Research On The Key Technologies Of WSN-based Underground Monitoring Network Platform In Coal Mine

It is helpful for the security productivity to establish the information and digital coal mine. In the process of coal mine information construction, it is required to establish a unified network platform as the information communication infrastructure. The thesis explored the uniform underground monitoring system based on Wireless Sensor Networks(WSN) .At first, the thesis introduced the status of coal mine information construction, analyzed the underground monitering system alive. Then it proposed the structure of the uniform communication platform, and talked the application models, featuers, good points, work scenes of the platform.Secondly, the thesis researched the characteristics of wireless transmission on work surface. From analzing the influence of hydraulic prop to the electromagnetic wave transmission, it introduced the camp theorem, constructed the wireless channel model, and did some analysises and simulation for the model.Thirdly, the thesis proposed MAC layer protocol which can switch between free competition model and RTS/CTS model combined with work models of wireless communication. It also derived the computing formula of loss rate as switch threshold, and designed the MAC algorithm.It concluded that data-centric routing protocol fits the coal mine through the analysis of uniform communication platform. The thesis proposed the improved GEAR routing protocol based on the directional spread of the path gradient.The communication platform may generate congestion for the multimedia signals. The thesis proposed to use PID control strategy based on BP in active queue management, and simulated the algorithm. It concluded that it is better than PID algorithm and adptive PID algorithm based on single neuron in stability, robustness and self-adaptivity.Finally, the thesis work was summarized, and some possible research directions in future were proposed.