Imagine car headlights that project millions of movable small cones of light instead of one broad fixed beam. Now make these millions of cones movable so you can direct them away from oncoming traffic at night (so drivers aren’t blinded) or project around angles when your car is turning. But why stop there, let’s make these lights capable of projecting arrows or lane markers onto the road as dictated by a GPS and local traffic control information too.
Welcome to the concept of programmable headlights. A team of engineers from Carnegie Mellon University (CMU) has developed a prototype of a programmable headlight that performs these functions and much more. The secret is a chip that has millions of small mirrors on it that are capable of being moved very rapidly. The chip itself is not new, it is a version of the Digital Mirror Device (DMD) chip that Texas Instruments has been making for video display devices for well over decade now. In older rear screen projection televisions and newer front projection monitors, DMD chips are mated with spinning color wheels to make bright, high resolution video images. In the Carnegie Mellon application, only a DMD-like chip and an ultra-bright light source are needed to light up the road and visual field ahead.
As you may imagine, driving the DMD chip in a programmable headlight device requires some sophisticated electronics and sensors. Currently the device’s on-board computer reacts to what it senses within 1 to 2.5 milliseconds and this is fast enough to perform most of the advanced features that have been imagined. Faster speeds will open it up to even more advanced features. One amazing feature still under development is the ability to make snow “disappear” when you drive. To make snowflakes disappear, the system tracks the falling flakes, predicts where they are going, and then turns off the beams that would otherwise reflect light off the flakes. This occurs so rapidly that to the driver it appears that that the snowflakes aren’t there. The driver effectively sees “between the flakes”.
Currently the CMU’s programmable headlight device is a bulky prototype that sits on the hood of a test car. Despite several years of work already, there is still a much work to do on the hardware and software before the programmable headlight sees commercial availability. For more information, Google “programmable headlight” and you will find a sizable number of articles and technical papers.