DARMSTADT
`
`
`
`UNIVERSITY OF
`
`TECHNOLOGY �PAL:
`
`PROGRESS IN AUTOMOBILE LIGHTING
`
`
`
`Laboratory of Lighting Technology
`
`
`
`
`
`September 25-26, 2001
`
`
`
`MOSAIC NICHE BY ALBIN MOLLER AT MATHILDENHOHE, DARMSTADT
`
`Mercedes EX1020
`U.S. Patent No. 11,208,029
`
`

`

`dedicated to
`dedicated to
`
`Mr. Val Roper
`Mr. Val Roper
`
`

`

`L:
`
`Progress in Automobile Lighting
`
`Proceedings of the Symposium
`
`Darmstadt University of Technology
`Laboratory of Lighting Technology
`
`Published by
`
`Prof. Dr.-lng. H.-J. Schmidt-Clausen
`
`~
`
`in the Series
`
`Darmstadter Lichttechnik
`
`Herbert Utz Verlag Wissenschaft
`
`MOnchen
`
`

`

`ISBN 3-89675-971-X
`
`PAL '01: 2 Volumes, Vol. 8 & Vol. 9; not to be sold separately
`
`Die Deutsche Bibliothek- CIP-Einheitsaufnahme
`Ein Titeldatensatz fur diese Publikation ist
`bei Der Deutschen Bibliothek erhaltlich
`
`ISBN 3-89675-971-X
`
`Das Werk ist urheberrechtlich geschOtzt. Die dadurch begrOndeten Rechte, insbesondere die der Ober(cid:173)
`setzung, des Nachdrucks, der Entnahme von Abbildungen, der Funksendung 1 der \lViedergabe auf photo(cid:173)
`mechanischem oder ahnlichem Wege und der Speicherung in Datenverarbeitungsanlagen bleiben, auch
`bei nur auszugsweiser Verwertung, vorbehalten.
`
`Die Wiedergabe von Gebrauchsnamen, Handelsnamen, Warenbezeichnungen usw. in diesem Werk
`berechtigt auch ohne besondere Kennzeichn'ung nicht zu der Annahme, dal5 solche Namen in Sinne der
`Warenzeichen- und Markenschutz-Gesetzgebung als frei zu betrachten waren und daher von jedermann
`benutzt werden dOrften.
`
`Copyright © 2001 Herbert Utz Verlag GmbH
`
`Herbert Utz Verlag GmbH, Munchen
`Tel.: 089-277791-00
`Fax: 089-277791-01
`utz@utzverlag.de
`www.utzverlag.de
`
`

`

`Content
`
`page
`
`Werner Adrian: University of Waterloo, Canada
`Visual Acuity and its Dependency on Observation Time and Contrast
`
`Yukio Akashi: Lighting Research Center, USA
`The effect of oncoming headlight glare on peripheral detection
`under a mesopic light level
`
`Daniel Armbruster: F. Porsche AG, Germany
`Motor vehicle signal lamps in a fog environment
`
`Gerd Bahnmuller: Automotive Lighting Reutlingen GmbH, Germany
`Headlamp Development - Reduced Time to Market
`
`Gerhard Bierleutgeb: Hella KG Hueck & Co., Germany
`Interior Lighting Control (ILC) System Aspects for a New Approach
`
`Werner D. Bockelmann: Ophthalmologist, Germany
`Coloured head-down displays (HOD) from the point of view of information
`transfer
`
`Doris Boebel, Automotive Lighting, Germany
`Signal Image in PES Systems
`
`Christian Boehlau: Hella KG Hueck & Co., Germany
`Optical Sensors for AFS - Supplement and Alternative to GPS
`
`Gary Brown: Mira, UK
`Integrating Pedestrian Impact Protection into Future Headlight Design
`
`Berthold Budel: Audi AG, Germany
`Clear lenses for lighting components - The actual trend and its problems
`
`John D. Bullough: Rensselaer Polytechnic Institute, USA
`Forward Vehicular Lightirig and Inclement Weather Conditions
`
`Michael Burg: Hella KG Hueck & Co, Germany
`Infrared Headlamps for Active NiQht-Vision Systems
`
`Tso-Wei Chang: Lunghwa Institute of Technology, Taiwan
`Driving Performance Analysis on Interactions among Factors of
`Center High Mounted Stop Lamp and Road Environment
`
`Christophe Chenevier: Valeo Lighting Systems, France
`Thermal Simulation in Lighting Systems - 5 Days / 5 Degrees
`
`Andreas Chudaska: Hella KG Hueck & Co., Germany
`Headlamp Cleaning Systems - Trends of Development and Future Demands
`
`Sharon Cook: Loughborough University, UK
`Warning beacon intensity
`
`V
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`

