激光捷联惯性导航系统动态锥动误差建模分析

Dynamic Coning Error Modeling Analysis of Laser Strapdown Inertial Navigation System

提出了一种机抖激光陀螺的锥动误差参数建模与补偿方法。首先从机理上分析了锥动误差产生的原因,利用有限元分析方法给出了在不同外界角加速度输入下激光陀螺敏感轴的变形情况;建立了锥动误差的补偿模型,将锥动误差的影响用锥动误差系数表示,该系数仅和激光陀螺自身相关;设计了锥动误差系数的系统级标定方案,利用圆锥运动前后系统的姿态误差与锥动误差系数的关系完成参数标定。然后通过激光陀螺和光纤陀螺的圆锥运动实验,证明了锥动误差的存在;通过系统级的圆锥运动实验,证明了锥动误差的补偿效果。最后通过系统级的振动试验,验证了本文提出的锥动误差补偿方法能够有效地减小振动环境下系统的姿态和速度误差,对提升惯导系统在复杂力学环境下导航精度有着重要作用。

This paper proposes a modeling and compensation method for the dynamic coning error parameters of the mechanical dithered laser gyroscope.Firstly,the causes of the dynamic coning error are analyzed in principle,and the deformation of the sensing axis of the laser gyroscope under different external angular acceleration inputs is provided.A compensation model of the dynamic coning error is later established,and the influence of the dynamic coning error is represented by the dynamic coning error coefficient,which is only related to the laser gyro.Then we propose a system level calibration scheme of the dynamic coning error coefficients considering the relationship between the attitude error of the system before and after the coning motion.The existence of the dynamic coning error,as well as the dynamic coning error compensation effect is proved via the coning motion experiment of laser gyroscope and fiber optic gyroscope.Finally,it is verified through the system level vibration test that the dynamic coning error compensation method can effectively reduce the attitude and speed errors of the system in the vibration environment,consequently improving the navigation accuracy of the inertial navigation system in the complex mechanical environment.