重力辅助惯性导航中延时误差补偿算法研究

Research on Time Delay Compensation Algorithm for Gravity Aided Inertial Navigation System

在重力辅助惯性导航系统中,由于重力仪的输出存在时间延迟,造成了观测信息滞后,采用常规扩展卡尔曼滤波算法难以保证滤波的精度。因此,该文首先建立了适应扩展卡尔曼滤波的数学模型,将重力仪实测重力异常与惯导系统指示位置的地图重力异常值之差作为量测信息;然后利用厄特弗斯效应计算重力仪的延迟时间;在此基础上,提出了一种延迟误差补偿算法,将其应用到重力辅助惯性导航系统中。仿真结果表明,该算法能有效地降低时间延迟给系统造成的不利影响,从而提高重力辅助惯性导航系统的定位精度。

In the gravity aided inertial navigation system,the observing information exists lag due to the gravimeter output delay,conventional EKF algorithm is difficult to ensure the accuracy of filtering.To solve this problem,the mathematical model for EKF is established,in which measurement information is the difference between gravity anomaly measured by gravimeter and the values in the gravity anomaly map according to INS.The delay time of gravimeter is calculated by using of Etvs effect,Based on which,an algorithm of time delay compensation is proposed and applied to the gravity aided inertial navigation system.The simulation results show that the algorithm can effectively reduce adversely affect by the time delay and improve the position accuracy of gravity aided inertial navigation system.