`Content
`
`Francesco Cortese: St Filippo Neri's Hospital, Italy
`Biological and Statistical Profile of Road Accidents Victims in an Urban Area
`A One-Year Experience in a Major Hospital
`
`Thomas Dahlem: Volkswagen AG, Germany
`Physiological Investigation of the Proportioning of Headlamp Illumination
`
`Maria Teresa Dalmasso: Automotive Lighting, Italy
`Signal LAMPs with hidden light sources
`
`Joachim Damasky: Hella KG Hueck & Co., Germany
`Trends in Auxiliary Car Lighting and the Influence on OE Development
`
`Ad de Visser: Philips Lighting B.V., The Netherlands
`Activities of CIE relevant to automotive lighting
`
`Detlef Decker: Hella KG Hueck & Co., Germany
`Aspects of dynamic light control in automotive applications
`
`Christophe Dubose: Valeo Lighting Systems, France
`Lighting Systems and Show Cars
`
`Alexis Dubrovin: Valeo Lighting Systems, France
`Optimised Lighting Systems Architecture
`
`Martin Enders: BMW Group, Germany
`Pixel Light
`
`JUrgen Ewald: Nippon Carbide Industries B. V., The Netherlands
`Visual Performance of Fluorescent Retroreflective Sheeting
`
`Frank Ewerhart: Robert Bosch GmbH, Germany
`Video Based Curve Light System - Sensor, System and Results
`
`Matthias Fiegler: OSRAM GmbH, Germany
`PLANON, a mercury-free flat panel light source, with high potential
`for automotive applications
`
`Michael J. Flannagan: The University of Michigan, USA
`Feasibility of Developing a Headlighting Rating System
`
`Helmut Frank: Mechatronic, Germany
`New Aspects for the Photometric Characterisation
`of Microprismatic Retroreflective Sheeting
`
`Gianpiero Fusco: Automotive Lighting, Italy
`Headlamps Beam Patterns Evaluation by CCD Camera
`
`Takashi Futami: Stanley Electric Co.,Ltd., Japan
`Development of the "Gatling Beam" Headlamps
`
`VI
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`page
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`316
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`

`

`Content
`
`Reiner Godecker: Hella KG Hueck & Co, Germany
`Hella introduces MOLIS® -
`the world's first ,free design' modular lighting system
`
`Martin Grimm: Hella KG Hueck & Co., Germany
`Improved Nighttime Visibility for Drivers through Dynamic Bend Lighting
`
`Martin Grimm: Hella KG Hueck & Co., Germany
`ECE Headlamp Performance Status and Potential for Improvement
`
`Helmut Hat: IHH lngenieurdienstleistungen, Germany
`SensorLEDIHH - Dual Operational Systemblock to Measure Perceived
`Brightness and to Simultaneous Adaptive Signal Image Display
`
`Michael Hamm: Automotive Lighting, Germany
`System Strategies for Adaptive Lighting'Systems
`
`Michael Hamm: Automotive Lighting, Germany
`Headlamp Performance Specification:
`A Summary of New and Comprehensive Evaluation Methods
`
`Takahiro Hara: University Yoto, Japan
`Evaluation of AFS from driver's point of view
`
`Wolfgang Hendrischk: Hella KG Hueck & Co, Germany
`From Xenon, BiXenon to Vario Xenon
`
`Henning Hogrefe: Automotive Lighting Reutlingen GmbH, Germany
`Headlamp Design with New Double Filament Bulbs
`
`Shao Hong: Fudan University, China
`The Investigation on Chinese Visual Perception
`
`Rainer Huber: OSRAM Opto Seminconductors, Germany
`Flexible SMT LED Submodules
`
`George Iatan: DBM Reflex Entreprises Inc., Canada
`Simulation software for complex reflectors
`
`S.E. Jenkins, Optical and Photometric Technology Pty Ltd, Australia
`Use and Measurement of LED Clusters for Signals
`
`Norbert L. Johnson: 3M Company, U.S.A.
`A comparison of Retroreflective Sign Performance in Europe and
`the United States based on Market Weighted Headlight Data
`
`Josef Kalze: Hella KG Hueck & Co., Germany
`Situation Adapted Light Distributions for AFS-Headlamps
`
`Hiroyuki Kanai: Shinshu University, Japan
`Proposition of Road Visual Environment Simulator for Evaluation
`Visibility of Driver
`
`VII
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`page
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`348
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`

