一种无源北斗/惯导闭环组合算法

提出了一种北斗卫星定位系统和惯性导航系统的组合导航无源定位算法。以伪距率为观测量,基于高稳定度用户时钟,结合北斗系统的热备份星,在三星共视下用两级卡尔曼滤波器对惯导进行闭环校正。给出了组合导航系统的构成,以及第一、二级滤波的数学模型。该法能根据收星情况在闭环与开环方式间稳定转换。仿真结果表明,此算法可提高丢星时组合导航系统的滤波定位精度,有效校正惯导的姿态误差角,并以较高的精度估计用户的三维速度。

A Kind of Passive Beidou/INS Closed-loop Integrated Algorithm

A passive location algorithm for the integrated navigation system of Beidou and inertial navigation system(INS) was put forward in this paper.The pseudo-range's velocity of changing was used as observations,and a two-level Kalman filtering model was applied to revise the attitude error of INS in a closed loop based on the high stable clock and the third hot backup satellite of Beidou navigation satellite system.The algorithm would change between the close-loop method and (open-loop) method steadily according to the navigation state.The simulation results showed that this scheme would improve the positioning precision effectively when the satellites in sight were less than two,revise the attitude error of INS effectively,and estimate the user's velocity with high precision.