Abstract: The assembly of fiber optic pigtails in Fiber Optic Gyroscope (FOG) mainly relies on workers to complete manually,and the consistency is difficult to be guaranteed as the assembly stress control is based on manual experience.Aiming at the difficulty of quantitative control of fiber assembly stress,an optical fiber dynamic modeling simulation method based on discrete differential geometry theory was proposed.An optical fiber kinematics framework was established based on discrete differential geometry,and the optical fiber dynamic equations including stretching,bending,and twisting deformation and stress calculations were derived from elastic potential.A numerical solution method of fiber dynamic equations based on Newmark implicit algorithm was proposed,and a collision detection and response strategy between optical fibers and surrounding objects during the assembly process was designed.Then the circumferential placement,bending and twisting simulations of optical fibers were conducted.The results showed that the position of circumferential placement was more accurate with a shorter free length between the control end and the fixed end of the optical fiber;the degree of bending and twisting deformation was larger with a larger optical fiber radius at the same torsion angle.A fiber optic gyroscope assembly layout was designed,and the stress distribution and maximum stress variation during the fiber assembly process were obtained through dynamic simulation.This research provided theoretical support for low-stress assembly and path planning of the gyro-optical paths.

Key words: fiber optic gyroscope, optical fiber pigtail, dynamic model, discrete differential geometry, stress calculation

摘要： 光纤陀螺仪(FOG)中光纤尾纤的装配主要依靠工人手工完成,装配应力控制凭借人工经验,一致性难以保障。针对光纤装配应力定量控制的难题,提出一种基于离散微分几何理论的光纤动力学建模仿真方法。首先,基于离散微分几何理论建立了光纤运动学框架,并由弹性势能推导了包含拉伸、弯曲和扭转变形的光纤动力学方程以及应力计算方法。其次,提出了基于Newmark隐式算法的光纤动力学方程数值求解方法,并设计了光纤在装配过程中与周围物体的碰撞检测与响应策略。随后,进行了光纤圆周布设和弯扭变形的仿真测试。结果表明,光纤控制端与固定端之间的自由长度越短,光纤圆周布设的位置越精确;光纤截面半径越大,在同样的扭转角下光纤产生的弯扭变形程度越大。最后,设计了一种光纤陀螺仪装配布局,并通过动力学仿真得到了光纤装配过程的应力分布及最大应力变化,为陀螺仪光路低应力装配与路径规划提供了理论支撑。

关键词: 光纤陀螺仪, 光纤尾纤, 动力学模型, 离散微分几何, 应力计算