基于最优四元数估计的摇摆基座粗对准技术

针对摇摆基座的粗对准问题,提出了一种精度更优的粗对准方法。根据三维坐标矢量与旋转四元数间的内在关系,基于Wahba问题的求解原理,将双观测矢量的最优姿态阵求取问题归结为一个典型三角函数最大值的求解问题。阐述了Wahba问题的求解原理,分析了Wahba问题与最优四元数估计法的关系,剖析了最优四元数估计算法的复共线性,设计了基于最优四元数估计的摇摆基座粗对准方案,并与传统TRIAD算法和最优TRIAD算法进行了应用比较。蒙特卡洛500个样本的仿真结果表明,采用基于最优四元数估计的粗对准法的方位姿态估计精度远优于TRIAD算法和最优TRIAD算法,能使方位失准角的变化幅值控制在角分级,在此基础上能更好实现摇摆基座下惯导系统精对准。

Coarse Alignment Technology Based on OQEM for SINS on Moving Base

The optimal coarse alignment method is introduced to solve the problem of coarse alignment for SINS on swing base. According to the relationship between three dimension vector and round quaternion, the solvability of optimal attitude matrix based on the Wahba problem is bolied down to figure out the maximum of typical trigonometric function. Basic principle of the Wahba problem is put in a nutshell. The relationship between Wahba problem and optimal quaternions estimation method (OQEM) and the multicollinearitie of OQEM is discussed. Coarse alignment method of SINS based on OQEM is analysed and compared with TRIAD algorithm and optimal TRIAD algorithm. The monte carlo simulations results with 500 sample show that the azimuth precision of coarse alignment based on OQEM is well above that of coarse alignment base on TRIAD algorithms and optimal TRIAD algorithm. The azimuth range in amplitude is reached angle minute grading. On the basis of this, the precision alignment can be easy to achieve.