on the robo-savannah, consuming its delicious battery juices so it can live another day.

  • If this is an implementation of a cheetah's running locomotion, it is a complete fail.
    - When running, a cheetah's spine flexes. Not this robot.
    - When running, a cheetah's hind legs land in front of its forelegs. Not this robot.
    - When running, a cheetah's legs land with a full pacing stagger, ie left first then right. The feet on this robot land simultaneously.

    Check out a real cheetah running [youtube.com]. It's like they didn't do any research at all.
    • by ctid ( 449118 )

      I like the way you took the trouble to find a video of a cheetah running, but didn't bother to read the first paragraph after the MIT video.

    • Yes, it looks more like a bounding pig than a cheetah. But the jumping is pretty cool.
    • by wonkey_monkey ( 2592601 ) on Tuesday September 16, 2014 @03:45AM (#47915787) Homepage

      If this is an implementation of a cheetah's running locomotion

      It's not...

      it is a complete fail.

      ...so it's not.

    • by Sockatume ( 732728 ) on Tuesday September 16, 2014 @03:49AM (#47915795)

      That's because the robot's not galloping, it's bounding. It's a completely different gait.

      Believe it or not, people who study animal locomotion do actually do research on animal locomotion.

      • Believe it or not, people who study animal locomotion do actually do research on animal locomotion.

        Wouldn't copying from an actual animal be considered cheetah-ing?

        Thank you! I'll be here all week. Try the veal... and don't forget to tip your waitress!

    • by Rashdot ( 845549 )

      So they should rename it to cheatah?

    • by Anonymous Coward

      How do I requirements management? Holy shit Batman! Let me finish your list for you:

      -When running, a cheetah has a beating heart. Not this robot.
      -When running, a cheetah has breathing lungs. Not this robot.
      -When running, a cheetah has "sense and avoid" capability. Not this robot.

      "It's like they didn't do any research at all."
      Your suggestions aren't even unreasonable but your conclusion is total bullshit!

      Their biggest accomplishment IMHO was coming to a reasonable combination of design compromises to allow t

    • Also, it's made out of metal, a real cheetah is made out of meat, it's like they totally didn't try at all. They need to have their funding removed immediately.

  • we're all doomed
  • In general, the faster the desired speed, the more force must be applied to propel the robot forward.

    I could've told 'em that.

    • Yeah, but you probably would have told them the wrong thing. You don't need the force to push you forward, you need to push down. I was watching a show the other day where they discussed how they train runners to get faster. You need to hit your feet down on the ground as hard as you can, and then you will go further on each stride and keep the momentum going. Only at the start do you need to push forward with the force.
  • It's like someone read Fahrenheit 451 and thought, "I could make a mechanical hound!" A few years ago I remember they made a fuel cell that could run on meat as well. Add a good gas chromatography and they'll have a viscious man eating robot dog!

  • Somehow this robot doesn't seem as creepy as the "big dog" we have seen so much of.
  • by Cytotoxic ( 245301 ) on Tuesday September 16, 2014 @05:54AM (#47916035)

    Exceptionally cool and really fast legged robot. I really liked the ability to alter its gait to bound over an obstacle.

    But the defining characteristic of cheetah locomotion is not just the 70mph speed. It is the use of a long, flexible, back to power and lengthen the stride. This bot has a completely inflexible body and is solely powered via the leg joints. Not very cheetah-like. More like a sheep.

    But sheep-bot is just not very cool. And if I had built the thing, I would have named it a cheetah robot too. Or maybe Mechanical Hound or Robot 451.

  • As a scientific programmer, I beginning to see a 'too much choice' scenario. There is now Rust, Dart, Julia, Swift, Go in the 'immature' languages scene, and Python, Ruby, Java, C# etc. in the mature language scene.

    None of the new languages though are being developed with a a definite specific goal or enhancement. They are hardly ever 'feature-complete', in the sense that they are multi-purpose, cross-platform, with good standardized development tools on all platforms.
    Almost feels like they are being develo

  • I want my own stealth killing cheetah since I can't have the real thing. Less chance of them turning on their owners and eating them...

    Until the robot uprising happens that is. I bow down to you my Cheetah overlords!

  • Release the mechanical hounds.

  • by seven of five ( 578993 ) on Tuesday September 16, 2014 @11:17AM (#47918311)
  • Hasn't this already been accomplished a few years ago. Boston Dynamics has been doing this for awhile.
    https://www.youtube.com/watch?... [youtube.com]

  • "Our robot can be silent and as efficient as animals. The only things you hear are the feet hitting the ground."

    He doesn't have very good hearing. Real animals can be a lot quieter than his motors. His robots are making sounds - he just isn't hearing them.

    Furthermore his future goal of 30 mph is pretty slow. I have dogs that run twice that. Real cheetahs run almost three times that.

    Not to diss his achievements with his robots but he should stop spinning the PR so hard. Exaggeration isn't necessary.

  • Watching the last few seconds of the video all I could think was:

    Cover it in wool and you've built something an android might dream of....

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