基于伪地球坐标系的捷联惯导全球动基座初始对准算法

Initial alignment algorithm with moving base for SINS based on pseudo-Earth frame in global regions

由捷联惯导系统建模原因造成的导航误差随纬度升高会被急剧放大,是实现惯导系统全球初始对准所面临的主要问题之一,且现有多种编排方案共存的全球初始对准算法也不利于初始对准算法在全球范围内统一。另一方面,极地地区越来越小的地球自转水平分量,使得极点及其附近的静态自对准是无法实现的,且动基座初始对准也有利于提高导航系统的快速反应能力。基于此,提出了采用伪地球坐标系惯导编排来实现惯导系统的全球动基座初始对准,消除由惯导建模造成对全球初始对准性能的影响,并期望探索一种统一导航编排的全球初始对准算法。最后通过仿真证明了该算法的可行性。

One of major problems for achieving the initial alignment of strapdown inertial navigation system （SINS） in global regions is that the SINS navigation errors are enlarged sharply with the increase of latitude, which is caused by the SINS modeling. Although different SINS mechanizations are applied to achieve the global initial alignment, it would be disadvantageous to achieve a unified global alignment algorithm. In addition, the static alignment would also not be achieved in or near the North/South pole since the horizontal component of the Earth rotation decreases to zero gradually. And the moving-base alignment would be advantage to improve the quick reaction capability of SINS. As a result, a novel moving-base alignment algorithm, which is based on pseudo-Earth frame, is proposed to achieve the initial alignment in global regions. The proposed algorithm can eliminate the influence of alignment model on the performance of initial alignment caused by SINS modeling in the global regions and is expected to unify the polar alignment algorithm as much as possible. Finally, the feasibility of the algorithm is demonstrated by simulation.