一种弹道导弹捷联惯导/地磁组合导航方法

Strapdown inertial/geomagnetic integrated navigation method for ballistic missile

基于惯性器件和磁强计的测量信息,提出一种弹道导弹捷联惯导/地磁组合导航方法。以捷联惯导误差方程为基础建立系统的状态模型,以磁强计测量值与根据地磁场模型计算的地磁场强度值之差作为量测,只用一个观测表达式即同时包含载体的位置及姿态信息。引入状态反馈,利用混合校正的卡尔曼滤波得到系统导航信息的最优估计。仿真结果表明,该算法能有效抑制捷联解算误差的发散,磁强计精度为100 nT时,定位精度2.68 km,姿态精度优于5′。该导航方法完全自主,精度较高,具有一定工程应用价值。

Based on the measurement information of inertial instrument and magnetometer,a strapdown inertial navigation/geomagnetic integrated navigation method for ballistic missile was proposed. The state model was established according to the error equations of strapdown inertial navigation system（SINS）,and the observation model was constructed by using the difference between magnetometer output and the geomagnetic field intensity calculated by the geomagnetic reference field model,which included carrier position and attitude parameters. With the introduction of state feedback,the optimal estimations of navigation parameters were obtained by the mixedly corrected Kalman filter. Simulation results show that the proposed method can effectively suppress the divergence of the errors. The positioning accuracy is 3.214 km and the attitude accuracy is better than 5 arcmin when the magnetometer＇s accuracy is 100 n T. This method has such advantages as fully autonomous navigation and high accuracy that it is suitable for engineering application.