Indoor user positioning using infrared LEDs and sensors

Applications in smart environments can make use of a user positioning service for various purposes such as activity recognition, context awareness and indoor navigation. We propose a novel solution to the user positioning problem based on inplane detection, which employs infrared light emitters and sensors placed horizontally on fixed positions along the circumference. The presented solution outputs all convex areas that are likely to contain the cross section of a user. The performance is evaluated in simulations of various indoor environments and for various numbers of users present using centroid offset, precision and ratio of equivalent diameters metrics. The simulation results show that the proposed solution determines the individual positions of multiple users in a room with very high performance.