Wireless: The new backseat driver?
By Stefanie
Olsen
Staff Writer, CNET News.com
Published:
SAN FRANCISCO--Just in case you don't have enough backseat
drivers, your car could one day tell you when you're about to screw up.
On Thursday, General Motors demonstrated a vehicle-to-vehicle, or
V2V, wireless communication system that alerts you when a collision is
imminent. The automaker equipped regular Cadillac STS sedans with wireless and
Global Positioning System antennae and computer chips that allow the cars to
communicate with other vehicles with similar equipment.
The technology,
demonstrated here with three cars navigating a special course, creates what
could be described as a digital-driving symphony. The wireless technology in
one car detects the presence of the other two Cadillacs and avoids collisions
by either alerting the driver of danger or by automatically stopping the
vehicle in an emergency.
In terms of an alert, the driver's seat gives off a heavy
vibration to the left leg if the driver signals to enter the left lane, unaware
of a car in his or her blind spot. Such a warning is an example of what, in the
auto industry, is called "haptic feedback"--feedback related to the
sense of touch. There's a visual cue too: An icon flashes in the car's rearview
mirror to alert the driver that there's another car in the way.
"We're trying to standardize the wireless communication
between cars, and we hope other car manufacturers will follow. This would be
the reinvention of the vehicle," said Priyantha Mudalige, senior research
engineer at GM and one of the four engineers who built the wireless safety
system.
Of course, that's the obvious downside to this intriguing
technology: For it to work effectively, all vehicles on the road would have
to be fitted with similar equipment. Theoretically, if just one car on a busy highway
lacked the right gear, the consequences could be severe.
"Before this works, we need to have market penetration,"
Mudalige said.
GM expects it could be five to 10 years before the safety system
could go into production, Mudalige said. That's because it will likely take
that long to sign agreements with other manufacturers and with standards
agencies like the Federal Communications Commission.
Here's how the technology works:
A GPS
antenna on the top of the car receives satellite information on the
positions of other cars. A wireless antenna on top of the vehicle also receives
up to 100 different data points from the car's internal network, including
information on speed, braking and the use of turn signals. The computer system
combines that data and broadcasts it.
That message is heard by any other equipped car within a
quarter-mile radius. To ensure privacy, the messages do not include car
identification numbers or personal information.
The car's
software constantly calculates, in real time, other vehicles' positions and
speeds. GM's proprietary algorithm, called the "threat assessment
algorithm," also processes data from the GPS and the car's computer
network, along with messages from other cars, in order to fire off warnings and
prevent collisions.
The car's dashboard computer screen will also show icons of nearby
vehicles. The typical green icon will turn yellow if there's reason for caution
(the distance between vehicles is decreasing at a fast clip, for instance). The
icon will change to red if there's imminent danger, and at that time, the
driver's seat will vibrate.
Drivers can turn on an
automatic braking feature to ensure the car will stop in the event of an
upcoming crash.
GM is using the communication protocol called Dedicated Short
Range Communication, or DSRC, to send and receive messages. The cars
communicate using the wireless spectrum 5.9 gigahertz licensed from the FCC for
public safety. Toll agencies already use the spectrum to automatically charge
commuters with digital IDs.
The Cadillac prototype itself has four computers in the trunk,
along with a GPS system and wireless communication module. GM would try to fit
much of the software onto a single chip by the time the cars would be ready for
production.
The technology was researched over the last two years, but serious
development began a year ago by four engineers in GM's internal research and
development department, said Mudalige.
One of the biggest benefits of the wireless system would involve
cutting the costs of radar and so-called lidar sensors, which measure speed and
distance. GM, BMW and many other carmakers currently use those sensors in
luxury cars for features like adaptive cruise control, which modulates the
speed of a car based on surrounding vehicles.
Mudalige said the wireless sensors could do the work of the
long-range and short-range sensor technology much more inexpensively because
they're relying on wireless communication between vehicles. To get the same
surrounding effect of wireless V2V sensors, carmakers would have to put radar
sensors in many places on the car, which would be too expensive. The wireless
sensors cost about $100, he said.
Cars like BMW's Mini Cooper already include sensing technology
that alerts the driver when the car is too close to another vehicle while
parallel parking, for example. Those sensors are lidar and radar sensors. To
get the same effect with wireless technology, GM and others would have to build
infrastructure in parking lots, for instance.
The V2V system is still far from perfect in other ways, too. In a
test drive with a reporter as passenger, the car's computer system failed
during an emergency stop. Luckily, Mudalige took over by braking
himself.
Despite such bugs, Mudalige is still confident about cars
communicating wirelessly. The technology could not only help protect people, it
could also help traffic advisers detect and deliver alternate routes to
commuters during traffic jams.
"The auto industry will definitely go towards wireless
because it's a significant benefit to society to save lives, reduce pollution
and for energy conservation," he said. "This is just the
beginning."