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Robotics Hardware

Hobby Humanoid Robot KHR3HV Rides Bike At 10k/h 114

Posted by timothy
from the not-even-training-wheels dept.
An anonymous reader points out a fun robot project from Japan, writing: "The robot pedals with its feet at variable speed. The steering is done by the robot hands as with a normal bike, and remote controlled by a human. Stability is achieved by relying on the inertial centrifugal effect of the front wheel and on a gyro aided by a PID controller that takes over steering when driving in a straight line. Seems like when the robot steers his arms he also bends the waist leaning a bit into the turn. Braking is achieved by taking the feet off the pedals and pointing them down to the ground using the metal feet as friction breaks."
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Hobby Humanoid Robot KHR3HV Rides Bike At 10k/h

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  • by Anonymous Coward

    slashdotted

  • by Anonymous Coward
    The site was probably written in opa
  • Slashdotted (Score:4, Informative)

    by definate (876684) on Saturday October 22, 2011 @09:59PM (#37807648)
  • only 6.2 miles /H

    • by hawguy (1600213)

      only 6.2 miles /H

      But he appears to be only around 1 foot/30cm high, so he's around 1/5 the size of a human rider, he'd ride much faster if he was full size.

    • Re: (Score:3, Funny)

      by Anonymous Coward

      a robot rode a bike without falling over...... and you're upset he didn't go faster?

      • Depends on whether or not that's the only function it can perform. If the robot can also be removed from the bike and walk, then it's an achievement. It appears that it has all the usual servo-hinges that other biped robots has, so my guess is that it can.
    • by Anonymous Coward

      I, for one, welcome it that the article tried to mention metric units. But c'mon. 10k/h? That means 10 kilograms per hour or what?

      • by Anonymous Coward

        I, for one, welcome it that the article tried to mention metric units. But c'mon. 10k/h? That means 10 kilograms per hour or watt?

        There, fixed that for you.

      • by tsa (15680)

        It means 10000/h.

  • by Jane Q. Public (1010737) on Saturday October 22, 2011 @10:09PM (#37807690)
    A number of very thorough studies have been done. Neither "inertia" or "centrifugal effect" from either front wheel or rear contribute anything significant to the stability of a bicycle. [wired.com] The fact is that even today, we do not fully understand the phenomenon. The only thing we are sure of is that it does not work the way most people think it does.
    • by definate (876684)

      What about the stability of a motorcycle? As this is often quoted quite a lot with those, and could be more accurate, since the weight of our wheels is a lot more, and they're spinning a lot faster.

      For instance, people suggest that when you lift your front wheel, you need to make sure you don't press the front brake, because if it stops spinning, you lose a lot of your stability.

      • by vivian (156520)

        If you are lifting your front wheel then you are doing it wrong. Both wheels are supposed to be on the ground at all times. If my friend had followed this simple rule, he'd still be around today instead of having gone under a bus.

        • by definate (876684)

          Pretty sure motorcycles don't work unless at least 1 wheel (often the front wheel) is off the ground.

      • by thestuckmud (955767) on Sunday October 23, 2011 @12:40AM (#37808048)
        This paper" [berkeley.edu] states that "contrary to common belief, gyroscopic forces play only a limited role in balancing and steering". The "feel" of a bike (pedal or motor) is said to be dominated by "trail", and aspect of steering geometry; gyroscopic torque is "non-negligible", but "much smaller than trail torques".

        Gyroscopic steering is said to assist no hands bicycle riding, but I'm not a motorcycle rider and don't know about wheelie stability.
        • BMX will lock the wheels when performing tricks (in mid air) - it makes the bike a lot less sluggish to manoeuvre. Mountain bike freeriders/dh'ers will leave the wheels running (usually subconsciously) to help keep the bike pointing in roughly the right direction. [try doing a long fast jump with the wheels locked and it definitely loosens everything up - usually ending in a big crash!] -- can't find any internet citations - except that I do it myself.

        • Okay, so it's not negligible. Still, it's not a major factor.

          However, according to the researchers at Cornell I originally linked to, "trail" has virtually no effect at all. The idea that it does is apparently a myth. Or in this case, actually negligible.

