Dynamic compass calibration in a portable device
First Claim
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1. A machine-implemented method for dynamic calibration of a compass in a portable device, comprising:
- detecting a sensed magnetic field in the device using the compass, over a given time interval;
detecting one of position, orientation and movement data about the device using position, orientation or movement (POM) sensor in the device;
computing a geomagnetic field based on the sensed magnetic field;
computing inclination of the geomagnetic field over the given time interval to maintain a running average;
comparing the sensed magnetic field and the position, orientation or movement data with predetermined criteria; and
signaling a recalibration of the compass based on the comparison.
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Abstract
The magnitude of a sensed, raw magnetic field in a portable device is monitored over a given time interval. The monitored magnitude is compared with predetermined criteria. Based on the comparison, recalibration of a compass function is signed. Other embodiments are also described and claimed.
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Citations
11 Claims
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1. A machine-implemented method for dynamic calibration of a compass in a portable device, comprising:
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detecting a sensed magnetic field in the device using the compass, over a given time interval; detecting one of position, orientation and movement data about the device using position, orientation or movement (POM) sensor in the device; computing a geomagnetic field based on the sensed magnetic field; computing inclination of the geomagnetic field over the given time interval to maintain a running average; comparing the sensed magnetic field and the position, orientation or movement data with predetermined criteria; and signaling a recalibration of the compass based on the comparison. - View Dependent Claims (2, 3)
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4. A portable device comprising:
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a portable device housing having integrated therein a position, orientation or movement (POM) sensor to provide one of position, orientation and movement data concerning the portable device, a magnetic sensor to provide a sensed, magnetic field, a compass calibrator coupled to the magnetic sensor, and an indicator module to monitor the sensed magnetic field and the position orientation or movement data over a given time interval, compare the monitored sensed magnetic field and the position, orientation or movement data with predetermined criteria, and, based on the comparison, signal the calibrator to recalibrate, wherein the indicator module is to monitor inclination of a geomagnetic field so as to maintain a running average of the inclination, over the given time interval. - View Dependent Claims (5, 6)
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7. An article of manufacture comprising:
a non-transitory machine-readable medium having stored thereon instructions that program a processor in a portable device to detect a sensed magnetic field in the device over a given time interval, monitor one of position, orientation and movement data from a position, orientation or movement sensor (POM sensor) in the device over the given time interval, compute inclination of a computed geomagnetic field so as to maintain a running average of the inclination, compare the sensed magnetic field with predetermined criteria, and signal a recalibration of a compass based on the comparison. - View Dependent Claims (8, 9)
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10. A machine-implemented method for dynamic calibration of a compass in a portable device, comprising:
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monitoring, by an indicator module, a magnetic field surrounding the device during a given time interval; monitoring, using a position, orientation, or movement (POM) sensor, one or more of position, orientation, and movement of the device during the given time interval; computing a geomagnetic field based on the magnetic field; computing inclination of the geomagnetic field during the given time interval to maintain a running average; comparing a change in the monitored magnetic field with a change in the monitored position, orientation, or movement; and signaling a recalibration of the compass when the change in the monitored magnetic field is large relative to the change in the monitored position, orientation or movement. - View Dependent Claims (11)
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Specification