基于SGHKF的SINS大方位失准角对准技术

Alignment of Large Azimuth Misalignment Angle SINS Based on SGHKF

为了提高捷联惯性导航系统(SINS)非线性对准的精度,缩短对准时间,降低非线性滤波器的计算量,针对SINS大失准角对准模型的特殊性,提出将简化的稀疏高斯厄米特滤波器(SGHKF)应用于SINS的非线性对准。SGHKF采用一组稀疏点求多维高斯厄米特积分。相比传统基于张量积的高斯厄米特滤波器(GHKF)、SGHKF不仅保留了GHKF精度高、精度等级容易调节等优点,而且将高斯积分点个数减小到常规无迹卡尔曼滤波器(UKF)sigma点个数,避免了维数灾难问题。理论分析和实验结果表明,基于SGHKF的大失准角初始对准精度和速度明显优于扩展卡尔曼滤波器(EKF),略微优于UKF,计算量明显小于GHKF。

In order to improve alignment accuracy,shorten alignment time of strapdown inertial navigation system and reduce computation of nonlinear filter,new Gauss-Hermite filter based on sparse gird gauss quadrature rule is used. Compared with conventional Gauss-Hermite filter based on tensor product gauss quadrature rule,the new GHKF not only maintains traditional GHKF’s advantage of precission controllable,but also avoid the curse of dimension problem. Theoretical analysis and experimental results show that initial alignment of sins based on new filter performs significantly better than EKF and slightly better than UKF in alignment accuracy and speed,and calculation amout is significantly less than traditional GHKF.