Software could make it easier to see in difficult driving conditions
A prototype headlight system can detect raindrops or snow streaks and “dis-illuminate” them, thereby increasing visibility on the road ahead.
The system uses a digital projector to illuminate raindrops for several milliseconds while a camera mounted on the side of the projector captures each raindrop’s location; software predicts where those raindrops will fall within the driver’s field of view. Light rays from the headlight that would normally hit the raindrop are automatically switched off, reducing glare and leaving only the beams of light which travel uninterrupted in between the falling drops.
The system’s operating range is three to four meters in front of the projector—the “critical range” at which glare is most distracting, according to tests conducted using a Toyota Prius.
The system was developed by Carnegie Mellon computer science professor Srinivasa Narasimhan, along with several others. Narasimhan presented his findings in a talk at Microsoft Research and at [email protected] 2012.
The researchers simulated different car speeds and rainfall intensity in the laboratory by varying the speed at which simulated rain streaks—using actual water propagated in front of the projector—shot past the screen. The system could reliably make rain streaks invisible at low speeds and still increase visibility at higher speeds by dimming some of the rain.