为解决组合导航姿态估计航向角可观性弱, 姿态估计精度低、易发散的问题, 提出了一种单基线GPS辅助观测的组合导航姿态估计算法, 通过四元数与修正的Rodrigues参数相互切换避免了四元数加权均值计算和协方差奇异问题, 确保了四元数的规范化; 通过有效利用单基线GPS航向角辅助观测, 改善航向角的可观性, 提高了三维姿态角的估计性能; 通过使用开关自适应UKF算法, 提高了算法的适用性和姿态估计的精度。实验结果证明,UKF姿态估计的精度优于EKF, 最终三维姿态角的最小均方误差均在0.36°以内, 估计误差均在0.5°以内, 满足了宽带移动卫星通信的波束指向要求。

To solve the problems of low yaw observability low attitude estimation precision and easily diverged estimated angles in the integrated navigation a low-cost attitude estimation algorithm based on the integrated navigation aided by the yaw of the single baseline GPS is proposed.The model adopts integrated navigation estimation model with 9 states as the system states.A method of conversion between the quaternion and the Rodrigues parameters is adopted to avoid the weighted average calculation of the quaternion and the single covariance.A method of assisted GPS track angle is proposed to improve the observability of yaw angle and the performance of the algorithm.An adaptive UKF is proposed to improve the applicability of the algorithm and overcome the low precision and easily diverging problems of the EKF.As a result accurate and real-time attitude estimation is eventually realized.The precision of the algorithm is higher than that of the EKF.The maximum estimation error is within 0.5°, and the RMS of attitude estimation values are less than 0.36° which meets the requirement of the beam alignment for Mobile Satellite Communications.