Analysis of the Influence of Vibration Pickoff Circuit on the Energy Dissipation Characteristic of Hemispherical Resonator Gyro

During the manufacturing process of Hemispherical Resonator Gyro, after the resonator is welded to the electrode-base, a Vibration Pickoff Circuit is usually used to detect the resonator vibration signal in a non-contact manner, to evaluate its mechanical performance. When the Vibration Pickoff Circuit samples the weak current signal generated by resonator vibration, the additional energy dissipation will arise, thereby affecting the accuracy of the quality-factor test of the hemispherical resonator. In this paper, a resonator vibration pickoff circuit model with a Trans-Impedance Amplifier circuit as the core is established, mechanism of additional energy dissipation caused by Vibration Pickoff Circuit is analyzed, and a high-precision testing method for the quality-factor of hemispherical resonator after assembled is proposed. The accuracy of the established theoretical model has been verified by experiments in kind. After compensating the energy dissipation parameters of Vibration Pickoff Circuit during the calculation process, the measurement accuracy of the quality-factor performance of the welded resonator has been significantly improved.