Hi everyone!

I'm proud to introduce you to... Arduway, a robot made of Arduino and Lego NXT components.
I'm releasing soon a software library to control LEGO NXT motors and a few sensors I have used: it's not as well documented as it could but I think it will still be better than nothing...



A short movie is coming soon as well!

Video: http://www.youtube.com/watch?v=Tw9Jr-SPL0Y
Hope you enjoy  

Nice! Thanks for sharing

I'll bite. How are you measuring the tilt?  A accelerometer, a gyroscope or both?  Or, are you doing it with distance sensors?

Tom

and how do you correct the drift ?

PS great work!

Quote:


To do it right, it sounds like you need an accelerometer, too.  David Anderson provides a pretty detailed description of how he did this on his nBot web site

He explains, "The gyroscope and accelerometer are combined with complementary filters to provide an inertial reference sensor. The ADXL202 accelerometer provides accurate static tilt information, when the robot is not accelerating. The gyroscope can be integrated to provide accurate dynamic tilt information, but the integration tends to drift over time. Combining the two sensors provides a robust inertial measurement."

But, there are apparently a number of different ways to make a balancing robot.  I've heard of at least one person who managed to do it using distance sensors to figure out the tilt based on the distance of the sensor to the ground.  

you've been blogged:

http://arduino.cc/blog/?p=89

/d

Well done,
Its a really nice project and great platform for control scheme design.

I have one question if you don't mind me picking your brain. How did you do the numerical integration? On the arduino itself? or integrate the signal before the arduino a/d?

If on the arduino what algorithm did you use? and what time step did you use?

Thanks and well done again.

David