Rezero the dancing ballbot English lesson

Péter Fankhauser: Meet Rezero, the dancing ballbot

You are going to view a presentation from Ted.com. Technology Entertainment Design.

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.

1. Questions:

Can you guess what a ballbot is?

What could it be possibly be used for?

2. Please review the new Vocab & Phrases

a little fellow



inherently unstable

his pitch angle with a sensor

he counteracts and avoids toppling over

his own axis at the same time

due to

in motion

Now here’s the trick !



the orbiting mode

a very small footprint

practical applications

3. You are going to watch a full presentation.

This listening is for general comprehension. Please try to take notes.

Questions 2.

  1. Who developed this robot?
  2. How does he keep the balance?
  3. How many times per second does he counteract the balance?
  4. What the trick?
  5. How is distance maintained?
  6. What are some of the applications?

4. You are going to listen to the presentation again but this time with the transcript from the presentation.

Péter Fankhauser: Meet Rezero, the dancing ballbot

Let me introduce to you Rezero. This little fellow was developed by a group of 10 undergraduate students at the Autonomous Systems Laboratory at ETH-Zurich.

Our robot belongs to a family of robots called Ballbots. Instead of wheels, a Ballbot is balancing and moving on one single ball. The main characteristics of such a system is that there’s one sole contact point to the ground. This means that the robot is inherently unstable. It’s like when I am trying to stand on one foot.

You might ask yourself, what’s the usefulness of a robot that’s unstable? Now we’ll explain that in a second. Let me first explain how Rezero actually keeps his balance. Rezero keeps his balance by constantly measuring his pitch angle with a sensor. He then counteracts and avoids toppling over by turning the motors appropriately. This happens 160 times per second, and if anything fails in this process, Rezero would immediately fall to the ground.

Now to move and to balance, Rezero needs to turn the ball. The ball is driven by three special wheels that allow Rezero to move into any direction and also move around his own axis at the same time. Due to his instability, Rezero is always in motion. Now here’s the trick. It’s indeed exactly this instability that allows a robot to move very [dynamically]. Let’s play a little. You may have wondered what happens if I give the robot a little push. In this mode, he’s trying to maintain his position.

For the next demo, I’d like you to introduce to my colleagues Michael, on the computer, and Thomas who’s helping me onstage. In the next mode, Rezero is passive, and we can move him around. With almost no force I can control his position and his velocity. I can also make him spin. In the next mode, we can get Rezero to follow a person. He’s now keeping a constant distance to Thomas. This works with a laser sensor that’s mounted on top of Rezero. With the same method, we can also get him to circle a person. We call this the orbiting mode. All right, thank you, Thomas.

Now, what’s the use of this technology? For now, it’s an experiment, but let me show you some possible future applications. Rezero could be used in exhibitions or parks. With a screen it could inform people or show them around in a fun and entertaining way. In a hospital, this device could be used to carry around medical equipment. Due to the Ballbot system, it has a very small footprint and it’s also easy to move around. And of course, who wouldn’t like to take a ride on one of these. And these are more practical applications. But there’s also a certain beauty within this technology.

Time 5:16

5. Discussion

Would you like to take a ride on one of these?

Can you think of any other possible applications for this technology?

In your home for example ?

Can you see the beauty in this technology?

6. Post class work

This presentation from Ted.com is available with subtitles and we suggest listening 1 time with subtitles and then another time with the English transcript on the right hand side. Make notes of unknown words and phrases and try to guess their meaning from context.

Email question: When the robot is circling a person what is it called?

7.Using new vocabulary

Please use the vocab from sections 1 & 2 in the following sentences:

Group 1

a little fellow, to develop,  undergraduate,  inherent,  unstable, to counteract, to avoid, to topple over.

  1. Recently the global economy has been very ______________ .
  2. One night after drinking too many drinks, I tripped and _______________
  3. Before releasing the latest product on the market we need to ___________ a strong business plan.
  4. There is an ____________ flaw in the system. It will eventually fail.
  5. I need to think of an excuse to _________ the party, I really don’t want to go.
  6. I was an __________________ for 5 years before eventually becoming qualified.
  7. Messi might be ______________ but he can run rings around most players.
  8. In order to ________________ losing my pawn, I castled my King and started to attack!

 Group 2

an axis, due to, in motion, the trick, to force , velocity, an orbit, a footprint,

practical applications.

  1. What are the ____________________ of this new app?
  2. __________ huge demand, there are no more places available.
  3. I think that ____________ is to hold the bottle top down first, then turn the handle left to open. It’s child proof.
  4. There are many meteors in __________ around The Earth.
  5. I locked my keys inside the car. I think I will have to ________ the door open.
  6. Do you have a high carbon ______________ ?
  7. The ball is in play, the players are __________ and we can’t stop the action !
  8. The new Virgin Galactic flight has to go at a huge _____________ to reach the edge of space.

8. Using the new vocab, discuss the following statements:

Gadgets or devices in your house have a “trick” or “knack” in using them.

About Author

Justin Donlon

English Teacher & Content Developer Over 15 years of experience in engaging educational content

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