Investigation on influences of phase delay on performance of resonator gyroscopes

Abstract

In this paper, the influence of phase shift induced by the front-end amplifier and the digital control circuits on the quadrature suppression and the force-to-rebalance control loops is theoretically analyzed. Due to the existence of a phase shift, the output of the resonator gyroscope is affected not only by the damping mismatch, but also by the frequency splitting of the gyroscope which is the main contribution to the nonlinearity of scale factor of a RG. Based on the analytical results and established mathematical model of scale factor, the phase delay was characterized and compensated in the room temperature. Detailed experiments of phase compensation were conducted and results were analyzed. Experimental results show that with phase compensation, the quadrature suppression signal changes far less with the variation of external angular rate than that before phase compensation. This means that the coupling between the quadrature suppression signal and the force-to-rebalance control signal is greatly decreased. In addition, residual errors of the scale factor of the resonator gyroscope were also greatly decreased. It is shown that after compensation of the phase delay the residual error is reduced by a factor of 45 and the linearity of the scale factor of the resonator gyroscope was extremely increased by more than 50 times compared with results before compensation.