Naslov
Close-Range Electromagnetic Tracking of Pulse Induction Search Coils for Subsurface Sensing

Autori
Ambruš, Davorin ; Šimić, Marko ; Vasić, Darko ; Bilas, Vedran

Izvornik
IEEE transactions on instrumentation and measurement (0018-9456) PP (2021); 1-13

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Electromagnetic tracking, pose estimation, search coil, extended Kalman filter (EKF), tunneling magnetoresistance (TMR) sensor, subsurface sensing, electromagnetic induction (EMI)

Sažetak
In this paper, we investigate a specific search coil tracking problem arising from the use of electromagnetic induction (EMI) sensors to classify buried low metal objects. In the proposed approach, a moving search coil is used as a magnetic field beacon, two triaxial tunnel magnetoresistance sensors are used as anchors, and the extended Kalman filter (EKF) is used to estimate 5-degrees of freedom information on coil’s relative pose. A specific feature of the analyzed application is the pulsed beacon field and the coil’s size comparable to the tracking distance. To address the resulting near-field effects and improve the tracking accuracy, we include a rigorous analytical multi-loop model of the search coil into the EKF estimation algorithm and introduce a novel sensor calibration scheme. The system is experimentally validated in realistic dynamic conditions using handheld pulse induction metal detector as a beacon, and a laboratory-grade optical tracking system with declared sub-millimeter accuracy as a source of ground truth data. For a near-horizontal zigzag scan pattern within a volume of ~ 40 x 50 x 5 cm, our system yields mean absolute errors < 3 mm for the coil’s x and y-coordinates, < 2 mm for z- coordinates, and < 0.5° for the pitch and roll angles, making it a viable solution for pose- referenced EMI sensing.

Izvorni jezik
Engleski

Znanstvena područja
Elektrotehnika

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