SYSTEM AND METHOD OF MAGNETIC COMPASS CALIBRATION
First Claim
1. A method of determining a magnetic field vector, the method comprising:
- storing, for each of a plurality of sensor orientations, one or more calibration components;
determining, for a sensor orientation not included in the plurality of sensor orientations, a magnetic field vector and a gravity vector;
iteratively estimating one or more calibration coefficients based on the stored components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations; and
determining a sensor-orientation-independent magnetic field vector based on at least one of the calibration coefficients.
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Accused Products
Abstract
A system and method of determining a magnetic field and magnetic compass calibration is disclosed. One embodiment is a method of determining a magnetic field vector, the method comprising storing, for each of a plurality of sensor orientations, one or more calibration components, determining, for a sensor orientation not included in the plurality of sensor orientations, a magnetic field vector and a gravity vector, iteratively estimating one or more calibration coefficients based on the stored components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations, and determining a sensor-orientation-independent magnetic field vector based on at least one of the calibration coefficients.
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Citations
20 Claims
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1. A method of determining a magnetic field vector, the method comprising:
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storing, for each of a plurality of sensor orientations, one or more calibration components; determining, for a sensor orientation not included in the plurality of sensor orientations, a magnetic field vector and a gravity vector; iteratively estimating one or more calibration coefficients based on the stored components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations; and determining a sensor-orientation-independent magnetic field vector based on at least one of the calibration coefficients. - View Dependent Claims (2, 3, 4, 5)
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6. A system for determining a magnetic field vector, the system comprising:
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a memory storing, for each of a plurality of sensor orientations, one or more calibration components; a magnetometer configured to determine a magnetic field vector for a sensor orientation not included in the plurality of sensor orientations; an accelerometer configured to determine a gravity vector for the sensor orientation not included in the plurality of sensor orientations; and a processor configured to i) iteratively estimate one or more calibration coefficients based on the stored components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations and ii) determine a sensor-orientation-independent magnetic field vector based on at least one of the calibration coefficients. - View Dependent Claims (7, 8)
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9. A system for determining a magnetic field vector, the system comprising:
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means for storing, for each of a plurality of sensor orientations, one or more calibration components; means for determining, for a sensor orientation not included in the plurality of sensor orientations, a magnetic field vector and a gravity vector; means for iteratively estimating one or more calibration coefficients based on the stored components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations; and means for determining a sensor-orientation-independent magnetic field vector based on at least one of the calibration coefficients.
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10. A computer-readable storage medium storing instructions relating to determination of a magnetic field vector, which when executed by a processor, cause the processor to:
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receive data, for each of a plurality of sensor orientations, indicative of one or more calibration components; determine, for a sensor orientation not included in the plurality of sensor means for determining, for a sensor orientation not included in the plurality of sensor orientations, a magnetic field vector and a gravity vector; iteratively estimate one or more calibration coefficients based on the data indicative of one or more calibration components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations; and determine a sensor-orientation-independent magnetic field vector based on at least one of the calibration coefficients.
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11. A system for determining a magnetic field vector, the system comprising:
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a magnetic compass comprising; a memory storing, for each of a plurality of compass orientations, one or more calibration components; a magnetometer configured to determine a magnetic field vector for a compass orientation not included in the plurality of compass orientations; an accelerometer configured to determine a gravity vector for the compass orientation not included in the plurality of compass orientations; and a processor configured to i) iteratively estimate one or more calibration coefficients based on the stored components, the determined magnetic field vector, and the determined gravity vector, wherein the calibration coefficients are updated during each of a plurality of iterations and ii) determine a compass-orientation-independent magnetic field vector based on at least one of the calibration coefficients, wherein the magnetic compass is mounted to a vessel configured to be navigable in bodies of water. - View Dependent Claims (12, 13, 14, 15)
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16. A method of calibrating a magnetic compass, the method comprising
receiving sample data indicative of a measured magnetic field vector and gravity vector from at least one sensor oriented at a first plurality of orientations; -
receiving a plurality of stored magnetic compass calibration components associated with a second plurality of orientations of the at least one sensor, wherein the second plurality of orientations includes at least one orientation that is absent from the first plurality of orientations; estimating a plurality of calibration coefficients based on the sample data and based on previously stored magnetic calibration components, wherein the estimating comprises; partitioning a first estimate of the calibration coefficients based on observability of the calibration coefficients at the first plurality of orientations, wherein observability of the calibration coefficients is determined based on the sample data at the first plurality of orientations; generating a weighting of the stored magnetic compass calibration components and the first estimate of the calibration coefficients based on the sample data; and determining the estimated plurality of coefficients based at least in part on the weighting. - View Dependent Claims (17, 18, 19, 20)
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Specification