Fault Diagnosis of Space-Borne Fiber-Optic Gyros Based on Random Walk Coefficient Prediction and In-Orbit Calculation

A novel fault diagnosis method for the space-borne interferometric fiber-optic gyroscope (IFOG) is presented in this paper. The noise source of the fiber-optic gyroscope is analyzed first. Then, the prediction model of the random walk coefficient (RWC) is established based on the radiation-induced attenuation effect on optical fiber, and the estimation model of RWC is developed by using the detected signal acquired by the photo-detector. In addition, an improved iterative method to calculate the RWC with the output data of the IFOG in orbit is proposed. The three RWC values mentioned above are compared to determine the operational state of the gyroscope. And an in-situ fault diagnosis strategy for the IFOG is proposed finally. Based on the ground simulation and fault injection, the feasibility of the strategy is proved.