Study On Visual Identity Effect Of The Changes Of Tunnel Entrance Lighting On Drivers

The tunnel is a special closed structure,which makes the environmental illumination of the tunnel portal different greatly.It will cause such phenomena as "black hole effect" and "visual adaptation lag",which will affect the drivers’ visual recognition ability and easily lead to traffic accidents.Therefore,based on the characteristics of human vision,this paper studies the influence of the changes of light environment at the tunnel entrance on human visual recognition.The main research contents and conclusions are as follows:(1)The simulation experiment was designed to recognize obstacles when the ambient illumination changed from light to dark.And 12000 groups of experimental data were analyzed.The relationship between the illuminance of the tunnel access zone and the reaction time of human eyes was obtained.The experimental results show that when the illuminance of the tunnel threshold zone is fixed,the larger the initial environmental illuminance(the illuminance of access zone)is,the greater the reaction time is.(2)The effect of vehicle speed on the reaction time of human eyes under constant environmental illumination was studied.Through mathematical fitting,the positive correlation between speed and reaction time is obtained.And the higher the initial environmental illumination is,the more significant the effect of vehicle speed on the reaction time of human eyes is.(3)The effect of the contrast of optotypes on the reaction time of human eyes was studied.The experimental results showed that there was a negative exponential relationship between the reaction time of human eyes and the contrast of optotypes.When the contrast is less than 1,the reaction time decreases greatly and changes significantly.When the contrast is greater than 1,the reaction time changes slowly.(4)The safety critical threshold of environmental illuminance in the tunnel access zone at different speeds was proposed.Relying on the Taihu tunnel project and through DIALux software,the environmental illumination inside the tunnel shading shed is simulated.The variation rule of illumination was analyzed.And to compare the safety critical threshold of illumination in the tunnel access zone at 100km/h,so as to optimize the design scheme of shading shed.In this paper,by studying the influence of the change of light environment at the tunnel entrance on human visual recognition,the relationship between the change of environmental illumination,the change of vehicle speed,the change of visual contrast and the reaction time of human eyes was analyzed.The safety critical threshold of the illumination in tunnel access zone at different speeds was proposed,which has theoretical reference value and engineering application significance for evaluating the design scheme of sunshades,improving the driving safety and reducing the energy consumption of tunnel portal lighting.