Inertial navigation system with automatic redundancy and dynamic compensation of gyroscope drift error

摘要

An inertial navigation system with automatic redundancy and dynamically calculated gyroscopic drift compensation utilizes three, two-degree of freedom gyroscopes arranged whereby any two of the gyroscopes form an orthogonal triad of measurement sensitive axes. The input axes of the three gyroscopes form three pairs of parallel input axes, each pair of parallel input axes corresponding to one axis of the orthogonal triad of axes. The three gyroscopes are operated in a plurality of preselected combinations of both clockwise and counter clockwise directions, thus changing the direction of the angular momentum vector by 180 DEG . Parity equations are formed from each pair of gyroscope outputs whose measurement sensitive axes are parallel. The parity equations include combinations of gyroscope pairs that have been operated in both the clockwise and counterclockwise directions. Gyroscope drift estimates are then computed using the parity equations to provide individual gyroscope lumped drift corrections (self-calibration) to the inertial guidance and navigation system.