Online Calibration of the Virtual Rotation Rate for Whole-Angle Hemispherical Resonator Gyroscopes Based on a Dual-Gyro Configuration

Virtual rotation plays a crucial role in compensating for circumferential errors of the hemispherical resonator gyroscope (HRG) operating in whole-angle (WA) mode. To eliminate undesirable effects introduced by rotation modulation, online virtual rotation rate estimation becomes the primary challenge. However, the difficulty lies in accurately resolving virtual rotation rate amidst the mixed outputs of virtual rotation and external rotation. This article provides a systematic analysis of the error mechanism in virtual rotation. To address the challenge of online virtual rotation rate estimation, a novel solution based on a dual-gyro configuration with an asynchronous virtual rotation modulation scheme is proposed and implemented. Experimental results demonstrate the superior performance enhancement achieved by this calibration scheme. In the presence of external disturbances, the signal-to-noise ratio (SNR) of precession angle measurements exhibits a remarkable 12.28-fold improvement. The maximum residual ranges of angular rate also show an average 13.86-fold improvement.