Researchers at Carnegie Mellon University say they’re working on a solution that could make raindrops nearly invisible while lighting the road in front of you.
The problem Carnegie researchers are trying to solve is that headlight beams are reflected back at the driver when it rains, snows, sleets, et cetera. The brighter your headlights, the brighter the light is reflected back at you, and the harder it is to see the road ahead of you.
Carnegie’s researchers came up with a possible solution involves a camera, a digital light processing (DLP) projector, and a reflecting mirror, alongwith a computer to control the whole setup. As rain falls, the camera can detect individual raindrops and predict their velocity and trajectory. It sends that information to the projector, which projects a small black dot over each rain drop’s location. The result, researchers hope, is the ability to light in front of the car but not the raindrops, which would result in the most light output without returned glare.
As expected, it’s very difficult to detect individual raindrops and light around them. The system takes about 13 milliseconds to find raindrops and respond accordingly, so the top portion of the light beam would still hit the raindrops like a standard headlight. As it stands today, the system also works best at a speed of about 19 mph, where it’s 68.9 percent accurate at blacking out raindrops while still keeping over 95 percent light throughput. Drive faster and the system steadily loses accuracy. As you can see, it still is a ways off from mainstream implementation.
As we always say with futuristic tech like this, it’s going to be many years until we see something commercially viable that works like this. The system will need some big strides in digital light processing projector technology to work better,
Still, the idea of going from halogen bulbs to xenon to LED to DLP projector headlights is intriguing, and having two DLP projectors and two wide-angle cameras mounted to the front of your car would open up a whole new world of active headlights that could shift to avoid blinding oncoming traffic or pedestrians.
Who knows, maybe eventually we can project movies from those headlights.