The Audi designers and developers are increasingly turning vehicle lighting into an information medium by replacing one-way signals with interactive lighting technologies. The lighting adapts to the prevailing conditions and communicates with both the driver of the car and its surroundings.
Audi is working on the use of organic light-emitting diodes (OLED) in the rear lights. One of the models for this is a light unit in which several OLED surfaces are positioned upright and one behind the other. It creates fascinating three-dimensional effects. Since the material can only withstand temperatures up to 80 degrees Celsius, OLED lighting requires extensive thermal management.
Laser rear fog light
The laser rear fog light – another predevelopment project at Audi – fulfills an important safety function. Generated by a laser diode at the rear of the car, it presents the trailing driver a bright, clear signal, thus keeping them at a safe distance. If visibility is good, the beam from the laser rear fog light, which is fan-shaped and inclined slightly downwards, is seen as a red line on the road. The width of this line depends on the distance to the trailing vehicle: At a distance of 30 meters (98.4 ft), the line is about as wide as the car. This clear signal is an unmistakable warning to the driver behind to maintain a safe following distance.
In fog or spray, the laser beam strikes the water droplets in the air and makes them visible; the line is then seen as a triangle. The laser rear fog light looks like a large warning triangle.
Car-to-x communication – the networking of cars among themselves and with the traffic infrastructure – also offers considerable potential in the lighting area. If cars share data among themselves, they can fine-tune the brightness of their headlights to one another. Consequently, together they can brightly illuminate the road, yet prevent glare at intersections or when facing oncoming traffic. When stopped at a red light or in a traffic jam, the headlights can be dimmed.
Besides road lighting, the second major field of work for the Audi lighting developers and designers is interior lighting. The interior light directly affects the driver and the passengers. It influences their mood and sends them important signals to further enhance safety.
The Audi experts take cues from architecture when it comes to interior lighting design. In many museums, lighting is used to showcase objects or rooms. A picture, a sculpture or a vase can look quite different depending on the lighting and illumination. The surface, the outline or even the texture can be emphasized.
In a car, small spots of light can enhance the surface effect of the upholstery and decorative inlays. Leather can appear velvety soft; a carbon fiber-reinforced polymer (CFRP) facing reflectively glossy. Carefully deployed lighting produces an exciting interplay of light and dark zones. At the same time, illuminating the walls can make a room appear larger.
Another topic is the moods and emotions evoked by colors of light – the color white alone has a wide range. Audi generally uses cool, “technical-looking” light corresponding to the progressive character of the brand.
In the new Audi Q7*, the owner can adjust the color of the light virtually at will if the vehicle is equipped with the top version of the ambient lighting. A choice of 32 colors is available both here and for the marker lights, which are extremely narrow light guides that trace the contours of the instrument panel, in the doors and on the center tunnel console.
The marker lights work intelligently together with the Exit Warning assistance system. If either the driver or a passenger want to open the door even though a bicycle or a vehicle is approaching from the rear, the light guide lights up in signal red and pulses at short intervals.
An interior model shows just how far the new information and safety functions could go in the future. The layered oak used as a decorative inlay on the center tunnel console, in the doors and on the instrument panel is backlit by LEDs. The light serves as a warning when exiting the car or parking. If the driver activates piloted driving in a traffic jam – a future assistance system – portions of the steering wheel rim light up in green. As soon as the driver has to take over the wheel again, the lighting changes color to red.
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.