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`Content
`
`Takeshi Kimura: Koito Manufacturing Co. Ltd, Japan
`Japan's Plan for Introducing ECE Regulations Into Japanese Safety
`Regulations
`
`Nils Knollmann: Audi AG, Germany
`Interior lighting concept on the basis of psychological and physiological
`influences on night-time driving
`
`Thomas Knoop: LichtVision GmbH, Germany
`Digital Light Measurement for Automobile Applications
`
`Shoji Kobayashi: Koito Manufacturing Co. Ltd., Japan
`Next Generation Lane Indication/Recognition System, Study of Phase II
`
`Toshiyuki Kondo: Stanley Electric Co. Ltd., Japan
`Developing Highly Efficient LED Combination Rear Lamps
`
`Prasad Koppolu: Visteon Corporation, U.S.A.
`Knowledge-Based Engineering Application for Lighting Design and
`Development - KBE-Smartlite
`
`Harald Kuster: Alanod Aluminium-Veredlung GmbH & Co. KG, Germany
`Large Area Coating of Aluminium Coils for Automotive Applications
`
`Peter Lehnert: BMW Technik GmbH, Germany
`Disability and Discomfort Glare under dynamic Conditions -
`The Effect of Glare Stimuli on the Human Vision
`
`Yandan Lin: Fudan University, China
`Visual Performance at Mesopic Light Levels
`
`Thomas Luce: Philips Automotive Lighting, Germany
`Optimized Light Source for High lncoupling Efficiencies
`in Distributive Lighting Systems (DLS)
`
`Peter Ludwig, Delphi Automotive Systems, Germany
`Wiring Integrated Illumination
`
`Karl Manz: Lichttechnisches lnstitut der Universitat Karlsruhe, Germany
`The Influence by Size of Headlamp on Discomfort Glare
`
`Karl Manz: Lichttechnisches lnstitut der Universitat Karlsruhe, Germany
`Tolerances of Cut-Off-Measurements
`
`Janusz Mazur: Warsaw University of Technology, Poland
`Computer Visualisation into Effect of Lighting Road
`by Car Projector with Using Programs from Group CAD
`
`Stefan Milch: smart microwave sensors GmbH, Germany
`Pedestrian Detection with Radar and Computer Vision
`
`VIII
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`page
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`

`

`Content
`
`Wolfgang Mohl: SCHOTT Glas, Germany
`Coating Technology and Materials for Lighting Applications
`
`Ulrich Moller: Dita Diemer & Fastenrath GmbH, Germany
`Non Dazzling Reading Lamp
`
`Kazumoto Morita: National Traffic Safety and Environment Laboratory, Japan
`Theoretical Analysis of Effect of Daytime Running Lamps on the Visibility
`of Automobiles
`
`Martin Muhlenberg: Hella KG Hueck & Co., Germany
`Vision Sensors and Image Processing -
`a Contribution to Intelligent Light Function Control
`
`Julius Muschaweck: Optics & Energy Concepts, Germany
`Constructive design of free-form optical components for illumination
`
`Kohei Narisada: Chukyo University, Japan
`Role of Adaptation in Perception under Traffic Lighting Conditions
`
`Rainer Neumann: Visteon Corp. Europe, Germany
`Future Rear Lighting Trends - Safety and Styling Aspects
`
`Bernhard Newe: Hella KG Hueck & Co., Germany
`Improved Signal Lighting
`
`Hiroo Oyama: Stanley .Electric Co. Ltd., Japan
`The Development of the "Vertical Shape Line-Beam Headlamp"
`
`Salvatore Pierro: Automotive Lighting S.p.A., Italy
`Plastic Transparent Reflectors for Clear Lens Signal Functions
`
`Wilfried Pohl, Bartenbach LichtLabor, Austria
`Enhancing Visibility by reducing Glare of Street Luminaires and Headllamps
`
`Thomas Reiners: OSRAM GmbH, Germany
`Introduction of Optical Features into Light Sources
`
`Justin Rennilson: RCS rennilson consulting service, U.S.A.
`International Cooperation in Establishing Requirements
`for Traffic Control Devices
`
`Lawrence M. Rice: Guide Corporation, U.S.A.
`Predictive Tools for Automotive Lighting
`
`Birgit Richter: Reitter & Schefenacker GmbH & Co.KG, Germany
`Innovative Tail Lamp Concept Enhances Perceptibility
`Under Bad Weather Conditions
`
`_Hartwig Riehl: OSRAM GmbH, Germany
`Interference Coatings in Signal Lighting
`
`page
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`665
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`IX
`
`

