数字闭环光纤陀螺振动误差分析

光纤陀螺的振动误差直接影响其使用精度.为解决振动问题,分析了陀螺振动特性的主要误差源.推导了闭环光纤陀螺光功率和输出关系的表达式,得出了光纤缺陷以及光纤、器件尾纤受振动产生寄生应力导致传输光偏振性能和光强变化是引起振动误差的根本原因的结论;对陀螺振动性能受结构谐振的影响进行了有限元分析和试验验证;提出了改善光纤陀螺振动性能的具体措施,包括光纤环及尾纤固化工艺、优化结构设计以及改进闭环控制.结果表明,经改进后的陀螺,振动条件下其动态精度接近静态指标,满足使用要求. 

Analysis of vibration error in digital closed-loop fiber optic gyroscope

Vibration error of fiber optic gyro affect its application performance directly. In order to solve the problem, the main causes of vibration error were analyzed. The expression between the closed-loop gyro output and optical power was conducted, The conclusion is that The inner stress of the fiber coil and the device pigtail caused by vibration leads to the variation of the polarization mode and optical power of propagating light. The vibration status of gyro mechanical structure, especially the resonance feature was analyzed with the method of finite element analysis (FEA) and verified by tests. So from the view of design and technique, some effective measures to improve the dynamic performance are put forward, included disposal of fiber coil and optical device pigtail, resonance free with reasonable structure design and improvement of closed-loop control. The result shows that the methods are valid. In vibration condition, the dynamic precision of fiber optic gyro is near static performance and satisfied application need.