文中提出一种逆向非线性EKF快速对准方法,该方法考虑了大失准角情况下捷联惯导误差模型的非线性特征,讨论了线性KF模型的不合理性,实现了基于EKF非线性滤波的正逆向对准。其实质是将惯导数据采集保存后,利用计算机的高速计算性能,反复对所保存的数据段进行正逆向分析,实现对准。为了验证文中算法的有效性和可行性,分别利用惯导仿真数据和实测惯导数据进行初始对准,并将文中算法与基于卡尔曼滤波的正逆向对准方法进行比较,结果表明,利用较少量的数据段通过正逆向分析也能够实现对准的目的,由于正逆向分析加剧了模型的非线性,基于扩展的EKF正逆向对准方法的精度要明显优于KF正逆向对准方法。
A kind of nonlinear EKF rapid alignment method is proposed in this paper. The advantage of quickness by reverse alignment and the nonlinear characteristics of the strap down inertial navigation error model. Its essence is that taking normal and reverse analysis repeat- edly on the saved SINS data by using of the high calculating speed of the computer to complete alignment, we carry on the task of alignment by the data of simulation data and measured data to checking the validity and feasihlility of the method. Then compare with the method of normal and reverse alignment respectively based on EKF and KF. It turned out that the EKF normal and reverse alignment method can give a more accurate result than the KF. It turned out that the EKF normal and reverse alignment method can give a more accurate result than the KF normal and reverse alignment method due to the nonlinear characteristics has been intensified using the method.