`

`Content
`
`Joachim Ripperger: BMW AG, Germany
`Luminance: the Future Photometric for Rear- and Brake-lights
`
`Ernst-Olaf Rosenhahn: Automotive Lighting, Germany
`Adaptive Headlamp Systems concerning Adverse Weather: Fog
`
`Kare Rumar: The University of Michigan, U.S.A.
`Intensity of High-Beam Headlights
`
`Kare Rumar: VTI Dev, Sweden
`Night traffic and the zero vision
`
`Arnulf Rupp: Osram GmbH, Germany
`Discharge Lamps in Automotive Lighting
`
`Torsten Ruths: Hella KG Hueck & Co., Germany
`Vehicle signature
`
`Luca Sardi: Automotive Lighting, Italy
`Light Guides for new Lighting Systems
`
`Takashi Sato: Stanley Electric Co. LTD., Japan
`The Smart Headlamp System with Variable Low-Beam Pattern
`
`Thomas Schnell: The University of Iowa, U.S.A.
`The Development of a Nighttime Driver Visibility Model
`for ultra-violet activated Pavement Markings
`
`Gabriel Schwab: Volkswagen AG, Germany
`GEOSim - a Tool for the Development of Adaptive Frontlighting System Control
`
`Touichirou Shiozawa: Koito Manufacturing Co. Ltd., Japan
`Thermal Air Flow Analysis of an Automotive Headlamp
`
`Michael Sivak: The University of Michigan, U.S.A.
`Quantitative Comparisons of the Benefits of Applying Adaptive Headlighting
`to the Current U.S. and European - Low-Beam Patterns
`
`Tomasz Targosinski: Motor Transport Institute, Poland
`Analysis of the Properties of the ECE Requirements Concerning Headlights
`
`Qifei Tu: The Institute of light sources, Fudan University, China
`Perspectives of LED Automotive Signal Lights in China
`
`Wout van Bommel: Philips Lighting, The Netherlands
`Road Lighting Research: yesterday, today and tomorrow
`
`Mark van den Berg: Lumileds Lighting, The Netherlands
`Development of High Brightness LED's for Automotive Applications
`
`John van Derlofske: Rensselaer Polytechnic Institute, U.S.A.
`Evaluation of High Intensity Discharge Automotive Forward Lighting
`
`X
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`

