Browse Topic: Headlamps
The objective of this study was to examine the effect of Correlated Colour Temperature (CCT) of automotive LED headlamps on driver’s visibility and comfort during night driving. The experiment was conducted on different headlamps having different correlated colour temperatures ranging from 5000K to 6500K in laboratory. Further study was conducted involving participants of different age group and genders for understanding their perception to identify objects when observed in light of different LED headlamps with different CCTs. Studies have shown that both Correlated Colour Temperature and illumination level affect driver’s alertness and performance. Further study required on headlamps with automatically varying CCT to get better solution on driver’s visibility and safety.
This SAE Standard provides test procedures, performance requirements, and guidelines for semiautomatic headlamp beam switching (SHBSD) devices.
Headlight glare remains a persistent problem to the U.S. driving public. Over the past 30 years, vehicle forward lighting and signaling systems have evolved dramatically in terms of styling and lighting technologies used. Importantly, vehicles driven in the U.S. have increased in size during this time as the proportion of pickup trucks and sport-utility vehicles (SUVs) has increased relative to passenger sedans and other lower-height vehicles. Accordingly, estimates of typical driver eye height and the height of lighting and signaling equipment on vehicles from one or two decades ago are unlikely to represent the characteristics of current vehicles in the U.S. automotive market. In the present study we surveyed the most popular vehicles sold in the U.S. and carried out evaluations of the heights of lighting and signaling systems, as well as typical driver eye heights based on male and female drivers. These data may be of use to those interested in understanding how exposure to vehicle
This SAE Recommended Practice applies to motor vehicle Forward Illumination Devices which incorporate limited adaptive beam pattern capabilities. This document is to be used in conjunction with other forward lighting standards and/or recommended practices which define the base beam procedures, requirements, and guidelines.
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document provides standardized laboratory tests, test methods and equipment, and requirements for lighting devices covered by SAE Recommended Practices and Standards. It is intended for devices used on vehicles less than 2032 mm in width. Tests for vehicles larger than 2032 mm in overall width are covered in SAE J2139. Device specific tests and requirements can be found in applicable SAE technical reports.
To ensure adequate visibility without excessive glare, vehicle headlights are designed to use a specific source of illumination. The optical designs of headlights gather the luminous flux produced by the light source to produce a useful beam pattern that meets the relevant requirements and standards for vehicle forward lighting. With the advent of solid state, light emitting diode sources for general illumination, an increasing number of LED replacement headlight bulb products has emerged over the past decade. In most cases, these LED replacement bulbs are not permitted for legal use on public roadways, but some countries have begun to permit specific LED replacement bulbs to be used legally on the road for specific makes, models and production years of certain vehicles. If they can be demonstrated to produce a beam pattern that meets the photometric requirements for a legal headlight, they are permitted to be used legally for on-road use. In the present paper we present photometric
This SAE Standard provides test methods, performance requirements, installation requirements, and guidelines for snowmobile headlamps.
Headlamps should illuminate the traffic scene ahead of the vehicle in such a way that the driver can operate the vehicle safely and in a relaxed manner. At the same time, negative effects on drivers of other vehicles, pedestrians and other people should be minimized. Various technical parameters such as beam pattern, mounting height, headlamp aiming, and source spectrum can be tuned to find the necessary compromise. The physiology of the vision system under specific nighttime conditions strongly influences these factors and how headlamps can be best optimized for visibility and comfort. The SAE Improved Roadway Illumination task force collected and reviewed relevant research on these topics. This document is a comprehensive summary of this information. The goal is to enable lighting experts, advocacy groups, and non-experts (journalists, consumer organizations, car drivers) to better understand the benefits and tradeoffs of improved roadway lighting with modern headlamp technology. It
When designing new vehicles, the legal requirements of the countries in which the vehicles are homologated must be observed and implemented. The manufacturers try to consider the legal framework of the UN-ECE (United Nations Economic Commission for Europe), CCC (China Compulsory Certification) and FMVSS (Federal Motor Vehicle Safety Standard) 108 in the same vehicle to keep the variance low. For the appearance of the vehicle, the position of the light modules in the front of the vehicle is important. In addition to the surface requirements of lighting functions, the positions of the low beam (LB), high beam (HB) and the position of daytime running lights (DRL) are also regulated. When it comes to these mounting positions, the legislation between the US and the EU differs quite significantly. The UN-ECE legal framework does not describe the distance between the left and right Adaptive Front Lighting System with a certain value, but only requires the distance to the outer edge of the
As new headlight technologies begin to take hold in vehicular forward lighting systems and they become more commonplace on vehicles, new frameworks for evaluating the performance of these systems are being developed and promulgated. The objective of each of these systems is the same, namely, improving safety by ensuring that vehicle lighting provides sufficient visibility for drivers without negative impacts such as glare. Recent research has shown the direct link between improved driver visibility and reduced nighttime crashes. To the extent that headlight evaluation systems can be compared using visual performance modeling approaches, it should be possible to relate improved visibility from high-performing headlight systems to the potential for reduced nighttime crashes. In the present paper we demonstrate how visual performance modeling in conjunction with vehicle headlight evaluations can lead to predictions of improved safety and ultimately, beneficial economic impacts to society.
