The Research Of Wireless Sensor Network For Realtime Structual Health Monitoring

Recently, the technology of wireless sensor network (WSN) has been applied in structural health monitoring widely. So the application of WSN received special interests. WSN is event-oriented network which are composed of many nodes. It integrates with sensor technical, embedded computing, wireless communication and distributed information processing. The target information can be monitored, processed and transported to remote users. The problem of tedious works to lay cables and high cost follow it in traditional system can be avoided by the monitoring system based on WSN. And the network features are high mobility, low cost of maintenance and etc.In this thesis, the wireless sensor network based on IEEE802.15.4 protocol has been built. And in this system, the GPRS module has been used in Sink node to transmit data frame to terminal. This scheme combine with the two advantages of high data rate radio in 2.4GHz RF and remote telecommunication the GPRS supported. So this scheme is significant to SHM used on infrastructure which located faraway area.The IEEE802.15.4 network protocol and network topology have been researched by this thesis. The whole system built on star topology in small area + peer-to-peer topology in large area with Sink node as gateway. The MD (mediation device) protocol is adopted in peer-to-peer network and the HHB protocol and PSFQ (pump slowly, fetch quickly) protocol are also adopted in order to improve transport layer services. The PHY layer and MAC layer protocol software of IEEE 802.15.4 are implemented in TinyOS by nesC language. Some protocols are also developed by nesC. Finally, the experimental results of WSN monitoring system are presented, and the stability of transport data and link quality are also given for reference.