联合神经网络和对角加载的GNSS中断定位算法

Joint neural network and diagonal loading-based GNSS outage positioning algorithm

GNSS/INS组合导航系统可以为移动载体提供长时间、高精度的导航信息,然而当载体处于恶劣环境中,无法获得滤波量测向量,导致导航定位结果迅速发散.为应对这一问题,越来越多的学者利用人工神经网络辅助组合导航系统直接进行信息融合.但惯性导航系统(inertial navigation system,INS)本身特性使得上一时间训练好的网络模型存在误差,中断时刻INS误差仍不断累积,因此提出了一种GNSS中断时的智能定位算法.该算法利用反向传播(back propagation,BP)神经网络训练得到滤波量测向量,再通过对角加载重构量测噪声协方差矩阵,对卡尔曼滤波(Kalman filter,KF)进行更新.所提方法减弱了神经网络训练误差对组合导航算法的影响,从而可以在GNSS信号长时间中断情况下,导航系统仍拥有较为可靠的导航性能.

The GNSS/INS integrated navigation system can provide long-term,high-precision navigation information for mobile carriers.However,in adverse environments where filter measurement vectors cannot be obtained,it leads to rapid divergence in navigation positioning results.To address this issue,an increasing number of researchers are employing artificial neural networks to directly fuse information in the integrated navigation system.However,the inherent characteristics of the inertial navigation system(INS)result in errors in previously trained network models,and inertial navigation errors continue to accumulate during interruption periods.Therefore,an intelligent positioning algorithm for GNSS interruptions is proposed.This algorithm utilizes backpropagation(BP)neural networks to train filter measurement vectors and then updates the Kalman filter(KF)by incorporating diagonal-loaded reconstructed measurement noise covariance matrices.This approach reduces the impact of neural network training errors on the integrated navigation algorithm,enabling the navigation system to maintain relatively reliable navigation performance even during prolonged GNSS signal interruptions.