Search Results

As we are proceeding to stage 2 of our ECE automotive lighting regulations [1] the target is to define simplified and technology neutral regulations that also can be used with newly developed technologies. With this simplification we do have the opportunity to look into the chance to harmonize SAE and ECE variants. For the upcoming new technologies we have to define those functionalities, which can contribute to a benefit in safety and which have to be defined jointly for both regions (ECE and SAE). This has to be justified by research studies, where the results will be reported. The opportunity to come up with new, proven technologies in the automotive market with a global valid regulation should be taken into account.

In the last years we recognize a big amount of innovative solutions in the field of automotive lighting and especially in front lighting systems. The major target to improve the light performance and to make driving at night safe is most important. The measure for the performance rating and the ability to compare different systems with a technology neutral process seems to be quite difficult. The legislation is looking for a simplification with clearly defined parameters for the future. Experimental test series recently published causing a lot of discussions as the sensitivity of the aiming of the headlamps can cause completely different performance test results. The paper will report on a study with various production vehicles, all in the same way initially aimed and prepared for all type of technologies.

Adaptive driving beam (ADB), which was first homologated in the ECE world (ECE 123) in 2012 has changed the automotive Front Lighting philosophy completely. Whereas we currently live with separate low beam and high beam features, also used in a combined way, we will have in the future a camera driven light distribution, which is a kind of modified high beam light pattern. ADB is a camera based lighting system, which enables the driver to achieve at night nearly high beam visibility without glaring oncoming or proceeding vehicles and road users. Once the presence of other vehicles is detected the headlamps change the light pattern and block the light where the oncoming or proceeding vehicles are located. The typical low beam light distribution with given and specified cutoff line will only be used in small speed areas. In US this development was well recognized and NHTSA is preparing a way to enable and approve the ADB systems with specific boundary conditions also for the US market.

Since 2012, adaptive driving beam (ADB) was homologated first in the ECE world (ECE 123). The idea behind is a camera based lighting system, which enables the driver to achieve at night nearly high beam visibility without glaring oncoming or proceeding vehicles and road users. Once the presence of other vehicles is detected the headlamps change the light pattern and block the light where the oncoming or proceeding vehicles are located. Light sources are typically High Intensity Discharge (HID) bulbs, but today also first LED applications are visible. For SAE, the definition of the parameters and the requested regulation changes to allow such systems are in progress. The paper reports about an extensive study executed in Germany at TU Darmstadt to investigate not only the improvement in visibility for the driver with such systems, but also evaluate the disability and discomfort glare for other road users.

With the introduction of the first LED headlamps with main functions (low beam, high beam) the comparison to the existing HID headlamps is always the benchmark. Due to the necessary heat management and the challenge to keep the temperature as low as possible, the light volume of 1000 lm or more is hardly to achieve with reasonable means. This will be improved in the future. This paper describes the opportunities of today with the introduction of LED light sources to combine the main functions with additional features in Front Lighting. The design of LED headlamps makes it possible to generate the full AFS functionality without any mechanical means. By using several LED modules and variation in current to generate specific light pattern one is able to adapt the light distribution according to the needs. This includes also the adaptive high beam or glare free high beam, which will be realized in the near future.

In the last decade Automotive Lighting has developed very rapidly. A lot of new technologies, and new Lighting Systems have been introduced. We are confronted with new light sources as well as new lighting functions. Both have been defined accurately within the existing regulations as addendum or new regulations. All these new features have been defined in order to improve safety when driving at night. The surveys conducted in the past have shown, that the consumer in general (both in NA and Europe) is quite satisfied with the light he has on his vehicle. The majority is also not informed very well about the different technologies available. On the other hand, the styling of a vehicle is playing an important role today including the headlamps and rear lamps. Aside the functional task of the lamps the appearance, the signature light and the kind of differentiator in comparison to other vehicles gets more and more important.

In Automotive Lighting, we have spent some time in the last years to discuss on the styling opportunities by introducing LED Light Sources instead of Halogen and/or Xenon bulbs. The appearance and the signature of a given vehicle defined by dedicated lighting equipment were and is still today a very important topic to develop a competitive vehicle. The light performance is under these boundary conditions a question of second priority. This is also valid, because lighting suppliers and car manufacturers achieved in the past decade a lot of improvements and have reached a level of performance, which is comfortable overall for the consumers. The issue with glare, which everybody has when driving at night is already accepted today as a given fact. This paper tries to define the next steps lighting suppliers need to take in order to improve this glare issue by considering alternative solutions.

