05:17
TEDGlobal 2011

Péter Fankhauser: Meet Rezero, the dancing ballbot

Filmed:

Onstage at TEDGlobal, Péter Fankhauser demonstrates Rezero, a robot that balances on a ball. Designed and built by a group of engineering students, Rezero is the first ballbot made to move quickly and gracefully -- and even dance.

- Roboticist
Péter Fankhauser is the leader of a team of students working on Rezero, a robot that balances on a single sphere. Full bio

Let me introduce to you Rezero.
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This little fellow was developed
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by a group of 10 undergraduate students
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at the Autonomous Systems Laboratory
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at ETH-Zurich.
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Our robot belongs to a family of robots
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called Ballbots.
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Instead of wheels, a Ballbot is balancing
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and moving on one single ball.
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The main characteristics of such a system is
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that there's one sole contact point to the ground.
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This means that the robot
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is inherently unstable.
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It's like when I am trying to stand
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on one foot.
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You might ask yourself, what's the usefulness
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of a robot that's unstable?
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Now we'll explain that in a second.
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Let me first explain how Rezero
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actually keeps his balance.
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Rezero keeps his balance by constantly
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measuring his pitch angle with a sensor.
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He then counteracts and avoids toppling over
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by turning the motors appropriately.
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This happens 160 times per second,
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and if anything fails in this process,
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Rezero would immediately fall to the ground.
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Now to move and to balance,
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Rezero needs to turn the ball.
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The ball is driven by three special wheels
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that allow Rezero to move into any direction
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and also move around his own axis
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at the same time.
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Due to his instability, Rezero is always
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in motion. Now here's the trick.
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It's indeed exactly this instability that allows
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a robot to move very [dynamically].
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Let's play a little.
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You may have wondered what happens
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if I give the robot a little push.
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In this mode, he's trying to maintain
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his position.
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For the next demo, I'd like you to introduce
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to my colleagues Michael, on the computer,
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and Thomas who's helping me onstage.
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In the next mode, Rezero is passive,
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and we can move him around.
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With almost no force I can control
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his position and his velocity.
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I can also make him spin.
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In the next mode, we can get Rezero
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to follow a person.
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He's now keeping a constant distance to Thomas.
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This works with a laser sensor
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that's mounted on top of Rezero.
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With the same method, we can also
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get him to circle a person.
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We call this the orbiting mode.
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All right, thank you, Thomas.
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(Applause)
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Now, what's the use of this technology?
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For now, it's an experiment, but let me
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show you some possible future applications.
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Rezero could be used in exhibitions or parks.
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With a screen it could inform people or show
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them around in a fun and entertaining way.
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In a hospital, this device could be used to
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carry around medical equipment.
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Due to the Ballbot system, it has a very small
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footprint and it's also easy to move around.
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And of course, who wouldn't like
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to take a ride on one of these.
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And these are more practical applications.
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But there's also a certain beauty
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within this technology.
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(Music)
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(Applause)
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Thank you.
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(Applause)
05:01
Thank you.
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About the Speaker:

Péter Fankhauser - Roboticist
Péter Fankhauser is the leader of a team of students working on Rezero, a robot that balances on a single sphere.

Why you should listen

Mechanical engineer Péter Fankhauser is leading a large team of student engineers and designers at the Swiss federal institute of technology in Zurich who are building a robot that balances and drives on a single sphere. Other roboticists have explored this idea, of stabilizing a robot on a ball, but what Fankhauser and his fellow students hoped to do was make it dance. “Adding dynamics was definitely one of our goals,” he says.

Working with researchers including Michael Neunert and Thomas Kammermann,  the team has produced Rezero, a ballbot prototype that can slalom around, resist toppling up to 17 degrees off vertical, and inspire myriad uses. Designed for high acceleration, it moves in an organic and even elegant way.  Fankhauser has started graduate studies in mechanical engineering this fall with a focus on robotics, control and construction.

He says of Rezero: "He wants to demonstrate what he can do, as if he was saying, ‘Backwards, forwards. I can do it all. Look at me!'"

More profile about the speaker
Péter Fankhauser | Speaker | TED.com