Feng Zexin, Luo Yi, Han Yanjun
State Key Lab on Integrated Optoelectronics/Tsinghua National Lab on Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 10008, China.
Opt Express. 2010 Oct 11;18(21):22020-31. doi: 10.1364/OE.18.022020.
A systematic method is proposed for designing an optical system for road lighting using an LED and a freeform lens that is optimized to produce a certain luminance distribution on the road surface. The proposed design method takes account of the luminance characteristics of the road surface, the energy efficiency of the system, the glare problem of the luminaire and the effects of four adjacent luminaries illuminating a single road surface. Firstly, the road surface illuminance with a polynomial of cosine functions along the road is optimized to maximize Q (the ratio of the average luminance to the average illuminance) as well as satisfying the lighting requirements provided by CIE. Then, a smooth freeform lens with this optimized illuminance is designed based on the variable separation method and the feedback modification method. Results show that, from two typical observer positions on the 2-lane C2 class road, luminaires with these freeform lenses can provide Q values of 7.90 × 10(-2) and 8.69 × 10(-2), the overall road surface luminance uniformity of 0.55 and 0.56, the longitudinal road surface luminance uniformity of 0.72 and 0.79, and the glare factors of 10.06% and 6.73% .
提出了一种系统方法，用于设计一种道路照明光学系统，该系统使用发光二极管（LED）和自由曲面透镜，该透镜经过优化，可在路面上产生特定的亮度分布。所提出的设计方法考虑了路面的亮度特性、系统的能源效率、灯具的眩光问题以及四个相邻灯具照亮单个路面的效果。首先，沿道路用余弦函数多项式优化路面照度，以最大化Q（平均亮度与平均照度之比），同时满足国际照明委员会（CIE）规定的照明要求。然后，基于可变分离法和反馈修正法，设计了具有这种优化照度的光滑自由曲面透镜。结果表明，在双车道C2级道路上的两个典型观测位置，配备这些自由曲面透镜的灯具的Q值分别为7.90×10⁻²和8.69×10⁻²，路面整体亮度均匀度分别为0.55和0.56，路面纵向亮度均匀度分别为0.72和0.79，眩光因子分别为10.06%和6.73%。
