The Design Of Tunnel Lighting Energy-saving Control System Based On PID Closed-loop Feedback

With the rapid development of China’s highways, the tunnels have become an essential part of the highways. However, no matter day or night, no matter if there have cars, no matter the light is good or bad, the tunnel lighting in most highways keeps 24 hours lighting state, which has resulted in a huge waste of energy. In recent years, there are a few tunnels have adopted some control methods among the newly-built tunnels, such as several tunnels in Tongdan highway of Liaoning Province, which adjust the luminance of tunnel lighting according to the information of if there haves cars, and have played a role of saving electric energy, but the control methods are simple, energy-saving effect is not obvious. Therefore, we need to come up with a new kind of tunnel lighting intelligent control system to achieve energy-saving purposes.The subject comes from Jilin Provincial Communications Department major project "The study of Changbai Mountain Heda highway tunnel and service area lighting energy-saving and wisdom control technology". The research results will be applied to the energy-saving control system of Heda highway tunnels in Jilin Province. There are 18 separate tunnels to be built in Jilin Changbai Mountain area, including 2 extra-long tunnels,12 long tunnels,3 medium-long tunnels and 1 short tunnel.Firstly, use DIALux lighting simulation software to simulate highway tunnel lighting scenes, then determine the best lighting pattern and the interval of lamp distribution in each paragraph of the tunnel under the condition of satisfying the existing highway tunnel lighting specification; according to the simulation results and requirements of the new specification, then set a luminance value for each paragraph of the tunnel under different time and environment condition. In the practical application of the tunnel, the actual luminance value is difficultly approximate equal to the set luminance value because of the change of environment, the damage of individual lamps, the light fades of lamps and other impact of factors, which will pose a threat to tunnel traffic safety. This paper has developed a kind of PID closed-loop feedback adjustment method to solve the problem of the actual luminance value can’t reach the set luminance value. The specific method is using illuminance measurement system which is composed by camera and light meter in the tunnel to real-time detect the actual luminance value on the road.In this paper, the PID closed-loop feedback adjustment method is developed under Visual Studio 2008 development platform, using C/C++ programming language.After the algorithm design and software implementation, in order to verify the algorithm’s validity and reliability, many experiments in the laboratory are completed, the results show that the PID closed-loop feedback adjustment method has achieved the effect of intelligent control.