Realization Of Wireless Sensor Network With Mesh Structure For Coal Mine Gas Monitoring

The nature and exploitation condition of the coal mine is very complicated and various. So there may have many kinds of disaster in coal mine which increase insecurity of exploitation and bring great accidents more easily. The gas disaster is more serious than the others, and it is the mainly minatory factor. At present, the gas monitoring mainly rely on the wired monitoring system, which have many locations and shortages for the security of coal mine and exist many security hidden troubles. Therefore, a wireless sensor network with mesh structure for coal mine gas monitoring is proposed. As a supplement of wired monitoring system, it will improve the level of coal mine gas monitoring and early warning greatly.There are 4 kinds of devices in the wireless sensor network with mesh structure for coal mine monitoring named coordinator, router, normal end device and improved end device respectively, and they all have different functions. The hardware and software of the wireless sensor node is designed to support the function of different devices.Considering that the self-organization of the wireless sensor network with mesh structure and the requirement of gas monitoring, the topology control mechanism, wireless nodes access mechanism and routing mechanism are designed. The topology control mechanism is mainly focused on the establishing of network, building of topology and control of power. The wireless nodes access mechanism is mainly focused on data collision in the network. And the routing mechanism is mainly focused on the transmission of data.The operating managers need to obtain the consistency of gas in each monitoring site during monitoring, so they can analyze and forecast the distribution of gas in the whole monitoring area. Moreover, the monitoring network should give an alarm in time when gas consistency is over the danger mark. Therefore, basing on the characteristic of the wireless sensor network and the requirement of saving energy, a network work mode with periodic and interruptive monitoring is designed to fulfill the requirement of the monitoring workThe designed network is tested in many times in the straight indoor aisle which is 90 meters long. And it also tested in the coal mine laneway in Yanzhou, Shandong province. The test results indicate that the wireless communication of the network is fine, network executed the stimulant monitoring task with the designed work mode, the topology control mechanism, wireless nodes access mechanism and routing mechanism are fulfilled the design requirement basically. The designed network can achieve the aim of the coal mine gas monitoring work.