低透过率下隧道照明亮度对能见度的影响

为了研究低透过率下隧道照明亮度对能见度的影响,为低透过率条件下隧道照明亮度的调节提供依据,分别以两种不同光谱特性的摄像机作为观测装置获得了透过率、照明亮度、目标/背景对比度三者之间的变化关系.实验结果表明:目标/背景对比度随照明亮度的增加而增加,两者呈非线性关系;透过率限定了目标/背景对比度所能达到的最大值;在一定的亮度范围内,提高亮度增加目标/背景对比度可以有效改善能见度.当照明亮度较高时,提高照明亮度对能见度影响不大;当照明亮度较低时,提高照明亮度对能见度提高的效果明显.因此,根据透过率按比例调节照明亮度能保证能见度和行车安全.

Influence of Tunnel Lighting Brightness on Visibility under Low Transmittance

In order to study the effects of tunnel illumination for visibility under low transmission,and to provide the theoretical basis for tunnel illumination brightness adjustment under low permeability conditions,two cameras with different spectral characteristics were used to be detectors for obtaining the relationship of observation transmittance,lighting levels,the target/background contrast.The results show that the target/background contrast increases with the increase of lighting luminance,there is nonlinear relationship between the two;the maximum value of the target/background contrast that can be achieved is limited by transmission;Improving the target/background contrast and the visibility by increasing lighting luminance can only be effective in a certain brightness range.According to the experiments it is concluded that improving lighting brightness has little effect on visibility under the condition of high lighting level,under the condition of low lighting level,improving the lighting luminance can effectively improve visibility.The lighting luminance should be adjusted in proportion on the base of the concentration of smoke and transmission in order to ensure visibility and driving safety.