Development of a local indoor positioning system based on artificially generated magnetic fields (MILPS-2)

• Applicant: Professor Dr.-Ing. Jörg Blankenbach
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2009 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 144589839

The aim of this research project are advanced investigations of a Magnetic Local Positioning System (MILPS). MILPS utilizes artificially coil-generated magnetic fields for indoor positioning. Therefore the coils serve as reference stations inside a building, whose magnetic fields are sensed by a magnetometer which acts as mobile station. Applying magnetic field theory, distances between coils and sensor can be estimated from the captured signals for position determination. Because magnetic signals are robust against multipath and able to pass building materials without fading or attenuation, localization is even in harsh None-Line-of-Sight indoor scenarios feasible.In the initial project the underlying mathematical and physical fundamentals were elaborated and a small-scale demonstrator for laboratory use was built. Based on simulative and empirical experiments an optimal signal processing strategy could be developed. For performance analysis (e.g. range, accuracy) of MILPS multiple experiments with different setups in indoor environments were accomplished.The research has been done so far confirm the enormous potential of this magnetic indoor positioning system for indoor positioning, but also lead to further fundamental research issues. Using a few bigger coils, it is conceivable covering an entire building by MILPS. In disaster scenarios this could be used to roll-out MILPS in-situ around a building for tracking the rescue workers without having a functioning power or communication network inside the building. In addition, MILPS could be used in environments where the automatic localization of people or objects has not been possible yet (e.g. industrial plants, mines).Hence, the follow-on research project is focused on fundamental investigation for MILPS in terms of using only a few coils covering an entire building. Through a 3D calibration of coil and sensor existing model errors are analyzed and, furthermore, permit ranging performance evaluation of the system. Studies concerning the convergence of the position estimation considering the quality of starting values as well as the geometric configuration of coils and sensors lead to an optimal positioning algorithm. Based on known trajectories an assessment of MILPS for kinematic use is accomplished in simulative and empirical studies.

• DFG Programme: Research Grants