          Note the distinction: bicycles have trail, but not caster. They are similar, but not the same.
          • Correction: I thought that caster and trail were calculated differently. But I learned that caster and trail are actually two names for the same property.
            • Well... Bicycle frame builders don't talk about caster, which refers to an angle related to head tube angle and possibly rake (I'm not sure which angle it actually refers to). We do talk about rake (the distance the fork is offset from the steering axis) and trail (the distance between the point where the steering axis intersects the ground and the vertical projection of the wheel axis onto the ground).

              Unfortunately, you are misinterpreting the conclusion of the very interesting article you cited. The
              • "Unfortunately, you are misinterpreting the conclusion of the very interesting article you cited."

                No, I misunderstood nothing. First, as this clearly shows, trail and caster are the same thing. [wikipedia.org] Second, I will quote, yet again, from the article:

                "The theory of gyroscopic precession holds that when a bike leans to the right or to the left, the spinning front wheel forces the bike to turn into the lean, effectively keeping it upright. Further, the caster effect likens the wheels of bicycles to those on shopping carts.

                Next time you go to the grocery store, notice how the point of contact for the cartâ(TM)s wheels are just behind the steering axis, which is the same imaginary line that extends downward from the forks of the bike. That makes wheels on casters self-righting: As soon as they start to tip, they turn into the direction of the fall, straightening themselves out again.

                To debunk the theory, Papadopoulous and colleagues built a bike that eliminates both effects."

                Okay? One of the two things they were specifically debunking was that trail (or caster) is responsible for the stability of a bicycle.

                I did not misunderstand it; perhaps you did. Feel free to read it over again.

                • First, try googling "bicycle castor". You will find that the unfortunate clause in the Wikipedia article you cite is the only reference on the internet that equates caster with trail. The word "caster" when used with regard to vehicle suspensions refers to an angle, not a linear measurement. The confusion probably arose due to the fact that castor angle can be inferred from rake, trail, and wheel size, which are all linear measurements.

                  Trail is a guideline used by bicycle designers. It is neither nec
                  • But you neglected the part of the study that showed eliminating trail had no significant effect on the stability. While that is not an explicit statement by a researcher, it strongly implies that trail is not, in fact, an important factor.
                    • Sigh...

                      On the contrary, the Science paper mentions that negative trail can have a dramatic effect on bicycle stability: "When Jones modified his bicycle by placing the front-wheel ground contact in front of the steer axis (negative trail, c < 0) he could not ride no-hands." Have you read the paper?

                      One of the most surprising results is that it is possible to construct an unusually weighted "bicycle" that remains stable despite having slightly negative trail. However, this has little relevance to t
                    • Yes, I have the paper, but it is irrelevant to the discussion.

                      It is not I who is having trouble here. You are confusing whether trail does have an effect on a standard bicycle, with whether it is necessary for the stability of a bicycle.

                      I apologize if my unfortunate choice of words (e.g., "not an important factor") misled from the point I was trying to make: that according to the Cornell study it is neither the most important factor, or even necessary.
                    • You are still incorrect. For the familiar bicycles we ride every day, trail is the most important factor governing bicycle self-stability. Sure, you can read the supporting text for the Science paper and find a half dozen or more two-mass-skate bicycles with surprising stability properties, and there may be more to discover, but if they do not reflect the properties of the designs we have found to be useful, or suggest new alternatives, then the analysis is of purely academic interest.

                      Here's A. L. Schw
                    • "You are still incorrect. For the familiar bicycles we ride every day..."

                      Ehhhhhhhh. (sound of buzzer going off). You lose. You simply proved the point I made in my last comment:

                      Repeat: "You are confusing whether trail does have an effect on a standard bicycle, with whether it is necessary for the stability of a bicycle." [emphasis added]

                  • I should add that your comment has also restored my earlier belief that caster and trail are indeed calculated differently.
        • by fatphil (181876)
          Curious link. Do you honestly expect people to believe this - "Did you know that to turn a bike to the right, you actually push the handlebars to the left?"?!?!?

          I certainly don't.

