The comprehensive efficiency analysis of tunnel lighting based on visual performance

Abstract

Few researches have focused on the comprehensive efficiency of tunnel lighting, which plays a role in improving the tunnel lighting efficiency. This article defined visual recognition time as the representation of visual performance. Three indices, visual performance, light efficiency, and production cost, were proposed to study the visual performance of test drivers, when drivers recognized an obstacle in LED lighting environment with different characteristics. A total of 15 light combinations were designed in the middle section of tunnel, composed by 5 color temperatures and 4 color rendering indices under 8 different kinds of light brightness. A total of 12 test drivers were selected to conduct the static recognition experiment in different lighting environments. Recognition time, lighting performance, and production cost were normalized, and K-means clustering was applied to analyze these indices to obtain the values of comprehensive efficiency of LED with different characteristics. The results indicated that increasing the light color rendering can improve the visibility without increasing the light power. The following combinations of color temperature with color rendering, 6500 K with 70, 5700 K with 70, 5700 K with 80, 3000 K with 80, 3000 K with 70, and 4000 K with 70, performed better comprehensive efficiency, showing better visual performance, higher light efficiency, and lower production cost.