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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.

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.

Vehicles with low power consumption, less CO2 emission and reduced fuel consumption rate are more and more in the focus and are required by customers. Lighting is able to contribute in introducing Low Power HID (High Intensity Discharge) and LED (Light Emitting Diode) light sources. The paper will present a new LED Headlamp system with Low Beam, High Beam, and Daytime Running Light (DRL). The DRL will be mandatory for all new vehicles according to ECE (Economic Commission for Europe) regulation in 2011. The multifunctional design of such a headlamp system makes it possible to achieve an optimum balance between the requested light performance at night and the challenge to reduce power consumption, to reduce CO2 and to achieve economic fuel consumption rates. The paper describes the new designed headlamp system, reports on the light performance results and indicates the opportunities for the future automotive market.

In 2003, the first AFS systems have been launched in various vehicles. The movable headlamps should improve the visibility mainly in curved roads. Especially the comparison between the Xenon (HID) - version and the Halogen system was noticed with considerably high interest. The paper describes the experimental study we did in order to find out, what the real benefit on the road for the consumer is going to be. The evaluation shows, that even with the AFS Halogen solution we can report a higher visibility in curved roads than with the static Xenon system. Additionally, the introduction of static bending lights and cornering lights in combination or as a stand alone system will be considered. The subjective impression for a better visibility for the drivers when parking or making U-turns could be clearly detected by the experimental survey. Nevertheless, the dynamic bending lights are getting the highest priority for the drivers at night.

The paper deals with the current progress in rear lighting technology. Within the competition in offering the best vehicle for the individual customer safety aspects but also the appearance of the rear lights are getting more and more important. Our investigation is based on the equipment of LEDs within rear lamps. In combination with the CHMSLs (Center High Mounted Stop Lights) the styling but also the safety feature which one can realize is different. In achieving shorter reaction times when using LEDs there were already made some general experiments in a laboratory (1). For the first time we did experimental analysis of reaction times of stop function of rear lamps including CHMSLs in various combinations in real traffic conditions, taking conventional tungsten halogen bulbs and LEDs as a light source. The results will be presented in this paper.

The paper deals with the current progress in rear lighting technology. In developing the best vehicle in terms of traffic and driver safety, a rear signal light becomes increasingly important. Many car manufacturers are offering an LED CHMSL (Center High Mounted Stop Lamp) as one mean of increasing traffic safety. This investigation is based on the comparison of reaction times between lighting devices equipped with conventional incandescent bulbs and those equipped with LEDs. In combination with the CHMSLs, LED signal lamps provide value in styling and safety features. Laboratory measurements had already been done resulting in shorter reaction times with LEDs. This study discusses experimental analysis of driver reaction times in response to the stop function of rear lamps including CHMSLs.

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.

Due to the general requirements in the automotive industry to reduce the power consumption, fuel consumption rate and CO2 emission a new HID (High Intensity Discharge) bulb with only 25W is under development for front lighting systems. A first headlamp integrated in a hybrid vehicle is now launched as a first application in the market. The current regulation in ECE allows to get rid of the mandatory headlamp cleaning system and the automatic leveling requirement once the 25W HID bulb is applied. The reason for this is the objective luminous flux of the 25W HID bulb, which emits less than 2000 lm, a boundary defined in the regulation, where a headlamp cleaning and an automatic leveling is requested. That simplifies especially the integration in smaller vehicles and electric and hybrid vehicles. The paper describes the special design of the headlamp, the projector unit, the light performance, packaging advantages and future outlook of further applications in the near future.

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.

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.

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 near future, first headlamps with white LED front lights will enter into the market, both in US and Europe. Two major criteria have to be satisfied in order to be successful: the light performance has to be competitive with current systems of today (HID) and the styling of LED systems has to be attractive, thus being able to differentiate (Fig. 1). The light source concepts, which are currently in discussion along with the optical design leads to various solutions, which will be covered within this paper. Optical calculations and results of first prototypes will be compared. Additionally, the acceptance level of the consumer by means of these LED concepts have been empirically tested. The results of this survey will be reported.

In the last years we do recognize an increasing number of driver assistance systems, which aims to help the driver to drive safely through the corresponding traffic conditions. In parallel, automotive lighting uses a part of these new information systems to direct the light towards the appropriate directions and make night time driving safer. The newly developed glare free high beam system is one example to use the information of oncoming vehicles and proceeding vehicles and other road users to avoid glaring and to enlarge the visibility for the driver at the same time. The target is the creation of an optimized visibility, which will be delivered automatically. The paper reports on the findings of a test procedure, where the subjects had to rate the new lighting system and also the degree of comfort, which is delivered with such automatic visibility controlled light distributions.

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.

A new automotive headlamp has been developed under the designation LITRONIC (Light Electronics). In order to improve the light quality and to increase driver safety on the road, a gas-discharge lamp was chosen as the light source instead of the conventional incandescent bulb. The projector headlamp is well-suited for the application of the LITRONIC system. Especially in the US market, there is currently a potential interest in applying projector headlamps in series production. Compared to conventional headlamps, advantages can be seen in the flexibility of this kind of headlamp from the styling view point. In this paper, newly developed solutions for projector headlamps from Bosch will be presented, for HID as well as for incandescent bulbs. Applications for low beam and for high beam are included. By means of concrete examples, the improvements in light quality compared to conventional systems will be demonstrated.

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.

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.

Within the automotive market the application of LEDs for rear lamp functions or CHMSL has been highly increased. The styling aspect as well as short rise time as a safety feature are the main reasons for this effect. In designing an LED application for both, CHMSL and rear lamps one has to take into account reliability of the total system. LEDs, as single components, have reliability higher than any incandescent or halogen bulb: from this point of view the LED rear lamp reliability should be higher than traditional rear lamp reliability. On the other hand, at the moment ECE specifications allow using LEDs as light source for rear lamps just in the case that the rear lamp is sealed. As a consequence if some LED fails it will be necessary to substitute the complete rear lamp: this will be a potentially very high maintenance cost for the final customer. Therefore LED rear lamp reliability has to be considered specifically under these boundary conditions.

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.