[XCSSA] Stumbling robot...

[X-otic Computer Systems of San Antonio]

I have seen a few of these self balancing robots made with the Basic 
Stamp but not with the Propeller.
So here is my version of the so called "Inverse Pendulum" robot...

Still need some tweaking but it looks like it's doable...
There is no gyro or accelerometer on the bot, in stead there is an ultra 
sonic distance sensor that measures the distance to the floor and tries 
to keep the balance that way.
The distance is measure every 20 ms and then a PID control is used to 
control the motors.

Pretty fun weekend project...

Picture,
http://i385.photobucket.com/albums/oo298/fsafstrom_2008/100_0091.jpg

Video,
http://s385.photobucket.com/albums/oo298/fsafstrom_2008/?action=view&current=100_0104.flv

/Fredrik