Smart Headlights' Beams Avoid Raindrops
A new headlight prototype sends light streaking between falling raindrops, so sparkling rain won't distract drivers during storms, MIT's Technology Review reported.
The system finds and switches off light rays coming from the car's headlights that would normally hit and reflect off of falling drops of rain or snow. To find the rays, a projector in the headlight system lights up precipitation at the very top of the cone of light created by the headlights. A camera snaps a photo of the drops just before they plummet down through the lighted air in front of the car. Then a computer system uses that data to swiftly calculate where each drop will fall and tells which rays to shut off when.
The whole process takes about 13 milliseconds. An animation on the system's website shows how the idea works.
In tests, the team of U.S. and French scientists working on the headlights found that the lights make 70 percent of raindrops disappear when driving at 19 miles per hour (30 kilometers per hour), while 15 percent to 20 percent of raindrops disappear at 62 miles per hour (100 kilometers per hour). The lights are effective in an area about 10 feet (3 or 4 meters) in front of the car, which is the range in which lighted snow and rain is the most distracting, Carnegie Mellon University robotics researcher Srinivasa Narasimhan told Technology Review. Narasimhan is leading the research on these so-called "smart headlights."
When Technology Review talked with Kent Larson, who studies futuristic technology for cities and cars at MIT, Larson made an interesting point. While smarter headlights may make cars safer and more helpful to drivers, all that might not matter in the far future, if people use autonomous cars.