A Novel Self-Modulation Method for Whole-Angle Resonator Gyroscope Based on High Harmonic Compensation

The whole-angle resonator gyroscopes (WARGs) have garnered significant attention as they break the contradiction between precision and volume in traditional gyroscopes. Self-modulation method is a key technique to address the bias drift resulting from damping asymmetry and frequency mismatch which are inevitable in WARG. However, the traditional self-modulation method is confronted with problems in extracting the real angular velocity. To address this barrier, this article proposes a novel self-modulation method for WARG based on high harmonic compensation. Initially, the propagation characteristics of damping asymmetry, frequency mismatch, and their correlation with control parameters are scrutinized by analyzing the error mechanism inherent in WARG. Leveraging the inherent-free precession characteristics of WARG, both forward and inverse rotations are used for calibrating the gyroscope’s scale factor and identifying high harmonic annular errors associated with vibration position, thereby facilitating a more precise modulation model. Subsequently, the novel self-modulation method based on the annular modulation model and virtual rotation scale factor is applied to compensate the bias drift and to remove a virtual rotation from the measurement. Experimental results demonstrate that high harmonic compensation improves the efficacy of eliminating virtual rotation rate for WARG. Specifically, bias drift suppression reaches 70.73% using second-order harmonic compensation and 84.86% using third-order harmonic compensation.