Experiment Research On Communication Performance Of Wireless Temperature Sensor Network In Goaf

Once the occurrence of coal spontaneous combustion,it is difficult to control,then doinggob temperature monitoring is particularly important.there are different defects in commonmonitoring methods,Wireless sensor networks has been widely used in mine productionbecause of its low cost and power, high scalability and coverage, flexible configuration andnetworking.But now it is mainly used to monitor the environment in mine undergroundroadway,having little study on coal spontaneous combustion in goaf.Therefore,it isparticularly important to carry out the study on communication performance of wirelesstemperature sensor network in goaf.This paper studied the relevant theory of Wireless temperature sensor network ingoaf,identified the monitoring temperature indicator,analyzed the detecting difficulty oftemperature Field in goaf and influencing factors underground environment for wirelesscommunication.By simulating the free space, straight roadway, curved roadway,inclinedroadway and Gob,then testing the packet loss rate of434MHz,868MHz,915MHz and955MHz,434MHz was selected to be the best communicating frequency.Then, based onWave Mesh protocol,the system considering the node and gateway hardware and software,equipment immunity and explosion proof enclosure,PC monitoring software weredesigned.Finally,the system test was done in NanTun Coal Mine.On the one hand,testing thesystem communication distance in mine underground roadway,on the other hand, testing thesystem communication performance in goaf.the maximum multi-hop distance between nodesburied gob in Nantun coal mine was3.5meters.The wireless temperature sensor networksystem could accurately monitor the temperature in goaf and provided basis for coalspontaneous combustion judjement in goaf.