Tunnel Lighting Research Articles

A novel tunnel lighting method aided by highly diffuse reflective materials on the sidewall: Theory and practice

Interior surfaces of tunnels can reflect light when a highly diffuse reflective material is used on the sidewalls. This study introduces a novel energy-saving method that uses the reflected light effectively. To validate the proposed method, the brightening effect of a highly diffuse reflective material is measured based on the bidirectional reflection distribution function (BRDF) of the sidewall materials. The BRDF specifies the reflective properties of the sidewall materials, and the incremental reflection is then quantified. The proposed method offers better computational certainty and sidewall material adaptability than those of existing methods. For different materials selected as test objects, the error between the calculated and measured values was controlled to be less than 5.35%. In addition, the relative error between the calculated and measured values, obtained using the proposed method, was 3.62% on average, and the corresponding errors obtained using China's lighting design rules and the Recommended Practice for Tunnel Lighting presented by the Illuminating Engineering Society of North America (IESNA) were 18.02% and 7.98%, respectively. Overall, the proposed method provides a theoretical basis to help realize the unification of tunnel lighting with safety, energy savings, and comfort.

Research on the Role of Driving Fatigue Regulation Based on the Change of Tunnel Lighting Environment

Research on the Role of Driving Fatigue Regulation Based on the Change of Tunnel Lighting Environment

Tunnel Lighting Equipment Design and Equipment Examples

Tunnel Lighting Equipment Design and Equipment Examples

Improved Maintenance by Reusing Tunnel Lighting

Improved Maintenance by Reusing Tunnel Lighting

Installation Standards for Tunnel Lighting

Installation Standards for Tunnel Lighting

A tunnel lighting control system based on human vision and variable reduction coefficient

A tunnel lighting control system based on human vision and variable reduction coefficient

Experimental demonstration of optical Bloch oscillation in electromagnetically induced photonic lattices

The optical Bloch oscillation (OBO) is an optical-quantum analogy effect that is significant for light field manipulations, such as light beam localization, oscillation and tunneling. As an intra-band oscillation, OBO was important for optical investigations in photonic lattices and atomic vapors over an extended period of time. However, OBO in reconfigurable platforms is still an open topic, even though tunability is highly desired in developing modern photonic techniques. Here we theoretically establish and experimentally demonstrate OBO in an electromagnetically induced photonic lattice with a ramping refractive index, established in a coherently-prepared three-level 85Rb atomic vapor under the electromagnetically induced transparency condition. This is achieved by interfering two coupling beams with Gaussian profiles and launching a probe beam that exhibits OBO within the resulting lattice. The induced reconfigurable photonic lattice possesses a transverse gradient, due to the innate edges of Gaussian beams, and sets a new stage for guiding the flow of light in periodic photonic environments. Our results should motivate better understanding of peculiar physical properties of an intriguing quantum-optical analogy in an atomic setting.

Evaluation of Mental Load of Drivers in Long Highway Tunnel Based on Electroencephalograph.

In recent years, the mileage of the tunnels has substantially increased with the rapid highway construction that led to increasing highway tunnels. Most studies on tunnel accidents have mainly focused on the external environments, such as tunnel structure, traffic volume, and lighting. In addition, although many studies on mental load of drivers have been conducted for public roads, such studies for highway tunnels have been limited. In this study, three scenarios with different front vehicle speeds (60, 45, and 30 km/h) in a two-lane long tunnel (one lane in each travel direction) were evaluated using a driving simulator. The experiment involved 24 participants (14 men and 10 women) with an average age of 25.8 years and an average experience of 3.2 years. The electroencephalogram (EEG) technology was used to collect the leading EEG indicators during the driving simulation of the scenarios: α, β, and θ waves and the wave ratio, (α + θ)/β. According to the β-wave energy measurements, the alertness of drivers was the lowest at 45 km/h after adapting to the tunnel environment, indicating that the drivers were more comfortable at this speed. This preliminary finding should help in determining the speed limit in this type of tunnel.

Exploratory research on the relationship between tunnel lighting design and driving behavior and cognition

Exploratory research on the relationship between tunnel lighting design and driving behavior and cognition

Investigating the Importance of Tunnel Lighting and its Role in Reducing Traffic Accidents

Traffic safety is a major concern worldwide. Road accidents are the ninth leading cause of death in the world. Tunnel accidents are less common than road accidents. However, the severity of the accidents is more severe. One of the key factors in preventing accidents in road tunnels is proper lighting system. Failure to pay attention to this issue causes the phenomenon of black hole when approaching the tunnel, visual mismatch inside the tunnel and the phenomenon of glowing hole when leaving the tunnel. The creation of these factors has increased the risk potential at the entrance and exit of the tunnel up to 4 times the middle area of the tunnel. At the entrance to the tunnel, the reflection of sunlight from the surroundings and the lack of sufficient light usually cause some vision problems. It may lead to drivers' eyes not adapting to changing the brightness level at the tunnel entrance, thus increasing the risk of road accidents in this area. The aim of this study was to evaluate the lighting safety in very long road tunnels based on the visual adaptation of drivers in the tunnels. In this paper, first, generalities about tunnel safety are stated and using the CIE88-2004 standard, the required luminosity in the threshold, transition, interior and exit areas of the tunnel is designed. Finally, solutions are proposed to increase the safety of tunnels.

