基于观测量扩展的捷联惯导动基座快速初始对准

Fast Initial Alignment Method of SINS In-movement Based on Measurement Augmentation

动基座条件下捷联惯导系统由于动态环境的影响,即使采用辅助信息下的组合初始对准也需要较长时间。针对这一问题提出了一种基于观测量扩展的捷联惯导动基座快速初始对准方法。在不改变系统状态方程的情况下,利用车体坐标系横向和垂直方向上速度为零这一约束条件,将基于车体坐标系横向和垂直方向的速度作为扩展的观测量。推导了扩展后的观测方程。进而利用卡尔曼滤波完成捷联惯导动基座初始对准。进行了运动条件下的仿真。仿真结果表明新方法在保证对准精度的同时缩短了对准时间。该方法算法简单,不需要增加辅助信息,具有很好的工程应用价值。

Long duration is needed to accomplish initial alignment of strapdown inertial navigation system（SINS） on moving base even on the condition of using supplementary information because of the influence of dynamic environment.To solve this problem,a new initial alignment method in-movement based on measurement augmentation was presented.Using zero transverse and vertical velocities in vehicle body coordinate as the constraint condition,transverse and vertical velocities in vehicle body coordinate are considered as extended measurement without changing state equations.Measurement equations are deduced according to the extended measurements.A Kalman filter also used for SINS initial alignment on moving base.Some simulations are carried out on moving base,the test results show that the new method not only converges more quickly but has the similar accuracy compared with the conventional Kalman filter method.This method is not only simple in arithmetic,but also doesn＇t need augment auxiliary information.All this characteristics prove that this method is valuable in engineering application.