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`Content
`
`Stephan Volker: Hella KG, Germany
`Investigation of the visible range of different types of headlamps
`
`Alexander von Hoffmann: Volkswagen AG, Germany
`Analysis of Adaptive Light Distributions with AFSim
`
`Pieter L. Walraven: Em TNO Human Factors, The Netherlands
`Required changes in VM(A)
`
`Herbert WambsganB: Hella lnnenleuchten Systeme GmbH, Germany
`Innovations in Lighting Technology in Vehicle Interiors
`
`Takao Watanabe: Koito Manufacturing Co. LTD., Japan
`The Research on the Effectiveness of AFS Bending Lamp
`in Japanese Road Environment
`
`Christine Weber: Reitter & Schefenacker, Germany
`Micro controlled LED rear combination lamp with innovative signal configurations
`
`Thomas Weber: Hella KG Hueck & Co., Germany
`Virtual Night Drive
`
`Peter Weissleder: Audi AG, Germany
`The Demand for Attraction - Styling meets Design
`
`Gosta Werner: Swedish National Testing and Research Institute, Sweden
`Conspicuouity of road workers at night and day,
`experiences of two Swedish studies
`
`Wei Xu: Institute of Electric Light Sources, Fudan University, China
`The Measurement of Photometric Parameters of Lamps
`
`Wojciech Zagan: Warsaw University of Technology, Poland
`Chosen luminance measurement results of the cars' signal lamps
`
`Jiyong Zhang: Fudan University of Shanghai, China
`Computer Simulation of Headlamp Beam Pattern and Its Potential Utilization
`
`Li Zhou: Institute of Light Sources, Fudan University, China
`The Monte Carlo Method in Design of Automobile Lighting
`
`Wei Zhou: Fudan University, China
`Measurement of the Temperature Distribution on the Filaments
`of the Automotive Lamps Using the Spectroscopic Method
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`XI
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`

`

`System Strategies for Adaptive Lighting Systems
`Michael Hamm, Automotive Lighting, Germany
`
`1 Introduction
`While driving at nighttime, illumination for the driver is predominantly provided
`by the car’s headlamps. This implies a particular responsibility and challenge
`for the headlamp technology. In past years in an effort to bring the day closer to
`the night (in terms of illumination), illumination quality as well as the luminous
`flux of the headlamps had been constantly improved. All improvements had
`been related to the standard illumination device: the low beam or dipped beam
`as it was defined decades ago in the ‘20s. In the early days of motor vehicle
`traffic, the low beam was used when other cars were passing by, for that
`moment replacing the high beam or main beam.
`
`Nowadays, with roughly 50 million cars in Germany alone, this situation is
`history. Low beam is the light function used most often, with a share of about
`95% having limited visual range and lateral spread.
`
`The new leap of innovation in lighting technology are the intelligent headlamps,
`that provide an adaptive light distribution in all traffic situations with and without
`oncoming traffic.
`
`Figure 1:
`Design ideas for new
`intelligent headlamp
`systems in future
`cars
`
`The car’s sensors analyze and evaluate the driving situation and generate a
`light distribution that is adapted to that particular situation. In this process, not
`only the driver’s comfort is increased but the visibility is improved also. This has
`a direct positive impact on traffic safety.
`
`368
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`

`

`HID Technology
`The most important characteristics of HID Technology is the generation of light
`by discharge technology. The discharge arc has a significantly higher
`luminance and the whole system a lifetime that exceeds the car’s lifetime.
`
`Since 1999 HID systems are available for low- and high beam application,
`coming out of one single module.
`
`Figure 2:
`Bifunction HID-
`System for Low and
`High Beam out of
`one projection
`module
`
`m
`
`50
`
`0
`
`- 50
`
`
`
`Bi-Litronic -Low Beam
`
`Bi-Litronic HighBeam
`
`100
`
`200
`
`
`
`300
`
`400
`
`In projection systems, the actor moves the shield in order to set the high beam
`light contribution. In reflection systems the HID bulb is moved. This changes the
`focal geometry in the system and leads to a perfect high beam. Both systems
`include a fail-safe system that returns low beam operation in any failure
`situation.
`
`HID Bifunction Technology allows both main headlamp functions to be supplied
`in a very limited volume. HID quality is available also for high beam. Important
`is in this technology that one ECU is sufficient to drive the actors, control the
`ignition and operation and supply the automatic levelling function. Additionally
`the microcontroller allows several options as end-of-line-programming,
`diagnosis, software update etc. This solution is the maximized compromise
`between driving comfort, glare reduction, good street
`illumination and
`maximized traffic safety.
`
`Starting with HID Systems, Adaptive Lighting Strategies have to improve this
`now well introduced technology by using new approaches in a new system
`environment.
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`369
`
`

