Analysis and compensation of temperature errors for fiber optic gyroscope scale factor

Temperature errors of scale factor of Fiber Optic Gyroscope (FOG) become primary errors instead of bias drift errors at high rate of rotation. The reasons causing the temperature errors of scale factor were analyzed, the temperature errors of scale factor were formulated, and the temperature performance of several parameters were tested. The temperature drift of feedback gain was compensated by using second closed-loop control. Meanwhile, it was proved that the effect of deviation of second closed-loop control upon scale factor was a third-order small quantity at most. The Output errors of FOG at different rates of rotation and temperatures were measured, and a third-order polynomial function and one-order polynomial function were defined based on the measured data. A temperature errors model of scale factor with double-input and single-output was developed based on Least Squares Error (LSE) criterion. The simulation results and test results of the compensation show that the scale factor error and nonlinearity were reduced to less than 100 × 10^-6 and 50 × 10^-6 after applying second closed-loop control and temperature errors model.