Temperature drift modeling and real-time compensation of interferometric fiber optic gyroscope

Influencing factors on the temperature drift of interferometric fiber optic gyroscope (IFOG) are analyzed. A distributed model of the temperature drift of IFOG is formulated by establishing the linear correlation between temperature and parameters of IFOG model. The temperature experiments with the 0.25, 0.75, 1.00 °C/min rates of temperature change are designed to improve the temperature model adaptability of IFOG, and a discrete wavelet transform is used to extract the trend items from the temperature data and IFOG data of the experiments. Based on the distributed model of the temperature drift and least squares error (LSE) criterion, a multi-variable combined linear model is developed to estimate the temperature drift of IFOG. The algorithm of the multi-variable combined linear model is simplified by respective modeling at rise and drop in temperature and implemented by using a time-sharing finite impulse response (FIR) filters in field programmed gate array (FPGA). The simulation results and real-time test results of the temperature compensation show that the simplified algorithm can decrease the temperature drift of IFOG by 1/10 to 2/10.