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.
Function and Design – LED-daytime running lights and LED-taillights
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
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.
LED headlights
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.
adaptive light
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 predicatively 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.
Written By: AUDI AG
Photography by: Audi
