三轴一体IMU组件中光纤环热分析

摘要

Influence of heating modules such as light source and accelerometer in inertial measurement unit ( IMU)on temperature field distribution of fiber coil is analyzed from structure perspective,finite element model ( FEM)for a certain type of three-axis integration optical fiber gyro strapdown inertial navigation system( INS)is established. Analyze and study heat transferring rule of IMU under the condition of room temperature(22℃)and steady state,which indicates that the heat generated by light source and accelerometer can not be transferred from box to IMU in the way of heat conduction,and influence of convection and radiation on temperature field distribution of IMU is great. Light source is the principal heating source which is the main reason affects nonuniform of temperature distribution of Y and Z axis fiber coil,and temperature distribution of fiber coil in X axis is influenced by heating of accelerometer. Through high temperature( 60 ℃)trans thermal analysis,study on temperature variation rule of fiber coils under the condition of extreme environment,it indicates that temperature gradient declines when temperature rises,fiber loop transient temperature difference increase in harsh environment. Both steady and transient thermal analysis can guide improvement of thermal designs of IMU paitial structure of INS.%对某型号三轴一体光纤陀螺捷联惯导系统建立有限元模型，从结构角度分析了惯性测量单元（ IMU）中光源和加速度计等发热模块对光纤环温度场分布的影响。分析研究IMU组件在22℃常温稳态下的传热规律，表明光源与加速度计等热源所产生热量将不以传导方式在箱体与 IMU台体之间传递，对流与辐射传热对IMU温度分布影响较大；光源为主要热源，是造成Y，Z轴光纤环温度分布不均匀的主要原因；加速度计发热将影响X轴光纤环温度分布。通过＋60℃高温瞬态热分析，研究光纤环在极端环境下温度变化规律，表明系统在极端环境下随着温度上升而温度梯度递减，光纤环瞬态温差增大。稳态和瞬态热分析可指导惯导系统IMU部分结构热设计的改进。