This SAE Standard provides test procedures, requirements, and guidelines for tail lamps (rear position lamps) intended for use on vehicles of less than, equal to, or greater than 2032 mm in overall width.
Visual sensors are widely used in autonomous vehicles (AVs) for object detection due to the advantages of abundant information and low-cost. But the performance of visual sensors is highly affected by low light conditions when AVs driving at nighttime and in the tunnel. The low light conditions decrease the image quality and the performance of object detection, and may cause safety of the intended functionality (SOTIF) problems. Therefore, to analyze the performance limitations of visual sensors in low light conditions, a controlled light experiment on a proving ground is designed. The influences of low light conditions on the two-stage algorithm and the single-stage algorithm are compared and analyzed quantificationally by constructing an evaluation index set from three aspects of missing detection, classification, and positioning accuracy. Five main environmental influencing factors are tested and analyzed in typical nighttime urban driving scenarios: illuminance, the lateral
This SAE Information Report will explain the differences between Class A, B, and C networks and clarify through examples, the differences in applications. Special attention will be given to a listing of functions that could be attached to a Class A communications network.
Most signal and marking lighting devices have light sources (bulbs), which can be based on either filament or LED technology. To assure field replacement, it is important that light source types employed be readily available in normal service channels. This document defines the physical, electrical, and photometric characteristics necessary to achieve a proper replacement for popular types of signal and marking light sources. Some of the design characteristics in this document are listed solely for the sake of standardization and are not intended to describe the performance of lighting devices (lamp assemblies) on the vehicle. Halogen filament light sources suitable for signal and marking lighting are specified in SAE J2560.
This SAE Recommended Practice applies to motor vehicle forward illumination systems and subsystems generated by discharge sources. It provides test methods, requirements, and guidelines applicable to the special characteristics of gaseous discharge lighting devices which supplement those required for forward illumination systems using incandescent light sources. The document is applicable to both discharge forward lighting systems, subsystems and components. This document is intended to be a guide to standard practice and is subject to change to reflect additional experience and technical advances.
Automotive headlamp designs have evolved considerably over the years, shifting from a utilitarian component of a vehicle to being a major part of its overall styling, particularly for the Front of the vehicle. In addition to this, Headlamps are a ‘mission-critical’ safety feature, especially for driving at night or in poor weather conditions. For this reason, they are subject to high performance requirements and must meet stringent automotive and highway safety standards. Modern headlamps are becoming bigger and heavier to accommodate attractive features like DRL lamps, Projector lamps and Adaptive lamps. The increased weight of the headlamp poses additional challenges with respect to the durability and loss of bolt preload during high road load events.
This SAE Recommended Practice applies to motor vehicle forward illumination systems and subsystems generated by discharge sources. It provides test methods, requirements, and guidelines applicable to the special characteristics of gaseous discharge lighting devices which supplement those required for forward illumination systems using incandescent light sources. The document is applicable to both discharge forward lighting systems, subsystems and components. This document is intended to be a guide to standard practice and is subject to change to reflect additional experience and technical advances.
This SAE Recommended Practice provides test procedures, requirements, and guidelines for rear fog lamp systems.
