Discussion: LED tunnel how to design lighting?

Tunnel lighting is different from the general road lighting, which has its obvious particularity. With the increasing number of tunnel projects, tunnel construction plays a more and more important role in modern transportation. The tunnel is a closed space, natural light irradiation which cannot, in order to ensure the coherence of the driving and driving safety of human life, even the whole day inside the need for artificial lighting, tunnel lighting is an integral part of the tunnel construction.

Automobile exhaust, noise, vibration, dirty air, corrosive gas, water and other harsh environment to form the particularity of tunnel lighting. In order to provide a safe and comfortable lighting environment for vehicles and pedestrians, the following steps are used to illustrate the ideas. In the design of the tunnel lighting program, we should take into account the person's adaptation and dark adaptation factors, the transition space and transition lighting design.

Discussion: LED tunnel how to design lighting?

In order to meet the requirements of the eye, a light and shade transition is needed at the entrance of the tunnel, so as to ensure the visual requirements. Due to the short time to adapt to the tunnel exit, generally less than 1s, it can not do other processing.

There is a general tunnel vision problem special the following: before entering the tunnel due to the great difference in brightness inside and outside the tunnel, so to see from the outside of the tunnel, the tunnel entrance lighting is not fully see the "black hole" phenomenon.

After entering the tunnel: the car from the bright outside into the tunnel even if not too dark, after a certain period of time to be able to see the situation inside the tunnel, known as "adaptive lag" phenomenon.

At the tunnel exit: during the day, the car went through the long tunnel near the exit, due to external high brightness through exports to see, exports seem to be a "light hole", there will be a strong glare, the driver will feel uncomfortable; night and day on the contrary, the tunnel mouth not see the bright hole but black hole the obstacle line and road so the driver can not see the outside of the road.

Some of the above special visual problems to the tunnel lighting put forward higher requirements, effective solution to these visual problems, through several aspects.

The tunnel lighting is usually divided into five sections: the introduction section, the adaptive section, the transition section, the basic section and the exit section:

Introduction section: to eliminate the "black hole" phenomenon, so that the driver can identify the obstacles in the daytime; for example, assuming that the tunnel environment brightness of 4000cd/ square meters, speed of 80KM/H, is introduced to meet some minimum requirements and the length of the brightness is respectively 40 meters and 80cd/ meters.

Adaptation: after entering into a tunnel, the driver can adapt quickly and eliminate the "black hole" phenomenon; according to the above conditions, to adapt to the length and intensity were 40 meters and 80 meters to 46cd/.

Transition: the driver gradually adapt to the internal lighting tunnel; according to the above conditions, the transition length and brightness were 40 meters and 40 meters to 4.5cd/.

Basic section: basic lighting in tunnel.

Exit section: in the daytime, so the driver can gradually adapt to the light exit, eliminating the "light hole" phenomenon; at night, the obstacle and the driver can see the road line in the road outside, eliminate the exit of the "black hole" phenomenon, the general practice is in use as a continuation of street lighting outside.

In the daytime, the lighting brightness lighting tunnel with the entrance section, should be higher than the basic lighting brightness in the tunnel; at night, on the contrary, the brightness of lighting in the tunnel should be lower than the basic value, when there is a street lighting outside the tunnel, the tunnel pavement brightness value of not less than 2 times the surface brightness value.

Two, the vehicle through the tunnel in the process of the problems

Black hole phenomenon

During the day, the driver of the motor vehicle has eyes to natural light outdoor lighting up to more than 100 thousand LX thousands of cd/m2, when the tunnel environment eyes to brightness of only a few cd/m2, limited to human eye brightness difference in perception, appeared to lag, you will see a black cave, but were unable to identify the states. In this case, the phenomenon of a black hole in a bright environment is called a black hole.

Once the black hole phenomenon, with the motor vehicle close to the tunnel, the driver's visual distance is shortened, not safe driving. The phenomenon of black hole is the most important problem in tunnel lighting.

In order to prevent the occurrence of black hole phenomenon, from the entrance of the tunnel to ensure a sufficient distance from the beginning of the brightness, this part of the length of the vehicle than the safety of the braking distance slightly longer.

Due to the existence of a large gap between the inside and outside of the tunnel, the driver can not adapt to the tunnel brightness rapidly, and it is difficult to see the inner condition of the tunnel.

In order to prevent this happening, should make the tunnel entrance brightness with the visual adaptation slowly reduced brightness to a smooth transition, to reduce the brightness of step by step, but the previous level after level of brightness and brightness ratio shall not exceed 3:1, and not 2m following the wall high brightness lower than the corresponding average surface brightness.