Caltech juniors Jeff Lamb (in baseball cap) and Ike Gremmer—two members of the Institute’s autonomous-car pit crew—get “Bob” ready for one of the qualifying rounds in the DARPA Grand Challenge.

THE LITTLE OLD CHEVY FROM PASADENA

By Michael Rogers

With apologies to ’60s surf-rockers Jan and Dean, there was no Dead Man’s Curve out in Barstow—just a barbed- wire fence—but that was enough to frustrate Caltech’s autonomous car (code-named Bob) in last March’s Grand Challenge race, sponsored by the federal Defense Advanced Research Projects Agency (DARPA).

Bob—a souped-up 1996 Chevy Tahoe named after the first three letters on the truck’s original license plate— had only traveled 1.3 miles in the 142-mile course from Barstow to Primm, Nevada, before it veered off course and ended its epic journey in a tangle of barbed wire. Nevertheless it came in fifth, and team members said they were pleased with the result.

“A month before the race, I wasn’t even optimistic that we could get to the starting line,” said David van Gogh, MS ’01, the team’s project manager. “The fact that we started and went over a mile is pretty amazing.”

Bob was one of a handful of strange-looking robotic vehicles that attempted to make the trek through the Mojave Desert unaided by either drivers or remote control. The point of the project was to help the military come up with a future autonomous battle vehicle. Altogether, the 13 vehicles that started the race covered only 29 miles, with the top performer—Carnegie Mellon’s modified Hummer—managing just 7.4 miles. That doesn’t mean that they didn’t try hard. Still, the $1 million prize went unclaimed.

Developing Bob took one year and cost approximately $500,000, including $100,000 in donated equipment and $200,000 in labor costs, bringing Bob’s sticker price to a bit under the cost of a 2004 Ferrari Scaglietti. While Bob received technical assistance from researchers at Caltech, JPL, and Northrop Grumman, most of the brains and brawn was provided by Caltech undergraduates.

Bob’s odyssey began in an undergraduate engineering course taken by 55 Caltech students in the spring of 2003. The students spent the term researching how to integrate sensors, computers, and the global positioning system with a gas-guzzler from Detroit so that the vehicle could navigate an off-road course independently. When the term ended, 23 of the students were paid to start building the vehicle in an off-campus garage. In December, they took over space on campus in the Guggenheim Laboratory and continued taking Bob out for field tests.

Unlike the typical SUV, Bob has no room for soccer moms, soccer-playing kids, or groceries from Costco. The day of the big race found it stuffed with seven personal computers, a laptop, a power-distribution system and generator, two long-range and two short-range cameras, and two laser detection and ranging devices to search the terrain for obstacles.

The first do-or-die challenge took place during the week of March 8, when 25 competitors out of an original 106 entries gathered at the California Speedway in Fontana for qualifying runs around the relatively safe confines of an oval track outfitted with obstacles. In its first qualifier, Bob became a bit too intimate with a concrete barrier, but on its second try, it successfully navigated the course and made it to race day, March 13.

There were last-minute adjustments, including the installation of a new power-steering gearbox. DARPA kept the precise course a secret until 3:20 a.m. on the big day, when it handed out CDs that contained the coordinates of 2,000 waypoints along the route. The Caltech team loaded the software into Bob, and at 6:40 a.m. it chugged out of the starting gate in at least a puff of dust. Bob went through about 30 waypoints before it swerved off course. When it tried to get back on track, it got itself into the barbed wire, and DARPA officials ended its run.

Commenting on Bob’s road not taken, van Gogh speculated that one of the sensors likely interpreted a rise in the road as an obstacle, causing Bob to veer off course. For the next race, tentatively scheduled for late next year, “we’re talking about using a contact sensor, so that the car has to hit something with more than 20 pounds of force before it stops.”

Bob was not the only would-be automaton with Caltech credentials. Golem 1, a pickup truck named after a clay homunculus in medieval Jewish folklore, was modified by a team that included five Caltech alumni and one current graduate student. Golem 1 powered its way 5.2 miles before it got stuck on a hill.

“We were very pleased with how we did on a cost-adjusted basis,” said team leader Richard Mason, PhD ’03, who financed the venture with $35,000 that he won in 2002 as a contestant on the game show Jeopardy. “I don’t regret spending the money on this for a minute. It captured my imagination and was just something that I had to do.” Mason, a product of Caltech’s robotics group, attributed the team’s relative success to the fact that the vehicle’s sensors were intentionally turned off before the race, leaving Golem to basically muscle its way through the course.

Mason said that his team will also be back for next year’s Grand Challenge, for which the top prize has now been sweetened to $2 million. “My hope is that we did well enough in this so that we’ll get more sponsorship next time,” he said. If not, Mason said that he may just have to go on another game show. Are you ready, Regis?