Design And Realization Of Underground Personnel Positioning System Based On ZigBee Wireless Sensor Networks

In recent years,Chinese economy has grown steadily while emphasizing the development concept of people-oriented and green production.As is known to all,the working environment of underground roadway in coal mine is bad,and the safe production of mine is a common concern of the society.Relevant Government departments attach great importance to safety issues and strengthen the supervision of coal mine safety production,but across the country,coal mine production accidents still occur from time to time.After the mine disaster,the complex topography of the roadway and the dangerous environment in the mine add difficulty to the rescue work.In order to seize the best opportunity of mine rescue,it is extremely important to locate the trapped miners accurately in the first time.In this thesis,aiming at the problem of inaccurate real-time positioning of underground personnel in existing coal mine personnel monitoring system,the underground personnel positioning system based on ZigBee wireless sensor network technology is designed.The system not only has the basic functions of monitoring environmental parameters and managing and dispatching underground workers,but also realizes the real-time positioning of underground workers.In addition,according to other environmental information obtained by the system,the positioning system can predict the occurrence of mine accidents in advance,and can alarm in time,thus ensuring the safety of coal mine production.This thesis summarizes the research status at home and abroad,analyses the existing positioning monitoring system,expounds the ZigBee wireless communication technology based on IEEE802.15.4 standard,and then designs the implementation scheme of the system according to the functional requirements of the system.The hardware design of the positioning system includes:choosing chip type,designing radio frequency circuit,mobile positioning node,routing reference node,coordinator central base station,gateway node,etc.The software design includes:setting up ZigBee wireless sensor network,constructing gateway node,designing wireless sensor network communication node,building monitoring center above the mine,etc.After the design of hardware and software platform is completed,the positioning algorithms(such as triangulation,trilateral measurement,centroid positioning,RSSI-based positioning)are tested,and an improved RSSI-based maximum likelihood estimation positioning algorithm is proposed.Then the simulation experiment of the positioning system is carried out and the actual effect is analyzed.The experimental results show that the underground personnel positioning system designed in this paper can realize the real-time and accurate positioning function of the target node,and the positioning error is within 1 meter,which meets the design requirements.This thesis presents a new type of underground personnel positioning system,which provides technical support for coal mine safety production and meets the needs of the market for coal mine monitoring system.Therefore,the underground personnel positioning system has considerable practical application value and broad market prospects.