Thirty-five teams started the DARPA Urban Challenge, a competition to create a driverless car to successfully navigate an urban landscape.
Cornell was one of only six to complete the trial. Mark Campbell, associate professor of mechanical and aerospace engineering and the team's faculty advisor, thinks Cornell was the only team for which most of the technical work was done by students – about 15 of them, led by PhD student Isaac Miller.
DARPA provided $1 million in funding. Some teams had as many as 40 or 50 people and considerable industry involvement. The biggest challenge, he says, wasn't automating the vehicle. Most of those problems were solved in DARPA's 2005 Grand Challenge, several veterans of which joined this effort. (Cornell's 2005 vehicle got its nose in a guard rail and couldn't reverse.)
Cornell's SUV included 17 rack-mounted computers, home-built out of off-the-shelf components including mobile processors. "We sacrificed a little bit of performance, but they didn't generate a lot of heat, so we could use the car's air conditioning. "
The computers ran on a streamlined version of Windows XP. "We had the car running for a year plus, and they never crashed," Campbell said. The two hardest problems they had to solve were first, tracking vehicles, and second, locating their own car in the lanes. The first included differentiating cars from bushes and rocks, identifying their lane and behaviours, and telling whether they were stopped. The second was difficult because of limitations in GPS. "Even if it's high-precision it might be off by half a meter."