Object Localization by Construction of an Asymmetric Isobody of The
Magnetic Gradient Tensor Contraction Using Two Identical Permanent
Magnets
- Dean Martinović ,
- Jelena Vuletić ,
- Dario Stuhne ,
- Matko Orsag ,
- Zdenko Kovačić
Abstract
This paper deals with predictive maintenance of infrastructure objects,
focusing on the inspection of bridges. To achieve this goal, unmanned
aerial vehicles place measuring units for data collection at different
points of the bridge. This work deals with the question of how these
measuring units can be found and removed by them later. For this
purpose, a magnetic localization method based on the STAR method is
presented. In contrast to the STAR method, which only detects the center
of a magnetic target, a modified version called SRIOD is implemented
here, where the orientation of the magnetic target can also be detected.
This is essential information if the unmanned aerial vehicle is to grab
the measuring unit with a robotic arm. In this regard, two identical
permanent magnets are integrated into the measuring unit, whose gradient
tensor contraction of the magnetic flux density distribution has a
directed asymmetric surface when considering the contours of constant
values. This creates a magnetic invisible reference plane that can be
detected with a magnetic gradiometer. The method is verified both in
simulation and experimentally in a laboratory setup.