Impact of inflection points on the performance of resonator integrated optic gyro

Abstract

Resonator integrated optic gyro (RIOG) is a high-accuracy inertial rotation sensor based on the Sagnac effect. Instead of square-wave frequency modulation and sine-wave phase modulation, triangle-wave phase modulation eliminates the pulse error in the serrodyne wave phase modulation and reduces the backscattering noise, and is widely applied in RIOG. However, the attributed to the inflection points in triangle modulation waveforms induce output random noise, which would degrade the performance of the RIOG. In this work, the influence of such fluctuations on the performance of RIOG is theoretically analyzed and simulated. By analyzing the frequency response of averaging filter and lock-in amplifier, Pectinate filter is proposed to suppress the random noise. The experiment results from the established RIOG experimental setup demonstrated that the random noise caused by discontinuous frequency-modulation is effectively eliminated and the gyro bias stability is greatly improved from 1.96 to 0.11°/s.