          I know that I'm right in that regard, as I've won many a bet, even against physicists, by making that very claim, and then demonstrating it! It seems to be even more how-does-it-work than even fucking magnets [ICP 2009].

          I shall definitely enjoy reading that paper - thanks for posting the link!
          • Forget about the handlebars for a moment. The fact is that you can't turn to the right unless your center of mass is to the right of the bicycle's wheels. If you try to turn from a stable position, you will soon find yourself fall to the left and will crash unless you correct your course by turning left. That's the crucial point.

            OK, so how do you get your center of mass to be positioned to the right? Most riders do so by countersteering - turning slightly left first. Most riders are not conscious of
      • by fatphil (181876)
        If you lift your front wheel and retard it, then you're basically asking to high side if it gets traction when it touches down. I think that risk far outweights any stability issue; you never want to high side, full stop.
      • by EETech1 (1179269)

        I remember reading about The Wheelie King about 25 years ago and this dude could ride wheelies literally forever, but he had to have an electric motor on the front wheel to keep it spinning for balance. You would think if anyone could ride successfully without the front wheel spinning, The Wheelie King could.

    • by Col Bat Guano (633857) on Saturday October 22, 2011 @10:39PM (#37807784)

      We do understand how to maintain balance on a bike.

      People steer into the continual tiny falls that happen all the time, actively steering the bike upright.

      • "We do understand how to maintain balance on a bike."

        That's completely beside the point, and in many situations not even true. If you read the article, they mention why bikes tend to be stable even on their own, with no human rider.

        • It is by the design of the steering mechanism that allows a bike to maintain balance even without a rider. A simple test: Stand beside your bike and with the front wheel straight, lean the bike to the left, the front wheel will turn to the left. Now repeat but lean the bike to the right, the front wheel will turn to the right. It is this that reaction that allows the bike to maintain balance when moving because when the bike begins to lean to either the right or left, the bike will automatically steer to th

          • Are you yet another one who didn't RTFA?

            That was the whole point: those things are what everybody thinks, but they are untrue!

            According to the Cornell researchers, it is the mass distribution of the bike -- both empty and with a rider -- that causes the steering effect. Not the steering design, not the caster or trail, and not a gyroscopic or centripetal effect.
            • Well, if a Cornell researcher says it, then it must be true. Though if you read what I had written, you will see that what I wrote relies heavily on the mas distribution of the bike to work. A simple test of my theory would be to change the steering mechanism of the bike to invert the direction of the wheel when the bike leans - if it is not the steering, then the balance of the bike would be unchanged.

              • "Though if you read what I had written, you will see that what I wrote relies heavily on the mas distribution of the bike to work."

                I have to disagree; it seems to me that what you wrote pretty much contradicted everything in that article. But I am willing to suppose that I misunderstood it all.

                I agree that a test such as you propose might clarify the issue, if it were carried out in a proper manner.

    • It is true that the gyro effects are not needed to ride a bike. That is why one can ride a bike with tiny wheels just as well as one with big wheels. However, at high speed it does have a very noticeable effect and does contribute to stability - for good or worse if your wheels are badly balanced. Once you reach speeds of 80km or over, the gyro effect becomes very strong indeed - you can literally hang off the side of a bike and not fall immediately, it will just turn slowly - been there.
      • by subreality (157447) on Sunday October 23, 2011 @12:59AM (#37808078)

        Actually, no, it's still not the gyroscopic effect keeping you upright. The caster and trail (parameters of a bike's front suspension geometry) result in the bike having a self-balancing effect: as you lean to the right, it wants to steer right, and the centrifugal force of the turn pushes you left, keeping you from falling over. This works fine with zero-mass wheels that do not have any gyro effect.

        At low speeds this effect is not enough for stability: with no active control it wants to turn constantly, and follows a squiggly, unsettled path. At mid-speeds it will want to turn, but they will be stable turns. At high speeds the bike becomes over-stable: if you let go mid-turn, the bike will automatically straighten itself out and return to a stable straight line. This is contrary to what you'd expect from the gyro effect, which would be to hold the bike leaning into the turn.

        The gyro effect does exist, but its really not that strong compared to your weight and all the other forces involved.

