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DIY Segway-Style Balancing Robot 63

clarionhaze writes "Many have tried, and failed, at getting a robot to sustain it's own balance. However; Steve Hassenplug accomplished it with with a small robot he made out of legos and a program in C that runs on BrickOS, an OS made for Legos! You can check out his site or read the article over at TechTV." Update: 01/18 15:52 GMT by T : Unanimous Cow writes "David Anderson of the Dallas Personal Robotics Group has an excellent web page with images and movies of his two-wheel balancing robot. This one uses a single-axis inertial measurement sensor and is very robust on uneven surfaces and off-road."
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DIY Segway-Style Balancing Robot

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  • Repeat... (Score:4, Informative)

    by Quixote ( 154172 ) on Saturday January 18, 2003 @10:30AM (#5107368) Homepage Journal
    Repeat from last year October []
    • for the record (Score:4, Interesting)

      by paRcat ( 50146 ) on Saturday January 18, 2003 @11:55AM (#5107626)
      I've read slashdot everyday for a few years, but for some reason never saw the original article. And given my interest in robotics, I'm very glad this was posted, repeat or not.

      I don't understand the mentality of someone who feels the necessity to point out every mistake that slashdot moderators make. I mean, you could be a troll, or you could just be anal. In either case, you contributed nothing to anyone. You apparently think someone has hired you to act as a critic. Critics annoy me to, unless they happened to be named Homer Simpson... then I just laugh.

      • Yeah, but from the other side of the fence, I read Slashdot every day, and have for years (less than you though :)) and the second I saw that, I thought "wasn't that on /. like a year a go or something?" It was kind of annoying wondering if this was new news or if it was a really old repeat.
        I think you would have been annoyed if you had seen it last time it got posted. Now, I am not one to criticize, and this is a free site, so I don't mean to suggest that anything should change, just that it's a little annoying.
        • This repeat wasn't so annoying. The really annoying ones are when CmdrTaco and Hemos start tag-teaming duplicates. Maybe it some sort of competition to see who can get the same article on the front page the most times?
      • I don't understand the mentality of someone who feels the necessity to point out every mistake that slashdot moderators make. I mean, you could be a troll, or you could just be anal. In either case, you contributed nothing to anyone. You apparently think someone has hired you to act as a critic.

        Well, aren't you Mr. Sunshine today?
        A critic is "one who forms and expresses judgments of the merits, faults, value, or truth of a matter." (from [], FYI).

        Read the 4 words that I posted. Do you see any judgement being expressed there, troll boy?

        I just pointed out that this article was a repeat from last year. Nothing more. Nothing less. Take it for what those 4 words mean. Don't try to read too much into things. And practice some reading (and thinking) skills while you're at it.

  • Whould'nt it be easier to give the bot 4 wheels?

    • Brilliant idea! Thanks for the tip.

      Hey, suddenly I'm thinking...if 4 are better than 2, how about 1,000? Please advise.
    • although I do see the benefit in people researching whatever and wherever their imaginations take them, and the point of this guy's project was to make the thing balance etc., yes, there is a point to be made that it would be a lot easier to just use four wheels. Kinda reminiscient of that old story about nasa spending big $$$ to develop a pen that would work in zero G while the russians just used pencils.

      All too often engineers and designers let the gee-whiz get in the way of practicality and usefulness, when it comes to everyday items.

      Still, legway is kinda neat. It looks a little dizzy at the end of the spinning video.
      • Actually, Snopes [] calls you on the American space-pen/Russian space-pencil legend []. Apparently, both the US and USSR used pencils until it was realized that floating bits of graphite (dust and broken lead) weren't the best things to have around electrical equipment, and that wood wasn't that great an idea in a pure-oxygen capsule environment

        Urban legends aside, it seems to me that a robot with two wheels would be able to move around in much smaller spaces than one with four, and that the ability to pivot on the spot might help in cramped maintinence areas where humans don't want to or can't go. After all, isn't the idea of robotics to replace humans in dirty or dangerous jobs?

        • I'm not surprised that the pen thing is false, but it makes a good story for telling around a table covered in beer and munchies :) Also, yes, surely there is a specialized practical application for a robot like this. Still, I stand by the gist of my post, even though I know that selling power comes into consideration with new products:

          All too often engineers and designers let the gee-whiz get in the way of practicality and usefulness, when it comes to everyday items.

