If you are the original author, please access your User Control Panel and update it.
In the video you can see that the robot stays at roughly the same spot on the floor and handles a lighter push without any problem. To achieve this I have two cascade PID controllers and low pass filter on both wheel speed and the robot's angle. Source code, component list and more info [Update 2012-07-27] I programmed a simple moving average filter. This will remove the rapid changes and make the robot calmer and with less overshoots. It also handles pushes much better than before. Video ...
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/robots/show/selfbalancing-robot-arduino