0 Preface Highway tunnels are widely used in highways, especially highway construction, because of their advantages of shortening mileage, improving transportation efficiency, saving land and protecting the ecological environment. As the scale and number of tunnel constructions become larger and larger, the operating electricity costs and maintenance costs of tunnel lighting facilities are also increasing, and the contradiction between lighting energy conservation and traffic safety is becoming more and more prominent. In order to solve the problem of lighting energy saving and traffic safety, it is necessary to conduct new theoretical and technical research on tunnel lighting. 1 Tunnel lighting features The purpose of tunnel lighting is the same as road lighting, in order to provide a good visual environment for the driver, to ensure traffic safety and improve transportation efficiency. However, the sides and top of the tunnel are closed, and the structure is quite special, which will result in the special adaptation and dark adaptation of the tunnel, especially the visual problems of daylight. In the daytime, when the driver enters the tunnel, the following visual problems arise: when the driver approaches the long tunnel, the driver sees a black hole, which is a "black hole" phenomenon; if the tunnel is short, a "black frame" phenomenon occurs. Because of the large brightness outside the hole, after entering the tunnel, the human eye needs to adapt to the time, that is, the "adapted hysteresis phenomenon for the middle section of the long tunnel, the automobile exhaust gas will form smoke, affecting the visibility of the driver; at the tunnel exit, it will be generated - A very bright hole, forming a strong glare, reducing the visibility of the driver, this is the "bright hole" phenomenon, which will make people only see the shadow of the obstacle, and the tunnel line shape, structure, road condition can not see Clear, distance can not be judged, etc. Therefore, tunnel lighting must properly solve the visual problems unique to tunnel lighting and create a good visual environment. At present, China's current "urban road lighting design standards" and "road tunnel ventilation lighting design specifications" do not consider the impact of the spectral power distribution of road and tunnel illumination sources on the driver's visual efficacy, that is, the light source color response is not considered. The effect of time; and all calculated by the photometric system of cone-shaped photoreceptor cells in bright vision under the condition of 2° field of view in the 2° field of view by the CIE recommendation in 1924, this is related to citopic The actual situation of the visual) does not match, that is, the effects of photobiological effects are not considered. Therefore, the corresponding standard value is not conducive to lighting energy saving. 2 The effect of the light color of the light source on the tunnel illumination The color reflected in people's eyes depends not only on the characteristics of the object itself, but also on the light color of the illumination source. The light color of the light source has two meanings: one is the surface color seen by the human visual observation light source, and is quantitatively described by the color temperature; the other is the objective effect of the color that the light source shines on the object, called the light source. Color rendering. Due to the psychological and physiological influences of different colors, the tunnel pavement will produce different visual effects and effects under the illumination environment of different color temperatures. People's reactions to the target will also be different. In the night driving process, the reaction time has important practical significance for ensuring road traffic safety. In the driving process, fast response time means high visual efficiency and reduced traffic accidents. Japan's survey data on the number of traffic accidents and reaction time shows that the number of accidents is proportional to the length of the driver's reaction time, as shown in Table 1. Table 1 Relationship between the number of accidents and reaction time Therefore, in order to ensure traffic safety, it is crucial for the driver to find the length of reaction time of obstacles on the road surface ahead. From the relationship between reaction time and traffic accidents, it can be seen that it is very important and necessary to use "reaction time" as a parameter for evaluating the light color of the tunnel illumination source and its luminous efficacy. The current tunnel lighting design standards do not consider the spectral distribution of the light source, that is, the effect of light color. In addition, under the actual tunnel lighting conditions, the dark target is observed under a bright background, that is, the human eye is more favorable for observing the target under negative contrast conditions. However, the current tunnel lighting research uses positive contrast, so it is necessary to conduct tunnel lighting research under negative contrast conditions, so that the proposed tunnel lighting design standard is more in line with the actual situation when driving. When the brightness, brightness contrast and angle of view of the target are the same, the visual effect of