Optimal design of optical system for LED road lighting with high illuminance and luminance uniformity

摘要

A new method is proposed to achieve high illuminance and luminance uniformity of the road surface in LED road lighting. Based on the reflection properties of the road surface, the illuminance and luminance are analyzed simultaneously with the least-square method; meanwhile, energy efficiency and glare requirements are considered. Through the analysis and calculations, the optimal light distribution of a luminaire is obtained, and then a freeform lens with this light distribution is designed. For a 2-lane C1 class road illuminated by LED luminaires mounted with these lenses, the overall illuminance and luminance uniformity on the road surface can reach over 0.9 and 0.85, respectively, and the glare factors less than 10%.