`

`Adaptive Lighting Systems
`In the Eureka-Project 1403 AFS (Advanced Frontlighting Systems) the
`European car manufacturers and their headlamp and bulb suppliers began
`investigating the object of an improved lighting technology. During the activity of
`this working group some American and Japanese car manufacturers had been
`involved. This gave AFS a worldwide foundation and importance.
`
`Figure 3: Selected Driving Situations with improvements by using intelligent
`adaptive headlamps
`
`
`
`
`
`While driving the research projects and doing market investigations the
`emphasis of research was turned to improvements in the driving situations
`Highway driving, Adverse weather driving, Curves, Turnings, City and Country
`road driving.
`
`The first experimental headlamp setups were used to investigate the lighting
`requirements to form an adaptive light distribution. In total 10 modules per side
`had been used to run the investigations. Although form and size had not been
`applicable for series implementation it was shown, in which way improvements
`in the light pattern would be possible. In parallel to these investigations the
`requirements for sensor informations available from the car network had to be
`defined. Modern car lines provide a large variety of sensors and data
`information systems (ABS, ESP, CAN) such that, in general, most information
`that might be relevant to adaptive lighting are already available, and new
`sensors need not be implemented in the car.
`
`370
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`

`

`Information, Sensors and Actors
`Basic informations that are needed to drive an adaptive headlamp system are,
`for example, speed, steering angle, body inclination, precipitation information
`(rain, fog) and the lighting devices status.
`
`The utilization of additional sensor information as is available in some cars, as
`for example yaw rate, GPS navigation data and distance radar information is
`currently being tested. Based on the initial functional and electronic concept,
`first styling samples have been presented to the public.
`
`For fulfilling the different requirements on the illumination of the street scenery,
`several approaches are considered:
`
`The easiest way is switching on or switching off additional modules in the
`headlamp. This means a relatively low using time of each module and a big
`waste of construction volume. Significantly better is the sophisticated approach
`of multiple use of elements. This means the use of actors in the headlamp that
`swivel, switch or change parts inside the headlamp.
`
`A simple, but tricky approach is the power control of the HID system.
`
`136 %
`
`Luminous flux/lm
`
`4000
`
`3000
`
`2000
`
`1000
`
`100 %
`
`0
`38 W
`32 W
`Figure 4: Power control of gas discharge bulbs with intelligent ECU
`
`
`
`
`Without changing the light colour and in the lamp specifications the possibility is
`given to achieve 36% more light out of the same module, the same space
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`371
`
`

`

`without switching additional devices. All light values can be shifted at once or
`continuously.
`
`The variation of luminous flux in the lamp specification range is equivalent to 2
`halogen low beam headlamps, that can be added as the variable part of the
`light distribution. Especially when using motorways, when an increase of visual
`range from 65 to 130 m should be provided this seems to be an appropriate
`solution. The power control is given by the ECU with the input parameters
`available, e.g. speed, navigation date etc.
`
`For the realization of curve lighting functions a horizontal movement of parts of
`the reflector with DC or stepper motors must be realized. In order to allow the
`light distribution to follow the course of the street, car specific informations as
`yaw rate, lateral acceleration, steering wheel angle or wheel angle are required.
`Ideal and predictive informations can be supplied by navigation and video
`systems. The following evaluation of three different driving situations shows the
`importance of the control and software concept. A car specific application from
`e.g. steering wheel angle and the photometric requirements for optimal
`illumination is needed.
`
`swivelling angle / °
`20
`
`10
`
`0
`
`-10
`
`-20
`
`0
`
`50
`Curved road driving
`
`100
`
`300
`250
`time / s
`Town driving
`Figure 5: Examples of required swiveling angles for adaptive light patterns
`
`150
`200
`Motorway driving
`
`
`
`
`
`On motorways the large curve radii show now big impact on the swiveling of a
`headlamp reflector, except the maneuvers for passing or exiting on the
`motorway. If the driving is done in mountain regions on serpentines or in town
`crossings and turnings, swiveling angles are exceeding 20°. Considering the
`construction volumes nowadays available this seems a hard challenge and
`
`372
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`

`

`barely not to be realized in a standard sized headlamp. So multiple step
`concepts have to be found, that help in such extreme situations.
`
`The interactions described create an additional amount of adaptation to
`hystereses, swiveling speed, switching time and switching point of all modules
`used in the concept.
`
`Figure 6:
`Modular elements
`may swivel and
`show the new
`functionality of Curve
`Lighting
`
`
`
`
`
`
`Software- and Control concepts
`The definition of type and content of the information that is required for the
`control of adaptive lighting systems has an important impact on the efforts that
`have to be scheduled for the development of an AFS-ECU. The system
`architectures in a car use more and more bus systems. Due to standardization
`development CAN bus seems to be one of the potential winners of the bus
`competition. The ideas shown in the following pictures are therefore based on
`CAN.
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`373
`
`

