Standing Wave Vector Control Error Analysis and Suppression Method for Rate Integrating Hemispherical Resonator Gyro

The high-precision vector control of standing wave is the foundation for implementation of Rate Integrating Hemispherical Resonator Gyro (RI-HRG). The unbalance electrical performance in excitation signal chain of gyro control circuit is the dominant factor causing vector control error. In this paper, by analyzing the causes of unbalance error, including unbalance gain error and excitation misalignment angle, a corresponding error model is established, the impact of unexpected excitation forces caused by unbalance error on the precession rate of standing wave is discussed, and an identification method of unbalance error that can effectively eliminate the influence of resonator damping anisotropy as well as a compensation method based on feedforward controller are proposed. The effectiveness of proposed unbalance error identification and compensation method is demonstrated by experimental results, the amplitude of standing wave circumferential drift error is decreased significantly after unbalance error compensation, and the gyro scale factor nonlinearity is improved.