DC Magnetic Field Based 3D Localization With Single Anchor Coil

Indoor localization technologies are rapidly attracting attention in recent years since those are required by indoor navigation, IoT, smart city, etc. However, currently available indoor localization techniques, such as Wifi based method and multi-anchor based method, require high installation cost and have an insufficient robustness problem. This paper proposes a DC magnetic field based robust indoor 3D localization method with a single anchor coil. The proposed method estimates the sensor position from both geomagnetism and artificially generated DC magnetic field. The proposed method does not require any pre-measurement or multi-anchor nodes in the minimal configuration, and hence it can realize instant 3D localization with lower installation cost. This work analyzed the magnetic field generated by a coil both with numerical simulation and prototyped sensor node. We experimentally evaluated the proposed method supposing tabletop-scale and room-scale applications. For table-top scale applications, the proposed method estimates the 3D position with the maximum error of 6.5 mm in the range of 250 mm. For room-scale applications, which require coverage area expansion with multiple anchor coils, the proposed method localizes the sensor with the maximum error of 14.7 cm in 3.0 m × 1.5 m area.