        • to prove the parent posters assertion - just try riding a bike with a negative rake.

          • "to prove the parent posters assertion - just try riding a bike with a negative rake."

            Your forks would cave in the first time you hit a bump. That was the reason designers included rake in the first place; no rake or negative rake cannot take road shocks. It puts all the strain where the forks are attached to the steering post.

            • by ultranova (717540)

              Your forks would cave in the first time you hit a bump. That was the reason designers included rake in the first place; no rake or negative rake cannot take road shocks. It puts all the strain where the forks are attached to the steering post.

              According to Wikipedia, ther purpose of the rake is to put the ground contact point of the wheel nearer to the steering axis, to reduce the caster effect and make the wheel easier to turn.

        • "The caster and trail (parameters of a bike's front suspension geometry) result in the bike having a self-balancing effect: as you lean to the right, it wants to steer right, and the centrifugal force of the turn pushes you left, keeping you from falling over. This works fine with zero-mass wheels that do not have any gyro effect."

          Did you even RTFA? According to the Cornell study, trail has no noticeable effect. They eliminated trail and it made no difference.

          Also, if you draw a line through the steering axis, you will see that bicycles do have trail, but they do not have caster. In fact the caster is negative on a bicycle; the wheel hub is in front of the steering axis.

          • Pardon me. I looked it up, and trail and caster are not different properties; they are in fact the same thing.

            Either way, according to the Cornell study it is not a major source of stability in a bicycle.
      • by tsa (15680)

        Did it hurt much?

    • by jklovanc (1603149)

      It would be nice if you actually read the article you are linking. They were also talking about gyroscopic and caster effect and not '"inertial" or "centrifugal effect"'. Here is a quote:
      "Gyro effects are important contributors to self-steering [and] so are caster effects. It's just that they are not essential."

      • "It would be nice if you actually read the article you are linking. They were also talking about gyroscopic and caster effect and not 'inertial' or 'centrifugal effect'. Here is a quote: 'Gyro effects are important contributors to self-steering [and] so are caster effects. It's just that they are not essential.'

        That's not a quote from the article *I* linked to. I have no idea where you got that. The words "gyro" (as opposed to "gyroscopic") and "essential" do not even appear in the article.

        So maybe YOU should read the article to which I was actually referring? Here's a direct quote, which directly contradicts what you wrote:

        "The theory of gyroscopic precession holds that when a bike leans to the right or to the left, the spinning front wheel forces the bike to turn into the lean, effectively keeping it upright. Further, the caster effect likens the wheels of bicycles to those on shopping carts.

        Next time you go to the grocery store, notice how the point of contact for the cartâ(TM)s wheels are just behind the steering axis, which is the same imaginary line that extends downward from the forks of the bike. That makes wheels on casters self-righting: As soon as they start to tip, they turn into the direction of the fall, straightening themselves out again.

        To debunk the theory, Papadopoulous and colleagues built a bike that eliminates both effects."

        Do you know what the word "debunk" means? Further, maybe you should pick up a physics book? While OP's original article did not use precise terminology, the fact is that "inertial" and "cent

    • by fatphil (181876)
      The article and paper seem to think that there are only two degrees of freedom for wheel placement geometry, but there are three. Quite why both avoided the words "rake" and "trail" is worrying too. I got the impression that these people really didn't understand the field at all.

      Your final sentence is certainly true, though.
      • The article about the Cornell research did not avoid the word "trail". In fact trail was one of the theories they were testing. Try reading it again.

        I stand corrected however, on one point. Earlier I wrote that caster and trail were two different things, apparently they are not.

        However, I am not aware of any theory that attributes stability to rake, except for its effect on caster or trail.
        • by fatphil (181876)
          The article is http://robosavvy.com/forum/viewtopic.php?p=32542
          Search in page for 'trail'
          Nothing.

