Research On Personnel Location Based On Emw-ranging In Coal Mine

Coal mine is a high-risk industry. Mine accident happens frequently and isbecoming a puzzle against safety of production. How to find trapped people andlocate them precisely are the keys of successful rescue after the accident. TheEMW-based location has a far effective detection range, precise location and capacityof resisting disturbance among the personnel detection and location technologies.In this thesis, the propagation characteristics of ultra high frequencyelectromagnetic wave in coal mine tunnels are studied. Also, the influence factors ofpropagation loss and the feasibility of location mode based on Received SignalStrength Indicator is analyzed. A location model with separated emitter and receiverthat based on Time of Arrival ranging technology is proposed in coal mine tunnels.Based on this model, two standards, Two Way Time of Arrival and Symmetric DoubleSides Two Way Time of Arrival are proposed to use as precision ranging methods andthe error analysis are done too.Based on the location model proposed before, Chirp Spread Spectrum（CSS）technology is going to be used to realize the ranging method. The theory of CSStechnology is analyzed and the advantages in ranging are drawn. In order to designand realize the whole system, the characteristics of CSS technology in Additive WhiteGaussian Noise channel are simulated with MATLAB. The result shows the bit errorrates of the system with different bandwidths and different rates of bit transmission.The theory of the traditional trilateration location algorithm is analyzed, based onwhich, an algorithm of triangular centroid is proposed to amend it. Then, anotheralgorithm frequently-used in wireless location, least-square method, with its theoryand procedure, is discussed in this thesis. To check the feasibility of these twoalgorithms, a simulation based on the range information has been done withMATLAB. In the simulation, the location error is analyzed and the method how toreduce it is drawn.Finally, based on the theoretical research and simulation mentioned above, a location system is constructed. It consists of two parts: a ranging subsystem andsoftware for location on computer. With this system, ranging and location experimentsprovide useful sample data, which lays solid foundation for the further research.