基于紧耦合GNSS/INS的高速列车精准定位方法研究

为了改善高速列车在行驶过程中定位不精准的现状，本研究采用全球卫星导航系统和惯性导航系统，构建了GNSS/INS紧耦合精准定位系统。提出等价权原理将UKF算法中的噪声协方差进行等价替换，使其能够在信息融合过程中对滤波增益进行调节，降低观测粗差带来的影响,提高UKF算法的鲁棒性。本研究在改进UKF算法的基础上，用地图匹配算法对滤波器处理后的定位数据进行再处理，进行仿真对比。结果表明：改进UKF算法和标准UKF算法仿真得到的位置速度误差曲线，其AVE和RMSE值均降低20%以上；又经过地图匹配算法处理后的定位精度更高，表明本研究能够提高高速列车的定位精准性、稳定性。

Precise Positioning of High Speed Train Based on Tightly Coupled GNSS/INS

In order to improve the status quo of inaccurate positioning of high-speed trains during running, this study adopts global navigation satellite system and inertial navigation system to construct GNSS/INS tightly coupled precise positioning system. The equivalent weight principle is proposed to replace the noise covariance in the UKF, so that the Filter gain can be adjusted in the process of information fusion, the influence of observation coarse error can be reduced, and the robustness of UKF Algorithm can be improved. Based on the improved UKF algorithm, this study uses map matching algorithm to reprocess the location data after filter processing, and carries on the simulation comparison. The results show that AVE and RMSE values of the position velocity error curves simulated by the improved UKF algorithm and the standard UKF algorithm are reduced by more than 20%. And the positioning accuracy is higher after the map matching algorithm processing, indicating that this study can improve the positioning accuracy and stability of high-speed trains.