Tracking Position and Orientation of Magnetic Objects Using Magnetometer Networks
2015 (English)Manuscript (preprint) (Other academic)
A framework for estimation and filtering of magnetic dipoles in anetwork of magnetometers is presented. The application in mind istracking of objects consisting of permanent magnets for controllingcomputer applications, though the framework can also be applied totracking larger objects such as vehicles. A general sensor model forthe network is presented for tracking objects consisting of (i) asingle dipole, (ii) a structure of dipoles and (iii) several freely moving(structures of) dipoles, respectively. A single dipole generates amagnetic field with rotation symmetry, so at best five degrees offreedom (5D) tracking can be achieved, where the SNR decays cubicallywith distance. One contribution is the use of structures ofdipoles, which allows for full 6D tracking if the dipole structure is largeenough. An observability analysis shows that the sixth degree of freedom is weaklyobservable, where the SNR decays to the power of four withdistance, and that there is a 180 degree ambiguity around a specificsymmetry axis. Experimental results are presented and compared to areference tracking system, and four public demonstrators based on thisframework are briefly described.
Place, publisher, year, edition, pages
Magnetometers, Tracking, Kalman filtering, Magnetic dipole
IdentifiersURN: urn:nbn:se:liu:diva-122395OAI: oai:DiVA.org:liu-122395DiVA: diva2:866121
FunderSwedish Foundation for Strategic Research , COOPLOC