基于五阶容积-二阶平滑变结构滤波算法的捷联惯导系统初始对准技术

Research on Initial Alignment Technology of Strapdown Inertial Navigation System Based on 5-cubature-2-order Smooth Variable Structure Filter

为了改进捷联惯导系统大方位失准角初始对准情况下的方位失准角对准精度和稳定性问题,提出了一种组合对准方法。该方法将Kalman滤波对准模型与罗经对准模型相结合构建了一种组合对准机制,并在此模型基础上提出了基于非线性滤波和鲁棒滤波的五阶容积-二阶平滑变结构滤波算法,将五阶容积-二阶平滑变结构滤波算法与组合对准机制相结合,从而实现大方位失准角的初始对准。仿真结果表明,五阶容积-二阶平滑变结构滤波对准方法得到的方位失准角对准精度明显优于常见的几种对准方法,且其对准结果的重现性更高。因此,提出的五阶容积-二阶平滑变结构滤波算法能够很好地适用于大方位失准角的初始对准。

In order to improve the accuracy and stability of initial alignment of strapdown inertial navigation system with large azimuth misalignment angle,a combined alignment method is proposed in this paper.This method combines Kalman filter alignment model with compass alignment model,and constructs a integrated alignment mechanism.A 5th-cubature-2nd-order smooth variable structure filter algorithm based on non-linear filter and robust filter is proposed.This 5th-cubature-2nd-order smooth variable structure filter algorithm is combined with integrated alignment mechanism to realize the initial alignment of large azimuth misalignment angle.The simulation results show that the alignment accuracy of azimuth misalignment angle obtained by the 5th-cubature-2nd-order smooth variable structure filter alignment method is obviously better than that of several common alignment methods,and the repeatability of the alignment results is higher.Therefore,the proposed 5th-cubature-2nd-order smooth variable structure filter algorithm can be well applied to the initial alignment of large azimuth misalignment angle.