VEHICLE COMPASS COMPENSATION
First Claim
1. A vehicular electronic compass system comprising:
- a magneto-responsive sensor assembly for sensing a magnetic field;
an electronic circuit responsive to said sensor assembly for determining at least one of a magnitude and direction of the Earth magnetic field, said electronic circuit collecting a plurality of data points relative to a coordinate system associated with the vehicle, each of said data points having at least two components relative to said coordinate system, said electronic circuit averaging at least one component of at least two of said data points to determine an estimated value of the Earth magnetic field along at least one axis of said coordinate system, thereby calculating an estimated offset of the Earth magnetic field, said electronic circuit adjusting a directional heading output to account for the offset; and
an electronic display coupled with said electronic circuit for displaying a direction of the Earth magnetic field.
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Accused Products
Abstract
A compass compensation system is provided for automatically and continuously calibrating an electronic compass for a vehicle, without requiring an initial manual calibration or preset of the vehicle magnetic signature. The system initially adjusts a two axis sensor of the compass in response to a sampling of at least one initial data point. The system further calibrates the compass by sampling data points that are substantially opposite to one another on a plot of a magnetic field and averaging an ordinate of the data points to determine a respective zero value for the Earth magnetic field. The system also identifies a change in magnetic signature and adjusts the sensor assembly.
75 Citations
1 Claim
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1. A vehicular electronic compass system comprising:
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a magneto-responsive sensor assembly for sensing a magnetic field; an electronic circuit responsive to said sensor assembly for determining at least one of a magnitude and direction of the Earth magnetic field, said electronic circuit collecting a plurality of data points relative to a coordinate system associated with the vehicle, each of said data points having at least two components relative to said coordinate system, said electronic circuit averaging at least one component of at least two of said data points to determine an estimated value of the Earth magnetic field along at least one axis of said coordinate system, thereby calculating an estimated offset of the Earth magnetic field, said electronic circuit adjusting a directional heading output to account for the offset; and an electronic display coupled with said electronic circuit for displaying a direction of the Earth magnetic field.
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Specification
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- Resources
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Current AssigneeDonnelly Corporation (Magna International Incorporated)
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Original AssigneeDonnelly Corporation (Magna International Incorporated)
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InventorsSchofield, Kenneth, Blank, Rodney K., Schierbeek, Kenneth L., DeVette, Gregory H., Hoekstra, Eric J., Veiseh, Merdad
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Granted Patent
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Time in Patent OfficeDays
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Field of Search
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US Class Current702/92
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CPC Class CodesG01C 17/38 Testing, calibrating, or co...