`

`The structure of the control is defined in modular levels, that allow a joint base
`and a diversification on car manufacturers ideas and requirements.
`
`Customer Specific Functions:
`Switching Parameters and Strategy
`Priority Override Options
`Application Specific Functions:
`CAN, EOL, Diagnostics, Levelling,
`Swivelling Control, PWM
`Library
`Input Output
`Software Modules
`Operating System
`Hardware
`
`System Functions
`
`
`
`Figure 7:
`Modular system
`design to combine
`customer specific
`requirements with
`independent platform
`design
`
`
`
`The functions available in the concept are stored in software libraries. The
`control and steering parameters are part of customer specific modules that can
`be depending on the car manufacturer’s concept and the switching and control
`strategy as well as from marketing conceptions.
`
`CAN
`Gateway
`
`AFS
` ECU
`
`AFS
` ECU
`
`Headlamp
`
`Driver
`PWM
`Halogen
`
`Driver
`Litronic
`
`Driver
`Actor
`
`Driver
`PWM
`Halogen
`
`Driver
`Litronic
`
`Driver
`Actor
`
`
`
`Figure 8: ECU concepts for adaptive light control
`
`
`
`Headlamp
`
`AFS
` ECU
`
`Halogen
`
`Litronic
`
`Actor
`
`AFS
` ECU
`
`Halogen
`
`Litronic
`
`Actor
`
`CAN
`
`CAN
`
`
`
`Implementing the adaptive control in the car electronic can be made on
`different ways. Dominating factor is the availability of an appropriate bus system
`for deciding the implementation and location of an interface box.
`
`374
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`

`

`Step 1 Basic
`Body Inclination, Speed
`
`Step 2 Comfort
`Steering Angle, Rain Sensor,
`Light Switch, Turning Indicator
`
`Stufe 3 Prediction
`ACC, Video Sensor, Navigation
`
`Rain sensor
`Video sensor
`
`Navigation
`
`Steering Anglel
`
`Speed
`
`Basic module
`
`Spot module
`
`Turning module
`
`
`
`Body Inclination
`Turn Indicator Switch
`Llight Switch
`
`
`
`ACC Distance Sensor
`
`Figure 9:
`Multiple Step
`approach on sensor
`information available
`in the car to be used
`for adaptive
`headlamp control
`
`the control of an adaptive system are
`for
`The minimal requirements
`informations about speed and levelling. Secondly, informations about the
`direction of the car as given by the steering wheel angle are required. European
`cars using HID systems usually have speed and levelling available. Cars using
`ESP systems also can supply the steering wheel and yaw rate.
`
`Adaptive Headlamp systems Impact on Traffic Safety
`When introducing adaptive elements in headlamp technology, high priority is
`given to the improvement of traffic safety. The improvement of the vision
`conditions and the seeing distances has direct influence to the ability of the
`driver to detect potentially dangerous situations in time.
`
`The increase of seeing distance provides the driver with additional reaction time
`that can be used for breaking or evasive maneuvers. An earlier start for a
`braking maneuver means a decrease of accident fatality. To show this
`experimentally, several driving situations had been investigated
`
`Different light distributions had been generated by a H4 system, a modern HID
`Xenon system and the new adaptive headlamp system. In static tests the light
`distributions were presented to 11 test persons who had to analyze the visual
`conditions. Grey visibility objects had been placed on the side of the street. In
`order to obtain comparable results, all object surfaces reflected with the same
`reflection coefficient. Depending on the light distribution, different numbers of
`visibility objects could be detected in the experimental setup.
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`375
`
`

