Autonomous Race Cars

Octothorp writes: "Though not as complicated as the underwater vehicles. There is an annual competition sponsored by National Semiconductors to build an autonomous race car. They move along pretty well too, at almost 9 ft/s. More technical information on how they are built is available on a Berkeley page, and there's a video of the winning run for 2002."

Comments

Re:I'd like cars that avoid sidewalls.

[Octothorp]

With a good onboard computer, the car could build a model of the track as it went around, and calculate the optimal path & speeds to use on all subsequent laps. Using lasers or ultra sonic distance sensors would let the robot know when a turn was going to happen a lot sooner the the few inches of warning it gets in their setup. If you put an accelerometer in the car, you could even have it self-calibrate, discovering it's own acceleration curve, maximum lateral acceleration, and braking. It could then use those values to find the perfect path through the track on the second lap.

Yes, it sounds like a good idea, and in fact that was the original plan for the winning car. But it sounds a lot easier than it is. First of all, time constraint wise - these cars are built from scratch, and tuned to perform well in under fifteen weeks. (Yes, that includes all the sensor circuits, and power supply electronics) Secondly, there is a major problem with wheel slippage - if your wheels slip, you don't know where you are anymore.

A entry from 2001 went slow around the track the first time to memorize it, and then used that information on the second round in order to predict turns and change speed. It used the track crossing location to resync where it thought it was on the track. But if you look at the track layout, there are large section with no track crossing. i.e. wheel slippage - knowing where you actually are - is the main problem to be solved for memorization type approaches.

You can't see it in the video, but the winning 2002 car does detect and speed up (slightly) on straight aways.

Why don't they just go their newsagent?

[MrCreosote]

My son is building one of these. He gets the parts from a magazine subscription. Light following/repulsion, sonar detection, line following. And seems to go pretty fast to boot.