白绿色LED道路光源小目标可见度研究

Research on Small Target Visibility of white green LED road lighting

小目标可见度是衡量驾驶安全性的重要指标,但夜间驾驶处于中间视觉的复杂环境,导致作为可见度水平的重要参数的阈限亮度差难以被准确评价。本文通过中间视觉环境下建立的背景亮度/敏感波长关系模型,对道路照明光源进行基于敏感波长的阈限亮度差研究,以实现对白绿色LED光源不同主波长的可见度研究。从负对比修正系数Kf和识别时间修正系数Kt出发,建立中间视觉阈限亮度差修正模型,提升可见度算法精确度,准确衡量照明光源安全性。利用小目标可见度算法在RP-8-00标准建议的夜间驾驶视看条件(视张角7.45'、驾驶员年龄60岁、识别时间0.2s)下,对机动车道路面照明亮度环境(0.75-3.0 cd/m2)中的照明灯具进行评价,得出在此视看环境下以528 nm作为主波长的白绿色LED光源可见度最高的结论,并通过道路平均亮度和反应时间验证了该光源相比传统照明光源安全性更好。

Small target visibility(STV)is an important indicator to measure driving safety,but driving at night is in the complex environment of mesopic vision.Its results in threshold luminance difference is difficult to be accurately evaluated,which is an important parameter of the visibility level.In this paper,the threshold luminance difference of road lighting based on sensitive wavelength is studied by establishing the background luminance/sensitive wavelength relationship model in the in-termediate vision environment.In this way,the visibility of color matching white green LED road lighting with different domi-nant wavelengths can be studied.Based on the negative contrast correction coefficient K f and recognition time correction coeffi-cient Kt,the intermediate visual threshold luminance difference correction model is established to improve the accuracy of visi-bility algorithm and accurately measure the safety of road lighting.The STV algorithm is used to evaluate the lighting lamps in the vehicle lane road illumination level environment(0.75-3.0 cd/m^(2))under the night driving viewing conditions(viewing an-gle 7.45',driver's age 60,recognition time 0.2 s)recommended by rp-8-00 standard,and it is concluded that the white green LED road lighting with 528 nm as the main wavelength has the highest visibility in this viewing environment,and the safety of this road lighting is better than that of traditional road lighting through the average road brightness and reaction time.