Research on Fuzzy Compensation Method of Temperature Drift for Fiber Optical Gyro

The thermally induced bias drift in the start-up phase ( start-up bias drift) of fiber optical gyro ( FOG) is investigated. And a fuzzy start-up bias drift compensation model,which is based on non-reciprocity theory of Shupe and heating experiment results of Mohr,is presented. The model takes the temperature and the temperature changing rate at the inner side of the fiber coil as inputs. And based on them,gyro bias drift is predicted to compensate the output of the FOG. The fuzzy rules of the compensation model are identified from the temperature measurements ( -25 ℃ ～45 ℃) and FOG outputs of a set of static-based experiments. And according to the rules identified,the start-up bias drift can be compensated on-line by performing the fuzzy inference step. A validity check experiment is conducted. The experiment shows that,after compensation by the model presented,the FOG bias stability is reduced from 0. 037° /h to 0. 017° /h and the start-up time is shortened from 30 minutes to 2 minutes.