Ernst-Olaf Rosenhahn

ANALYSIS OF LIGHTING PARAMETERS DURING ADVERSE WEATHER CONDITIONS

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 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. (A) For the covering abstract of the conference see ITRD E206480.

Cornering Lamps and Static Bend Lighting - Performance Aspects and Technical Comparison in AFS-Systems

This paper describes how 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 the 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 and they are compared with respect of technical and performance aspects.

Fog Headlamp-Visibility Investigations and Performance Requirements for Redefinition in Adaptive Headlamp Systems

This paper describes how, during haze and 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 Beta = -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 the investigations concerning fog beam pattern will be given in this paper and the conclusions for an improved fog beam patter will also 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. Taking into account that several sensors for the detection of the visual range are under development and automatic adaptation of the car’s beam pattern to the weather conditions will be possible in the future, the driver’s requirements for different fog situations should be defined.

Facts and Feelings Regarding Motorway Light in Adaptive Headlamp Systems

This paper describes how 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 this paper. 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. The improvements of an FAS motorway function are investigated in visibility/detection distances, reaction distances and braking distance calculation. The results will be presented in this paper.