From Darpa Grand Challenge 2004Clash of the Headless Humvees

The Mojave isn't your Lawrence of Arabia, poetic sort of desert. The valleys are skillet-flat and scrubbed up with sage and creosote bushes, and surrounded by sandstone-and-grit mountains. When we're on paths and unpaved roads, the types of surfaces that most observers figure will constitute the majority of the racecourse, the SUV handles like a dream. We hurtle over the valley paths, lightly corrugated and filled with loose sand, at anywhere from 30 to 50 mph. Our tentative cross-country forays into deep sand and bushes at 5 or 10 mph are not so encouraging -- except perhaps to Robertson. He sticks his head out of a second loaner Acura SUV bumping and
jittering along and yells, "Whoo, this is fun!" The other Road Warrior adults along for the ride say a little prayer for the edge-recognition capabilities of the team's as-yet-unwritten software, and for a Grand Challenge course that doesn't go too far into the rough.




We come to a steep, twisty, three-foot descent, "the Chinese Wall," and we first get out of the car to mentally work out a route so the Honda doesn't stick between the uneven rocks or flip altogether. The car manages it like a pro, but how well are any of the competitors' onboard computers going to do this sort of thing?




The kids in my car, none of whom are key technical players, seem not unduly perturbed. "Hey, Jeff, you've been voted off the island," Ashton Larson yells from the way back. Jeff, son of Honda benefactor Tom Laymon, replies, "Too bad, it's my car."




"Dude," Larson fires back, "you're acting like me and my sister. That's a bad thing."






Before jetting off to Atlanta and Houston to beg for free technology, Whittaker convenes an early afternoon council of war with a core Red Team group. The subject, of the meeting and the begging, is mapping -- and it's a big one.




Given the state of the technology, there is no way a race vehicle could average 20 mph over rough desert terrain without some stored knowledge of the route. (Humans are no different. Send a driver onto an obstacle course he's never seen before, and he'll nose around it gingerly. Let that driver practice the course for a year and he'll fly, continually moving back and forth in his brain between what he knows and what he sees.) It is the Red Team's aim to construct the most precise, detailed maps possible, maps not of the course, since its exact coordinates are as yet unknown, but of the entire area the course might run through.




The team starts with U.S. Geological Survey aerial photography of the area. Then it adds additional layers -- USGS vector maps that show roads, paths and riverbeds, and data from a U.S. Bureau of Land Management Web site that gives the team a good idea of what parts of the region legally can and can't be used for the race. The end result, the Red Team hopes, will be a mapped image of every square meter of potential course. For the finishing touch, CMU is visiting areas that have a high probability of being on the actual course -- riverbeds, old paths and the like -- and marking its own GPS waypoints every few meters. The team will then combine all this data to generate so-called breadcrumbs at 1-meter intervals -- information the team will program into its race vehicle.




The ideal here is that when the Red Team gets the true course waypoints on race day, members will crunch some data and come up with a map of their perfect course before the Humvee has even moved off the starting line: a triumph not of racing but of pre-racing. "Over the years," Whittaker admits, "some people in the robotics community have looked at the machines I've built and said, 'That isn't robotics; these aren't machines that are reasoning about their world.'"




So what? he figures. They work.






When I return to Berkeley two weeks after our model-motorcycle race, Levandowski and I make our way to the testing grounds with his full-size bike strapped down in the back of his Nissan pickup. The steering software has been patched together in a fit of last-minute improvisation.




Levandowski's challenge is to design the computer algorithms that will register how far the bike is tilting in either direction and apply just the right amount of counterforce via the electronic steering and acceleration controls that are powered by a 12-volt electric motor mounted atop the bike. His Yamaha, like all the vehicles in the race, is internally monitored by an inertial measurement unit (IMU) that registers, among other things, its orientation in space, or attitude -- its pitch (front-and-back motion), roll (side-to-side) and yaw (left-to-right). For any vehicle, attitude must be taken into account to get a precise IMU read on how far it has traveled along the course. For a motorcycle, the skillful manipulation of attitude, the rate of roll in particular, is the only thing keeping the machine up. Making a computer perform at the necessary skill level is a trick Levandowski has not yet mastered.




In the face of the gulf between his vision and the current reality, Levandowski reassures himself by focusing on the big picture. "For other teams," he says, "the race is what makes their vehicle important. For us, the race is just a field test. Our work starts the day after." Levandowski sees himself in the business of developing the next generation of autonomous military vehicles, this in contrast to many team leaders -- including Red Whittaker, who visibly blanches at the mention of military applications, his own field-general persona notwithstanding. "The other teams are working on perception and terrain recognition," Levandowski says, "and I'm working on increasing the mobility of autonomous vehicles. That's fine. Someday, their systems will be on my chassis."




His blueprint for a roboticized military future is an influential 2002 National Academy of Sciences document that sketches out an entire genealogy of future military unmanned ground vehicles (UGVs). He says that the other teams are, whether they choose to be aware of it or not, helping to lay the technical foundations for UGVs like Donkey and Wingman, which are supposed to perform troop supply and support in the coming decade. Levandowski is under no illusions about where his single-track vehicle concept fits in -- not the Yamaha per se, but something more stable with, say, a double set of front and back wheels. "I'm doing the Hunter-Killer," he says -- the machine whose mission, in the bloodless language of the NAS report, is "doctrinally quite straightforward."