There are certain weather conditions that make it quite difficult for a driver to see where they are going. A good example is when driving during heavy snowfall, hail, or rain at night. The problem being, your vehicle’s headlights reflect off the rain/snow/hail rather than lighting the way ahead, and therefore reduce visibility significantly through glare. It also means cars traveling in the other direction don’t see you until much later, therefore increasing the risk of an accident happening.
There’s no obvious way to solve a problem like this as you need to have your headlights on at night, and you can’t remove weather conditions from the equation. However, a research team at Carnegie Mellon University have managed to come up with a solution that improves the situation immensely.
Working out of the Robotics Institute at the University, Srinivasa Narasimhan and his team came up with a new smart headlight that manages to adjust the direction of the light being output by a headlight to avoid illuminating the raindrops. They did this by employing a high-speed camera that detects raindrops and uses an algorithm to work out their location just a few milliseconds later.
With that information known, the headlight flickers very rapidly and manages to light around the drops. To the driver the rain is effectively not there, or at least not lit up. The flicker is also not visible to human eyes because it happens so quickly.
Because of the flicker, some of the lighting capability of the headlamp is lost, but it’s no more than a 6% light low. However, up to 80% of the rain/snow/hail is no longer caught in the light, making for a much clearer view. It is also hoped that the speed of the system can be increased so as to improve visibility even further.
The prototype system uses a DLP projector, but a final headlight would most likely be made up of lots of LEDs that could be turned on and off very quickly.
As well as the visibility improvements, Narasimhan points out two further benefits of this smart headlight design. The first is that it can be setup to detect other vehicles and ensure no light is directed into the eyes of the driver. Also, if the detection system fails, the light just reverts back to a normal headlight, so the driver can continue driving.
So far the system has only been tested in the lab, but it did function as intended. The next step is not only to make it work more quickly, but also to reduce it in size so as to easily fit in a typical headlight casing on a car. In other words, it’s going to be a few years before a manufacturer like Mercedes manages to roll out smart headlights on one of their luxury vehicles as a selling point.