Lego Ball Balancing Robot

[Del]

Someone made this balancing robot using the Lego NXT:

[youtube]f8jxGsg3p0Y[/youtube]

http://www.youtube.com/watch?v=f8jxGsg3p0Y

[frodo]

  wow, how do they make it balance like that on a bal!!??

[cooldog]

the ball is placed between 4 wheels and the robot activtates each wheel depending on witch way it is leaning

[frodo]

the ball is placed between 4 wheels and the robot activtates each wheel depending on witch way it is leaning

yes, i got that part. what i don't get, is how it knows which way it is leaning.

[Trumpkin]

what i don't get, is how it knows which way it is leaning.

Gyro.

[frodo]

ok, so not accelerometer then which is what i was thinking.  what is a gyro? is it like a spinning thing like you see on tv?

[Trumpkin]

Take a look at this http://www.hitechnic.com/index.html?lang=en-us&target=d24.html

[frodo]

oh, i get it now. thanks Trumpkin 

[HDL_CinC_Dragon]

is it like a spinning thing like you see on tv?

Youre thinking of a gyroscope

[frodo]

i know, i've just figured it out. 

[Indiana_Geoff]

I wonder if you used a captured ball as a hip on a walking robot, could you increase it's flexibility and make it more adaptable to shock and motion?

[HDL_CinC_Dragon]

In theory you probably could but you would have to worry about the strength of the joint i think

[hazzer123]

Hmm what i'd like to see is an extension of this type of robot similar to the inverted double pendulum. So a robot on 2 balls balancing

Now that would be impressive!

[chelmi]

is it like a spinning thing like you see on tv?

Youre thinking of a gyroscope

A MEMS gyro *is* a type of gyroscope. It doesn't use a spinning wheel but a vibrating part.
See http://en.wikipedia.org/wiki/MEMS_gyroscope