Audi is already developing the lighting technologies of tomorrow. In cooperation with the exterior and interior designers, its engineers are pursuing lines of thought in various directions; there are scarcely any limits to their creativity.
Nonetheless, two central topic-areas are emerging: the lighting on tomorrow’s Audi models will react even more intensively to environmental conditions, it will communicate in various ways with its surroundings and in this way will increase active safety still further. New dynamic functions will make the lighting system still more attractive.
Matrix Beam is the name for Audi’s future headlight technology. It is a principle that divides the LED light up into many distinct sources. The small individual diodes backed by lenses or reflectors provide excellent illumination in all situations without needing a swivelling mechanism. They are simply switched on and off or dimmed to suit the situation.
Matrix Beam headlights obtain the information they need from a camera, the navigation system or additional sensors. If the camera detects other vehicles or the lights of a built-up area ahead, these innovative headlights fade out the appropriate area of the high-beam headlights, which contain various light-source sectors. They are already aware of the topography of the road and can also vary the illumination they provide according to weather conditions, for example rain or fog.
During the last two years Audi has exhibited widely differing visual and technical versions of its Matrix Beam technology on a series of show cars. The number of individual LEDs, their layout and the size and styling of the headlights open the way to a broad range of fascinating designs.
In technical terms the Matrix Beam principle represents a series of new, exciting challenges. They relate to the extremely low tolerances permitted during manufacture and assembly, the methods used to energise the headlights and control them independently, the overall efficiency of the package, the uniformity of the conical light beam and the airflow path through the headlights. Audi is already in a position to answer all these questions, so that the new technology will soon be introduced on production cars.
Audi uses the acronym AFS for its “advanced frontlighting system”. The term defines the next but one step forward in headlight technology – a further development of Matrix Beam. The system aims to pick out important individual objects in the driver’s field of view by illuminating them more directly. The objects concerned may be people or animals on the road that have been detected by the night vision system, but also road signs or those used to indicate road works.
AFS technology callss for the LEDs to be movable, and they are therefore mounted on the ends of piezo rods. When a voltage is applied, the numerous small plates made up of piezo crystals are pulled together. The rod then pivots up or down. Another method adopted by AFS technology uses small beamers in the headlights that can project navigation arrows on to the road.
Intelligent rear lights
Every driver has experienced the situation: when visibility is poor because of rain, fog or snow, there is an instinctive tendency to drive closer to the vehicle in front, in order not to lose sight of its rear lights. This can be very dangerous if the driver in front has to brake suddenly.
Audi solves this problem by means of its intelligent rear lights. A newly developed sight sensor determines visibility and increases rear light intensity if necessary. The driver behind can still see the car’s rear lights clearly and therefore has no need to drive closer to it. The sight sensor can be located at the rear of the car in a position where it measures the the spray thrown up by the wheels. Alternatively, it can be installed at the front and its measurements suitably converted.
Laser rear fog light
The laser rear fog light fulfils a similar function to the intelligent rear lights: it is generated by a laser diode at the rear of the car and displays a bright, clear signal to the vehicle behins that encourages its driver not to come too close.
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 from the following vehicle: at a distance of 30 metres (98.43 ft), the line is about as wide as the car. Like a “stop” line, this signal is an unmistakable warning to the driver behind to keep a safe distance away.
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 then looks like a large warning triangle. Altogether, laser light can be said to be of great potential interest – for headlights as well.
The wipe-action flasher is also intended to transmit unmistakable signals to its surroundings. With present-day flashers this is sometimes not the case; if the vehicle is partly concealed or the flasher has failed, the driver behind is unable to tell whether a turn or a hazard warning signal is being indicated.
Audi has now developed “smarter” flasher technology. When a turn is indicated, the light always performs a “wiping” movement from the inside outwards. This provides information that can be clearly seen and understood even a fairly considerable distance away. The signal is provided by a horizontal row of LEDs that are energised in successive blocks.
OLED technology is yet another example of Audi’s pioneering work in the vehicle lighting area. The initials stand for “organic light emitting diode”. Unlike the LEDs currently in use, which consist of semiconductor crystals, OLEDs are made from an organic material.
In its initial condition the material is a paste that is spread extremely thinly – the coating is only a few thousandths of a millimetre thick – on an absolutely flat surface such as highly polished display glass. When an electrical voltage is applied, the molecules in the paste emit photons and the surface lights up. Depending on the distribution of the electrical input, the illumination can be either uniform, include specific light-dark effects or generate dynamic movement.
OLED surfaces can only be bent to a relatively slight radius, which imposes limits on their use on the surface of a vehicle’s body. They are on the other hand very suitable for use inside the vehicle or in rear lights. Audi engineers have built an experimental 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 lights need extensive thermal management.
External light design using OLED technology, which Audi is aiming to adopt, will be as intelligent as it is attractive. For example, it is possible to envisage a scenario in which the lights react to the approaching driver, follow his or her movements and highlight the main contours of the vehicle or the door handle. When the driver has entered the car, restrained OLED lighting will become active inside. This new technology will not only transform the car into a mobile “light sculpture” but generate benefits and emotions at the same time.
A scenario in the OLED technology area to which intensive thought has already been devoted is the “swarm”. With this model, Audi engineers have transformed the rear of the vehicle into a large, continuous illuminated surface, on which a large number of small points of light fluctuate like individual fish in a swarm.
Movements of the red dots take their orientation from movements of the vehicle. When a right turn is made, they flow to the right; when the car is braked they flow rapidly forwards. The faster the car is driven, the faster the dots move. In this way the following driver can always see what the driver of the car in front is doing. The OLED swarm combines a highly attractive effect with a specific gain in safety.
The initials MID stand for “moulded interconnected devices”. With these new components, Audi accesses the third dimension of lighting terminology. They enable engineers and designers to develop lighting assemblies in any desired form – a giant step forwards compared with today’s two-dimensional printed circuit boards.
MID technology is based on an innovative plastic material that contains an organic metal complex. The first step is to produce the required shape by injection moulding. In a second step, a laser inscribes the electrical circuit on the component. The uppermost polymer layer is vaporised and the metallised core to which metals can adhere is exposed. The third step is production of the circuit paths by galvanising. They are sufficiently thick to supply electric current to LEDs.
The first result from the use of MID at Audi is an illuminated sphere approximately 15 centimetres in diameter. It is made up of two half-shells with a number of apertures, and has 52 integrated LEDs. The new technology still has to prove its worth by testing at the loads encountered in a car, but Audi development staff is already delighted with the absolute design freedom offered by the MID principle.
Future car-to-x communication – radio networking of cars among themselves and with the traffic infrastructure – also offers considerable potential in the lighting area. One of many conceivable scenarios is when the car is halted at a red traffic light or in a traffic jam. During this period the headlights are dimmed to a large extent or switched off completely, to save energy and avoid imposing a possible burden on other road users.
When cars are able to exchange data directly, they can coordinate the brightness of their headlights, for instance in dense stop-and-go traffic or at crossroads. The road can always be effectively illuminated without dazzling the drivers.
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.