In lighting technology, Audi is driving progress at high tempo. Today, its xenon plus-and LED headlights already provide excellent illumination of the road and give the cars with the four rings an unmistakable look. In the future, vehicle lighting from Audi will react even more precisely to environmental conditions, and it will feature full electronic control. The first step in this direction will be taken this year in the form of innovative matrix LED headlights.
Daytime running lights that consist of white light-emitting diodes are a safety and design feature that reflects Audi’s frontrunner role among the competition. They made their debut in the Audi A8 W12 in 2004.
This was the first step towards giving an Audi a unique and unmistakable headlight design. Meanwhile, the LED daytime running lights are now offered in all of the brand’s model series. In each model, the light-intense diodes offer many new degrees of freedom in designing the inner life of the headlight. Whether its lines are curved or straight, a model series from Audi is unmistakably linked to a specific type of lighting.
In the A1, two light-emitting diodes are used per unit; they emit their light into a transparent polymer tube, the light guide, which generates a uniform contour. In the Audi A7 Sportback, the daytime running lights of the optional LED headlights also appear linear, but they originate from 18 individual LEDs with a polymer body in front of them. The LED daytime running lights consume fewer watts of power, have extremely long life and are maintenance-free.
The introduction of full-LED headlights to the A6, A7 Sportback, A8 - and most recently to the A3 model series -, gives the cars unmistakable styling and a resolute look. The small LEDs can be arranged in lines, and they various lighting functions can be implemented by individually controlling the diodes.
The headlights generate a light pattern that is unmistakable and in many cases achieves three-dimensional effects. Such impressive design features could only be realized by close cooperation between engineers and designers. Stephan Berlitz, Head of Development for Lighting Functions/Innovations at Audi, says: “We always find a way to perfectly harmonize technology and styling.” Cesar Muntada Roura of Audi Exterior Design explains: “It is our understanding of one another’s areas of competence that make us so strong.”
Lighting technologies of today
Whether xenon plus or LED – the headlights and taillights in Audi models make a strong statement. The brand’s lighting technologies combine their attractive effects with a high level of active safety – with adaptive light, today’s headlights already react to the environment and to other vehicles in traffic.
Xenon plus headlights are offered in all models of the Audi lineup, either as optional or standard equipment. Xenon headlights are gas discharge lamps. Two tungsten electrodes are fused in a quartz glass cylinder, known as the burner, and a concentrated light arc burns between. The xenon inert gas charge in the burner, which is pressurized up to 100 bar, gives off a slightly violet light, while metallic salts in the glass cylinder charge reduce its color temperature to the spectrum of daylight.
Xenon headlights provide a much brighter light and better illumination than halogen headlights with incandescent bulbs, their energy consumption is about 20 percent lower and they have much longer life. In xenon plus technology from Audi, a single burner generates both the low and high beam lights, and they are switched by a moveable shutter. Of course, all xenon headlights are mercury-free.
Audi is also far ahead of the competition in the area of LED headlights. This high-end technology was introduced in the R8 in 2008, and today it is being implemented all the way to the A3 model series. With a color temperature of around 5,500 Kelvin, the LED light resembles daylight, and this reduces eye fatigue. The light-emitting diodes are maintenance-free, designed to last the life of the vehicle, and are highly efficient. The low-beam light, for example, only consumes around 40 watts, which is five percent less than xenon plus units.
In the new A3, nine high-performance LED chips in two free-form reflectors generate the low-beam light, while the high beam uses ten high-performance LEDs to emit light through an aluminum trim aperture. The static turning and all-weather lights are housed in a separate module; while the daytime running lights, parking and flasher lights are formed by a light guide that wraps around the upper and inner headlights as a narrow contour. The “wing” gives structure to the interior of the headlights.
LED headlights from Audi have not only proved themselves on the streets, but also in car racing. They made their debut in the R 15 TDI Le Mans sport protoype in 2010. In 2011, full-LED headlights were installed for the first time in the next generation race car, the R18 TDI. With their combined lighting power of over 200 watts, the LEDs generate a light pattern with a range of over one kilometer. Their equivalent luminous intensity of over 1,000 lux is five to seven times greater than headlights in production cars.
