Wireless sensor and actuator networks for lighting energy efficiency and user satisfaction

Buildings consume more than one third of the primary energy generated in the U.S., and lighting alone accounts for approximately 30% of the energy usage in commercial buildings. As the largest electricity consumer of all building electrical systems, lighting harbors the greatest potential for energy savings in the commercial sector. Fifty percent of current energy consumption could be reduced with energy-efficient lighting management strategies. While commercial products do exist, they are poorly received due to exorbitant retrofitting cost and unsatisfactory performance. As a result, most commercial buildings, especially legacy buildings, have not taken advantage of the opportunity to generate savings from lighting. The emergence of wireless sensor and actuator network (WSAN) technologies presents an alternative that circumvents costly rewiring and promises better performance than existing commercial lighting systems.;The goal of this dissertation research is to develop a framework for wireless-networked lighting systems with increased cost effectiveness, energy efficiency, and user satisfaction. This research is realized through both theoretical developments and implementations. The theoretical research aims at developing techniques for harnessing WSAN technologies to lighting hardware and control strategies. Leveraging redundancy, a sensor validation and fusion algorithm is developed for extracting pertinent lighting information from the disturbance-prone desktop-mounted photosensors. An adaptive sensing strategy optimizes the timing of data acquisition and power-hungry wireless transmission of sensory feedback in real-time lighting control. Exploiting the individual addressability of wireless-enabled luminaires, a lighting optimization algorithm is developed to create the optimal lighting that minimizes energy usage while satisfying occupants' diverse lighting preferences.;The wireless-networked lighting system was implemented and tested in a number of real-life settings. A human subject study conducted in a private office concluded that the research system was competitive with the commercial lighting system with much fewer retrofitting requirements. The system implemented in a shared-space office realized a self-configuring mesh network with wireless photosensors and light actuators, and demonstrated a 50% energy savings and increased performance when harvesting daylight through windows is possible. The cost analysis revealed a reasonable payback period after the system is optimized for commercialization and confirms the marketing feasibility.