Indoor Positioning via Artificial Magnetic Fields

Indoor positioning approaches are often based on electromagnetic wave signals with high frequency. However, signal reflections and the corresponding signal superpositions are challenging. As a result, there is still no indoor positioning technology established in commercial products, like smartphones or smartwatches. Recent publications have shown that this indoor positioning problem can be addressed by using artificial magnetic fields. However, the cubic attenuation of the magnetic field challenges technical implementations and limits the ranges. In this work, we propose an approach striving to address these issues of magnetic indoor positioning via a simple electro-mechanical single-anchor concept in combination with a small wearable sensor circuitry. The terrestrial magnetic field together with amplitude and phase measurements resolve the position and the orientation of the tag. The proposed indoor positioning approach via artificial magnetic fields is tested in a corridor for a spacial region of approximately 100 m2. The mean positioning error in this experiment was calculated to be μ = 1.0±0.81 m. The proposed indoor positioning approach via artificial magnetic fields and the corresponding measurement system can therefore be useful alternatives when considering applications in which simple implementation is more important than positioning precision.