结构材料对光纤陀螺动态性能的影响

Effect of structural material upon the dynamic performance of FOG

光纤陀螺(FOG,Fiber-Optic Gyroscope)在动态运用过程中输出易产生非互易性误差,分析FOG产生振动误差的原因,提出结构材料的性质对FOG动态性能有显著的影响.对作为FOG结构核心的本体采用不同结构材料,分别建立对应的FOG有限元模型,进行模态分析以及谐响应分析,定性分析结构材料的比刚度对FOG动态性能的影响,通过扫频振动和随机振动实验验证模型建立的正确性.结果表明,将比刚度高的铍铝材料替换铝合金材料应用在FOG本体上,能将FOG的一阶固有频率由1452 Hz提高至2213 Hz,可显著提高FOG的动态输出精度,并减小FOG整体质量,特别适用于轻小型FOG.

In a dynamic process, the fiberoptic gyroscope （FOG） generates a nonreciprocal error easily. After analyzing the reason of the FOG generating dynamic error, the principle that structural material perform ance has a significant influence on the FOG dynamic performance was proposed. Applied different structural materials in the structural body that as FOG the major part, the finite element models were made respectively. The ratio stiffness of structural material impacting on the FOG dynamic performance was qualitatively analyzed through modal analysis and harmonic response analysis. Random vibration and sine sweep vibration experi ments were also executed for confirmation with finite element model. The results show that the first resonance frequency of the FOG is increased from 1 454 Hz to 2 213 Hz by applying beryllium aluminum alloy which has higher ratio stiffness instead of aluminum alloy. FOG dynamic accuracy is significantly improved with the reso nance frequency increasing. Deserve to mention that beryllium aluminum alloy makes the FOG become lighter and more suitable for use in a small and light FOG.