A Novel Phase Error Quantitative Characterization Method for Whole-Angle Micro Hemispherical Resonant Gyroscope

This article studies the effect of the control circuit phase errors on the micro-hemispherical resonant gyroscope (µHRG) under whole-angle (WA) mode. The causes of the phase error in WA µ HRG are first analyzed. Then, a WA dynamic model containing phase error is established, and the impact of the phase error in WA mode is analyzed. The analysis demonstrates that the phase error induces the coupling between the orthogonal control loop and the angle detection loop. Based on the coupling relationship of the self-precession control voltage to the orthogonal control voltage, a novel phase error quantitative characterization method is proposed, and the phase error is characterized. The characterization result shows a phase delay error of 13.44° in the WA µHRG control circuits. The phase error calibration is conducted using the characterization result. The results show that after calibration, the WA µHRG's angular velocity drift error reduced from 2.0016°/s to 0.38°/s, reduced by 81%; the zero bias instability reduced from 0.605°/h to 0.438°/h, reduced by 27.6%. The results validate the validity of the presented phase error characterization and calibration method.