Читать книгу Global Navigation Satellite Systems, Inertial Navigation, and Integration - Mohinder S. Grewal - Страница 99

These are methods used for cancelling the effect of some sensor output bias errors on navigation errors by rotating the sensor input axis either continuously (carouseling) or discretely (indexing), effectively zeroing the inertial integral of the sensor‐fixed errors.

Carouseling was first introduced at the Delco Division of General Motors in the early 1970s for gimbaled systems, using a vertical gimbal axis for the rotation. It has also been applied to strapdown systems, using ISA rotation about a nominally vertical yaw axis, and to strapdown MEMS systems for navigation [7], and evaluated for MEMS gyrocompasses [8].

Indexing (also called “gimbal flipping”) has been used quite extensively in the US Navy's electrostatically supported gyro navigator (ESGN), using independent indexing around and end‐to‐end on the spin axes of its electrostatic gyroscopes. This indexing does not cancel the effects of rotor axial mass unbalance, but it cancels just about everything else.