Modeling and simulation of digital closed-loop fiber optic gyroscope based on sigma-delta modulation

Abstract

This paper proposes a closed-loop fiber optic gyroscope control method based on the Sigma-delta modulation technique to improve the fiber optic gyroscope proportional-integral control method. Firstly, the sampling control system of digital closed-loop fiber optic gyro is established. Secondly, the fiber optic gyro digital closed-loop Sigma-delta modulator is designed and combined with the original system after the integrator. Simulation analysis is performed for both closed-loop control methods. Simulation results show that the maximum output noise amplitude of the original system is 2.8 deg/s and the maximum noise amplitude of the improved system is 0.8 deg/s under the input of a ramp signal with 100dB white noise. The noise amplitude is reduced by one order of magnitude, and the noise density is also significantly reduced. The proposed closed-loop control method of fiber optic gyro based on Sigma-delta modulation can effectively suppress the high-frequency noise of the weak signal of the gyro output, which has a promising application for the dynamic performance and noise suppression of fiber optic gyro.