A Method for Suppressing Electrical Feed-through in Force-to-Rebalance Mode Hemispherical Resonator Gyroscopes

Hemispherical resonator gyroscopes (HRGs) are a type of solid wave gyroscopes with high precision and high reliability. The electrical feed-through from the driving signals to the detecting signals degrades the performance of HRGs severely. In this paper, the influence of the electrical feed-through induced by the amplitude control loop on the scale factor and the bias of the force-to-rebalance HRGs is theoretically analyzed. An automatic gain control (AGC) structure based on parametric excitation is proposed and demonstrated in a force-to-rebalance mode HRG. Experimental results reveal that, with parametric excitation, the electrical feed-through can be effectively suppressed, and the performance of the gyroscope was greatly improved.