A case study of life cycle cost analysis on high pressure sodium lamp and LED lamp for tunnel lighting

A case study of life cycle cost analysis on high pressure sodium lamp and LED lamp for tunnel lighting

Comparative Study of Energy Savings for Various Control Strategies in the Tunnel Lighting System

Tunnel lighting is the most significant component in total energy consumption in the whole infrastructure. Hence, various lighting control strategies based on light-emitting diode (LED) technology have been investigated to conserve energy by decreasing luminaires’ operating time. In this study, four kinds of tunnel lighting control strategies and the development of their associated technologies are evaluated: no-control low-consumption lamps (LCL), time-scheduling control strategy (TSCS), daylight adaptation control strategy (DACS), and intelligent control strategy (ICS). This work investigates the relationship between initial investment and electrical costs as a function of tunnel length (L) and daily traffic volume (N) for the four control strategies. The analysis was performed using 100-day data collected in eleven Chinese tunnels. The tunnel length (L) ranged from 600 m to 3300 m and the daily traffic volume (N) ranged from 700 to 2500. The results showed that initial investment costs increase with L for all control strategies. Also, the electricity costs for the LCL, TSCS, and DACS strategies increased linearly with L, whereas the electricity cost for the ICS strategy has an exponential growth with L and N. The results showed that for a lifetime equal to or shorter than 218 days, the LCL strategy offered the best economical solution; whereas for a lifetime longer than 955 days, the ICS strategy offered the best economical solution. For a lifetime between 218 and 955 days, the most suitable strategy varies with tunnel length and traffic volume. This study’s results can guide the decision-making process during the tunnel lighting system’s design stage.

Can You Feel It?

Virtual reality exposure therapy (VRET) has been widely acknowledged as an effective alternative for in vivo exposure therapy (iVET). So far, previous research focused on long- and short-term effectiveness and comparisons to iVET, whereas the impact of design choices is understudied. Hence, the present study focuses on the effectiveness of several types of anxiety cues for the manipulation of anxiety. More specifically, five interoceptive cues (i.e., “fake” bodily sensations for tunnel vision, light flickering, heartbeat audio, blurred vision, and dizziness) and a physical cue (i.e., heat stimulation) are implemented in the VRET design of a within-subjects experiment with people who have claustrophobic and panic tendencies (N = 24). Results show that adding interoceptive cues significantly increased reported levels of anxiety, independent of the type of interoceptive cue. However, introducing a physical cue in VRET can also be effective but has no real added value when combined. Studies focusing on the design of anxiety cues can be valuable in understanding the effectiveness of VRET.

Analysis of power usage and illuminance changes due to the replacement of tunnel lighting source from high pressure sodium lamp to LED

Analysis of power usage and illuminance changes due to the replacement of tunnel lighting source from high pressure sodium lamp to LED

Characteristics of driver fatigue and fatigue-relieving effect of special light belt in extra-long highway tunnel: A real-road driving study

To study the characteristics of driver fatigue and effect of a special light belt to relieve driver fatigue in an extra-long highway tunnel, real-road driving tests were conducted in the Yanglin extra-long tunnel. The tests were conducted separately under two conditions: a condition with a conventional tunnel lighting environment and a condition with a special light belt zone in the tunnel. In the tests, the electrocardiography method and Karolinska Sleepiness Scale (KSS)-based self-rating method were selected as the fatigue assessment methods. The study established mathematical models between the heart rate variability (HRV) indicator and driving time in the tunnel under the aforementioned conditions by employing principal component analysis and obtained the KSS rating values before and after driving through the tunnel. The results demonstrated that driver fatigue occurred after driving through the extra-long tunnel with variations in the HRV indicators and an increase in the KSS self-rating. The driver fatigue accumulated slowly in the first 5 min in the tunnel, followed by a rapid accumulation after the sixth minute, and it slowed down again at the end of the tunnel owing to the outside light. When the special light belt was turned on, the variations in HRV indicators and increase in the KSS rating diminished. The paired samples t-test showed significant differences in the HRV indicators and KSS ratings between the two driving conditions after passing the light belt zone. This indicates that the special light belt was effective in relieving driver fatigue in the extra-long tunnel.

Research on Power Line Carrier Communication Based on HVDC

This paper mainly studies the control of LED lamps under the condition of centralized DC power supply by power carrier mode, and modifies the mature power carrier scheme in AC system to adapt to the DC system environment and realize reliable communication in DC system. Through the analysis of system functional requirements and the comparison of existing communication technologies, the overall architecture of DC tunnel lighting system is proposed. The system adopts two-tier structure, including monitoring center, communication controller and HVDC tunnel lighting control terminal. This system realizes the master-slave monitoring of the communication controller to the control terminal of HVDC tunnel lamps, and puts forward the modification scheme to the conventional power carrier scheme, and verifies the improved power carrier scheme of DC system through the Qijiashan tunnel lighting project.

