一种导弹捷联惯导/地磁/雷达高度表组合导航方法

Strapdown Inertial/Geomagnetic/Radar Altimeter Integrated Navigation Method for Missile

基于雷达高度表和磁强计的测量信息,提出一种弹道导弹捷联惯导/地磁/雷达高度表组合导航方法。以磁强计测量值与磁场模型的磁场强度值之差和高度表与惯导解算高度之差作为量测,只用一个观测表达式即可同时包含载体的姿态及位置信息。引入状态反馈,利用混合校正的Kalman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,当磁强计精度为100nT,雷达高度表精度为50m时,仿真1000s后姿态精度优于20′,定位精度为2.68 km。该导航方法自主性高,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/radar altimeter integrated navigation method for ballistic missile was proposed. 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 corrected extended Kalman filter. Simulation results show that the proposed method can effectively suppress divergence of the errors. After 1000 s of simulation, the positioning accuracy is 2. 68 km and the attitude accuracy is better than 20′ when the magnetometer's accuracy is 100 nT and the radar altimeter's accuracy is 50 m. This method has such advantages as autonomous navigation and high accuracy that it is suitable for engineering application.