Indoor location-finding using magnetic field anomalies
US9326103B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2013 |
| Grant date | Apr 26, 2016 |
| Priority date | — |
| Expiry date | Feb 2, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W4/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Techniques for indoor location-finding are described herein. Inside buildings, anomalies in the Earth's magnetic field may be caused by the buildings' structures. These anomalies tend to be location specific and temporally stable. Accordingly, a database or map may be constructed of field strength measurements, and made available to clients, either online (e.g., through cloud services) or offline. As a user carrying a portable device walks within a building, magnetic field measurements may be made. The measurements may be configured in as vectors and compared to the database. A specific location may be indicated by anomaly information seen in both the vector(s) and database. Optionally, techniques may be combined with a particle filter that may be operated step-by-step as the user moves within the building. In another option, fusion with Wi-Fi signals may be performed, such as with a two-pass bidirectional particle filtering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.