“It was a dark and stormy night …”
It’s a great opening sentence for a scary story while sitting around a
campfire, but it’s also the scene of many a horrible car wreck. Part of the reason is that driving on rainy
nights means reduced visibility -- and that increases our chances of having a
collision. Unfortunately, our headlights
often compound the problem. Instead of
lighting up the road ahead, they reflect off the raindrops, making it nearly impossible
to see what’s in front of us. That’s why Srinivasa Narasimhan, an engineer at Carnegie
Mellon University, has been working on a better headlight design.
Narasimhan and his engineering team
have come up with a headlight that will illuminate the pavement, not the water,
making for safer driving and reduced accidents due to low visibility.
The technology for producing the
smart headlights is still in the formative stages, but Narasimhan says the concept
behind them is pretty basic. He compares it to a spotlight following an actor
as she moves around on a stage. His headlight is composed of an array of tiny
bulbs, a projector, a computer algorithm and a digital camera that tracks the
movement of the raindrops. Put those
things together and the headlight is able to detect the size, speed, and
trajectory of precipitation. This ‘reactive illumination’ system is able to
turn off individual bulbs in the path of the rain. Essentially, only the bulbs in between the
raindrops will stay illuminated, thus reducing the amount of glare from light reflection. It also works on snowflakes.
Getting Narasimhan’s smart bulbs
on the market is a few years away, because the prototype can only react in 13
milliseconds, or the equivalent of driving 18 mph. Another glitch is that
oncoming headlights still throw the system off its game a bit.
Making the process more efficient
is only a matter of tinkering, says Narasimhan, who notes that even in a heavy
downpour, the technology should still work. They’re also working on a safety
measure that would ensure that the light output never drops below the level
needed to see what’s in front of you, even in a deluge.
While getting your car equipped
with the ‘Einstein’ headlights is at least a couple of years off, it is
something to look forward to, especially for drivers who live in rainy and