In Bangkok Thailand, a beautiful tunnel equipped with Fonda smart tunnel lighting control system has just been put into use and is currently in good condition.
The tunnel lights need to be powered 24x7 hours and brightness needs to adjusted automatically for safety. A reduction in energy consumption and maintenance cost were also highly demanded from the customer side. Fonda RS485 solution is designed for tunnel lighting control based on the characteristics of the tunnel. With the tunnel hole, driving direction, and other settings, it could generate a tunnel simulation map, dimming tasks could be set for the tunnel entrance, the middle, the tunnel exit section, linked with vehicle sensors and lux meter. The system automatically reports abnormalities on the circuit and lamps, to prevent large-scale failure in advance, reduce the inefficient daily inspection, and greatly shorten the maintenance working time.
The special visual phenomena must be considered in tunnel lighting. In the daytime, when just enters the tunnel, as the brightness outside the tunnel is much higher than that inside the tunnel, the driver sees a dark hole or a black frame. This is the phenomenon of "black hole". After entering the tunnel from the bright outside into a darker tunnel, the vision will have a certain adaptation time, and then can see the situation inside the tunnel clearly, this phenomenon is called "adaptation hysteresis." When there is a very bright exit, it will produce strong glare to the driver, so that the road conditions are not clear, which is prone to occur car accidents. For this reason, tunnel lighting is usually divided into entrance lighting, interior lighting, and exit lighting. Among them, the requirements for entrance lighting are more strict, requiring a gradual decrease in brightness similar to the outside.
In the daytime, the brightness of the tunnel entrance lighting during the day is automatically adjusted according to the brightness outside the tunnel. At night, the lighting brightness in the tunnel can be kept very low, which can shorten the time for drivers’ eyes to adapt and greatly reduce the energy consumption of the lamps. The average energy saving rate of the Bangkok Tunnel reached 30.99% during the test period alone.