Dual-channel Phase Delay Compensation for Hemispherical Resonator Gyroscopes with Angle-dependent Bias Reduction to 3.190×10-5°/s

This paper presents a high-precision hemispherical resonator gyroscope (HRG) capable of compensating for dual-channel phase delay induced by both control circuit and control circuit asymmetries. Conventional phase delay identification methods, which target aggregate phase delay, fail to resolve phase delay mismatch between two channels, thereby limiting the achievable precision of HRGs. This work contributes dynamic models analyzing dual-channel phase delay effects on control force coupling and angle-dependent bias (ADB). Novel identification method of dual-channel phase delay is proposed leveraging the quadrature control force under controlled standing wave angles and external rotational rates. Compensation efficacy is benchmarked against conventional phase delay identification methods under identical conditions, and results show the superiority of the proposed method with significant performance improvement: after dual-channel phase delay compensation at room temperature, the ADB decreased from 5.130×10^-3°/s to 3.190×10^-5°/s with a reduction of 99.378 %, while the bias instability (BI) improved from 1.215×10^-1°/h to 8.740×10^-3°/h with an improvement of 92.805%.