Improving Augmented Reality Relocalization Using Beacons and Magnetic Field Maps

In this paper, we show how beacon-based indoor localization and additional environmental fingerprints like magnetic field data can be used to both accelerate and increase the robustness of Augmented Reality (AR) relocalization. We show how the combination of Visual Inertial Odometry (VIO) and beacons can be used to construct a dense indoor magnetic field map that can act as a fine-grained calibration for compasses to quickly determine a mobile device's orientation. Unique to our approach is that we leverage accurate VIO trajectories to provide full vector magnetic field mapping that can be collected and used with devices placed in any orientation. We demonstrate a system running on an iPhone that can acquire location with 80th percentile 3D accuracy of 27cm in LOS and 46cm in NLOS, and our magnetic field mapping approach can instantly estimate orientation with 80th percentile accuracy of 11.7 degrees. We demonstrate an end-to-end system for generating a magnetic field map and subsequently localizing and tracking mobile users using beacons and VIO. This has the side effect of enabling multi-user (even cross-platform) AR applications, as all users can now be localized with respect to a common global reference without any sharing of visual feature maps.