Dynamic illuminance measurement and control used for smart lighting with LED

Abstract

The indoor energy management of lighting is essential for the construction of a smart city; a lighting system that dims electric lights based on the daylight level helps in energy conservation. One of the most common methods to achieve such daylight control is to measure the combination of daylight and electric light, and to determine the dimming level of the electric light. Based on the PWM dimming principle, we present a low computation cost and partial-feedback closed loop control scheme for LEDs, which only measures and feedbacks the contribution of daylight, not that of both light levels, to determine the output of the electric light. Using the photo sensor TEMT6000, a prototype is presented to verify the partial feedback scheme. Experiments show that the partial feedback controller has the capability to stabilize illuminance satisfactorily.