          OK, that's only one experiment, but I don't think it's too much to conclude that no matter how many times I read it, I will still not see the word.
          • But you were replying to ME, and the article I linked to specifically covered trail.
            • by fatphil (181876)
              Good point. My attention wasn't on slashdot yesterday (messing about with trying new lightweight browsers) and I misspoke. The article I was refering to, the one that doesn't mention trail, is indeed the one you linked too. So I was right about that. However, I also misspoke in that I should have said "abstract" rather than "paper". So I boobed about that. If the abstract doesn't give me confidence in the reliability of the paper, clearly I'm not going to download the paper.
              • No, apparently you are still somewhat confused. The article that I linked to is about some research done at Cornell, but doesn't include an abstract. And it does discuss trail.
  • by Anonymous Coward
    Kilo what per hectare?
  • Is that inspired by some anime - or hentai - that I've never heard about?

  • Sarah Connor? *ding ding-aling* Come with me if you want a backy.

  • by antifoidulus (807088) on Saturday October 22, 2011 @10:16PM (#37807728) Homepage Journal
    Unfortunately most Japanese tend to ride their bikes at about 10km/h, so speed won't be an issue for this robot.....
    • by hawguy (1600213)

      Unfortunately most Japanese tend to ride their bikes at about 10km/h, so speed won't be an issue for this robot.....

      Given that they tend to ride on crowded sidewalks, riding slowly is a good thing.

  • by voidptr (609) on Saturday October 22, 2011 @10:47PM (#37807806) Homepage Journal

    Brakes. A device that stops the motion of a moving part is called a brake.

    • by dmomo (256005)

      Huh, by "as friction breaks", my head adjusted for the misspelling, and I took it to mean "as friction begins to fail" and was none the wiser.

  • K/H? I did WT*. Among Techies, this is major fail. https://secure.wikimedia.org/wikipedia/en/wiki/International_System_of_Units [wikimedia.org]
    • by Rennt (582550)
      Fun Fact: People in metric countries actually talk in K/H, not m/s.
      • by Anonymous Coward

        Uh no, we never use kelvins per henry to represent speed.

      • Re:k/h? (Score:4, Informative)

        by Noughmad (1044096) <miha.cancula@gmail.com> on Sunday October 23, 2011 @02:36AM (#37808360) Homepage

        Correct Fact: People in metric countries actually talk in km/h.

        • by don.g (6394)

          Possibly only correct in my country fact: When speaking, people often talk about "K"s rather than kilometres -- e.g. "I cycled 7 Ks to work today". Worse, they often use the same thing for kilometres per hour, e.g. "I was doing 12 Ks over the limit when the speed camera got me."

          • by xaxa (988988)

            Possibly only correct in my country fact: When speaking, people often talk about "K"s rather than kilometres -- e.g. "I cycled 7 Ks to work today"

            In my experience, that's true for Kiwis and Australians (and I don't know about other English-speaking metric countries). I've only ever heard 'kilometres' from non-native-English-speaking-Europeans, and had confused looks when I've said 'kay'.

      • The article states k (lower case) which is a prefix, not a unit.

  • Seems like when the robot steers his arms he also bends the waist leaning a bit into the turn.

    You steer a bicycle at almost any sort of speed by leaning, not turning the handlebars. In fact, if you turned the handlebars without leaning or shifting your weight, you and bike would tip over to the outside of the turn.

    https://secure.wikimedia.org/wikipedia/en/wiki/Countersteering#Need_to_lean_to_turn

    Make sure to have the "outside" pedal down and put weight on that foot, which shifts the Cg of you and bike low

    • by subreality (157447) on Sunday October 23, 2011 @12:42AM (#37808052)

      You should read your link more carefully. Leaning is necessary to turn, but it is not what causes you to turn.

      Read the next section. If you want to turn right, you briefly turn the handlebars left. That leans you to the right. You then turn the handlebars to the right, and enter a stable right turn. To exit the turn, you turn right a little harder, which brings you vertical again, and then you straighten out.

      • by Hentes (2461350)

        Turning the handlebar helps, but it's not necessary. That's why you can ride a bike without hands, as leaning will cause the handlebar to turn by itself.

        • Sure, when riding without hands, an initial lean causes the handlebars to turn, due to the angle of the steering pivot, and that's what causes the bike to change direction. Then the lean needs to be adjusted to stop the bike from falling over.

          Point is it's the steering that changes the direction of a bike, not the leaning. Even when steering is initiated with a lean, it's doing it via the steering. The leaning is primarily to stop the bike from falling over.

