The Research On ZigBee Wireless Sensor Network And The Application In Hazard Monitoring System

Wireless sensor network system integrates sensor technology, embedded technology, computer technology, distributed information processing and communication technologies.It can collaborate in real-time monitoring, sense and collect networks distribution environmental information.within the region or the monitoring of objects information.And it processes these information, accesses to detailed and accurate information, sends the information to users need.This is one of the hot research directions in today's cutting-edge region.IEEE 802.15.4/ZigBee protocol is constituted of IEEE 802.15.4's PHY layer and MAC layer,ZigBee network layer and application layer. Its characteristics are stability and self-repair,supporting a large number of network nodes,transmission reliability,long battery life,security,cheap and universal,etc.In recent years,frequent explosions and fire accidents gave rise to many grief and regret in the petrochemical and coal industries.By accident data analysis,we can obtain that the accident rate is high caused by the explosive,toxic or harmful gases.We need strengthen monitoring for these gases and hazards.Currently, there are monitors with cable systems in most of the coal and chemical industry.There are maintenance difficulties, wiring inconvenience,high cost of secondary development.For the major hazard monitoring in this situation,a hazard monitoring system based on ZigBee technology is proposed.Using wireless data acquisition and transmission to replace the traditional wired data acquisition and transmission,it improves and enhances the monitoring of the limitations of traditional wired and facilitates follow-up subsystem reliable data transmission link.The topology of wireless monitoring systems,collection networks,sensor selection and the host computer needs are discussed and presented for.The paper round-depth researchs and analyses the ZigBee protocol, including stack frame structure,protocol stack network architecture, protocol stack API functions,etc.Focus on the ZigBee networking process and routing,the paper makes a thorough research for it,and summarizes the method of using protocol stack..For hazard monitoring system,it gives the software and hardware of the system and detailed circuit,including the gateway, routing and terminal.The establishment and maintaining the network is discussed,equipment connected to network is discussed,and the ZigBee routing,power consumption is discussed.A PC management system is developed.It completed data acquisition and integration of treatment, waveform display of real-time data,collecting network topology query, fire detection and other functions.Finally, the paper tests the node communication,and shows the process network,and verify the routing and address allocation mechanism. Combined with PC operation,remote control and data acquisition and processing are carried out.