Drive-by-wire control makes driving decisions almost human

Julie Kalista
Online Editor

The Challenge is a robotic vehicle R&D program that hopes to expand technologies that will keep soldiers off the battlefield. The Challenge features unmanned cars and trucks maneuvering in a mock city environment, executing simulated military supply missions while merging into moving traffic, navigating traffic circles, negotiating busy intersections, and avoiding obstacles.

Victor Tango, the Virginia Tech team, is one of the 36 semi-finalist teams vying for the $2 million dollar top prize. They have converted two Escape hybrids donated by Ford Motor Co. into robotic vehicles with drive-by-wire system, four computers, cameras, and a GPS. Drive-by-wire lets the computer control throttle, brake, steering, and shifting. On Odin, Virginia Tech's vehicle, the computers process sensor acts.

From three laser scanners mounted on the vehicle's bumpers, they scan a combined 360° field of view 12.5 times per second. Four more laser scanners are mounted on the roof rack: two to detect small obstacles like curbs and potholes and the others to check the vehicle's blind spots when it changes lanes or merges into traffic. Odin's GPS works with an inertial measurement unit and wheel-speed sensors to measure movement in all directions.

Odin can drive on marked roads, follow moving traffic, pass stopped vehicles, handle four-way intersections, and perform three-point turns. The team is working on merging, passing, and parking.

Urban Challenge is conducted as a series of qualification steps leading to a competitive final event, scheduled for November 3, 2007. The exact location will be announced before the National Qualification Event for October 2007. DARPA is offering $2M for the fastest vehicle, and $1M and $500,000 for second and third place.