基于模态分析的三轴一体光纤陀螺仪轻量化设计

针对某型光纤陀螺仪的轻量化要求, 以构建框架式本体结构为基础, 采取三轴一体和光路复用方案, 通过器件的小型化和陀螺电路的多路集成实现了小型化三轴一体陀螺仪的设计.利用模态仿真讨论了框架式本体的壁厚尺寸、陀螺敏感环的接口尺寸和安装方式以及不同本体材料对光纤陀螺仪装配体模态的影响.分析表明:在进行三轴一体光纤陀螺仪的轻量化设计时, 采用框架式的本体结构可充分利用其空间几何构型对整体刚度的贡献, 有利于陀螺仪装配体一阶模态的提高, 而陀螺敏感环在本体结构上的安装方式较本体壁厚尺寸对陀螺仪装配体模态的影响更为显著.同时对框架式本体的壁厚及敏感环安装尺寸进行优化后, 光纤陀螺仪装配体的一阶模态提高了226 Hz.将镁铝合金应用于三轴一体陀螺仪并不具有振动模态上的优势, 而采用铍铝合金加工陀螺仪本体, 陀螺仪装配体的一阶模态可提高59%, 质量可降低74 g, 无论是实现陀螺仪的轻量化设计还是对提高整体一阶模态都有明显优势.

Light Weight Design Based on Modal Analysis for Triaxial Integrated FOG

Based on the design of frame-type bracket,the triaxial integration and optical multiplexing technique were used to accomplish the light-weight design of triaxial integrated fiber-optic gyroscope( FOG) through the optical-component miniaturization and multichannel-integration of gyroscope-signalprocessing circuits. The influence of the bracket wall thickness together with the mounting-interface dimension of fiber-ring and different structure materials of the bracket were discussed by using modal analysis. The frame-type bracket can improve the first-order nature frequency of the gyroscope assembling through its spatial structure,and the mounting-interface dimension of fiber-ring had obvious effect than the wall thickness of the bracket on improving the first-order vibrational mode of the gyroscope assembling. By optimizing the wall thickness of the bracket and mounting-interface dimension of fiberring together,the first-order nature frequency of the gyroscope assembling increased 226 Hz. For the light weight design of triaxial integrated FOG,the magnesium-aluminum alloy did not have advantage in constructing of bracket of gyroscope to improve the mode shape of assembling,while the first-order nature frequency of the gyroscope assembling can increase 59% and the weight can decrease 74 g by using Be-Al alloy to build the bracket.