LED Matrix Headlight System Aims To Revolutionize Night Driving

Jul 6, 2015

The rate of traffic crashes in the United States is about three times higher at night than in the daytime. Visibility is a large contributing factor to that statistic. But a Rensselaer Polytechnic Institute professor is leading a study in the Capital Region that may revolutionize the way we drive at night. 

I’m standing here on a deserted road in East Greenbush, and a car is flashing its headlights at me. A sleek, black Audi passes me by. It’s heading down the street and it’s going to turn around, and I’m going to see if I can tell when the high beams change.

That’s the crux of the experiment that RPI Professor John Bullough is conducting. And the clincher is, he actually does not turn his high beams off.

"As part of a study we’re doing for the Transportation Lighting Alliance, the vehicle maker Audi has loaned us an A7 with an LED Matrix headlight system for a few weeks to do some evaluations," Bullough says.

"This is a system that has the ability to give you high beams without having to feel guilty about creating glare for oncoming drivers. So it actually dims the headlights in the direction of oncoming drivers, just in that direction so the driver gets their high beams everywhere else, the oncoming drivers look like they’re seeing low beams."

I could have sworn they were low beams. And I’m not the only one. Bullough recruited about a dozen volunteers over the course of June to come out to this road in East Greenbush and do the same thing. They all had the same reaction.

So how does it work?

"Well the headlights on this car are using light emitting diodes or LEDS. There’s actually a matrix of about a dozen or more LED modules inside that headlight," Bullough explains. "So instead of having a single bulb, you have many LEDs that each produce light in a different direction. And that allows them then to use a camera that faces forward and identify headlights and tail lights, and actually dim that portion of the beam just in that direction."

So what does it look like when the high beams are actually on? Bullough uses a toggle on the control panel to switch the car to manual control of the headlights and then flicks them on.

It’s the brightest bright lights I’ve ever seen in my life. Bullough says high beams that bright are actually illegal in the U.S.

"The limit is 75,000 candela for the U.S. and in Europe, it’s actually greater than 200,000 candela. And that’s part of the reason why we seem to be more sensitive to glare here in the U.S. We’re not used to those high beams."

The LED Matrix system on this car—which Bullough says is a growing trend among car manufacturers in Europe—is not yet legal in the United States either. That’s why Bullough and his team at RPI’s Lighting Research Center are studying it.

"We’ll publish these results of our study in a technical report that we will provide for lighting manufacturers vehicle manufacturers and the Department of Transportation," Bullough says. "We hope it will help facilitate decisions that they might want to make about whether this type of lighting has benefits and how they can start to define what it should do or what it should not do."

But it’s not just about being nice to the other drivers on the road. I’m now in the car with Bullough, seeing things this time from the driver’s perspective.

"Thirty miles per hour is about as fast as you can go with your low beams on and still be able to see something and respond quickly enough to come to a stop," he explains, as we drive.

Bullough's team uses a black cardboard cutout of a little girl that’s placed by the side of the road. Across the street, he enlists the help of another driver to sit in a parked car with the headlights off. We’re going to drive down the street, turn around and come back. When we round the bend, the other driver will turn their lights on, and we’ll see what happens to our high beams and visibility.

From the driver’s perspective, the high beams still appeared on. And we could easily see the little cardboard girl.

"On the open road you don’t really notice the system responding, just every once in a while," Bullough notes.

So how long is it before you don’t have to do anything when you’re driving? You don’t have to flick your high beams, you don’t have to push the gas pedal? How far is that in the future?

"There are some tests of autonomous cars right now…these may become a relic for the times when we want to drive our own cars again," Bullough says.

It will be a nice pastime, right?

"I think I could get used to that as a hobby."

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