Detection of ferromagnetic target based on mobile magnetic gradient tensor system
| Autor: | Yin Gang, Li Zhining, Fan Hongbo, Ren Guoquan, Zhang Yingtang |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Physics Curl (mathematics) Mathematical analysis 010502 geochemistry & geophysics Condensed Matter Physics Direction vector 01 natural sciences Electronic Optical and Magnetic Materials Nuclear magnetic resonance Unit vector 0103 physical sciences Displacement field Complex lamellar vector field Eigenvalues and eigenvectors 0105 earth and related environmental sciences Vector potential Euclidean vector |
| Zdroj: | Journal of Magnetism and Magnetic Materials. 402:1-7 |
| ISSN: | 0304-8853 |
| DOI: | 10.1016/j.jmmm.2015.11.034 |
| Popis: | Attitude change of mobile magnetic gradient tensor system critically affects the precision of gradient measurements, thereby increasing ambiguity in target detection. This paper presents a rotational invariant-based method for locating and identifying ferromagnetic targets. Firstly, unit magnetic moment vector was derived based on the geometrical invariant, such that the intermediate eigenvector of the magnetic gradient tensor is perpendicular to the magnetic moment vector and the source–sensor displacement vector. Secondly, unit source–sensor displacement vector was derived based on the characteristic that the angle between magnetic moment vector and source–sensor displacement is a rotational invariant. By introducing a displacement vector between two measurement points, the magnetic moment vector and the source–sensor displacement vector were theoretically derived. To resolve the problem of measurement noises existing in the realistic detection applications, linear equations were formulated using invariants corresponding to several distinct measurement points and least square solution of magnetic moment vector and source–sensor displacement vector were obtained. Results of simulation and principal verification experiment showed the correctness of the analytical method, along with the practicability of the least square method. |
| Databáze: | OpenAIRE |
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