Mapping and localization are the hottest trends in robotics today. And what's more exciting is they can be both implemented with a low-cost robotics kit like LEGO Mindstorms!
I tried to make a self-driving car, after Google's famous car, but I got stuck on the mechanical side of things. I can't figure out how to build a revolving ultrasonic sensor on top of the robot, in order to do mapping and localization.
Any help is highly appreciated!