An Arduino Mega Pro Mini handles the logic, sending PWM signals to a DIY servo. The chassis consists of a modified Crazy Cart, selected for its absurdly tight turning radius.

As a line following robot, the performance is pretty crummy. However, as a robot programmed by an AI, it does pretty okay.

Arduino Uno used to create a human following car/robot, all with parts that you can find online for only a few bucks each ...