Research Of Coal Mine Monitoring System Based On Wireless Sensor Network

Coal mine monitoring system is an important part in the coal mine safetyproduction. The progress of technologies and needs of safety production in coal mine,promote greatly the monitoring system of coal mine to be intelligent and network. Thetraditional coal mine monitoring system has many drawbacks, which can’t meet theneeds of current coal mining.Based on the research of school-enterprise cooperated project "coal minemonitoring system", combined with application of Wireless Sensor Networks, andaiming at some problems existing in the monitoring system, for example, theexpandment of network is difficult, its real-time stability is poor, communicationstechnology can’t upgrade and with other shortcomings, design a coal mine monitoringsystem based on the Wireless Sensor Networks. In this system, the monitoringfunctions can be realized through two major parts: sensor nodes and base stations, thesensor nodes are used for data acquisition, the base stations work for datatransmission and processing. The wireless technology, sensor technology, embeddedtechnology and network technology are adoptded in this wireless network and CANbus system. This kind of design way can improve the network flexibility and real-timepreformance, and the network data transmission stability can be ensured, a guaranteefor coal mine safety is provided. The innovations of this article can be listed asfollow:(1) Through hardware switching circuit design and energy dynamic management,the MCU and wireless module will change to be a low-power sleep state after a dataacquisition is finished, and the sensor power supply circuit and the A/D referencepower supply circuit will be disconnected immediately, so that the powerconsumption is low;(2) Due to the economic benefits of the practical application, the chips selection,circuit design and size designed of the PCB system are carefully considered to ensurelow-cost design of the base station and sensor nodes. Based on the research of highfrequency PCB electromagnetic compatibility, some high frequency circuit designexperience are used to ensure the stability of the base stations and sensor nodes;(3) To realize multiple task scheduling and management for base stations, aμC/OS-II system is transplanted to MCU, ensuring high stability and real time performance. CAN bus and wireless monitoring system for double coverage is put touse to improve the real-time performance, stability and flexibility of layoutingnetwork;(4) Aiming at the characteristics of the fixed installation position of the sensornodes and base stations, a static wireless routing is uesed so that the sensor nodes canfreely join or exit the network, the scalability and maintainability of the system isenhanced. Considering the practical application’s area-coal mine tunnel, an improvedLEACH algorithm is proposed. Simulation results show that the algorithm has lowerdelay and longer survival time.The designed system has been tested in a small coal mines in Shanxi Province,which confirms the system’s feasibility and stability, which will greatly help thesystem to apply in the coal mine.