the human eye is determined by the size of the sleep hole: if there are many components of blue-green light in the radiation spectrum of the illumination source, the sleep hole of the human eye will shrink. Much more, the target is clear, the sensation is less, and the visibility is better; on the contrary, the visibility is poor. In order to correctly evaluate the influence of the blue-green light component on the visual effect in the radiation spectrum of the light source, the brightness of the sleep hole can be used to evaluate the brightness in the bright vision; since the average brightness of the middle section of the tunnel is generally less than 4 cd/nf, the illumination belongs to the middle vision category. Under the conditions, it is worthy of further study to determine the appropriate reaction time expression, which can change the current tunnel illumination evaluation index without considering the influence of the light source color on the vision, and according to the spectral response characteristics of the third photoreceptor cell in the human eye. Re-examine and review the rationality of the current tunnel lighting evaluation index system. 3 The effect of photobiological effects on tunnel lighting 3.1 Photobiological effects The photobiological effect is one of the top ten discoveries in the world in 2002. It can gain a biological effect on the light radiation entering the human eye and gain an understanding of the outside world. It can control the human rhythm and intensity, and affect the pupil size of the human eye. Therefore, it has an important influence on the level of human viewing and reaction time. For more than 150 years, people have always believed that there are only two photoreceptor cells, cone-shaped photoreceptor cells and rod-shaped photoreceptor cells. However, in 2002, David Berson and other scholars at the University of Brown in the United States found a third kind of photoreceptor cell-ganglion cells in the retina of the human eye. Its sensitivity to different wavelengths of light is different, and the peak is at 490 nm. It is called citopic (China's temporary translation is Sichen Vision). Although the photobiological effect is a non-image visual effect, it controls the human rhythm and intensity, and affects the size of the human eye. Studies on changes in sleeper size have shown that pupil size varies with the amount of illumination and spectral distribution that illuminates the subject's eye. The photobiological effect process is different from the visual process. Although they are also started by the human eye, they do not transmit the image information directly to the posterior cortex, but the optical signals are transmitted by the ganglion cells of the retina. The thalamic pathway (RHT) re-enters the suprachiasmatic nucleus (SCN), the extraventricular nucleus (PVN) and the upper cervical ganglion, and finally passes to the pineal gland. The upper nucleus of the optic nerve is an endogenous oscillator, which is a biological clock with an oscillation period of 24.5 h. Under normal circumstances, it is mainly relying on the stimulation of light to adjust the biological clock. Every morning, the light adjusts the wake-up and sleep cycle to coincide with the day and night cycles. In dark conditions, the pineal gland synthesizes melatonin and is absorbed by the blood to the whole body, which is good for people to rest and sleep. In addition to the circadian rhythm of melatonin, the human body temperature, the body's dexterity and hormone cortisol also have a circadian rhythm. 3.2 Application of Photobiological Effects in Tunnel Lighting The use of different illumination sources will produce different photobiological effects, which will have an impact on the driver's alertness, that is, the reaction time to find obstacles, and will affect traffic safety. In the middle vision, the retinal ganglion photoreceptor cells, cone-shaped photoreceptor cells and rod-shaped photocells in the human eye have to work at the same time. The visual effects produced by these three photoreceptor cells have an impact on traffic safety, especially in the human eye. The effects of three kinds of photoreceptor cells, one-citopic, on biological effects such as human susceptibility. Therefore, in the tunnel lighting, not only the impact of intermediate vision on traffic safety, but also the impact of photobiological effects on traffic safety should be considered. The spectral light effect of the photobiological effect has a maximum value of 38,501 m/W and a corresponding peak wavelength of 490 nm. For the photobiological effect, it can also be carried out in the luminous flux calculation formula under illumination visual conditions: Wherein φc-photobiological effect luminous flux, the unit is 1m; Kmc---photophotoeffect time maximum performance, the value is 38501m / W; Φe(λ)--the spectral power distribution of the source under study, in W/nm; The spectral light efficiency of Vc(λ)-a photobiological effect is shown in Figure 1. Figure 1 Spectral light efficiency of photobiological, dark and bright vision Now using the measured values ​​of the spectral power distribution of a 400W metal halide lamp and a 400W high pressure nano lamp, the luminous flux of the 400 W metal halide lamp and the high voltage xenon lamp under different visual