Blind Drivers Plot Their Own Course
Va. Tech Prototype Vehicle Lets Visually Impaired Students Take the Wheel
By Daniel de Vise
Washington Post Staff Writer
Saturday, August 1, 2009
A voice rose above the chatter in the University of Maryland parking
lot: "Blind man driving!"
Twenty people took turns piloting a car on this muggy Friday morning,
the first public test of technology that might one day overcome
barriers to putting the blind behind the wheel.
The quest to drive has captivated the blind community as it has
become more integrated into a car-centric society. Some likened
Friday's test to a moon landing -- a fitting analogy, considering
that the prototype vehicle vaguely resembled a lunar rover.
"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 and the first to test the vehicle.
The event capped a
<http://www.blindscience.org/ncbys/youth_slam.asp>summer science
academy organized by the National Federation of the Blind for 200
blind and low-vision young people from across the country. The youths
had spent the week rock climbing, bungee-jumping and launching
weather balloons, activities tailored to teach that there is no limit
to what a blind person can do.
Virginia Tech engineers started work on the vehicle in response to a
2004 challenge from the blindness advocacy group to build a vehicle
that the blind could drive with the same freedom as the sighted.
"Blind people can do all sorts of things that the public doesn't
think we can do," said Chris Danielsen, spokesman for the federation.
The blind can read ordinary books with a hand-held device that
translates type to synthetic speech. Adaptive devices permit blind
users to interact with computers and surf the Internet.
Driving without sight became a conceivable goal in this decade with
the development of autonomous, computer-guided vehicles. The Defense
Advanced Research Projects Agency ran a series of
<http://www.darpa.mil/grandchallenge/index.asp>contests to inspire a
driverless car that could navigate complex terrain. By 2007, vehicles
from Virginia Tech and several other universities could complete the
DARPA course.
But 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
<http://www.me.vt.edu/romela/RoMeLa/RoMeLa.html>Virginia Tech's
Robotics & Mechanisms Laboratory.
The design team first sought to customize Virginia Tech's entry in
the 2007 DARPA contest, a modified Ford Escape that finished third in
the competition. But the engineers decided it would be easier to
start from scratch. They purchased an all-terrain vehicle online for
$1,300 in fall 2008 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.
"We call it a back-seat driver," Lippy said.
The increments correspond to notches cut from the steering wheel. The
driver turns the wheel and hears an audible "click."
The computer communicates speed with vibrations fed through a vest
worn by the driver. Stronger vibrations indicate it is time to stop.
Sensors automatically kill the engine if the vehicle gets too close
to an impediment. For the test drives, engineers rigged the buggy for
a top speed of 15 mph.
One by one Friday morning, drivers buzzed around Parking Lot 1D,
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 single cone. In fact, the
blind drivers -- who had never driven before -- fared better than the
engineers themselves, who tried steering the car blindfolded. Lippy
thinks that the experienced drivers tended to ignore the computer
signals and follow their own instincts; the blind drivers obeyed the
computer to the letter.
The blind drivers posed questions that had not occurred to the
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 say 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 air holes that shoot bursts of air, using
various pulses and pressures, to convey topographical data. (A higher
pressure could signal hills or bumps.)
"You have to understand, this is a prototype," said Dennis Hong, an
associate professor at Virginia Tech who directs the robotics lab.
"First time in the history of mankind."
He predicts a safe, stable technology for blind motorists will arrive
"within the next three years. The problem is not the technology. The
problem is public perception and legal issues."
He urges detractors to think of the last time they flew in an
airplane. "On autopilot," he said. "Nobody questions that."
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