Precision Of Fiber Optic Gyroscope Research Articles

Analysis of Time Delay in Modeling and Compensation of Temperature Error for FOG

In order to improve the precision of fiber optic gyroscope (FOG), multiple linear regression has been widely applied into identification and compensation of FOG bias drift causing by temperature variation. There exist inconsistencies between the measured temperature and the actual temperature of the FOG’s sensing unit. In this paper, the time delay between FOG bias data and temperature signal is considered before modeling the multiple linear regression for FOG. Then, by using FOG data collected at different time, we can establish more than one regression model. After that, these regression parameters are smoothed to obtain a comprehensive model, which has good parametric adaptability. Experimental results, on periodic and nonperiodic temperature cycling, show the superior performance of this proposed method in compensation of FOG temperature drift and improvement of FOG accuracy. The bias stability of FOG is superior to 0.01°/h at full temperature range -40°C ~ +60°C with temperature change rate -1°C/min ~ +1°C/min.

Analysis and Optimization of Dynamic Measurement Precision of Fiber Optic Gyroscope

In order to improve the dynamic performance of high precision interferometer fiber optic gyroscope (IFOG), the influencing factors of the fast response characteristics are analyzed based on a proposed assistant design setup, and a high dynamic detection method is proposed to suppress the adverse effects of the key influencing factors. The assistant design platform is built by using the virtual instrument technology for IFOG, which can monitor the closed-loop state variables in real time for analyzing the influence of both the optical components and detection circuit on the dynamic performance of IFOG. The analysis results indicate that nonlinearity of optical Sagnac effect, optical parameter uncertainty, dynamic characteristics of internal modules and time delay of signal detection circuit are the major causes of dynamic performance deterioration, which can induce potential system instability in practical control systems. By taking all these factors into consideration, we design a robust control algorithm to realize the high dynamic closed-loop detection of IFOG. Finally, experiments show that the improved 0.01 deg/h high precision IFOG with the proposed control algorithm can achieve fast tracking and good dynamic measurement precision.