双轴捷联惯导多位置对准方法研究

On Multi-position Alignment Method of Dual-Axis SINS

针对传统车载捷联惯导初始对准方法中存在方位陀螺误差可观测性差、对准精度不高的问题,研究了基于谱条件数可观测度分析的多位置对准方法。建立捷联惯导静基座对准误差模型,利用基于谱条件数法的分段线性定常系统理论分析了单位置、最优二位置和双轴转动三位置对准的可观测度,对比研究了惯性器件估计误差和对准精度,探讨了最优二位置对准时间分配问题,得到在相同对准时间内最优二位置对准精度更高、三位置对准可提高后续导航中方位陀螺常值漂移估计精度的结论,并通过仿真结果验证了理论分析的正确性。

In order to improve the observability and precision of initial alignment of traditional vehicle-mounted Strap-down Inertial Navigation System(SINS)a multi-position alignment method based on the theory of spectral condition number observability analysis is researched.The error model of SINS stationary base alignment is established the Piece-Wise Constant System(PWCS)theory based on spectral condition number is used to analyze the observability of single-position alignment optimal dual-position alignment and three-position alignment.The estimating error and alignment precision of inertial devices are contrastively researched and time distribution of optimal dual-position alignment is discussed.The conclusions are achieved that the optimal dual-position alignment gets higher precision in the same alignment time and three-position alignment can improve the estimating precision of orientation gyro for the subsequent navigation.The correctness of theoretical analysis is verified by simulation.