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Effects of the Wet Retroreflectivity and Luminance of Pavement Markings on Lane Departure Warning in Nighttime Continuous Rain with and without Glare Sources

3M-Susannah Clear, Thomas Hedblom, Jordan Whitney
Texas A&M Transportation Institute-Adam Pike, Timothy Barrette
Published 2019-04-02 by SAE International in United States
A common challenge for both machine vision (MV) systems based on visible-spectrum cameras and for human drivers is detection of pavement markings in nighttime rainy conditions. This occurs because a layer of water refracts the light differently than air, causing conventional markings to substantially retroreflect the light away from the driver or camera when the marking is immersed. This reduces the marking retroreflectivity in wet conditions, and thus the contrast in the image collected by the camera at longer viewing distances. MV lane departure warning (LDW) systems also depend on pixel data from shorter viewing distances; the contrast here also depends on diffuse luminance of the marking, which typically is reduced if the marking is soiled or worn. The efficacy of LDW systems is also known to be influenced by the presence of glare, as regions of glare test the limits of the high dynamic range of the sensor and reduces the contrast between the marking and the surrounding roadway surface. In this study, the authors explored the effects of wet retroreflectivity and luminance of…
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Evaluation of After-Market Light Emitting Diode Headlight Bulbs

Rensselaer Polytechnic Institute-Yi-wei Liu, John Bullough
Published 2019-04-02 by SAE International in United States
Taking advantage of growing consumer interest in light emitting diode (LED) headlights, an increasing number of after-market LED replacement bulbs is available on the market. They are designed to have similar socket shapes and sizes as halogen bulbs, in order to fit into existing headlight housings. Although none of these LED replacement bulbs conform to present federal headlighting regulations, and some are labeled for "off road use" only, others claim to meet current regulations. Regardless, many different LED bulbs can be easily purchased and installed by vehicle owners, who may or may not be aware of their regulatory status. Several different LED replacement bulb kits, each designed to replace a conventional 55-W H11 halogen bulb, were purchased and tested in three different low-beam headlight units. Photometric measurements at several critical test points for headlight performance revealed that none of the resulting distributions met all of the test point photometric requirements. Some intensity values were lower than allowed minima while others exceeded allowed maxima. Photographs of the resulting beam patterns for each combination of LED bulb…
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Nighttime Visibility in Varying Moonlight Conditions

4M Safety-Michael Kuzel
Kineticorp LLC-William Neale, James Marr, Nathan McKelvey
Published 2019-04-02 by SAE International in United States
When the visibility of an object or person in the roadway from a driver’s perspective is an issue, the potential effect of moonlight is sometimes questioned. To assess this potential effect, methods typically used to quantify visibility were performed during conditions with no moon and with a full moon. In the full moon condition, measurements were collected from initial moon rise until the moon reached peak azimuth. Baseline ambient light measurements of illumination at the test surface were measured in both no moon and full moon scenarios. Additionally, a vehicle with activated low beam headlamps was positioned in the testing area and the change in illumination at two locations forward of the vehicle was recorded at thirty-minute intervals as the moon rose to the highest position in the sky. Also, two separate luminance readings were recorded during the test intervals, one location 75 feet in front and to the left of the vehicle, and another 150 feet forward of the vehicle. These luminance readings yielding the change in reflected light attributable to the moon. In…
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Influence of LED Spectral Characteristics on Glare Recovery

Rensselaer Polytechnic Institute-Nicholas Skinner, John Bullough
Published 2019-04-02 by SAE International in United States
Headlight glare is a major concern of the driving public. In the past couple of years there have been concerns expressed about the use of light emitting diode (LED) lighting technologies and possible impacts LEDs may have on people, including circadian disruption, retinal hazards, and glare. Under typical use cases, vehicle headlight exposures are insufficient to cause circadian disruption or retinal damage, but can result in disability and discomfort glare, as well as glare recovery. In general, white LEDs used for illumination have greater short-wavelength content than halogen lamps used in many headlights, and short wavelengths have been implicated in visual discomfort from bright lights at night. Previous literature is inconsistent regarding whether the spectral (color) content of a glare source affects the amount of recovery time needed to see objects, following exposure to a bright light such as a vehicle headlight. Warm and cool white LEDs were used as glare sources in the present study. They were energized and exposed to study participants at one of two illuminances (low, high) for either 3 or…
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Development of Surfactant-Free Anti-Fogging Coating for Automotive Headlamps

Hyundai Motor Company-Min Jin Choi
Published 2019-03-25 by SAE International in United States
Recently, the design of automotive headlamps has become diversified and complicated according to customer needs. Hence, structural complexity of the headlamps has also increased. Complex structure of the headlamps inevitably causes a disturbance in air circulation. For this reason, inadvertent micro-sized water droplets, called fogging, are condensed on the inner surface of headlamp lens due to temperature difference between the inner and outer lens surfaces. To circumvent fogging inside of the headlamp lens, an anti-fogging coating is indispensable. Conventionally, diverse surfactants have been adopted as substantial material for the anti-fogging coating. However, the usage of the surfactants causes undesirable side effect such as water mark arising from vapor condensation, which is an important issue that must be fully resolved. In this study, we developed an innovative anti-fogging coating material without using conventional surfactant. For this purpose, crosslinkable hydrophilic-hydrophobic random copolymer was utilized. The detailed experimental procedure is as follows: (1) Thermosetting resin composed of hydrophobic monomer (methacrylic acid and methyl methacrylate), hydrophilic monomer (ADEKA™ Resoap ER-10, Adeka Corp.), and crosslinker was synthesized. It should be…
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Motorcycle Auxiliary Front Lamps

Motorcycle Lighting Committee
  • Ground Vehicle Standard
  • J1306_201808
  • Current
Published 2018-08-13 by SAE International in United States
This engineering design specification provides parameters and general requirements for auxiliary front lamps to be used on motorcycles.
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Reflex Reflectors

Signaling and Marking Devices Stds Comm
  • Ground Vehicle Standard
  • J594_201806
  • Current
Published 2018-06-19 by SAE International in United States
This SAE Standard provides test procedures, requirements, and guidelines for reflex reflectors.
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Performance Requirements for Motor Vehicle Headlamps

Road Illumination Devices Standards Committee
  • Ground Vehicle Standard
  • J1383_201805
  • Current
Published 2018-05-16 by SAE International in United States
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 performance requirements for headlamps.
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Controlling LED Based Adaptive Front-Lighting System Using Machine Learning

Tata Elxsi, Ltd.-Sivaprasad Nandyala, Sriharsha Santhapur, Kshitij Kumar, Mithun Manalikandy
Published 2018-04-03 by SAE International in United States
Accidents in nights have a major share in all automotive accidents. Even though, the average distance driven in dark is 75% less as compared to the average distance driven during the day, the fatalities in nights due to road accidents are 300% of the day time. Again, the statistical studies from the National Safety Council disclose the fact that 55% of all road accidents in nights occur at the curved roads due to insufficient illumination and poor judgment of curves. The paper proposes a control algorithm with machine learning that controls LED matrix headlamp to provide precise beam pattern shaping and beam intensity (i.e. high and low beam). The system is designed to give the driver improved visibility under varying driving conditions. Adaptive Front Lighting System is an intelligent system, designed in MATLAB\Simulink environment that optimizes the illumination of roads during the night, on the basis of inputs from different sensors in the vehicle.
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Development Optimization with System Bundled Engineering in Body Exterior Lighting at an Automobile Manufacturer

Ford-Werke GmbH-Elena Hansch
Published 2018-04-03 by SAE International in United States
If I had asked people what they wanted, they would have said faster “horses”. Henry Ford [5].The automotive industry is in an environment where things are constantly moving and so Original Equipment Manufacturers (OEMs) have to move. Continuous technological progression is a key factor for the industry to be economically successful, to shape the future and with that to achieve maximum profit and benefits for the enterprise from the social transformation. Today the automotive industry uses all kind of innovation to create advanced new vehicles and solve tomorrow’s overall transportation challenges. In particular, exterior lighting has become a key contributor of the vehicle’s first impression and appearance. The features and technologies that provide as much light as possible on the road to improve the driver’s visibility at night have become more relevant and even safety standard. Additionally, recent technology innovations enable exterior lighting to be a personalized user experience as well as an identification and communication tool with the whole environment to leverage car-to-x (C2X).Exterior lighting is known as a commodity with a high speed…
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