Natasa Jovanovic

Iterative node localization for intelligent street lighting

In intelligent street lighting systems where light posts communicate wirelessly, location awareness is necessary for the system to provide context-aware services. To solve the specific localization problem, we developed an iterative algorithm based on the relation between the received signal strength and the distance to assign the known locations to the nodes. Our experimental results show small error rates in the number of wrongly localized nodes, which indicates the algorithm is applicable in practice.

Intelligent street lighting clustering

The advances in dynamic street lighting introduce new functionality for control and maintenance of the street lighting infrastructure. Vital elements in this infrastructure are the powerful controlling devices that control separate groups of light poles and collect information from the system. For an infrastructure based on wireless communication, this paper describes a fast heuristic algorithm for selecting the locations of these controllers and computing their light poles assignments. In addition, we present the analysis of the simulation results obtained by testing our algorithm for six street lighting networks with real geographic locations of their light poles.

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.