Self-calibration method for assembly errors of hemispherical resonator gyroscope

The assembly error calibration methods for Coriolis vibrating gyroscopes based on rate fluctuation heavily rely on external equipment and cannot track changes in assembly errors in real time. To address this issue, this paper proposes a self-calibration method for assembly errors based on virtual rotation modulation (VRM). First, a systematic association model between assembly attitude errors and channel coupling errors under the time-division multiplexing control scheme is established. Based on this, a coupling drift model of the hemispherical resonator gyroscope (HRG), incorporating channel coupling errors, is developed, revealing the control voltage coupling mechanism induced by assembly errors. Finally, a self-calibration method for assembly errors based on VRM is proposed according to the evolution pattern of the amplitude control voltage, eliminating the dependence on external equipment during the calibration process. Experimental results demonstrate that this method reduces the preheating time of a navigation-grade HRG from 2 h to 5 min, while decreasing the scale factor nonlinearity and bias instability by factors of 12.5 and 4.3, respectively, to only 0.79 ppm and 0.0108°/h. This study provides a new approach for the efficient calibration of axisymmetric vibrating gyroscopes, offering significant theoretical value and broad application potential.