First LED headlamps will be released into the market in 2007. Special permissions allow this introduction although the official regulation is still under discussion in ECE. The LED technology for front lighting has entered into a new phase from theoretical, prototype status to real and practical applications. Additionally in Europe the legislation, which is under preparation, defines LED modules with one or more LED chips in a row which should be replaceable. With this boundary conditions headlamp suppliers needs to balance between an attractive and innovative styling, demanded by car manufacturers and the light performance to gurantee good visibility at night. The paper describes the methods how to design an LED headlamp with high efficiency by keeping in mind the parameters: packaging, weight, styling and light perfromance. Results with specific design proposals are shown.

Within the last decade we have noticed considerable improvements in Automotive lighting devices. Xenon headlights, Systems with low beam and high beam out of one Xenon bulb, so called Bi-Function headlights and in the near future, advanced front lighting systems (AFS) will lead to an important contribution in terms of safety when driving at night. In parallel the philosophy of automotive engineering has changed from individual technical solutions contributing to improved value within the vehicles to a system integration concept, where individual technical solutions will be combined to one specific innovation. The use of various sensors and information tools for different and multiple applications within a vehicle is highly appreciated and will lead to synergies with reduced costs for the individual components. This philosophy will also be applied for lighting systems in the future. The potential applications and possible solutions will be described within this paper.

In most cases of night time driving the low beam light function is used for the road illumination in front of the car. This conventional low beam function has a constant light pattern: no matter whether the driver is actually driving on a straight or curvy road, whether the road is wet or dry, always the same beam pattern is applied. Test experiences of the last years prove that a headlamp with an „adaptive light pattern” having different optimum light pattern adapted to different driving situations should give a better illumination than the conventional constant low beam pattern which can only be a compromise. In this paper an outline of the basic idea of the „adaptive light pattern” is given. Different driving situations and their corresponding optimum light pattern, basic technical concepts and the legal situation regarding homologation of such an advanced lighting system will be discussed.

In the last years the possibilities to design the light pattern of automotive headlamps have been increased drastically. Headlamps are playing an important role in the design of a vehicle. Today there are various computer programms allowing a detailed layout of the light distributions, other than simple parabolic reflectors with a given light pattern. The questions: where to put the extra light and: what is the ideal distribution of the light volume on the road have been raised quite often and where mainly discussed between experts in lighting. In this paper we report the results of a customer inquiry about the criteria of a good light pattern and the ratings of different light distributions given by some concrete examples. We will report the results by comparing the answers of different customers with the theoretical ratings. In this paper we will concentrate on the application of low beam, the most important light function in night-time driving.

Car Designers are asking more often for headlamps that adapt well to highly inclined and low vehicle bodies or other exotic shapes e. g. of sports cars. In other cases headlamps are additionally used as stylistic elements and must therefore have a certain appearance e. g. oval shape or a clear, unprofiled cover glass. To realize a headlamp for such applications and at the same time keep it cost-effective with good light quality special headlamp systems have to be developed. Especially the normally used profiled scattering lens in front of the reflector causes complications under these circumstances. Therefore headlamp systems with complex reflector shapes have been developed whose reflectors produce an almost complete light distribution. Some different reflector concepts to realize this idea are presented in this paper and concrete examples for the application of this new technique are discussed.

In the last years, motor vehicle lighting systems were required to be more efficient, to have shorter development times and to be of higher quality. One important tool used in complying with these demands is the computer calculation of the optical characteristics of the complete headlamp system. A newly developed software package is presented in this paper which permits the configuration of a headlamp in its basic optical components and the quantitative calculation of its light distribution, luminous flux and other optical quantities. It is now possible for the first time, to assess a headlamp's total light pattern in advance, without hardware (e.g. model headlamps etc.) being required. The simulation results show a high degree of concurrence between the computed and the measured light distributions. This will be demonstrated in detail using concrete examples.

The built-in space available for a headlamp in motor vehicles has been steadily reduced by vehicle manufacturers over the last few years. In order to continue to provide the driver with the necessary safety equipment, new headlamp designs with improved efficiency are necessary. One such new design, the reflector with variable focus (VF Reflector), is presented in this paper. The mathematical concept of VF reflectors is explained and the advantages in lighting technique over conventional reflector systems are illustrated by means of concrete examples.

This report gives an overview of the current status of developments intended to improve the low beam of motor vehicle headlamp systems by use of segmented reflectors. In addition to advantages in terms of lighting technique (gain in luminous flux, increasing safety for the driver as a result of improved lateral illumination level and foreground brightness), the segmented reflector also accommodates the stylistic wishes of the automobile manufacturers (smaller overall height, larger angle of inclination of the lens), and thus represents a genuine alternative to the Polyellipsoid headlamp (PES) for the future. The advantages will be explained and quantified using concrete examples.