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The goal of the investigations was to find out if there is a correlation between the luminance distribution on the lens surface of projection type headlamps (e.g. maximum luminance) and the average subjective glare rating (discomfort glare) of subjects under night time traffic conditions. The luminance distributions of different projection type systems are measured with a luminance measurement system and compared concerning their characteristics. For the validation a glare rating experiment has been carried out with a standard type glare source of different size and luminance peaks similar to projection lens luminances. It was found out that for glare peaks up to a diameter of α = 2′ (observation angle) the candle power of the glare source is the proper parameter to calculate the subjective glare effect. For larger sizes of the glare sources there is a dependency to the diameter of the glare source for the glare effect.

During haze or fog situations particularly at night time the visual range of drivers can be decreased in the dependence of the transmittance of the atmosphere. Today fog headlamps with an inclination of the cut-off-line at β = -2% and a focus on improved side illumination can support a better guidance along the road course, but can't compensate the disadvantages during fog concerning the reduced driver's visual range along his own driving lane. Improving the range of fog headlamps in comparison to standard fog beam patterns can provide safety benefits during night time fog conditions. Some results of investigations concerning fog beam pattern will be given in this lecture and the conclusions for an improved fog beam pattern will be described. In the field of future adaptive headlamp systems further improvements can be provided by activating the fog headlamp or by adapting the beam pattern to different fog density conditions automatically.

Adaptive Frontlighting Systems (AFS) generate different lighting patterns according to the environmental situation that is evaluated by electronic control units. Especially the Motorway function will be investigated in the paper. 1 On one side, the photometrical performance will be shown in measurements, e.g photometric data and comparison to the existing driving situations with standard headlamps. 2 The improvements of an AFS motorway function are investigated in visibility/detection distances, reaction distances and braking distance calculation. The results will be presented at the lecture. 3 A new approach will be the evaluation how the improved light performance is accepted by the driver when driving adaptive lighting systems. It can be assumed that the fact that during night time driving the fixation is mostly oriented in front of the car in illuminated areas, the visible change of light performance will lead to clear statements about acceptance among drivers.

One of the most important features of a headlamp with adaptive light distribution is the improved side illumination for driving situations in towns, at intersections and in small radius curves. Pending legal requirements will allow use of bending light realized by side illumination from either a part of the low beam or a separate cornering lamp. The first part of this paper compares the legal requirements of both SAE and ECE regulations for bend lighting and cornering lamps. The second part discusses the performance of different lamps developed on the basis of these regulations. They are compared with respect to technical and performance aspects.

In the next few years a lot of car manufacturer will offer adaptive headlamp systems as an option or as standard equipment for their products. These headlamps will provide an advantage concerning comfort and traffic safety for the driver, but on the other hand for a general acceptance of all traffic participants the level of glare has to be controlled carefully. Developing an adaptive headlamp new techniques have to be installed in the headlamp and in combination with the electronic control unit, which analyzes various sensor information, a complex system of different lighting modules and moving optical parts will be introduced in future headlamps. The high level of complexity requires for the case of failure special concepts, which have to be fixed in the development process of the headlamp with the target of finding effective and cost saving solutions. Some main aspects of this control strategy are presented and discussed in this paper.

The development of headlamps was found to experience a dynamic process. For more than 50 years the tungsten double filament bulbs (Bilux) had been dominating the lighting technology, followed in the seventies by the H4 bulb. Since the middle of the eighties the modern filament bulbs as H7 (now H9, H11) have been available. The Xenon gas discharge (or HID-) technology reached the automotive market in the nineties. Now the development is heading towards the new technology step. Adaptive „intelligent“ headlamps will bring the headlamp from its isolation in the front module back into the world of electronics and car networking systems.

High intensity discharge lights (HID) are the innovation step that is now beginning to penetrate in all car classes. Investigating drivers, all results show that the benefits are visible to them and positively accepted. The quantification of the improvements has yet been insufficiently examined. In this article some of the aspects will be highlighted.

The introduction of innovative new technologies is related to aspects of safety and to human factors as comfort level and visual appearance. The intelligent headlamp system that is currently being developed allows the combination of the different aspects of driving comfort and safety. The top performing headlamp generations of the future will be the successors of the today’s standard low beam. By using the sensor information available in the car, the light distribution will be adapted to different driving situations and generate an optimized light distribution. Relaxed and safe driving is the goal. Investigations concerning adaptive headlamps are presented. Highway, country road, curves and turning situations are examined by investigating detection distances of standard objects and by rating safety and comfort. Photometric measurements rating glare effects during curve road driving for different headlamp control algorithms are carried out.

The most frequent adverse weather situation zones is the rain situation. Therefore the lighting properties of the traffic situation with a wet road surface are measured in great detail. The target of the investigations is to show the necessity and the potential for an improvement of headlights for this situation. In the first part of this paper the results of experiments are shown, which analyse the visual performance of drivers during glare in wet road situations. In the second part rating experiments concerning comfortable luminance levels in front of the car during rainfall are described. To illustrate the result of these experiments the obtained rating parameters are applied to one example of a headlight beam pattern for a situation with wet road surface.