Comprehensive Modeling and Mechanism Analysis of Assembly Errors in Hemispherical Resonator Gyroscopes

The hemispherical resonator gyroscope (HRG) is a high-precision angular rate sensor whose output accuracy strongly depends on the assembly precision of its resonator-electrode structure. Conventional research on HRG assembly errors has mainly focused on the effect of gap variation between the hemispherical resonator and the flat electrodes. However, assembly misalignments such as eccentricity and tilt also alter the effective electrode-resonator overlapping area, which changes the electrostatic coupling characteristics and introduces additional output errors. In this study, the influence mechanism of HRG assembly errors on output performance is systematically investigated. First, the major assembly errors of the hemispherical resonator gyroscope are analyzed, and their geometric relationships are modeled. Then, the effects of these errors on both the capacitive gap and the effective capacitance area are examined through theoretical derivation. Finally, a comprehensive assembly-To-output error model is established, which incorporates all significant error sources in the HRG sensor head. The proposed model reveals that the assembly deviation affects the standing wave azimuth detection. The results provide a theoretical foundation for optimizing HRG assembly precision and improving its output accuracy and stability.