Rotatable orientation independent gravity sensor and methods for correcting systematic errors
First Claim
1. A method to correct for a systematic error of a sensor comprising a plurality of collocated accelerometers configured to measure gravitational acceleration, the method comprising:
- rotating the plurality of collocated accelerometers about a first axis, the plurality of collocated accelerometers providing output used for measuring the gravitational acceleration, each accelerometer in the plurality having a direction of sensitivity wherein at least two of the accelerometers in the plurality have different directions of sensitivity;
obtaining a first set of calibration measurements from the plurality of accelerometers from the rotation about the first axis;
determining a first systematic error for each accelerometer in the plurality using the first set of calibration measurements; and
removing the first systematic error from sensor measurements to correct for the systematic error.
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Accused Products
Abstract
A method to correct for a systematic error of a sensor having a plurality of accelerometers configured to measure gravitational acceleration, the method including: rotating the plurality of accelerometers about a first axis; obtaining a first set of calibration measurements from the plurality of accelerometers from the rotation about the first axis; determining a first systematic error for each accelerometer in the plurality using the first set of calibration measurements; and removing the first systematic error from sensor measurements to correct for the systematic error.
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Citations
20 Claims
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1. A method to correct for a systematic error of a sensor comprising a plurality of collocated accelerometers configured to measure gravitational acceleration, the method comprising:
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rotating the plurality of collocated accelerometers about a first axis, the plurality of collocated accelerometers providing output used for measuring the gravitational acceleration, each accelerometer in the plurality having a direction of sensitivity wherein at least two of the accelerometers in the plurality have different directions of sensitivity; obtaining a first set of calibration measurements from the plurality of accelerometers from the rotation about the first axis; determining a first systematic error for each accelerometer in the plurality using the first set of calibration measurements; and removing the first systematic error from sensor measurements to correct for the systematic error. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A sensor for measuring gravitational acceleration and correcting for systematic error, sensor comprising:
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a plurality of collocated accelerometers providing output used for measuring the gravitational acceleration, each accelerometer in the plurality having a direction of sensitivity wherein at least two of the accelerometers in the plurality have different directions of sensitivity; a rotational device configured to rotate the plurality of collocated accelerometers about a first axis; and a processing system in communication with the plurality of collocated accelerometers, wherein the processing system is configured to; obtain a first set of calibration measurements from the plurality of accelerometers from rotation of the plurality about the first axis; determine a first systematic error for each accelerometer in the plurality using the first set of calibration measurements; and removing the first systematic error from sensor measurements to correct for the systematic error. - View Dependent Claims (15, 16, 17, 18, 19)
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20. An apparatus for measuring gravitational acceleration in a borehole and correcting for systematic error, the apparatus comprising:
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a logging instrument; a plurality of collocated accelerometers disposed at the logging instrument, the plurality providing output used for measuring the gravitational acceleration, each accelerometer in the plurality having a direction of sensitivity wherein at least two of the accelerometers in the plurality have different directions of sensitivity; a rotational device configured to rotate the plurality of collocated accelerometers about a first axis; and a processing system in communication with the plurality of collocated accelerometers, wherein the processing system is configured to; obtain a set of calibration measurements from the plurality of accelerometers from rotation of the plurality about the first axis; determine a systematic error for each accelerometer in the plurality using the set of calibration measurements; and remove the first systematic error from sensor measurements to correct for the systematic error.
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Specification