Research On Underground Personnel Location Technology Based On ZigBee Network

At present, regional personnel positioning system is widely used in the field of domestic coal, to achieve the localization of underground staff activities. It can only judge the activity area of staff, but its precision is not high, playing a limited role. Thus, accurate positioning technology is becoming a hot research in the mine. Research of precise personnel positioning system in mine, can achieve the underground staff location in time. This research is of great real meaning for underground staff rescue after disaster and self-help. Based on ZigBee technology, this paper mainly carried out the following:Due to the shortage of ZigBee distributed address assignment mechanism, it limits the number of underground staff joined the network. There exits an inevitable phenomenon that miners carrying unknown node devices are unable to join the network, causing part underground personnel location information omission. Therefore, a network algorithm for underground staff in a crowded area is proposed. From the perspective of choosing appropriate shiftable nodes, the network algorithm improves the existing CIM algorithm and staff position information omission.Based on research of range-based and range-free localization method, RSSI algorithm is easily affected by environmental factors. For the sake of the underground complex circumstances, a RSSI ranging module for adaptive environment called EADM is established. EADM module is used for determine the actual environmental parameters. To improve the positioning accuracy, a weighted likelihood estimation algorithm based on path loss parameters is proposed, improving the maximum likelihood estimation algorithm. Miners usually dense work in the main roadway. It is likely to signal conflict problems about transmission between underground staff in near, this paper adopts the idea of grouping protocol to solve it.In view of complex mine environment and comparison of wireless sensor network communication technology performance, it is feasible to achieve the personnel positioning system in main roadway area using ZigBee technology. According to the function and the hard structure of node equipment in personnel positioning system, CC2530 chip is used as core processor module in this positioning system. This paper completed every node function written and process design in the IAR Embedded Workbench integrated environment, displayed multiple personnel position function at any time in the presentation software. The localization algorithm proved the feasibility and effectiveness in the laboratory environment.