conditions, the ratio of the luminous flux to the light source power can be calculated. The luminous efficiency of the halide lamp and the high-pressure uranium lamp, the luminous flux of the light source and the luminous efficiency are shown in Table 2. Table 2 Luminous flux and luminous efficiency of metal halide lamps and high pressure uranium lamps under different visual conditions In the human eye, the ganglion photoreceptor cells are more sensitive to short-wavelength light radiation. Since the short-wavelength light of the metal halide lamp is more than the high-pressure uranium lamp, the light of the metal halide lamp calculated by the formula (2) The biological effect luminous flux is much larger than that of high pressure uranium lamps (see Table 2). The photobiological effect of the metal halide lamp has a luminous efficiency of about 3431 m/W, while the photobiological effect of the high-pressure lamp has a luminous efficiency of about 1051 m/W, and the former is more than three times that of the latter, which affects the size of the human eye. For tunnel lighting, if the sleeping hole is enlarged, problems such as focusing and glare will occur, which will affect the driver's visibility of the obstacle on the road ahead, which will adversely affect safe, fast and comfortable operation. Because when the power of the light source is the same, the light source with high luminous efficiency will radiate more light flux and the illuminance will be larger, so when the power equivalent radiation component is rich in short-wavelength metal halide lamp, it will be higher than the high voltage system. The lamp produces greater illumination, which is more conducive to the collapse of the sleeping hole and improves visibility. In summary, it can be seen from Table 2 that the radiant fluxes of the same source are different under different visual conditions, and the luminous flux of different kinds of sources varies with different visions, which is due to the spectral power distribution of different sources. The difference in response to light from different photoreceptors of the human eye is caused by the difference in light wavelengths of the three photoreceptor cells: cone-shaped photoreceptor cells, rod-shaped photoreceptor cells, and ganglion photoreceptor cells in the human eye, respectively, at 555 nm, 507 Nm and 490 nm, and the corresponding maximum light efficiency are 6831 m/W, 1 700 1 m/W and 38501 m/W, respectively. It can be seen that when the illumination source is rich in blue-green light components, it is possible to make the dark vision time flux larger than the bright vision light flux. For the metal halide lamp, the dark vision light flux is almost double that of the clear vision light flux. The photobiological effect luminous flux is more than twice as large as the visual visual flux. Therefore, when the visual work needs to consider the photobiological effect, it is necessary to study the influence of the difference of the spectral power distribution of the illumination source. For the tunnel illumination, it is necessary to consider the influence of the photobiological effect on the focus, so as to achieve the tunnel illumination. Safety and energy saving requirements. 4 Summary In tunnel lighting research, the light color of the light source is an important factor that cannot be ignored. In a light source with similar spectral energy distribution and different color temperature, selecting a light source rich in short-wavelength can further improve the lighting effect, while saving energy and realizing green lighting. The influence of photobiological effects on tunnel lighting is still under study in the world. "Blank believes that with the deepening of research in this area, in the future tunnel lighting design, the light of the tunnel illumination source can be more comprehensively and scientifically evaluated. The problem of efficiency can better control the influence of tunnel light source color on tunnel lighting, thus solving the contradiction between energy saving and safety in tunnel lighting, and improving the safety and comfort of road traffic. Edit: Cedar 1. Indoor LED Curtain Poster Display with price Advantage: We have the best competitive price in the market, we also have the same or even better quality. Indoor LED Curtain Light Box,LED Curtain Slim Light Box,LED Curtain Poster. Shenzhen Macion Optoelectronics Technology Co.,Ltd. , https://www.macion-led.com
(1) 
2. Indoor LED Curtain Poster Display with quality advantage: From material to finished product, from design to production, we control all processes.
3. Indoor LED Curtain Poster Display service advantage: We also provide best service after sales and we prioritize every customer's needs.
4. We ensure that our LED Curtain Poster Display are CE certified, ROHS compliant, FCC identified.
5. Indoor LED Curtain Poster DisplayWith specially designed fast lock system, easy to install and dismantle.
6. The new structure design enablesIndoor LED Curtain Poster Display diversified installation to meet the hanging-up and stacking requirements.
7. Full Color Indoor LED Curtain Poster Display with High contrast rate up to 5000:1 by using black LED.
8. Indoor LED Curtain Poster Display with high refresh rate with NOVA control system, no scan line when photographed.