[dailydriver]

Driving at night during rains is a constant pain, specially on undivided roads. The lack of visibility due to inadequate headlights of our own cars and more importantly the glare from the headlights of oncoming vehicles make it difficult to judge the roads with precision. Although it is considered a good practice to drive with low beams, the lack of traction on wet roads resulting in increased braking distances forces many to keep their high beams on and thereby get those few extra micro seconds of anticipation/decision time. While this may appear prudent on our part, the high beams are surely a nuisance to others.

These days, most cars are either equipped with or have provision for fog lamps. They differ from normal headlights because of their ability to show/shine through fog and thereby increase visibility. The front fogs show the way to the driver and the rear ones show the car to others!

We also have something called DRLs or Daytime Running Lights which - though intended to function as visibility enhancers - are more of a style statement in many cars. Apart from these, we also have ORVM or door mounted puddle lamps, high mount stop lights and in a few extreme cases DJ lights too.

One thing that was essential but missing from the portfolio of lights was rain lamps; lights that would penetrate through rain and light up the road without actually causing others any inconvenience. Scientists at the Carnegie Mellon University in US claim to have developed a system that improves visibility by constantly redirecting light to shine between particles of precipitation.

The system constantly redirects light to shine between particles of precipitation, and prevents the distracting glare that occurs when headlight beams are reflected by rain...can help drivers see through heavy rain or snowfall and safely navigate roads during stormy nights.It prevents the distracting and sometimes dangerous glare that occurs when headlight beams are reflected by precipitation back toward the driver.

“If you're driving in a thunderstorm, the smart headlights will make it seem like it's a drizzle. A human eye will not be able to see that flicker of the headlights“ said Srinivasa Narasimhan, associate professor at CMU.

The system uses a camera to track the motion of raindrops and snowflakes and then applies a computer algorithm to predict where those particles will be just a few milliseconds later. The light projection system then adjusts to deactivate light beams that would otherwise illuminate the particles in their predicted positions. And because the precipitation particles aren't being illuminated, the driver won't see the rain or snow either. To people, rain can appear as elongated streaks that seem to fill the air. To high-speed cameras, however, rain consists of sparsely spaced, discrete drops. That leaves plenty of space between the drops where light can be effectively distributed if the system can respond rapidly.

Lab tests showed that the smart headlight system could detect raindrops, predict its movement and adjust a light projector accordingly in 13 milliseconds. At low speeds, such a system could eliminate 70 to 80 per cent of visible rain during a heavy storm, while losing only 5 or 6 per cent of light from the headlamp. New LED technology could make it possible to combine LED light sources with image sensors on a single chip, enabling high-speed operation at low cost.

Another benefit is that the system also can detect oncoming cars and direct the headlight beams away from the eyes of those drivers, eliminating the need to shift from high to low beams.

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[audioholic]

I guess this would give the same effect of a strobe light which makes things look stationary for a moment, albeit at a higher frequency. Innovative stuff I must say. But for such a system to come into mass production is highly unlikely since in the coming years, we are moving towards night vision, semi and fully autonomous driving and so on. And the cost of implementing such a complicated technology might surpass the cost of adding ADAS to a car, which will make the latter an obvious choice. Currently, the cost of adding Multi-Beam LED lighting to a Mercedes E Class is somewhat close to adding the first level of ADAS features from the customers end. The regular LED package is what is the more common choice since it is relatively cheaper. And with the introduction of Laser headlights, maybe that will put such an algorithm to better use since it has higher control over the beam.

That said, apart from the rain droplet thing, the E class Multi-Beam package already portrays many use cases like adverse weather, anti glare and traffic sign recognition in the production version itself:

https://www.youtube.com/watch?v=0OJjvYPV3oc

I believe Audi and BMW are not behind either. However, these are expensive technologies and will cost a bomb to replace. On a side note, the Indian E class gets a toned down version of the intelligent LED lights and not the Multi-Beam LED lights which are an option even in foreign countries.