METHODS AND DEVICES FOR DETECTING MAGNETIC INTERFERENCE AFFECTING THE OPERATION OF A MAGNETOMETER
First Claim
1. A method for detecting magnetic interference in a mobile device, the method comprising:
- monitoring magnetometer sensor data generated by a magnetometer for a first time interval;
detecting a change in the magnetometer sensor data for the first time interval;
computing expected motion data that characterizes an expected motion of the mobile device based on the magnetometer sensor data;
comparing the expected motion data with reference data; and
deferring recalibration of the magnetometer when the expected motion data does not correspond to the reference data.
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Accused Products
Abstract
Methods and apparatus employing non-magnetometer navigational sensor data to assist in determining whether a change in a magnetic field detected by a magnetometer is likely due to a source of internal or external magnetic interference, and more generally, whether such interference is likely to be persistent or transient. If the magnetic field data detected by the magnetometer indicates a large change in magnetic field, but the non-magnetometer navigational sensor (e.g., gyroscope) data does not indicate a corresponding change in orientation of the mobile device contemporaneous with the change in magnetic field, then the cause of the magnetic field change may be determined as likely originating from a localized external interference source and the device may prompt the user to move away from the interference source, rather than initiating a recalibration of the magnetometer.
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Citations
24 Claims
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1. A method for detecting magnetic interference in a mobile device, the method comprising:
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monitoring magnetometer sensor data generated by a magnetometer for a first time interval; detecting a change in the magnetometer sensor data for the first time interval; computing expected motion data that characterizes an expected motion of the mobile device based on the magnetometer sensor data; comparing the expected motion data with reference data; and deferring recalibration of the magnetometer when the expected motion data does not correspond to the reference data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A non-transitory computer readable medium storing instructions executable by a processor of a mobile device, the instructions for carrying out a method for detecting magnetic interference in the mobile device, the method comprising:
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monitoring magnetometer sensor data generated by a magnetometer for a first time interval; detecting a change in the magnetometer sensor data for the first time interval; computing expected motion data that characterizes an expected motion of the mobile device based on the magnetometer sensor data; comparing the expected motion data with reference data; and deferring recalibration of the magnetometer when the expected motion data does not correspond to the reference data.
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14. A mobile device comprising:
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a magnetometer; one or more sensors; a processor coupled to the magnetometer and the one or more sensors, the processor configured to; monitor magnetometer data generated by the magnetometer for a first time interval; detect a change in the magnetometer data for the first time interval; compute expected motion data that characterizes an expected motion of the mobile device based on the magnetometer data; compare the expected motion data with reference data; and defer recalibration of the magnetometer when the expected motion data does not correspond to the reference data. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification