Research on stress mutation of fiber optic gyroscope

Temperature-variation sensitivity of fiber-optic rings is a bottleneck problem that restricts the engineering application of fiber optic gyroscopes in high-precision fields. At present, techniques such as quadrupole-symmetry and octupole-symmetry schemes are commonly used to enhance the length and position symmetry of fiber optic rings, achieving mutual cancellation of external temperature changes. This article is based on engineering applications, focusing on the conventional symmetry of fiber optic rings, and focusing on the process factors that affect the stress symmetry of fiber optic rings. It is found that there is a significant stress mutation in the bottom layer of the fiber optic ring using the conventional four pole and eight pole symmetric winding schemes. By analyzing the curing mechanism and the stress curve before and after curing, it is found that the tension of the fiber optic ring is affected. The difference in modulus between the fiber optic and the skeleton jointly causes a sudden change in the underlying stress curve. This paper proposes a buffer layer design method with batch-producible process, which can effectively suppress stress mutations in the central area of the fiber optic ring. The gyroscope products equipped with this process fiber optic ring can improve the temperature and bias instability index by 29 % while ensuring vibration performance. It has successfully achieved batch production of 0.01°/h fiber-optic gyroscopes, completed the production and development of over 3000 axes, and demonstrated significant engineering application value