Research on Ultra-wideband Ranging Method in Tunnel Environment

Aiming at the serious non-visual range problem in the complex and variable tunneling environment, which leads to the unsatisfactory results of most existing ultra-wideband (UWB) clock drift optimization schemes. We propose a straightforward and powerful high accuracy ranging method for tunnel environment. First, to address the impact of severe occlusion on UWB ranging in tunnels, we propose a simple non-line-of-sight (NLOS) error identification and correction scheme to minimize the clock drift error caused by NLOS. Moreover, for the clock drift problem of two-way ranging (TWR), we employ automatic correction by sending messages twice in a short period of time, taking into account the high mobility of nodes and NLOS range occlusion errors in the correction, which improves the ranging accuracy without increasing the equipment cost. Finally, the distance values are classified and filtered using the DBSCAN clustering algorithm and Gaussian filtering to achieve accurate distance measurements. Experimental results show that the algorithm can achieve a range accuracy of 0.1 m in a non-direct aiming and high maneuverability environment, which has a higher range accuracy compared with other algorithms.