Accelerometer compensation in an inertial navigation system

Abstract

The invention is a method and apparatus for improving the accuracy of an inertial navigation system. The method comprises (1) obtaining a measure of the angular velocity of a body frame of reference having a first axis, a second axis, and a third axis, (2) obtaining a measure of the acceleration of a first reference point in the direction of the first axis, a second reference point in the direction of the second axis, and a third reference point in the direction of the third axis, the first, second, and third reference points being fixed in the body frame, and (3) determining compensated acceleration values. A compensated acceleration value is the difference of the measure of acceleration of a reference point and a compensation quantity. A compensation quantity is an estimate of the portion of the acceleration of the reference point resulting from the rotation of the body frame. The method further comprises establishing the optimum navigation center based on a criterion of goodness. The criterion of goodness is minimal weighted acceleration error where acceleration error is a function of the direction of the angular velocity vector and weighted acceleration error is obtained by multiplying the acceleration error by a weighting function and integrating the result over all directions of the angular velocity vector.

Dependencies are inferred from the claim text.