EKF_Tight_GNSS_UWB_Time_Calibration.pdf (2.87 MB)
Download fileEnhanced EKF-based Time Calibration for GNSS/UWB Tight Integration
preprint
posted on 2022-05-25, 19:48 authored by yihan guo, OLIVIERO VOUCHOLIVIERO VOUCH, Simone ZoccaSimone Zocca, Alex MinettoAlex Minetto, Fabio DovisTight integration of Global Navigation Satellite System (GNSS) and Ultra-Wide Band (UWB) is growing popularity as a positioning strategy relying on mass-market devices for applications dealing with localisation and tracking of agents in challenging environments. However, due to independent clocks of Commercial off-the-shelf (COTS) devices, the offset between the time-scales with respect to which measurements are time tagged must be mitigated to achieve accurate state-estimation via centralised, recursive filtering architectures. In this paper, it is analysed a GNSS/UWB Tightly-Coupled (TC) scheme based on an Extended Kalman Filter (EKF), and the integration of asynchronous GNSS/UWB measurements is investigated to highlight how it can induce state-estimation errors under different receiver kinematics. GNSS/UWB time calibration is addressed as a filtering problem, for which an EKF-based framework is developed to recursively model the GNSS/UWB time-offset as a further unknown in the system state-space model. Moreover, a double-update filtering model is proposed with embedded optimisations for the adaptive tuning of UWB ranging statistics. Experimental results with simulated data show that the double-update EKF algorithm can achieve a horizontal positioning accuracy gain 41.60 % over a plain EKF integration with uncalibrated time-offset and of 15.43 % over the EKF with naive time-offset calibration.
Funding
Politecnico di Torino Interdepartmental Centre for Service Robotics PIC4SeR
Chinese Scholarship Council (CSC)
History
Email Address of Submitting Author
oliviero.vouch@polito.itORCID of Submitting Author
0000-0002-6379-8887Submitting Author's Institution
POLITECNICO DI TORINOSubmitting Author's Country
- Italy