System and Method for Determining a Magnetic Field using a Mobile Device

• US 20130316736A1
• Filed: 05/25/2012
• Published: 11/28/2013
• Est. Priority Date: 05/25/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Oliver, Robert George, Almalki, Nazih, Carmel-Veilleux, Tennessee, Buchanan, Nathan Daniel Pozniak
• Granted Patent: US 9,161,170 B2
• Time in Patent Office: Days
• US Class Current: 455/456.3
• CPC Class Codes: H04W 4/026 using orientation information, e.g. compass

Abstract

A method and system are provided for determining a magnetic field using a mobile device. The method includes determining location information of the mobile device, obtaining magnetic field data based on the location information, determining orientation information of the mobile device and applying the orientation information to the magnetic field data to compute a magnetic field corresponding to the orientation of the mobile device.

Claims

1. A method of determining a magnetic field using a mobile device, the method comprising:

determining location information of the mobile device;

obtaining magnetic field data based on the location information;

determining orientation information of the mobile device; and

applying the orientation information to the magnetic field data to compute a magnetic field corresponding to the orientation of the mobile device.

2. The method of claim 1, wherein the orientation information comprises angular position information of the mobile device.

3. The method of claim 1, wherein applying the orientation information comprises rotating the magnetic field data using a rotation matrix.

4. The method of claim 1, wherein the magnetic field data is obtained from a predetermined set of magnetic field data arranged according to location.

5. The method of claim 4, wherein the predetermined set of magnetic field data is located remote from the mobile device.

6. The method of claim 1, wherein the magnetic field data is obtained by performing a predetermined set of computations using the location information.

7. The method of claim 1, further comprising adjusting the magnitude of the magnetic field based on a magnetometer reading.

8. The method of claim 1, further comprising using the magnetic field as input to an application that was developed to use one or more magnetometer readings as input.

9. The method of claim 1, further comprising removing at least a portion of the magnetic field from a magnetometer reading to detect magnetic interference.

10. A computer readable storage medium for determining a magnetic field using a mobile device, the computer readable storage medium comprising computer executable instructions for:

determining location information of the mobile device;

obtaining magnetic field data based on the location information;

determining orientation information of the mobile device; and

applying the orientation information to the magnetic field data to compute a magnetic field corresponding to the orientation of the mobile device.

11. The computer readable storage medium of claim 10, wherein the orientation information comprises angular position information of the mobile device.

12. The computer readable storage medium of claim 10, wherein applying the orientation information comprises rotating the magnetic field data using a rotation matrix.

13. The computer readable storage medium of claim 10 further comprising computer executable instructions for using the magnetic field as input to an application that was developed to use one or more magnetometer readings as input.

14. The computer readable storage medium of claim 10 further comprising computer executable instructions for removing at least a portion of the magnetic field from a magnetometer reading to detect magnetic interference.

15. A mobile device comprising a processor coupled to a memory, a magnetometer and an accelerometer, the memory comprising computer executable instructions for:

determining location information of the mobile device;

obtaining magnetic field data based on the location information;

determining orientation information of the mobile device; and

applying the orientation information to the magnetic field data to compute a magnetic field corresponding to the orientation of the mobile device.

16. The mobile device of claim 15 further comprising a gyroscope for determining angular movement of the mobile device.

17. The mobile device of claim 15, wherein the orientation information comprises angular position information of the mobile device.

18. The mobile device of claim 15, wherein applying the orientation information comprises rotating the magnetic field data using a rotation matrix.

19. The mobile device of claim 15, wherein the memory further comprises computer executable instructions for using the magnetic field as input to an application that was developed to use one or more magnetometer readings as input.

20. The mobile device of claim 15, wherein the memory further comprises computer executable instructions for removing at least a portion of the magnetic field from a magnetometer reading to detect magnetic interference.