High Precision Position System In Tunnel & Its Data Procession Technology

The mineral resource is one of the main sources of energy in China, and the mineral industry has become the backbone of the economy. However, many mining accidents happened every year because of the complicated environment in the mine. Aiming to guarantee the safety of coal miners, State Administration of Work Safety(SAWA) and State Administration of Coal Mine Safety(SACMS) jointly issued a document in 2011 that the advanced and high accuracy positioning system for coal miners must be improved by coal mining enterprises.This thesis mainly proposes a high accuracy positioning system based on the internet of things of industry framework where a four-level structure is utilized. Unlike conventional three-level framework(i.e. Sensing Layer, Transmission Layer and Application Layer), this new four-level structure is upgraded to instruments layer, network layer, data/service layer and application layer. This thesis focuses on the design of instruments layer and data/service layer.The remainder of this thesis is organized as follows. The channel modeling for wireless network in tunnels is firstly illustrated while the RF frequency of EM wave, polarization of antenna, parameters of tunnel wall are taken into consideration. The requirements for the dynamic characteristics, consumption, concurrent identification number and location range of this positioning system are analyzed according to the the national policies and regulations.As for the device layer, it is defined as the core technology of the high accuracy positioning system. A high precision ranging method, which can reduce the influence of frequency synchronization and time synchronization, based on phase difference is proposed according to the requirements above. The effectiveness of this method is verified by outfield experiment.As for the data/service layer, it mainly solves the matching problem of the ranging information and the tunnel’s geographic information by sending messages to Application Layer through the one-dimensional map matching method. Meanwhile, five common problems of this system are analyzed, and a data processing technology based on kalman filter and kalman prediction is proposed to deal with these common problems.At last, the design scheme of the high accuracy positioning system is proposed and the basic architecture of the system software is analyzed. The performance of this positioning system is verified through the field experiment in a real tunnel. The results show that the accuracy of the system is up to 2m, the rate of abnormal data lower than 2%, the coverage distance more than ±300m, the amount of Concurrent identification more than 80 and the inspection cycle less than 5s.