Optimization Of Tunnel Lighting Source Based On Visual Fatigue Suppressed And Visual Acuity Improved

In recent years, economy keeps growing fast. This situation puts forward higher requirements on the transportation network-density and road safety construction. As an important part of road, people tend to pay more attention on the construction of road tunnels. Because of the tunnels of which special structure, respectively, at the exit of the tunnel there is "white hole effect" and the entrance the "black hole effect". Moreover, there are "strobe effect" and "zebra effect" in the course of road lighting, which will affect the drivers’driving safety seriously. Meanwhile, the data show that the traffic accidents which are caused by fatigue driving accounted for a large proportion. And 80 percent of the way we get outside information is by eyes. Based on the above considerations, this paper conducts a simulation study of the light how to affect the eyes’ visual fatigue and visual acuity in tunnel lighting environment and carries out the following work:Firstly, in this paper, the luminescence mechanism, advantages and disadvantages of the commonly used lighting source were integrated and analyzed. According to the analysis we can figure out that the LED has better lighting effects. Therefore, the subject chosen tunnel lighting commonly used high-pressure sodium and high, medium and low color temperature LED lamps for lighting study. Based on tunnel lighting environment is in the intermediate visual state this paper selected visual effect evaluation methods from others.Then, this paper put forward biological effects of light as theoretical foundation of the study and analysed its mechanism. Research shows that exclude photopic and scotopic vision, there is a third vision which is called cirtopic vision. According to the cirtopic vision theory, light can affect the human body in a biological way through retinal photoreceptor cells, such as controlling human physiological parameters and affecting people’s circadian rhythm, etc. Research shows that cirtopic vision is more sensitive to shorter wavelength. Moreover the most sensitive wavelength is at 460nm.Finally, from the view of security, the existing lighting conditions and technology, through simulating the tunnel traffic environment indoor and selecting high pressure sodium and high (color temperature 4765K), middle (color temperature 4054K), low (color temperature 3177K) three color temperatures of white LED as the testing light, we conducted the experiment with the method of control variables to explore the differences in the visual fatigue and visual acuity in different case. The results show that high color temperature LED lamp has a higher flicker fusion frequency index and lower pupil diameter index in both two experiments. According to the inverse relationship between flicker fusion frequency index and visual fatigue and inverse relationship between the diameter of the pupil and visual acuity index, the high color temperature LED shows the best lighting performance. That it can not only reduce the fatigue of the human eyes, but also improve the driver’s visual acuity in the same brightness. Also, this paper calculated the equivalent brightness of four by equivalent brightness formulas. In the condition of cirtopic vision, the data show that equivalent brightness of high color temperature LED lamp is 605cd/m2, which is significantly higher than other light sources, verifying exactness of the experimental results.