The vibration error of the fiber-optic gyroscope rotation rate and methods of its suppression

The error of the fiber-optic gyroscope (FOG) rotation rate measurement is considered. This error is induced by FOG vibrations (for open- and closed-loop FOGs). For a closed-loop FOG, a differential equation describing the loop dynamics is derived. The coefficients of this equation contain terms varying in time with the vibration frequency. For the first time, it is shown that, in addition to the traditional rotation rate measurement error due to the superimposition of vibration-induced optical power oscillations and the phase difference in the FOG coil, there is one more error, which is due to vibration modulation of the loop bandwidth. Alternative methods of information processing are investigated, and, on the basis of them, a new circuit is proposed for the suppression of vibration errors.