Blind students test-drive experimental vehicle

WASHINGTON — A voice rose above the chatter in the University of Maryland parking lot: "Blind man driving!"

Twenty blind people took turns piloting a car Friday, the first public test of technology that might one day overcome barriers to putting the sightless behind the wheel.

The quest to drive has captivated the blind community since the advent of the automobile. Some likened Friday's test to a moon landing, a fitting analogy, considering that the prototype vehicle vaguely resembled a moon buggy.

"One day, we'll be on the road with them," said Ishaan Rastogi, 15, a blind New Jersey high-school student with a Yankees cap pulled over his eyes, who was the first to test the vehicle.

The event capped a summer camp organized by the National Federation of the Blind for 200 blind young people from across the country.

Virginia Tech engineers started work on the vehicle in response to a 2004 challenge from the blindness-advocacy group, which asked which U.S. university could build a vehicle that the blind could drive with the same freedom as the sighted.

At the same time, the Defense Advanced Research Projects Agency (DARPA) was running a contest seeking a fully autonomous vehicle that could navigate bumpy terrain.

An autonomous vehicle wasn't enough.

"We want the blind person to be the driver, not to be driven," said Matt Lippy, 21, a member of the nine-person design team at Virginia Tech's Robotics and Mechanisms Laboratory.

The design team first sought to customize Virginia Tech's entry in the 2007 version of the DARPA contest, a modified Ford Escape that finished third in a competition called the Urban Challenge. But the engineers decided it would be easier to start from scratch. In fall 2008, they purchased an all-terrain vehicle online for $1,500 and began anew.

They mounted a laser sensor to the front of the vehicle to sweep the terrain ahead and return a signal. A powerful computer at the rear of the buggy interprets the signal to build a two-dimensional map, showing obstacles in the vehicle's path.

But how to show that map to a person who cannot see?

Researchers boiled down the data to two crucial factors: direction and speed. A computer voice signals the driver through headphones how to steer to avoid a collision: one click to the left, for example; three clicks to the right.

The increments correspond to notches cut from the steering wheel. The driver turns the wheel and hears a "click."

The vehicle's computer communicates speed with vibrations fed through a vest worn by the driver. Stronger vibrations say it is time to stop. Sensors automatically kill the engine if the vehicle gets too close to an impediment. Engineers rigged the buggy for a top speed of 15 mph.

One by one Friday, drivers buzzed around the parking lot, empty save for traffic cones placed at intervals around light poles. There were no mishaps.

"It's finally a chance to drive," said Angel Reyes, 16, a junior at New Brunswick High School in New Jersey, as he climbed from the vehicle. "Finally a chance to be more independent in getting where you want to go."

When the team first tested the buggy in May, three blind drivers completed a curved course without hitting a cone. Indeed, the blind drivers — who had never driven before — fared better than the engineers, who tried steering the car blindfolded. Lippy thinks the experienced drivers tended to ignore the computer signals and make their own driving decisions based on feel, while the blind drivers obeyed the computer.

The blind drivers also posed questions that had not occurred to engineers: How would they find the vehicle in a parking lot? If they had to jump the battery, how could they tell the positive cable from the negative?

The engineers said their first Blind Driver Challenge vehicle is crude. The computer can sense and avoid obstacles but cannot plot a course to a destination. The team is working on a more sophisticated interface to deliver signals to drivers. Their goal is to convert the two-dimensional map plotted by the computer into something a blind driver can touch.

They have tested a grid of holes that shoot bursts of air, using various pulses and pressures, to convey topographical data. A higher pressure could signal hills or bumps.