For many years now, LED technology has also been utilized in taillights – as standard or optional equipment. Unlike incandescent light sources, the light-emitting diodes reach full luminous intensity at lightning speed and without delay – when the driver brakes quickly, for example, the quick reacting brake lights give the driver of the vehicle behind additional valuable fractions of a second in reaction time.
Various adaptive light versions are available for the headlight systems. An electronic control module controls the swiveling xenon plus modules, or the LEDs, so that they always deliver the best possible lighting for city, highway and freeway driving. The driver can configure its mode of operation in the Audi drive select vehicle dynamics system.
One special component of adaptive light is smoothed dynamic headlight leveling. A video camera is used to detect vehicles ahead and oncoming vehicles; then the control module adapts the car’s lighting to the distance to the other vehicles – via a soft transition that always maximizes the amount of illumination.
The all-weather light illuminates the area in front of the car significantly better than with fog lights. Depending on the specific system installed, this function might be implemented by activating the static turning lights in addition to other lights, which improves lateral illumination considerably. In addition, the xenon units (with xenon plus headlights) may be swiveled downward, and the LEDs (on LED headlights) that are responsible for the low-beam light might be switched off or dimmed. The interplay of these actions substantially reduces “self-glare” to the driver.
In the A6, A7 Sportback and A8 model series, an additional function is activated as soon as the optional night vision assistant detects a pedestrian. The system flashes three light pulses to the pedestrian with the high-beam light according to the specific situation. This clearly highlights the person and surroundings and warns the pedestrian. The system detects any oncoming traffic to avoid any potentially hazardous glare.
Use of route data
Networking of the headlight control module with the MMI Navigation plus system represents a unique selling proposition of Audi. The navigation system’s route data enables such functions as early activation of higher freeway lighting range as the car is about to enter the freeway.
Route data is also used in the city. Close networking lets the lighting systems implement prepared solutions as needed. On city streets, a wider angle of the light pattern better illuminates the areas to the left and right in front of the car. In addition, whether within or outside city limits, the system activates the intersection light immediately before reaching an intersection, which makes it easier for the driver to look down cross streets. When turning, the cornering light is activated, which illuminates the curve better - either in the city or on highways. Another benefit is that in countries like England the headlights are automatically switched over to left-hand traffic.
Turn signal flashers with dynamized display
In updating its high-performance sports car, the R8, Audi introduced another innovation to production cars – a turn signal with dynamized display. It sends clearer signals to the environment than conventional turn signals. Today, the vehicle behind the car in traffic cannot determine whether a flashing light is a hazard light or a turn signal when the view of the vehicle ahead is partially blocked.
This technology from Audi - which is used in the taillights - makes the turn indicators smarter. When operated as turn signal flashers, their light always runs towards the side in the direction the driver wishes to turn. This function is implemented on each side by a band of 30 LEDs with seven segments that are sequentially activated every 150 milliseconds.
The lighting technologies of tomorrow
Audi is already developing tomorrow’s lighting technologies today, and four key trends are clearly discernible here: The Audi vehicle lighting will react even more precisely to conditions of the environment, it will communicate with it in a variety of ways and thereby further increase active safety. Lighting of the future will feature full-electronic control and will be even more attractive and distinctive based on new dynamic functions.
Audi Matrix LED headlights
The technology of the future is known as Audi Matrix LED headlights – it subdivides the LED high-beam light into numerous individual segments. The individual light-emitting diodes, which work in tandem with lenses or reflectors in front of them, always deliver excellent illumination, without requiring a swiveling mechanism – instead they are separately activated, deactivated or dimmed according to the situation. This new technology gives Audi engineers and designers fascinating possibilities for configuring the number of LEDs, their arrangement and the size and design of the headlights.
The Audi Matrix LED headlights get the information they need from a camera, the navigation system and other sensors. When the camera detects other vehicles, this causes the high-beam light, which is subdivided into multiple sectors, to be blocked in a certain subarea. In complex situations, the headlights can also illuminate the spaces between several vehicles.
Based on navigation data, the high beam light predictively swivels into the curve even before the driver begins to turn the steering wheel. Essentially, the high beam light guides the driver along the road. This functionality is also reflected in the special headlight design. Illumination of the segments can also be experienced from outside. The matrix LED headlights will make their debut later this year.