捷联惯导系统的姿态算法是其导航算法的关键环节,应用四元数来描述运载体姿态的变化在实际工程中应用广泛,其中的初始四元数提取精度直接影响到导航解算精度.针对这个问题,在传统提取算法的基础上,得到了基于K-矩阵的初始四元数提取算法,并对正交和非正交初始姿态矩阵的四元数提取进行了对比分析.初始姿态矩阵算例的提取验证表明,基于K-矩阵的提取算法运算量较小,且对于非正交姿态矩阵能有效提高四元数提取的精度,为改进姿态解算的初始四元数提取算法提供了参考.

The attitude algorithm of strapdown inertial navigation system (SINS) is a key part of its navigation algorithm.Describing the change of carriers attitude with quaternion has found a wide application in practical engineering,of which,the accuracy of initial quaternion extraction has a direct influence on the calculation accuracy of navigation.To this problem,on the basis of traditional extraction algorithms,an initial quaternion extraction algorithm based on K-matrix was obtained,and a comparative analysis of quaternion extraction with orthogonal and non-orthogonal initial attitude matrix was made.The extraction and verification of initial attitude matrix example showed that the extraction algorithm based on K-matrix has a lower computational complexity,and it can effectively improve the accuracy of quaternion extraction for non-orthogonal attitude matrix.The method provides a reference for improving initial quaternion extraction algorithm of attitude calculation.