The Control And The Energy Saving Technology Of The Tunnel Lighting Based On LED

The operation of expressway tunnel is an important measure to protect the traffic safety in expressway. Tunnel lighting takes a large proportion in the costs of tunnel operating. With the expressway tunnels rapid increase, lighting costs have become a huge burden on operation departments. The light source and the lighting control method currently used can not conservation the energy. Through the research of lighting energy-saving technologies based on LED in expressway tunnel can not only provides the driver with more comfortable and safe driving environment, but also reduce operating costs and have the great significance of saving energy.According to the visual characteristics of expressway tunnel lighting, this paper analyzing the main factors with which affect the quality of tunnel lighting at first. Then the paper researches the energy-saving methods from the light source selection, optimization of the tunnel lighting design, lighting control method. And given the methods of energy saving which are using LED light source, improving the tunnel lighting design, using automated real-time control. The methods mainly include the following contents: improved the digital cameras method in order to measure the lighting design parameters L20(S) accurately; used regression model to establish the inter-relationship besides the traffic volume, the car speed and the visibility in order to obtain the light brightness accurately; designed the automatic real-time control systems of the tunnel lighting based on LED. Control system design includes building fuzzy control model based on neural network for the middle segment of tunnel lighting, building stepless dimming mode based on PWM of LED, building LED lighting control network based on Optical Ethernet and RS485 bus and DALI protocol, designing hardware circuit which contains an LED display and keyboard interface of the DALI local controller and MCU-controlled LED ballast and AC/DC converter circuit module and so on, designing operating software. So that the control systems can continuously dimming the tunnel lighting based on ambient light, traffic flow, speed and other external environmental factors.Finally, with the example of a tunnel in Chongqing YUHE expressway, the paper makes a brief evaluation on the economic of the tunnel lighting energy saving from the whole life-cycle costs of the LED tunnel lighting and the automatic real-time control system of LED. This evaluation indicates that the tunnel lighting energy saving can gain not only considerable economic benefits, but also well environmental. The verified practicality and necessity by the paper provide useful experience and an effective exploration for tunnel lighting.