Adaptive compass calibration based on local field conditions

Patent metadata

Field	Value
Publication number	US-10648809-B2
Application number	US-201816204388-A
Country	US
Kind code	B2
Filing date	Nov 29, 2018
Priority date	Oct 22, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Disclosed is a system and method for calibrating a magnetometer. The method comprises responsive to a determination that a magnetic inclination is less than a threshold, measuring first magnetic field data by detecting a magnetic field with the magnetometer through a first rotation path, measuring second magnetic field data by detecting the magnetic field with the magnetometer through a second rotation path, and determining calibration values for the magnetometer based on the measured first magnetic field data and the measured second magnetic field data.

First claim

What is claimed is:

1. A method for calibrating a magnetometer, the method comprising:
responsive to a determination that a magnetic inclination is less than a threshold:
measuring first magnetic field data by detecting a magnetic field with the magnetometer through a first rotation path;
measuring second magnetic field data by detecting the magnetic field with the magnetometer through a second rotation path; and
determining calibration values for the magnetometer based on the measured first magnetic field data and the measured second magnetic field data.

2. The method of claim 1 , further comprising:
responsive to a determination that the magnetic inclination is greater than the threshold:
measuring third magnetic field data by detecting the magnetic field with the magnetometer through a third rotation path;
measuring fourth magnetic field data by detecting the magnetic field with the magnetometer through a fourth rotation path; and
determining calibration values for the magnetometer based on the measured third magnetic field data and the measured fourth magnetic field data.

3. The method of claim 1 , further comprising:
determining a position with a global navigation satellite system receiver; and
determining the magnetic inclination based on the determined position.

4. The method of claim 1 , wherein determining whether the magnetic inclination is less than the threshold comprises:
determining whether an absolute value of the magnetic inclination is less than the threshold.

5. The method of claim 1 , wherein measuring the first magnetic field data by detecting the magnetic field with the magnetometer through the first rotation path comprises:
associating data from the first magnetic field data with orientation data detected by an inertial measurement device.

6. The method of claim 1 , further comprising:
outputting, responsive to the determination that the magnetic inclination is less than the threshold, an indication to rotate the magnetometer through the first rotation path.

7. The method of claim 6 , wherein outputting the indication to rotate the magnetometer through the first rotation path comprises:
transmitting, to an output device through a wireless network, a command to display the indication on a screen of the output device.

8. A non-transitory computer-readable storage medium comprising computer program instructions to calibrate a magnetometer, wherein the computer program instructions, when executed by at least one computer processor, cause the computer processor to:
responsive to a determination that a magnetic inclination is less than a threshold:
measure first magnetic field data by detecting a magnetic field with the magnetometer through a first rotation path;
measure second magnetic field data by detecting the magnetic field with the magnetometer through a second rotation path; and
determine calibration values for the magnetometer based on the measured first magnetic field data and the measured second magnetic field data.

9. The non-transitory computer-readable storage medium of claim 8 , further comprising computer program instructions that when executed cause the computer processor to:
responsive to a determination that the magnetic inclination is greater than the threshold:
measure third magnetic field data by detecting the magnetic field with the magnetometer through a third rotation path;
measure fourth magnetic field data by detecting the magnetic field with the magnetometer through a fourth rotation path; and
determine calibration values for the magnetometer based on the measured third magnetic field data and the measured fourth magnetic field data.

10. The non-transitory computer-readable storage medium of claim 8 , further comprising computer program instructions that when executed cause the computer processor to:
determine a position with a global navigation satellite system receiver; and
determine the magnetic inclination based on the determined position.

11. The non-transitory computer-readable storage medium of claim 8 , wherein the instructions to determine whether the magnetic inclination is less than the threshold further comprise instructions to:
determine whether an absolute value of the magnetic inclination is less than the threshold.

12. The non-transitory computer-readable storage medium of claim 8 , wherein the instructions to measure the first magnetic field data by detecting the magnetic field with the magnetometer through the first rotation path further comprise instructions to:
associate data from the first magnetic field data with orientation data detected by an inertial measurement device.

13. The non-transitory computer-readable storage medium of claim 8 , further comprising computer program instructions that when executed cause the computer processor to:
output, responsive to the determination that the magnetic inclination is less than the threshold, an indication to rotate the magnetometer through the first rotation path.

14. The non-transitory computer-readable storage medium of claim 13 , wherein the instructions to output the indication to rotate the magnetometer through the first rotation path further comprise instructions to:
transmit, to an output device through a wireless network, a command to display the indication on a screen of the output device.

15. A device, comprising:
a magnetometer;
a processor, the processor configured to execute instructions to:
responsive to a determination that a magnetic inclination is less than a threshold:
measure first magnetic field data by detecting a magnetic field with the magnetometer through a first rotation path;
measure second magnetic field data by detecting the magnetic field with the magnetometer through a second rotation path; and
determine calibration values for the magnetometer based on the measured first magnetic field data and the measured second magnetic field data.

16. The device of claim 15 , wherein the instructions further comprise instructions to:
responsive to a determination that the magnetic inclination is greater than the threshold:
measure third magnetic field data by detecting the magnetic field with the magnetometer through a third rotation path;
measure fourth magnetic field data by detecting the magnetic field with the magnetometer through a fourth rotation path; and
determine calibration values for the magnetometer based on the measured third magnetic field data and the measured fourth magnetic field data.

17. The device of claim 15 , further comprising:
a global navigation satellite system receiver to determine a position of the device, wherein the magnetic inclination is determined based on the determined position.

18. The device of claim 15 , wherein the instructions to determine whether the magnetic inclination is less than the threshold further comprise instructions to:
determine whether an absolute value of the magnetic inclination is less than the threshold.

19. The device of claim 15 , further comprising:
an inertial measurement device, wherein the instructions to measure the first magnetic field data by detecting the magnetic field with the magnetometer through the first rotation path further comprise instructions to:
associate data from the first magnetic field data with orientation data detected by the inertial measurement device.

20. The device of claim 15 , wherein the instructions further comprise instructions to:
transmit, responsive to the determination that the magnetic inclination is less than the

Assignees

• Gopro Inc

Inventors

• Diem Fabio
• Oberhauser Tim
• Omari Sammy

Classifications

• G01C17/38 Primary

  Testing, calibrating, or compensating of compasses · CPC title

• G01C17/02

  Magnetic compasses · CPC title

• B64C39/024

  of the remote controlled vehicle type, i.e. RPV · CPC title

• G05D1/0016

  characterised by the operator's input device (input arrangements for computing systems in general G06F3/00) · CPC title

• G05D1/102

  specially adapted for vertical take-off of aircraft · CPC title