2 wheels balancing robot. Modified for line following.
About this creation
When I had to build a line following robot to go to my first contest, I was trying to build something fast and accurate. Unfortunately I didn't had enough programming experience to do a good program for the robot and it didn't work. So I have decided to adapt an older robot that I have built just for fun, capable of dead reckoning and using an IR sensor for obstacle detection. Of course I didn't need the extra features but I have left them in place and I just replaced the IR sensor with a light sensor mounted on a long beam. Then I just draged and dropped blocks to build a simple line following program that wasn't optimised enough at that point.
The robot construction stands out by having only 2 wheels, canted inwards, with the motors and RCX mounted below the rotation axle. This way the robot balances on it's 2 wheels and looks pretty cool.
Take a look at the pictures (on BrickShelf) and if you want to build one just like it I have the MLCAD file.
This robot got me the "People's Choice Award" at that Line following contest in Ann Arbor.