Event-based sensor activation for indoor occupant distribution estimation

The information of the distribution of occupant in an indoor environment is important for building energy saving under normal conditions and for evacuation under emergent conditions, and thus is of great practical interest. Due to low set-up cost, wireless sensor networks powered by batteries are usually used for such estimation. The question is how to activate the sensors to minimize the estimation error within a given period of time. In this paper we develop an event-based activation policy which can be easily implemented in a decentralized way. We use numerical experiments to compare this policy with four other policies and to demonstrate the impact of various factors on the performance of these policies, such as the topology, sensor accuracy, battery capacity, occupant movement model, and occupant population. Our method outperforms the other policies in all the tested scenarios.