UWB, Multi-sensors and Wifi-Mesh based precision positioning for urban rail traffic

Precision positioning for moving targets is the key issue in urban rail traffic safety assurance and operational energy saving. Precision vehicle positioning can improve transportation capacity. Meanwhile, personnel tracking can enhance daily operations as well as rescue capabilities in the event an accident or emergency. This paper discusses the development of precision positioning solution based on UWB, Multi-sensors and Wi-Fi Mesh Network. Difference from the existing rail positioning technologies, the proposed approach is specially designed for underground tunnels, culverts and architectural indoor environments. The paper will also introduce a Time synchronization method which integrates the time base of COMPASS (Beidou) with IEEE 1588 technology, so as to avoid sole dependence on GPS clock signal. An innovation integration solution which will eventually reduce the investment of targets tracking system of urban rail and the personnel precision positioning technique will be the first-of-the-kind in Urban Rail Safety and Security applications.