Here is our 2011 drive train and basic robot structure.
The signal light is hung inside the superstructure and allows for the lights to be visible at just about any angle.
Each color corresponds to the tube colors, and the green light informs us that we have successfully grabbed a tube.
Our drivetrain is a 6 wheel tank drive configured with four omnis and two treads.
It is VERY fast, and scary, especially in turbo mode.
It does have light sensors on the bottom and can detect following a line with an awesome correction space of +/- 2 inches.
penfieldrobotics.com
livestream.com/1511