基于加性四元数的SINS/CNS非线性紧组合方法

SINS/CNS nonlinear tightly integrated method based on additive quaternion

针对SINS/CNS组合导航系统中的非线性特性,提出了基于加性四元数的SINS/CNS非线性紧组合方法。从捷联惯性导航系统误差非线性建模和天文角度非线性量测两个方面出发,推导了基于加性四元数的捷联惯导误差传播特性,构建了天文导航的非线性量测模型,采用二阶插值滤波算法实现了SINS和CNS的非线性信息融合。计算机仿真显示,SINS/CNS非线性紧组合方法充分考虑系统的非线性特性,机动情况下的峰值误差较小,相对线性紧组合方法导航精度提高约15%。

A SINS/CNS nonlinear tightly integrated method based on additive quaternion was put forward in accordance with the nonlinear characteristics of SINS/CNS integrated navigation system.From the nonlinear error modeling of SINS and the nonlinear measuring of CNS,the error transmission property of strapdown inertial navigation based on additive quaternion was deduced,and a nonlinear measurement model for celestial navigation was constructed.SINS and CNS nonlinear information fusion was also realized using 2-order interpolation filtering algorithm.Computer simulations demonstrate that the SINS/CNS nonlinear tight coupling method takes the system’s nonlinear characteristics into account,and its peak error in maneuvering flight situation is small.The navigation precision by this method can increase by about 15% compared with that by linear tight integrated method.