Networked illumination control with distributed light-harvesting wireless sensors

We consider networked control of luminaires to adapt illumination in an indoor environment to occupancy and daylight based on distributed light-harvesting wireless sensing modules. Each light-harvesting wireless sensing module consists of an occupancy sensor, a light sensor, a wireless radio, a microcontroller unit, and a photovoltaic cell. The occupancy sensor and light sensor, respectively, determine presence and illumination level within their fields-of-view. This local sensor information, along with control information from neighboring sensing modules, is used by a local controller to determine the dimming level of its luminaire so as to achieve its reference setpoint. To realize this system, we propose a low-power wireless sensing protocol and a neighbor-aided illumination control method considering the harvesting constraints of the sensors. The proposed methods are implemented in an indoor lighting system testbed and the performance is shown to meet desired illumination conditions.