Occupancy Sensor System : For Context-aware Computing
Daniel Hübinette · 2007
This masters thesis project, "Occupancy Sensor System", was conducted at Kungliga Tekniska Högskolan (KTH), Stockholm, Sweden, during the period 2007-04-24 – 2007-12-17. The goal of the project was to design an occupancy sensor system that determines if there exists more than one person in a defined region. The output of this system is for use in a context-aware system at the KTH Center for Wireless Systems (Wireless@KTH). The system is important because there is a need for specific input to context-aware systems concerning occupancy of spaces and because this thesis has focused on a problem that enables new complex and interesting services. Additionally, the specific problem of determining not only occupancy, but if this occupancy is zero, one, many has not been widely examined previously. The significance of zero occupants indicating an empty room has already been recognized as having economic and environmental value in terms of heating, ventilating, air-conditioning, and lighting. However, there has not been an effort to differentiate between a person being alone or if more than one person is present. A context-aware system might be able to use this later information to infer that a meeting is taking place in a meeting room, a class taking place in a classroom or that an individual is alone in a conference room, class room, etc. Thus enabling context-aware services to change their behavior based upon the differences in these situations. An occupancy sensor system prototype was designed to monitor a boundary by using a thermal detector, gumstix computer, an analog to digital converter prototype board, laptop computer, and a context broker. The testing and evaluation of the system, proved it to be sound. However, there are still further improvements and tests to be made. These improvements include: dynamic configuration of the system, communication between the different system entities, detection algorithms, and code improvements. Tests measuring accuracy of a detection algorithm and determining optimal detector placement need to be performed. The next step is to design applications that use the context information provided from the occupancy sensor system and expand the system to use multiple detectors.