基于QCKF的大失准角快速传递对准

提出了一种机载武器捷联惯导系统大失准角情况下快速传递对准QCKF（Quaternion Cubature Kalman Filter）算法.采用乘性四元数表示失准角，建立了基于四元数的速度加姿态匹配传递对准模型.将噪声扩维为状态思想应用到CKF（Cubature Kalman Filter）中以解决非线性过程噪声和量测噪声问题.考虑到表示旋转的四元数具有规范化以及符号相反的四元数表示相同旋转的性质，对CKF算法中关于四元数部分加权求均值转变为约束条件下基于投影长度的加权求均值，对CKF算法中关于四元数部分求方差进行符号预处理.仿真结果表明算法能在大失准角情况下提高对准精度.

QCKF based rapid transfer alignment for large misalignment angles

A quaternion cubature Kalman filter(QCKF) based rapid transfer alignment for airborne weapon-s strapdown inertial navigation system with large misalignment angles was presented. The transfer alignment of velocity plus attitude match model based on multiplicative quaternion was derived. The idea of augmenting the noise into the state vector was adopted to handle the nonlinear process and measurement noise. Considering the rotation quaternion has the characteristics of normalization and quaternion with opposite sign represents the same rotation, the weighted averaging of quaternion part in cubature Kalman filter(CKF) algorithm was changed into projection length weighted averaging with constraint conditions and the quaternion-s sign was processed before calculating covariance in the CKF algorithm. Simulation results show that the proposed algorithm can improve the alignment accuracy in large misalignment angles case.