`

`The results show, that significant improvements can be proven by the adaptive
`headlamp system, without generating additional glare for oncoming traffic.
`
`Curve Lighting
`The results presented show that the detection distance of objects in a left curve
`is increased from 53m to 89 m. This is an improvement of 68% compared to the
`standard halogen light distribution.
`
`It can be assumed that, if the object will be detectable in longer distance, the
`driver will experience an increase in time to decide further actions. This gain in
`detection distance for left hand curves corresponds to a gain in detection time
`of appr. 1,9 seconds, assuming a speed of 70 km/h. This additional time is now
`available to the driver, who can decide to break earlier, and in more controlled
`fashion, leading to a possible stop in time, before reaching the detected object.
`
`89 m
`
`65 m
`
`53 m
`
`Figure 10:
`Static test: Results of
`the investigations
`about visibility
`distances obtained
`with halogen-, HID-
`and adaptive
`headlamps.
`
`R = 250 m
`
`Halogen
`Xenon
`Adaptive
`Lighting
`
`Curve Left
`
`
`
`376
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`

`

`
`
`Motorway lighting
`The improvements in motorway situations could become even more important.
`The results of the investigations are shown. The detection distance doubles
`from 70m to 148m (211%).
`
`Assuming a speed of 130km/h (recommended on German highways) this
`improvement means 2,16 seconds more travelling time before the object will be
`reached. Within that time the driver is able to evaluate the situation he is
`approaching. Additional reaction scenarios can be checked and this gives the
`chance to make optimized decisions, to brake, stop or pass.
`
`Assuming the maximum speed on US highways with 70 mph the improved
`detection distance equals 2,49 seconds.
`
`Since the braking distance increases nonlinearly with increasing speed, this
`dramatic increase in detection time may constitute one of the most effective
`measures that can be taken to reduce the number of fatal accidents during
`travel at night.
`
`Due to the fact that accidents or dangerous situations will be avoided before
`becoming serious, this also corresponds to the comfort of driving at night time.
`
`The increased detection distance is available at any time and gives more
`information about the course of the street in distances below the standard one.
`The driver will be better prepared for any change and will therefore drive with
`higher comfort.
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`377
`
`

`

`Halogen
`Xenon
`Adaptive
`Lighting
`
`148 m
`
`85 m
`
`70 m
`
`Figure 11:
`Static test: Results of
`the investigations
`about visibility
`distances obtained
`with halogen-, HID-
`and adaptive
`headlamps
`
`13 m 17 m
`
`32 m
`
`Motorway
`
`Turning / Crossing
`
`
`
`
`
`Turns/Crossings Lighting
`Driving through turns or crossings with adaptive headlamp systems will open a
`new dimension in experienced driving safety. When approaching a typical
`crossing or intersection, conventional headlamp illumination just barely reaches
`the areas where pedestrians are crossing.
`
`The pedestrians are often only visible after the turning or driving maneuver has
`already fully developed. Often enough will the driver have a feeling of driving
`into a “black hole”, into a situation that he or she was not able to evaluate
`before. The adaptive headlamp system will enable the driver to triple the
`distance for detection. This will mean a drastic improvement over all previously
`uncertain turning and crossing maneuvers.
`
`378
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`

`

`
`
`Detection Distance Curve Lighting
`53
`Halogen / m
`
`Motorway
`70
`
`Turning/Crossing
`13
`
`Percentage
`
`100%
`
`Xenon / m
`
`65
`
`Percentage
`
`122,6%
`
`Adaptive Lighting
`
`89
`
`Percentage
`
`167,9%
`
`100%
`
`85
`
`121,4%
`
`148
`
`211,4%
`
`100%
`
`17
`
`130,8%
`
`32
`
`246,2%
`
`Table 1: Comparison of improvement in detection distance between Halogen,
`HID and Adaptive Lighting Systems
`
`
`Summary
`With the Adaptive System, an optimal illumination can be achieved even in
`challenging situations, thus eliminating to a large extent risky or fatal driving
`situations because more time is available to judge the driving situation correctly
`and to take the appropriate steps in time.
`
`The introduction of Adaptive Lighting Systems will generate an even more
`integrative simultaneous engineering process. Additionally,
` Adaptive
`„intelligent“ headlamps will bring the headlamp from its isolation in the front
`module back into the world of electronics and car networking systems.
`
`
`© PAL 2001 Symposium; Darmstadt University of Technology
`
`379
`
`

`

`Literature
`AFS – Advanced Frontlighting Systems, Eureka Project 1403.
`
`Boebel, D., Eichler, H.; Hebler, V.: Bifunction HID Headlamp Systems-
`Reflection and Projection Type.
`In: SAE Technic