Identification and Compensation of Driving Electrode Imbalance Errors of Force-to-Rebalanced Micro-Hemispherical Resonator Gyroscope

The imbalance errors of the driving electrode are one of the factors that constrain the accuracy of the force-to-rebalance (FTR) micro hemispherical resonator gyroscope (mu HRG). The driving electrode imbalance errors of the mu HRG comprise driving gain asymmetry error and driving force coupling error. In this article, the driving electrode imbalance errors source analysis and dynamic modeling of the mu HRG are carried out. Moreover, the influence mechanism of the driving force imbalance errors on the FTR mode is investigated, and the mathematical models between the driving force imbalance errors and the closed-loop scale factor, as well as zero drift bias, are established. Additionally, the imbalance errors of the driving electrode are characterized and identified by the proposed rapid identification method, and the compensators are designed to conduct error compensation experiments using the identification results. The detailed experimental results reveal that the zero bias stability (1 sigma) of the FTR mu HRG is reduced from 5.587 degrees/h to 3.362 degrees/h, a decrease of 39.8%. The zero bias instability decreased from 0.829 degrees/h to 0.453 degrees/h, reducing 45.4%. The experimental results demonstrate that this method can effectively suppress the zero bias drift caused by the imbalance errors of the mu HRG's driving electrode, thereby further enhancing the accuracy of the FTR mu HRG.