  • Dean has a neat trick - every year he unveils a contest that asks the kids to do something new, engineering-wise. In two of these, it seems it was something he'd already figured out - the iBot wheelchair and the Segway - this just blew our minds in FIRST when we realized he and his companies had already come up with one method for something, and we were working on the same idea, guerilla, six-weeks to ship, Apollo 13 style.

    Damn neat. Leaves you speechless.

    Site seems /.'d - can't wait to see an RCX on two wheels...
    • The iBot has been a part of discussion at work lately.

      I work for a DME (Durable Medical Equipment) company and we were discussing an article about Medicare funding which brought up some issues about getting funding for newer products on the market.

      While talking about this the iBot came up. Our service manager, with 18 years of experience with repairing different standard and power wheelchairs, made some comments about the iBot I wanted to share.

      1. If it gets stuck on the stairs, would you want to be in it?
      2. Would you want to try to get a loved one out of it if stuck in earlier postition?

      Please discuss!
  • Asimo (Score:3, Informative)

    by DrunkenPenguin ( 553473 ) on Saturday January 18, 2003 @10:48AM (#5107410) Homepage
    Interesting story.. Here's something related: Humanoid robot ASIMO [] designed by Honda. Check out these impressive movies [] (realplayer format supported) of ASIMO in action. It would be nice to have one around to clean up the flat for example ;)

  • not news... (Score:5, Interesting)

    by IdahoEv ( 195056 ) on Saturday January 18, 2003 @10:50AM (#5107418) Homepage
    "Many have tried, and failed, at getting a robot to sustain it's own balance

    Many have tried and succeeded, as well. Balancing a two-wheeled robot (or balancing a pole from the bottom, or a four wheeled robot on top of a randomly rolling cylinder, etc.) is a fairly common design project for undergraduate engineering students in control theory. I'm not surprised someone did it in legos; they're a perfectly good platform for such an experiment.

    Kamen was not the first to come up with a balancing machine -- he's just the first I know of to market a useful (?) consumer product using such a system for human control of a vehicle. One of those head-smackers ... "why didn't I think of that?".
    • Re:not news... (Score:3, Insightful)

      by Bender_ ( 179208 )
      is a fairly common design project for undergraduate engineering students in control theory.

      Yes, its known as the "inverse pendulum problem" and is routinely modelled and solved in control system classes.

      .. maybe the interesting thing about the LegWay is, that the author managed to build it without knowing proper control theory ? The "controller" looks like a stupid two-point controller. A PID controller with properly tuned parameters would probably have improved the characteristics a lot.

    • Entrepreneurs (Score:4, Insightful)

      by JaredOfEuropa ( 526365 ) on Saturday January 18, 2003 @11:50AM (#5107613) Journal
      One of those head-smackers ... "why didn't I think of that?".

      Someone may well have thought of it before... someone may even have tried to whip one up in his basement, but Kamen took the idea and turned it into a commercial product.

      That takes a special kind of human being. A friend of mine is a little like that: he keeps a small recorder on him (and under his bed) and dictates ideas he gets to himself. He may wake up one night thinking "What if I printed ads for companies on those flexible magnetic sheets, slap them on cabs and pay the cabbie a sum for the privilege?" (In Holland cabs generally have no ads on them). Next morning he starts making phone calls, to buddies in advertising firms, to cab companies, to printers, ect. etc. He spends an enormous amount of energy, and 49 out of 50 times it comes to nothing. It's that successful nr. 50 that counts though.

      You have to admire people like that, having the drive to follow through on an idea and getting a company off the ground. Me, I am much to lazy for that... I'd wake up with an idea, think "Hmm neat" and go back to sleep.
      • I got the chance about a year ago to ride a Segway when one of the lead designers talked to a class I was in.

        Interestingly enough, he said Kamen came up with the idea when one day he slipped in the shower, and started thinking about stability.

        He also pointed out that the Segway is a great example of technology push, as everyone who's ever ridden one (and I'll include myself here) comments that there should be more of them.
    • Notice that he has to lift up the inverted pendulum before the robot can balance it. If a non-linear controller is used, it's possible for the robot itself to swing the pendulum upright(and keep it upright) from a horizontal position.
  • Some have failed, (Score:3, Informative)

    by Openadvocate ( 573093 ) on Saturday January 18, 2003 @10:58AM (#5107441)
    but then there are others [].
    There's some Quacktime and Real movies.
  • Only for embryos age 1 to 4 months.
  • by Isle ( 95215 )
    No BrickOS is not an OS for legos. Because legos is a competing OS made for LEGO and LEGO bricks.
  • I played with LEGO as a kid and now as an adult. I really wish someone would have nurtured that facination and help me learn a few things. You know, back in the old days, before you could look everything up on the internet. You actually had to have something documenting some basic technologies then.

    now a days, a kid could search google for a few things, and then find the answers or a great little document written by some MIT type. Where's that little thing that turns you into a kid when you need it.
    • by Poeir ( 637508 )
      I spent a lot of my childhood playing with Legos, and the time I wasn't spending playing with Legos, I was playing with computers.