        • by ap7 (963070)

          Should one of the reasons not be the curvature of the tire cross section itself? As you lean to a side, the inner side of the tire has a smaller radius than the outer side. This will cause the vehicle to turn, won't it? Think about high speed race tracks and cars turning at high speed or think about trains and how curves are handled by them.

    • Make sure to have the "outside" pedal down and put weight on that foot, which shifts the Cg of you and bike lower.

      Not so - shifting your weight does not alter your center of mass. Weighting the outside foot is good practice for aggressive riders whose inside pedal might otherwise strike the ground in a sharp turn.

      I don't see what makes bicycling "nerdy", but if that's what you are looking for try a unicycle.

    • You guys are way overthinking this. Countersteering only takes effect past a certain velocity, as any motorcyclist will tell you. Yet, while it greatly increases efficiency, you can get by without it through EXTREMELY PRECISE steering or a drastic reduction in speed. I've heard cases of motocross racers being asked 'Why don't you counter steer?' & they go all 'Counter-what?' Leaning, on the other hand, is required to balance any 2-wheeled vehicle. I'll assume that when the robot turns the handlebar
    • by Spacejock (727523)
      I have a road bike, a flat bar and a hybrid. The hybrid is the most comfortable for long distances, but I added a pair of tri-bars which allows me to lean forward and put the weight on my elbows. I'm used to spending hours in that position, which is probably why it's the most comfortable way to ride.
      • by hawguy (1600213)

        WHen I took my MSF course, the most valuable I learned was that steering is counter intuitive. Well, I take that back - steering is 100% intuitive since my body knows how to do it, even if it doesn't always make sense to my brain.

        When doing a panic turn in obstacle avoidance, if you want to move the bike to the left to avoid the obstacle, you push the handlebar on the left side (i.e. you steer to the right). That quickly tips the bike over into a lean toward the left and your bike moves to the left. Even t

    • by xaxa (988988)

      For any slashdotters looking for a somewhat nerdy form of exercise, you can't get much better than cycling, and I highly recommend looking into it! [...] I do strongly recommend you NOT get a hybrid bicycle, however; the upright position is horribly inefficient and NOT comfortable for any more than a few miles because your weight is not split as evenly between your arms and butt as it is on a road bike.

      It's much more complicated than that...

      If the bicycle is just for exercise, and all you're going to do is ride for the sake of exercise, then a road bike is fine.

      But if you want a more practical bicycle -- something to use to get to work, go shopping, etc -- then a road bike is not the best choice -- far from it. You want something you can attach mudguards and a rear rack to, with a riding position that gives you a clear view. Sensible choices are a hybrid or upright/city bike. A hybrid bike is lighter a

  • Make it's face either Hello Kitty or a mecha drill, put it on a scale Honda Super Cub & fit it with a scale Malaysian stereo kit that blasts the J-poppiest happy hardcore you can find. Or YMCK. Then I'm sold.
  • This is a complicated mechanical task, especially the self-balancing mechanism. Nice work.

  • by jb_nizet (98713) on Sunday October 23, 2011 @04:25AM (#37808580)

    10 k inches? meters? feet? yards?
    k means kilo (1000). It's not a distance unit. I guess it's 10 km (1000 meters). Isn't it basic stuff that every nerd learns at school, at the age of 8 or 9 years?

  • Didn't the segway do this do something like this for a while now?

  • Outstanding job on the arms. I wonder what process was used to develop the routines, trial and error or machine learning. I can't find any additional info on the "Heart to Heart 4" software.

  • It almost sounds like the hardware in a phone could be used to keep this thing stable. I wonder if it runs Android.
  • This is awesome. Just a few years ago, it took Toyota research to put this little guy together : http://www.youtube.com/watch?v=VDm22U_teoQ [youtube.com] And it used active internal gyro wheel to balance itself. Now a pretty much off the shelf stock humanoid does the trick without special aids. It won't be long before these little hobby "toys" will be surpass the current capabilities of best lab robots. Several underlying technology trends are making them more and more capable. Rapidly advancing sensors of all sorts ( a

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