Tunnel Lighting Intelligent Control System Based on Ambient Light Ratio

Based on the research problems of modern tunnel lighting control technology, a tunnel lighting intelligent control system based on ambient luminosity ratio is designed, which is characterized by “car close lights bright, car passing lights dark”, intelligent analysis of system failures, etc. The core technology is LED Tunnel light group brightness automatic adjustment, python data analysis, etc. The design of the core control unit of the system is based on the STC89C52 chip, which uses the numpy module in python to matrix the data in the database through the information collected by the sensor (the light intensity inside and outside the tunnel, the traffic condition of the vehicle in the tunnel, and the working condition of the tunnel lighting equipment, etc.) Level storage and use principal component analysis and other algorithms to perform a large number of calculations and processing on the obtained data. The controller generates a corresponding PWM signal to control the brightness of the LED tunnel light group to solve the problem of excessive lighting or insufficient brightness; through other controls The components exchange information, and the downstream controller performs calculation and processing according to the control instructions sent by the previous stage and the real-time signals detected by the sensors to realize the selective brightness and automatic brightness adjustment of the tunnel section lighting, and finally achieve intelligent control, energy saving and emission reduction the goal of. In addition, we use the seaborn library and matplotlib library in python to visually display the obtained tunnel lighting equipment working condition data, and send the results to the relevant road management department. This will play an important role in greatly improving the efficiency of activities such as equipment maintenance, collecting equipment work information, and optimizing the work structure of road management. To a certain extent, it is conducive to the implementation of specific work of relevant departments.

Simulating Human Visual Perception in Tunnel Portals

To study the characteristics of light and dark adaptation in tunnel portals, and to determine the influencing factors in light–dark vision adaptation, basic tunnel lighting and linear design data were obtained. In this study, we used a light-shielded tent to simulate the dark environment of a tunnel, observe the driver recognition time for target objects during the light–dark adaptation process, and analyze the light–dark adaptation time of human vision. Based on the experimental data, we examined the relationships between age, gender, illuminance, and light and dark adaptation times, and established a model for these relationships. The experimental results show that the dark adaptation time is generally longer than the light adaptation time. The dark adaptation time is positively related to age and exhibits a cubic relationship. There is no significant correlation between the light adaptation time and age, but the overall trend is for the light adaptation time to gradually increase with increasing age. There is no correlation between gender and light and dark adaptation times, but there is a notable correlation between light and dark adaptation times and illuminance. When the illuminance ranges from 11,000 to 13,000 lux, the light and dark adaptation times are the longest.

The impact of LED spectrum and correlated color temperature on driving safety in long tunnel lighting

According to the Chinese Guidelines JTG/T D70/2-01-2014, there are many long tunnels in China, especially in mountainous areas. In long tunnels, tunnel lighting influence not only visual performance but also non-visual effects. Non-visual effects has enhanced the importance of some factors directly related to driving safety, such as pupil constriction and visual fatigue which seriously affect reaction time of driver. In this work, the relationship between LED spectrum, correlated color temperature (CCT) and reaction time, pupil area difference are analyzed respectively by the experiment of reaction time. Five LEDs with different CCT and short-wave relative spectral value (RSV) are compared to HPS and MH under different tunnel lighting conditions. Experimental results show that, in the threshold and transition zone of long tunnel at luminance160cd/m2, 80 cd/m2 and 24 cd/m2, reaction time is the shortest and pupil constricted the most for LED lighting with CCT 5100 K and short-wave RSV 0.312. While in the interior zone of long tunnel at luminance 4.5 cd/m2 and 2.5 cd/m2, reaction time is the shortest and pupil constricted the most for LED lighting with CCT 3800 K and short-wave RSV 0.215. Based on the results, combining the impacts of visual performance and non-visual effects in long tunnels, this work proposed the recommended values of CCT and short-wave RSV for LED light sources that are suitable for the luminance level of different zones. In this way, the precise lighting can be implemented to meet the needs of long tunnel lighting for driving safety and energy saving.

Simulation Experiment on Tunnel Lighting Aided by High Diffuse Reflectance Materials

The existing tunnel lighting calculation methods only consider the effect caused by direct light source and ignores the reflection effect of light flux emitted by lamps inside the tunnel closed pipe, which is not conducive to the energy saving and safety of tunnel lighting.In this paper, a tunnel illumination calculation method considering the reflection increment of tunnel sidewall is proposed. This method is based on the diffuse reflection coefficient of tunnel sidewall material which can characterize the reflection characteristic of its surface, so as to calculate the illuminance of road surface.Matlab software was used to simulate the real lighting environment of the tunnel with energy storage luminescent material as the side wall. It was found that the increase of reflection caused by high-quality tunnel interior materials could effectively improve the tunnel lighting