A 3-D indoor location tracking and visualization system based on wireless sensor networks

This paper describes a 3-D location tracking and visualization system using wireless sensor nodes in indoor environment. The system is based on modified radio-location fingerprinting algorithm and it uses inexpensive, programmable wireless embedded platforms operating in ZigBee wireless network protocol. The main emphasis of this study is on the ability to estimate the location of mobile wireless nodes in 3-D indoor spaces, without any costly infrastructure. The wireless nodes have been deployed in an experimental test bed, for location tracking and motion estimation. K-nearest neighbor algorithm has been implemented for location estimation over a set of radio location fingerprints collected in a 3-D space. A 3-D visualization interface has been generated in VRML in order to display the real-time sensor positions and the data in the 3-D world. Preliminary experimental results show that the proposed scheme can achieve accurate and stable location tracking in indoor environments.