      Anyway, to the point, during middle school, one of my projects was to build simple robots and control systems, using Legos and an Apple][e. It's been quite a few years, so I barely remember the details, but one of them drove around, another one acted as a motion sensor; the most complex one undertook a series of actions when the motion sensor was triggered, so it was nothing extraordinary; but Legos are (or at least were) used in some schools. This was a few years before Technics were even available, I think; so they may have even been the prototype.
  • You can just build one of these out of scaled up, 1 foot legos. Save thousands!
  • by RandySC ( 9804 ) <<SlashDot> <at> <Calligaster.Net>> on Saturday January 18, 2003 @01:04PM (#5107892)
    Using the DMCA, Dean Kamen and Segway have sued a group of nerds who, in their garage, built an open source Segway for $50 that uses Linux and a Beowulf cluster comprised of 4 386's and a rotary bladed push mower from a garage sale.
  • by Animats ( 122034 ) on Saturday January 18, 2003 @01:16PM (#5107964) Homepage
    Two-wheeled dynamic balancing isn't that hard. A simple feedback loop coupled to a sensor that measures tilt angle will do it. (A "tilt sensor" or accelerometer alone won't give you valid tilt, though. But see below.) One wheel, though - that's hard.

    A friend of mine built a self-balancing unicycle at the Stanford robotics lab in the 1980s. That's a much tougher problem. There's no metastable point that can be maintained with small corrections.

    If you want to do this, the correct sensor suite is a rate gyro and a pair of accelerometers. Back in the 1980s, both were expensive; now they're cheap ICs. They're auto parts. To get a good value for "down", you integrate the rate gyro and run it through a high pass filter, then add the accelerometer value,filtered through a low pass filter.

  • by Anonymous Coward
    More background on pole-balancing, fuzzy logic, neural networks and autonomy.

    Intelligent Autonomous Systems, neat robot projects including a neural-network pole-balancer, with pictures and whitepapers
    Link []

    Pole-Balancing Mini-Robot using neural networks
    Link []

    Intelligent fuzzy logic and PCB fab with pictures and video
    Link []

    Reinforcement Learning Pole-Balancing Applet by Appl
    Link []

    Demonstrations of Several Solutions to the Pole-Balancing Problem by Jeff Lawson and Chris Lewis
    Link []

  • sorry about the dupe guys... i'll search more thuroughly before i submit an article... still pretty interesting.
  • I remember October [], do you?


    Is halloween just this fuzzy "where was I?" feeling? I distinctly remember carving tux (onto a pumpkin).

  • it's quite simple (Score:2, Insightful)

    by JustKidding ( 591117 )
    It really is simple to build a robot that will retain it's balance, even without any electronics. You simply need big wheels and a heavy weight under the axle, so that the point of gravity is underneath the point of rotation (the axle). My guess is he did that, if only to assist in keeping the balance. The wheels seem pretty big, and it looks like to motors are right in between them. The last thing you want to do is make the robot top-heavy.
    • You just described a "weeble".

      Rest assured, the pictures on his web show no place you could hide enough weight to overcome the mass of that RCX brick. It sure looks real enough at first glance.

      Hey, if you doubt him, he's got building instructions on his web site, and source code to the program. Go build your own. It'd be far more scientific that accusing him of cheating.

  • by aclaudet ( 148067 ) on Saturday January 18, 2003 @03:10PM (#5108658)

    The balancing act is a very old automatic control problem. Solutions are given in almost every text on the subject. You can get more information on it by searching for "inverted pendulum" on google.

  • by Alexander ( 8916 )

    See, why overpay for a Segway, when I can build a better machine out of 10 GHZ Athalon's, a 500 GB HD, 15 GB of RAM and run Open Office, GIMP and Gnome!

    Oh, wait, I got Segway confused with Apple....

  • I really must say, I'm amazed by some of the comments. This robot wasn't built to prove anything to anyone. It was built because the builder wanted to challenge himself. If you don't like it, close your browser. Steve Hassenplug

"Say yur prayers, yuh flea-pickin' varmint!" -- Yosemite Sam