基于重构伪地球坐标系的捷联惯导初始对准算法

针对捷联惯性导航系统的方位误差对系统误差特别敏感,容易引起闭环卡尔曼滤波初始对准的发散,提出了一种基于重构伪地球坐标系惯导机械编排的初始对准算法。重构伪地球坐标系惯导编排方案在初始位置实现了线性运动误差和方位误差之间解耦,从而消除了导航坐标系旋转角速度误差对方位对准的影响。因此该算法可以减小由系统误差引起的方位对准估计振荡,从而降低了对准系统发散的可能性,进而提高对准系统的稳定性,并改善了捷联惯导初始对准的性能。另外,它不仅适用于常规纬度初始对准,也可以解决极区静态对准问题。最后,常规纬度和极区静态对准仿真证明了该算法具有优良性能。

Initial alignment algorithm for SINS based on reconstructed pseudo-Earth frame

In view that the SINS's heading error is very sensitive to system errors,which may lead to divergence in the initial alignment by closed-loop Kalman filtering,this paper proposes an initial alignment mechanization based on reconstructed pseudo-Earth frame.The decoupling between the level linear movement error and the heading error is realized at the initial position,eliminating the coordinate rotation angular velocity error's influence on the azimuth alignment.Therefore the proposed algorithm can decrease the oscillation of azimuth alignment caused by the system errors,and improve the SINS's alignment stability.In addition,it can also be applied to the static alignment in polar region.Simulations on static alignments in conventional latitude and in polar regions both show that the proposed algorithm has superior performances.