Real-time dynamic simulation of angular velocity and suppression of dead zone in IFOG

Abstract

The mechanism of the dead zone in closed-loop IFOGs is theoretically analyzed. The digital closed-loop transfer model for fiber-optic gyroscope is modified and the electronic cross-coupling interference from the feedback channel in the output signal of the detector in the forward channel is added. Using this model, we achieve a real-time dynamic simulation for the dead zone. The simulation results are basically consistent with experiment results. Before the electronic cross-coupling has been eliminated, the dead zone of the high-precision fiber-optic gyro is about $0.04^{ \circ } /h$, while the medium precision fiber-optic gyro is $0.4^{ \circ } /h$. After modifying the modulator circuit boards, the dead zone and the noise of the IFOG are of the same order of magnitude, better than $0.001^{ \circ } /h$ and $0.01^{ \circ } /h$, respectively.