为了在较短的时间内获得较高的SINS初始对准精度,提出一种基于累积误差极小值的初始对准方法。首先给出SINS力学编排过程;然后在此基础上导出SINS导航误差传播公式;基于速度误差和位置误差公式推导出累积误差与初始对准误差的关系,给出基于载体最后静止时刻累积误差极小值的确定初始姿态角(航向角)公式。最后用两组实测数据对这种新算法进行验证。结果表明当载体初始对准时间较长时,Kalman滤波精对准和基于累积误差极小值的初始对准方法都可以获得较高精度的对准角;当载体初始对准时间较短时,Kalman滤波精对准精度较低,而基于累积误差极小值的初始对准方法仍可以获得较高精度的对准角。
A new method of SINS initial alignment based on the minimum of cumulated error is presented for the situation of short time for initial alignment. Firstly, the mechanization and the error formulas of SINS are given. Furthermore the relation between attitude angles and cumulated errors are deduced based on position error and ve- locity error formulas, and the principle of fixing initial yaw angle based on cumulated error checking is given. Fi- nally, two real experiments are carried out to show that when the initial static time is long enough, Kalman filtering and the new method can both bring about good results; but when the initial static time is very short, Kalman filte- ring can not obtain accurate yaw angle while the new method is able to fix the accurate yaw angle.