New smart headlights prevent glare, improve vision

Scientists, including one of Indian-origin, have developed a smart headlight that enables drivers to take full advantage of their high beams without fear of blinding oncoming drivers or suffering from the glare.
The programmable headlight senses and tracks virtually any number of oncoming drivers, blacking out only the small parts of the headlight beam that would otherwise shine into their eyes.
During snow or rain showers, the headlight improves driver's vision by tracking individual flakes and drops in the immediate vicinity of the car and blocking the narrow slivers of headlight beam that would otherwise illuminate the precipitation and reflect back into the driver's eyes.

"Even after 130 years of headlight development, more than half of vehicle crashes and deaths occur at night, despite the fact there is much less traffic then," said Srinivasa Narasimhan, associate professor of robotics at the Carnegie Mellon University's Robotics Institute.
"With our programmable system, however, we can actually make headlights that are even brighter than today's without causing distractions for other drivers on the road," said Narasimhan.
The system devised by Narasimhan, Robert Tamburo, the project's lead engineer, and colleagues uses a DLP (Digital Light Processing) projector instead of a standard headlight or cluster of LEDs.

This enables the researchers to divide the light into a million tiny beams, each of which can be independently controlled by an onboard computer.

A camera senses oncoming cars, falling precipitation and other objects of interest, such as road signs. The one million light beams can then be adjusted accordingly, some dimmed to spare the eyes of oncoming drivers, while others might be brightened to highlight street signs or the traffic lane.
The changes in overall illumination are minor, however, and generally not noticeable by the driver.
System latency - the time between detection by the camera and a corresponding adjustment in the illumination - is between 1 and 2.5 milliseconds, Tamburo said.
This near-instantaneous reaction means that in most cases the system doesn't have to employ sophisticated algorithms to predict where an oncoming driver or a flake of snow will be by the time the headlight system responds.

"Our system can keep high beams from blinding oncoming drivers when operating at normal highway speeds," Narasimhan said.
Rain and snow present a more difficult problem, he noted; the system reduces glare at low speeds, but becomes less effective as speed increases.
In addition to preventing glare, the projector can be used to highlight the traffic lane - a helpful driving aid when roads have unmarked lanes or edges, or when snow obscures lane markings.
When tied to a navigation system, the programmable headlights also can project arrows or other directional signals to visually guide drivers.