Dynamic attitude measurement method and apparatus
AssigneeCrossbow Technology, Inc.
InventorMichael A. Horton
Life of this patent
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Abstract
A method and system attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object.
Claims12
A method for determining an attitude of an accelerating object exclusively from acceleration and angular rate, comprising:
- determining an angular rate of the object to obtain a quaternion representation of attitude;
- converting the quaternion in to a direction cosine matrix;
- determining a level frame acceleration value of the object based upon the direction cosine matrix and an acceleration of the object;
- supplying attitude error and rate sensor bias estimates to a Kalman filter operating on the level frame acceleration value as a reference to determine the attitude of the object.
Dependencies are inferred from the claim text.