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:Real-life application?

[rueba]

That depends on the route.

On the Boston-New York-DC corridor Amtrak is doing pretty well.

The price and travel time(once you include getting to and from the airport) are about the same.

On the train you have enough time to read a book, do some work or just enjoy the view, no hassle with airport security and you arrive smack in the center of the city.

For the plane you might have to travel a ways to the airport, get your nail clippers confisticated, then fly for like 30 minutes and then get try to get a cab or something into the city in snarling traffic.

Its really a matter of preference, but it certainly seems that trains are viable in more densely populated areas.

At first glance..

[Sweetums]

You might get the impression this is about NASCAR size cars... still interesting when you realize that 9fps is coming from a single NiCad in Tyco size vehicles.

Just to clarify for those who made the same initial assumption I did.

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.

Re:Pretty Simple

[Octothorp]

This is a very simple control problem to solve... I actually think that you could do best in this competition by working on making the car faster; Most of the cars are going to have similar line following abilities.

Actually, that's not the case at all. If I remember correctly, the motor is capable of doing something in the 30 MPH range (though probably not for too long). It turns out that working on the control problem, and the accuracy/reliability of inforation you're working with is much more important.

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.