Automotive Assembly: The Future Looks Bright for Smart Headlights
The first low-beam headlights appeared on automobiles 100 years ago. Today, engineers are scrambling to develop a new generation of smart headlights that will soon make traditional products as obsolete as kerosene lanterns.
The goal is to create lights that react to the road environment and enhance driver safety. Smart headlights will better illuminate the road; spotlight obstacles, signs and lanes; project directions on the road; reduce glare; and increase visibility in fog, rain and snowstorms.
Headlights equipped with LEDs have been slowly creeping their way into the auto industry over the last decade. LEDs are smaller than typical headlamps and are easier to package. They first appeared on luxury vehicles and high-end sports cars several years ago.
But, the new Ford F-150 pickup truck will be one of the first mass-produced vehicles equipped with state-of-the-art headlights. An innovative design that uses semiconductor chips to control light allows engineers to use a single LED per lamp.
According to Strategy Analytics Inc., by the end of this decade, 12 percent of light vehicles will feature LED headlights. “As with many other electronic features, intensifying competition among automakers is forcing the growth of LED headlights,” says Kevin Mak, an analyst who specializes in automotive electronics.
“Challenges facing [engineers] include brightness levels from current LED chips, thermal issues, complexity of controlling LED headlights and their increased functionality, and ultimately, the higher assembly costs when compared to competing halogen- and xenon-based systems,” Mak points out.
“The next step in front lighting is adaptive driving beam technology,” says Mike Godwin, director of LED products at Osram Opto Semiconductors Inc., which provides components for lighting suppliers such as Hella and ZKW.
Osram has pioneered several advanced lighting systems, such as a hybrid headlight that’s used in the Audi A4 sedan. The LEDriving Xenarc headlight boasts a combination of xenon and LED technologies.
Osram engineers also recently developed an LED light source that can emit 256 pixels. Each separate beam of light can be individually controlled thanks to advanced semiconductors.
Another recent Osram innovation is laser headlights, which debuted last year on the BMW i8 sports car. Laser light modules are extremely compact, opening up a wide range of design options. Benefits of laser light include its long range and high system efficiency.
Automotive engineers are eager to adopt LED technology, because it offers new opportunities, especially when it comes to packaging. “LEDs are extremely thin, so you can reduce the package size tremendously,” says Godwin. “Because LEDs are point emitters, you can package and optically guide them in a much thinner space. Traditional halogen, on the other hand, needs a lot of depth, due to focal lengths.”
Engineers at Carnegie Mellon University’s Robotic Institute are also developing next-generation automotive lighting technology. They recently unveiled a programmable headlight that may be commercially available by the end of this decade. The system uses a digital light processing projector instead of a standard headlight or a cluster of LEDs. This allows the light to be divided 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 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. However, the changes in overall illumination are minor and generally not noticeable by the driver.
“Standard vehicle headlights illuminate everything in their pathway, which is necessary for nighttime driving,” says Robert Tamburo, lead engineer on the Carnegie Mellon project. “Recently, headlights that adapt to the environment have made their way to the road. However, they tend to be one-off solutions that can perform only one task.
"[Our] programmable headlight has one hardware configuration—with no mechanical parts—that can be programmed to perform many tasks,” explains Tamburo. "The prototype that we built has unprecedented spatio-temporal resolution, permitting reaction to objects of all shapes and sizes."