Guiding Light: Eye-Tracking Technology from Opel/Vauxhall

Car headlamp beams that are directed by the driver’s eyes? What may still sound like science fiction fantasy in the United Nations’ International Year of Light is not all that far away from reality. Engineers at Opel/Vauxhall are already busy developing automotive lighting for the day after tomorrow: with its eye-tracking technology, Opel/Vauxhall presents the future of situation-appropriate lighting and once again takes on a pioneering role in lighting technology. This announces a third generation of automotive adaptive lighting, that will be introduced after the current, widely-praised and multi-award-winning AFL+ bi-xenon system featuring up to 10 lighting functions available in most Opel/Vauxhall models, and Opel/Vauxhall’s LED matrix light that will soon go into series production.

“We’ve been pursuing this concept of controlling the direction and intensity of light based on where the driver is looking for around two years. The more we understand the benefits of this technology, the more intensively we push ahead with our joint project,” says Ingolf Schneider, Director Lighting Technology at Opel, describing the collaboration between Opel/Vauxhall’s International Technical Development Center and the Technical University of Darmstadt.

In contrast to high-performance eye-tracking systems requiring five to 10 cameras, a simple webcam was at first used. Focused on the driver’s head, it scanned prominent points, such as the nose and eyes, to detect movement and thereby the driver’s line of sight.

The system then translated the information gathered into data commands for electronically-controlled actuators, which quickly aligned the vehicle’s headlamp projectors. While this technique came very close to achieving eye-control of the headlamps, calculation of data still took too long and the recording rate of the webcam was also too slow to meet the demanding requirements of road traffic conditions.

Fast reaction and intelligent delay

Optimization of the camera’s operating parameters and the adaptation of the eye-tracking algorithm brought the breakthrough. The camera is now equipped with peripheral infra-red sensors and central photo-diodes which together enable it to scan the driver’s eyes more than 50 times per second in dusk and night-time conditions. And with much faster data processing and transmission, the headlamp actuators react instantaneously to make both horizontal and vertical adjustments.

Only one problem remained. In practice, a driver’s eyes very naturally and unconsciously jump from one focal point to another. So if the headlamps were allowed to follow this movement precisely, the vehicle’s light cone would jerk around erratically. “To overcome this problem, we have successfully developed a sophisticated delay algorithm which ensures a suitably flowing movement for the light cone,” says Schneider. “Another major benefit is that the eye-tracker doesn’t have to be individually calibrated for a particular driver. The system works perfectly with anyone behind the wheel, no matter what their size.” Even if the driver is momentarily distracted from looking at the road ahead, lighting is always provided in the direction of travel. That’s because the low beam of the headlamps is programmed to ensure sufficient illumination.

Modern safety lighting already widely accessible today: AFL+ from Opel/Vauxhall

Even as Opel/Vauxhall is developing eye-tracking as the lighting system of the future, it already provides advanced technologies which ensure optimal night vision and highest driving safety on roads today. Opel/Vauxhall has brought a break-through in automotive lighting in offering the current generation of AFL+ in a wide range of models, from the Mokka, Cascada and Zafira Tourer to the Astra and Insignia families, thus once again delivering on the company’s ambition of making premium technologies available to a wider audience. In combination with the Opel/Vauxhall Eye front camera, it features up to 10 lighting functions, using xenon headlamp beams which automatically adapt to a diverse range of driving situations. For different road and weather conditions, variable light distribution is automatically provided as appropriate for pedestrian areas, city driving, country roads, highways and adverse weather. AFL+ also includes functions such as dynamic curve light, cornering light and the use of energy-saving LED daytime running lights. The direction and intensity of the light beam is adjusted according to both steering angle and vehicle speed. In addition, high beam light assistant switches the headlamps to low beam whenever the forward-facing Opel/Vauxhall Eye camera, integrated in the interior mirror mounting, detects the proximity of headlamps or tail-lights of other vehicles. A Light and Visibility Pack also includes automatic low beam lighting, together with tunnel recognition. With this array of automatic lighting functions, AFL+ not only improves the visibility of one’s own vehicle but also reduces driver stress and night-time drowsiness.

Bright as day: The LED matrix light system

Parallel to refining the proven AFL+ and conducting the development of the future eye-tracking lighting generation, engineers at Opel/Vauxhall’s International Technical Development Center in Rüsselsheim are currently completing the final validation tests on their next-generation lighting system for upcoming Opel/Vauxhall vehicles. LED matrix light provides glare-free, high beam lighting, which is automatically and constantly adapted for varying traffic situations. In this way, the LED matrix light functions with the Opel/Vauxhall Eye front camera, but its accuracy and adaptive capacity go one step forward. When light sources are detected from oncoming or preceding traffic, individual LEDs in the relevant zone are deactivated, while the rest of the road remains brightly illuminated. This Opel/Vauxhall automotive lighting system turns night into day for drivers without dazzling other road users. It will be introduced within the next 18 months.