用于消除缓变伪距偏差的抗差扩展卡尔曼滤波方法

针对卫星导航系统中伪距观测量存在缓变伪距偏差,导致定位精度下降的问题,提出了一种基于滑动积累的抗差扩展卡尔曼滤波方法。该方法在抗差扩展卡尔曼滤波算法的基础上,通过滑动窗口内多个历元残差矢量的累积,增大标准化残差矢量的伪距偏差,来提高对缓变伪距偏差故障的抗差能力。仿真表明,该方法能有效消除或者减弱微小伪距偏差和缓慢增长伪距偏差造成的位置误差,与传统抗差扩展卡尔曼滤波算法比较,定位精度得到明显改善。

A New Robust Extended Kalman Filter Method for Eliminating the Slowly Growing Pseudo-range Error

According to the errors of pseudo-range measurements are slowly growing in the satellite navigation system, which led to decrease the position accuracy, this paper proposes a robust EKF method based on the sliding accumulation. The method based on the robust EKF algorithm cumulates the residual vectors for multi epoch in the sliding windows, the pseudo-range error of standardized residual vector is increased, which improves robustness of pseudo-range error. The simulation results show that, this method can effectively eliminate or weaken the position error caused by the slight pseudo-range error and the slowly growing pseudo-range error. Compared with the traditional robust EKF algorithm, the positioning accuracy is improved obviously.