The hybrid lighting system with natural light and LED for tunnel lighting

Abstract

The traditional tunnel lighting has the problem of poor lighting environment and huge energy consumption. This study uses natural light and LED as the light source to design two different lenses. When the natural light is sufficient, the natural light illumination system is used in the threshold zone and the exit zone, give tunnel lighting to reduce the number of LEDs used. When the natural light is insufficient, the sensor will detect the natural light level of the collimator exit to control the LED to compensate for the light or to illuminate the tunnel alone. In the two designs, the linear Fresnel lens is established by the Fresnel structure, and the free-form asymmetric lens of the LED is established by the catadioptric method. Finally, the model of the Hsueh-Shan tunnel was established by DIALux, and the two lenses were used simultaneously for mixed illumination to simulate average luminance, total uniformity, and longitudinal uniformity. The lens design reduces the influence of glare, and the design of the lamp spacing reduces the zebra pattern on the road surface. Combined with natural light and artificial light source, the tunnel light does not need to be 24 h of operation can save energy.