Ball inverted pendulum

We’ve seen several different balancing bot styles over the past few years, but this one is new to us. The BallP, short for Ball inverted Pendulum, balances on top of a ball. We’re not sure what the advantages are to this layout though. Anyone care to enlighten us? Even though we hadn’t seen this style, it is apparently not new. The Ballbot has been around for a while and might seem even more impressive visually.

40 thoughts on “Ball inverted pendulum

  1. I think the obvious advantages of the ball vs. 2 wheels is the ability for lateral movement and the ability of pin-point 360 degree rotation.

  2. Wheelbarrow mode is sweet. I wonder what the payload is, or could be scaled up to. Also how would/could this be made to handle things like, dust, dirt, mud, wood shavings, grease/oil, leaves/petals? Three of these would make for an interesting wheel chair base. Now to solve the stairs and mud/gravel problems.

  3. the advantage of BallP’s drive system over BallBot’s is that the BallP can spin on its vertical axis. for the purposes of navigating through halls or carrying a load alone, this is probably not useful. But doing the tandem load carrying thing with other BallPs or a human the ability to spin on axis would be quite useful.

  4. “We’re not sure what the advantages are to this layout though.”

    Wait… Did Hack a Day just ask “What’s the point?”

  5. Hmmm…This would be a nice innovation for something like the automotive industry. Remember the cars in iRobot?

  6. 3 points always make a plane. With your plane being defined by the ball circumference, the actual gradient of the terrain your ‘bot is on is now fairly irrelevant.

    It doesn’t matter what the slope is because it’s simply manipulating the ball to keep it steady against gravity (which it does to move anyway), and not worrying about balancing on the slope as well.

    With a ball that’s bigger than your stair hypotenuse (to avoid bouncing), stairs would also be a fairly trivial exercise. You could probably add in some suspension and dampening on the wheels to get the same effect for larger stairs or rough terrain.

  7. I can see this being very practical where moving industrial sized equipment with trucks is difficult through tight fit areas. using this with a gps system you can move very large objects with even more precision than a truck would be able to move said object.

  8. The problem is with distribution of the weight of the load. The concept is cool, but since it is a sphere the weight distrubution is only over the tiny part of the ball in contact with the floor. If the surface is soft it will bog down. Or if you put any significant weight on top, it could start tearing up, or causing significant wear, on the flooring material.

  9. A semester of control systems allows me to appreciate the work that went into this inverted pendulum controller. Simply awesome.

  10. @TJ,

    The problem with stairs is that there are a lot of types, making the ball larger will make the whole contraption larger. For my wheel chair example, that could mean that the chair + rider would no longer fit through a door. I use wheel chairs as an example mostly because i feel that all of them would not be what i would want in mine, if i needed one later in life.

    A compressible gas filled ball would take care of a lot of the suspension problems. If you had more than one of these under a chair it wouldn’t need the auto balancing system like this one. You should also be able to use this system as a way to track movement, by measuring the amount of change the omni-wheels move, and doing the same math you use to make controlled movements.

  11. I saw one and though about the work that went into it…

    then I saw two more and was amazed!

    This prof does good work!

  12. 1: Now they need to teach it to juggle and/or jump through a hoop of fire.

    2: Anyone else get the urge to stand on 2 of them and ride them around like roller-stilts?

    3: Think they can handle being stacked on top of each other? Especially after teaching the top one to juggle and the bottom one to roll across a tightrope?

    4: Is the name E-Circus trademarked yet?

  13. ChalkBored:

    1. I like it, but it might lose the ball on the way up and be unable to find it on the way down.

    2. A little bit, yes.

    3. The probably would be fine with that. They would have to be in “return to origin” mode, so that they stay in the middle of the bot they are sitting on. The bottom bot could be in passive mode, though.

    Juggling and tight-roping would require extra sensors/appendages, but it could be done.

    4. IT IS NOW! >:D $$$$$

  14. Err, just to clarify there: Point 1 was referring to the jumping, not the juggling. I was thinking of the bot leaping off the ball and landing on the ground :S

  15. You could have the single ball set in the center of a triangle of three balls. This would disperse the load over a much greater area and allow it to gimble and stay level while traversing uneven ground. This is a pretty cool platform I think.

  16. I was just thinking of this same idea earlier today while tearing apart an old ball mouse to get the rotary encoders. What if they made one a lot smaller, say the size of a ball point pen. Sure the printer already exists, but it would be cool having a “magic pen” that writes whatever you tell it to. You just need this same concept on a far smaller scale and an ink dispenser that pours the ink on the ball with a solenoid valve. I’m thinking about trying this with a mouse ball.

  17. One of the main strategies of this layout vs. the 2 wheel standard segway layout is that it is holonomic, meaning that it can instantaneously move in any direction. I heard once that segway built a similar device… imagine an indoor segway that could fit through doors. However, the draw back is that you only have one point contact with the ground . So if you lose contact, say by driving over uneven terrain or a slippery surface the chances for catastrophic imbalance are very high relative to 2 wheel balancing devices, like the segway, which have some redundancy.

  18. @Rob. I like that idea! I think the ink over the ball would cause the driving wheels to slip though.
    Personally I don’t think it would be possible to go much smaller than a mouse ball but it would be cool to get it down to that size.

  19. I also thought of the cars from iRobot. Maybe with an off-vertical setup, it would be possible. Or, more than 3 control points. Or, primary vs secondary control points. For example, 2 control points in contact with the ball, and a third to swivel direction of rotation. With the proper application, this could easily be converted to control a 2+ “ball” vehicle in all directions. If the control points handled the role of the suspension, this is very feasible… IMO.

    Just some thoughts

  20. @ iSmael: If it was just 3 balls mounted to a frame (and presumably some form of arduino) it wouldn’t be as impressive. While they don’t need any of the hard work that went into balancing them and making them move independently when all three are connected like that, it makes it that much cooler. Isn’t that almost half of what hack-a-day is about?

  21. As for uses, maybe this can be used as a PART for other robots so they can get some sense of balance, instead of having to program every movement bit by bit?

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