Study On The Impact Of Visibility On Tunnel Lighting Effect

With the acceleration of the construction of highway,the number of tunnel is more and more.Tunnel lighting system is the maximum overhead of a tunnel system.How to ensure the safety of tunnel lighting at the same time to achieve energy-saving,is a problem that people pay special attention to.Meteorological visibility refers to the maximum horizontal distance that sighted people can see and identify the target from the sky background at that time.To improve the visibility of tunnel and ensure the appropriate visual contrast of the driver are important aspects that should be considered to ensure the safe operation of highway tunnel,but actually,the effect of increasing the lighting brightness on the improvement of visibility and the raising degree of the visual contrast is unknown.Therefore this paper proposed the relationship model of visibility and tunnel lighting brightness,and the model was established based on the calculation of visibility equation;Then,the influence of visibility on tunnel lighting was studied through the experiment of the relationship between visibility and lighting brightness;According to the experimental model,the standard of tunnel lighting was modified and optimized,and the real-time illumination was adjusted based on the visibility data at the time.Firstly,the qualitative relation between visibility and lighting brightness was determined by the derivation and calculation of visibility equation and the establishment of the relationship model between visibility and lighting brightness.,confirming that in a certain range,with the decrease of visibility,the minimum lighting brightness that was need in tunnel will increase.Secondly,the experiment of the relationship between visibility and lighting brightness determines that the target/background contrast will increase nonlinearly with the increase of the lighting brightness;Visibility defined the maximum value of the target/background contrast that can be achieved;In a certain range of brightness,improving brightness could increase the target/background contrast and improve the lighting effect.When the lighting brightness was higher(L>30cd/m~2),improving the brightness of the illumination had little effect on the target/background contrast;When the lighting brightness was lower,the effect of improving the brightness of the illumination on the target/background contrast was obvious.Finally,the tunnel lighting standard were revised and optimized through the experiment model of the relationship between visibility and lighting brightness,so as to achieve the best lighting effect with the least energy;And based on the visibility data to adjust the real-time illumination in tunnel,so as to realize the tunnel energy saving more effectively.