This SAE Standard defines requirements relating to the elements of design, operation, and maintenance of light utility vehicles (LUVs). The safety specifications in this document apply to any self-propelled, operator-controlled, off-highway vehicle 1829 mm (72 inches) or less in overall width, exclusive of added accessories and attachments, operable on three or more wheels or tracks, primarily intended to transport material loads or people, with a gross vehicle weight of 2500 kg (5500 pounds) or less, and a maximum design speed less than or equal to 40.23 km/h (25 mph). This document is not intended to cover go-karts (ASTM F2007-07a), fun-karts (ASTM F2011-02e1), dune buggies, and all terrain-vehicles (ATVs) complying with ANSI/SVIA 1.
This SAE Standard provides test procedures, requirements, and guidelines for motorcycle turn signal lamps. It does not apply to mopeds.
The main task of the automotive headlights on cars is to illuminate the roadway and facilitate the driver fatigue-free and safe driving. An automotive headlamp is exposed to thermal variations during its operations and also exposed to the different environmental conditions. Automotive headlamp compartment is not completely sealed and vents are provided to exchange the air between environment and headlamp compartment for thermal cooling of the internal components. An automotive headlamp compartment is an environment with high thermal and low air flow exchanges with the ambient as results humidity can accumulated inside the headlamp compartment and there is a possibility of thin mist layer formation on the lens inner surface [1]. The combined use of numerical simulation and experimental studies is an important approach for headlamp design. This paper summarizes CFD simulation results for automotive headlamp condensation and de-condensation using ANSYS FLUENT. In this study, transient
Automotive exterior lighting systems has to meet several regulatory requirements & manufacture specific internal standards to achieve desired performance. These test specifications are usually generic in nature and formulated mainly to validate the standalone product under standard laboratory conditions. Most of the time these specifications are common for entire vehicle portfolio. The rationale of these standards is to define the basic illuminance in the safe braking distance. Thus, however, using the requirements in these standards to evaluate the performance of front lighting systems is only qualitative. Research on working out method for quantitative evaluation of front lighting system is necessary [1] In practice, however, the luminance levels at road surfaces are usually very dynamic; depend largely on the variations in vehicle parameters, ambient weather conditions, road surface uniformities and effects of light intensity & color contrasts on target visibility. Unavailability of
This SAE Standard provides test methods, performance requirements, installation requirements, and guidelines for snowmobile headlamps.
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document establishes additional performance requirements specifically for road illumination devices using light emitting diode (LED) sources.
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document provides standardized laboratory tests, test methods and equipment, and requirements for lighting devices covered by SAE Recommended Practices and Standards. It is intended for devices used on vehicles less than 2032 mm in width. Tests for vehicles larger than 2032 mm in overall width are covered in SAE J2139. Device specific tests and requirements can be found in applicable SAE technical reports.
Transportation safety agencies are working to consider how to best incorporate the potential safety benefits of intelligent vehicle lighting systems such as adaptive driving beam headlights and other systems on vehicles used by the general public. As these deliberations continue, additional data on the impacts of lighting technological developments are important to generate and share. An analytical study was performed to assess how different vehicle lighting configurations including ADB and other technologies can assist drivers in achieving visual acquisition of potential hazards along the road. The investigation also compared drivers varying in age and whose visual performance differs because of optical changes in the visual system. The importance of considering visibility for older drivers is critical because this group is an increasingly large proportion of the overall driving population. Analyses use the relative visual performance (RVP) model, a predictive system for ascertaining
Understanding when an object enters into the headlamp projection from a vehicle is useful to assist the driver in detecting the object in dark or nighttime conditions. Understanding the specific illumination pattern of a vehicle headlamp beam is useful for the evaluation of nighttime visibility issues in accident reconstruction. Determining when an object entered in the headlamp beam at a specific illuminance may be of particular importance to driver avoidance capabilities. Headlamp illumination patterns may be unique to each vehicle make and model. In this study, the headlamp illumination patterns of multiple vehicles were mapped, and the measured illumination distances were compared with empirical predications. In general, individual headlamp illumination distances fell within the range of minimum and maximum empirical predictions. However, the empirical relationships can have large standard deviations, which may influence the available time for the driver to detect and respond to
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