Doppler Effect Mitigation for High-Speed Train Localization With UWB/IMU Fusing

Accurate location information is an essential prerequisite for location-based service and operation safety in railways. Ultra wide band (UWB) fused with inertial measurement unit (IMU) has been thought as a promising localization technique for trains. However, due to trains’ high speed, ranging results from UWBs are seriously influenced by Doppler effect. Most existing work focused on Doppler effect mitigation in single round of communication, but ignored its negative impact on two-way time of flight (ToF) and fusion performance. In this paper, we propose an adaptive fusion model with ranging rectifications for high-speed trains. Firstly, two-way ToF ranging errors caused by Doppler effect are studied. Secondly, Doppler effect is mitigated effectively, with prior information of trains’ states in time series. Finally, an adaptive UWB/IMU fusion scheme is proposed, where residual errors of UWB observations after Doppler effect mitigation are modeled by a closed-form expression. Simulation results show that, regarding single time-slot localization, the proposed ranging rectification algorithm outperforms four typical algorithms, with gains of 78.42%, 60.22%, 58.09%, and 28.38%, in terms of RMSE. Regarding continuous localization with temporal correlation, the proposed adaptive fusion model achieves gains of 75.07%, 73.27%, 53.52% and 70.02%. Furthermore, its effectiveness is verified in practical platform.