Glad to see there's *some* interest in robotics on this forum
The white line was a reflective sort of tape. Heh actually it was electrical tape. Under the line was a wire running 100mA of current @ AC 75Khz. Not much.
Teams can use any method they want to find the "track" but spec rules determine that at no point in time will your car drift further than 18 inches from the main line of the track. If you can imagine bombing down a straight section and then suddenly coming up on a turn, this is pretty hard. This was the reason behind the cones in the video, and also the placement of the cones were designed to catch cars in the easiest places to make mistakes. Every cone hit added 2 seconds to your time trial.
Our car did the course in 25 seconds and the 2nd place team did the course in approx 26.5 seconds, just to let you know how devastating hitting ONE cone would be to our team.
The Berkeley teams all used radio frequency sensing of the track. We used tiny antennae to pick up the amplitude of the oscillating current in the wire (through magnetic field). Then onto some amplifiers that we built. The challenge with all the electronics is to make it high-power, and FAST. The faster your stuff is, the quicker your robot can use the data and respond. Our CPU was running at 20MHz, which is mildly respectable for a microcontroller but surely not the fastest out there.
This competition is part of a senior project course at Berkeley, but other schools may treat the competition as a club event. Personally, I am a graduate student at the university and did the competition for fun, since I never had a chance to delve into robotics as an undergraduate. I must say it was a life-changing experience and I highly recommend anyone who has interest in robotics to simply JOIN A COMPETITION, and THEN build your robot.
As far as "how hard" the programming was, the microcontrollers usually come with software kits to do such things. I am not the expert in our software setup since I was more of the circuit designer, but I can tell you a few things. The software was a dialect of C. The software we used was called Keil Microvision and DaVE (Siemens Digital Application Virtual Engineer). DaVE is a piece of shit, avoid using it at all costs as it only sets up certain initializations for you. Once my team figured out how to dump DaVE, we never used it again.
If you understand how to write a program and use: printf, updating registers, hex numbers, and know how to read a manual, you will be fine. Start with Lego Mindstorms and then pick up a Motorola microcontroller through Digikey or Jameco. They actually make kits. This year I may try to form another team to do autonomous helicopter competitions. I can honestly say, I love robotics.
Best of Luck and please let me know if there are any other questions. I leave you with some pictures of my TC3 in robotic trim. Too bad I never got to run it.
By the way, the competition is called: NATCAR
Other robotics competitions are: