1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside U
4、SA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visit http:/www.sae.org/technical/standards/J2584_201102SURFACEVEHICLEDRAFT TECHNICALREPORTJ2584 FEB2011 Issued 2002-09 Stabilized 2011-02
5、Superseding J2584 SEP2002 Headlamp Mounting Height for Passenger and Pickup Truck Vehicles RATIONALE The technical report covers technology, products, or processes which are mature and not likely to change in the foreseeable future. STABILIZED NOTICE This document has been declared “Stabilized“ by t
6、he SAE Road Illumination Devices Standards Committee and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability of technical requirements. Newer technology may exist. Copyright SAE International Provided by IHS under lic
7、ense with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1. ScopeThe Mounting Height Task Force was tasked to determine the extent of the problem(s) associatedwith vehicle headlamps mounted at or above the level of the mirror(s) in passenger vehicles; the level
8、 of glareexposure caused by high-mounted headlamps; the appropriate height differential needed to maintain a glarelevel consistent with past and/or current passenger vehicle headlamp mounting; and the necessary headlampmounting height necessary to control mirror glare at an accepted/acceptable level
9、. The report hereinaddresses these passenger vehicle mounting height issues.2. References2.1 Applicable PublicationsThe following publications form a part of this specification to the extent specifiedherein. Unless otherwise indicated, the latest version of SAE publications shall apply.2.1.1 SAE PUB
10、LICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J2338Report of the Task Force on Headlamp Mounting Height for Large TrucksSAE Paper #740962 1974Miller, Baumgardner, Mortimer, “An Evaluation of Glare in Nighttime DrivingCaused by Headlights Reflected in Rearview Mir
11、rors”SAE Paper #970911 (1997)Kosmatka, W., 1997, “Comparison of Models for Detection of HighwayObstacles with Headlamps”2.1.2 UMTRI PUBLICATIONSAvailable from UMTRI, RIPC, 2901 Baxter Road, Ann Arbor, MI 48109-2150. Email:umtridocsumich.edu, 734-764-2171.1. Sivak, Flannagan, Traube, Kojima, UMTRI 97
12、-23, The Influence of Stimulus Duration on DiscomfortGlare for Persons With and Without Visual Correction, Univ. of Mich. Trans. Res. Inst., May 19972. Sivak, Flannagan, Kojima, Traube, (1997). A market-weighted description of low-beam headlightingpatterns in the U.S. Report UMTRI-97-37. Ann Arbor:
13、The Univ. of Mich. Trans. Res. Inst.3. Rumar, Sivak, Traube, Miyokawa (1999), Nighttime Visibility of Retroreflective Pavement Markingsfrom Trucks Versus Cars, No.UMTRI-99-34, Ann Arbor, Univ. of Mich. Trans. Res. Inst.SAE J2584 Stabilized FEB2011 Page 2 of 19 Copyright SAE International Provided by
14、 IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2.1.3 OTHER PUBLICATIONSa. Olson,P, Sivak,M., Glare from Automobile Rear Vision Mirrors, Human Factors, 26(3), 269-282, 1984b. Schmidt-Clausen, Bindels (1974) Assessment of discomfort glare
15、in motor vehicle lighting. LightingRes. and Tech., 6, 79-88c. Kosmatka, W., Minutes of the Mounting Height Task Force, May 2, 1995, Southfield Michigand. Consumer Reports Magazine, Jan Sept, 1999 New vehicle driving test reports3. Definitions3.1 Sport Utility Vehicle (SUV)Types of passenger vehicles
16、 designed with potential for off-road use. Theygenerally have increased ground clearance and are higher than conventional passenger vehicles.3.2 De Boer Glare Rating ScaleA nine-point scale for describing the relative levels of discomfort glare.Qualifiers, for the odd points, are as follows: 1 unbea
17、rable; 3 disturbing; 5 just acceptable; 7 satisfactory; 9 just noticeable.3.3 Luxmeter CellA light sensitive transducer capable of turning incident radiometric flux into current or voltage.The device output, in an appropriate electrical circuit, is proportional to the intensity of the incident radia
18、tionand can be reported by an output device as “lux,” “foot-candles” or “candela.”4. BackgroundIn 1996, the Mounting Height Task Force published SAE J2338 addressing the problems withhigh-mounted headlamps on heavy trucks. The report suggested that headlamp mounting height on theselarge vehicles be
19、limited to 0.9 m to 1.0 m. Due to the increased popularity of Sport Utility Vehicles (SUVs), there is evidence of increase in publicawareness and dissatisfaction with mirror glare from the headlamps on these passenger vehicles. NHTSA hadindicated an industry need to control this apparent problem wit
20、h voluntary limits on headlamp placement orrulemaking actions. In May of 1999, in response to public sentiment and at the request of members of theRoad Illumination Devices Committee, the chair reconvened the Mounting Height Task Force to evaluateproblems associated with small vehicles, including pi
21、ckup trucks and SUVs that were specifically omitted fromthe “heavy truck” recommendations.The task force reviewed approximately 70 letters written by motorists to NHTSA (excerpts recorded in TaskForce meeting minutes of September 1999). In general, the writers express dissatisfaction with glare from
22、high-mounted headlamps (generally) on SUV vehicles. Both frontal and rear glare are mentioned. Side mirrorglare is noted along with interior mirror glare. The interior mirror is dimmable at the drivers option. It was theopinion of the task force, that the location and relative height of the side mir
23、ror represented the more extremecase in the case of driver discomfort glare. For these reasons the task force focused its investigations on thedriver side mirror in the matter of addressing mounting height for headlamps.5. Review of Discomfort Glare StudiesThe task force reviewed several published g
24、lare studies as part ofreevaluation of headlamp mounting height. 5.1 Foveated SourceMiller et al. (1974) used driver voluntary dimming as a measure of the level of glare from afoveated source that drivers were willing to tolerate. They found that 60% of drivers dimmed their headlampsat 360 m (1200 f
25、t) or greater and that another 28% had dimmed them by 180 m (600 ft). Using informationabout headlamps of that vintage, the authors concluded that drivers would accept near-foveal illuminance of0.43 to 1.72 lux (the report actually found “0.04 to 0.16 fc”). Miller et al. determined that side mirrors
26、 wereexposed to 1.9 lux for normally aimed headlamps and 11.9 lux for misaimed headlamps.SAE J2584 Stabilized FEB2011 Page 3 of 19 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5.2 Peripheral Sourc
27、eOlson and Sivak (1984) studied glare from peripheral sources. They found side mirrorglare levels just below “admissible” for eyepoint illumination of 2.37 to 8.61 lux (for “long” exposure durationsand “short” exposure durations respectively). They also noted disability effects for side mirror glare
28、 atperipheral eyepoint illumination levels of 7.75 and 75.5 lux.5.3 Admissible LevelSivak et al. (1997) studied “oncoming” vehicle glare and concluded that the “justadmissible” level, (De Boer level 5) and the less than “admissible” level (De Boer level 4) ranged from 3 lux to4 lux. This study used
29、a controlled glare angle of 3.5 degrees and a controlled glare duration time of 3 s.5.4 Peripheral AngleSchmidt-Clausen and Bindels (1974) documented discomfort glare as a function of theperipheral angle to the point-of-focus. They found an inverse relationship of the 0.46 power between the angleof
30、the glare source to the drivers point-of-focus, to the De Boer rating.6. Acceptable Discomfort Limits for Side Mirror GlareWith the information previously, along with anassumption for windshield losses (10%) and side-mirror/side-window losses (50%), the task force was able todefine a range for “acce
31、ptable” discomfort glare in various driving situations. The progression of thecalculations of acceptable mirror glare is described in Table 1. a. Miller et al: Direct Glare at the Eyepoint: 0.4 to 1.6 lux near-foveal glare (applying a 90% for“windshield transmittance” for vehicles circa 1974 and rou
32、nding to the first decimal place)b. Olson and Sivak Side Mirror Illuminance: 2.37 to 8.61 lux for approximate De Boer “level 5” sidemirror glare (“3 minute” and “10 second” exposure; no side mirror/window transmittance factor)c. Sivak et al. Duration Effect: Interpolation from “Figure 4” (see Append
33、ix A), long durations increasethe discomfort effect by about 1 to 2 De Boer units. E.g., acceptable range for near-foveal glareranges from 3.0 to 0.8 lux.d. Schmidt-Clausen “6” for intermediate duration; and “7” for long durations. Theinterpolation yielded eyepoint illuminance of 3 lux, 1.5 lux, and
34、 0.8 lux respectively.6.2 Peripheral Glare ToleranceThe glare tolerance levels previously are for foveated glare at the nominalangle of 3.5 degrees (210 arc-min) to the point-of-focus. In order to account for the peripheral nature of theside mirror glare (versus the foveal tolerance values) angular-
35、ratio factors were calculated for angles of 35, 40,and 45 degrees using Schmidt-Clausen and Bindles algorithm. The algorithm shows that discomfort glare isinversely proportional to the angle between the point-of-focus and the peripheral glare source (minutes of arc),raised to the 0.46 power. The imp
36、lied effect of peripheral glare light is less than that of foveated glare light.The tolerance ratios for the angles previously are 3.06, 3.15, and 3.24 respectively for the three anglespreviously. The products of the peripheral-glare-ratios and the glare tolerances for different exposuredurations ar
37、e in Table 1.SAE J2584 Stabilized FEB2011 Page 4 of 19 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLE 1METHODOLOGY FOR DEFINING “JUST ADMISSIBLE” LIMITS FOR SIDE MIRROR GLARE(1)1.Italicized nu
38、mbersare from the actual study; other values are derived by application of appropriate ratio factors.Sivak, Flannagan, Traube, Kojima(UMTRI 97-23)3 s ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-23)3 s ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-23)3 s ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-2
39、3) 10 to 20 s ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-23) 10 to 20 s ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-23) 10 to 20 s ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-23) 1 to 3 Min ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-23) 1 to 3 Min ExpSivak, Flannagan, Traube, Kojima(UMTRI 97-2
40、3) 1 to 3 Min ExpOlson UMTRI 97-23 algorithm; 1.0 and 2.0 De Boer unitsXXX1.5 lux1.5 lux1.5 lux0.80.80.8XXPeripheral Glare45deg11.34.862.458.61 lux2.37 luxAdjust UMTRI 97-23 data40deg10.74.62.528.61 lux2.37 luxusingSchmidt-Clausene.g., selection of the “10 lux” side-mirror glare limit.The task force
41、 concluded that “acceptable” side mirror glare is 10 lux in the majority of driving situations thathave intermediate exposure times, less than a minute in length. 7. Side Mirror Illumination from HeadlampsSeveral studies of side mirror glare were undertaken in order toquantify the actual levels of d
42、rivers exposure to side mirror glare light. 7.1 Field MeasurementsMirror illumination measurements were made for eight vehicles engaged in passing orfollowing a test vehicle on Cleveland area expressways. A color corrected Luxmeter cell was mounted at thelower extreme of a side mirror centered at a
43、height of approximately 900 mm (36 in). The vehicle was drivenalong interstates having a reasonable amount of pre-dawn traffic. At such times as the vehicle was beingfollowed or passed by other vehicles; illumination readings of the side mirror illumination were recorded. Themeasured mirror illumina
44、tion levels are listed in Table 2:TABLE 2MEASURED MIRROR ILLUMINATION LEVELSVehicle Type and Location Side Mirror IlluminationHeavy truck following in the right lane 5 to 15 lux (during the measurement interval)Heavy truck following in the right lane 5 to 10 luxHeavy truck passing on the left 20 to
45、60 lux (as the vehicle overtook/passed)Heavy truck passing on the left 5 to 30 luxHeavy truck passing on the left 5 to 20 luxPassenger vehicle following in the right lane 3 to 6 lux (during the measurement interval)Passenger vehicle following in the right lane 3 to 8 lux SUVs following in the right
46、lane 5 to 15 lux (during the measurement interval)SAE J2584 Stabilized FEB2011 Page 6 of 19 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-7.2 Historic Levels of Side Mirror Glare from Sealed Beam H
47、eadlamps; Illumination CalculationsIn orderto help define a baseline of drivers historical perspective of side mirror glare, levels of side mirror illuminancewere calculated using headlamp-to-mirror differential heights of +15 cm (6 in), i.e., mirror is 15 cm higher thanthe headlamps. (The different
48、ial height of 15 cm was based on historic information on passenger vehicle drivereye elevation, originally derived for SAE J2338).Using a nominal lane width of 3 m (10 ft), a height differential placing the mirror 15 cm (6 in) above theheadlamp, the angular location of the side mirror at several following distances was determined. Iso-candeladiagrams of typical beam patterns were than used to interpolate the luminous intensity in the direction of theside mirror position; the mirror illumination was calculated using the inverse-distance-squared law.
