Application In Bridge Health Monitoring System Based On Zigbee Wireless Sensor Network

Bridge construction and maintenance is an important part of national infrastructure, bridge health monitoring technology ensures effectively the security of operation of the bridge and protect s people's lives and property. Bridge health monitoring system, through monitoring and analysis of the state of the bridge structure, releases warning signals in special climate, the complexity of traffic conditions and abnormal structural condition of bridges, and provides a scientific basis for the management, conservation and maintenance of bridges.Currently, most of bridge monitoring systems at home and abroad are cable network system with flaws of the traditional means of health monitoring of bridge, namely, high cost of cable network installation, lack of mobility and flexibility in the network, low intelligence of nodes. To overcome the limitation, this paper designed and implemented a wireless sensor network system based on the Zigbee protocol for bridge health monitoring with advantages of low-cost, high reliability, easy installation and low maintenance cost.Firstly, this paper introduces current research achievements in bridge health monitoring and applications with wireless sensor network; then the structure of WSN, layer model and core technique of that. By analysis above, this paper point out that WSN based on Zigbee protocol is suitable for BHM featured with power-economical, communication liability, self-organization, self-healing and low cost; afterward Zigbee protocol framework and its network configuration, then analysis with Z-Stack in TI Zigbee2006 protocol. Thus, the paper proposed a general design for BHM based on WSN by figuring out topology for BHM with consideration on monitoring objects.According to the schema of a BHM system, the paper proposes detailed hardware design. Hardware design establishes modularized hierarchical architecture, which is based on Atmega128L microprocessor and CC2420 wireless sending and receiving module, with consideration of need of bridge health structure monitoring and features of WSN.Under the modularized architecture, this paper accomplished software design of nodes in BHM based on Z-Stack Zigbee network, including terminal nodes, network flow of coordinator, data collection and communication, under which the system achieves its proposed functions of data communication, serial port driver revising via computer terminal, database querying, real-time display and historic data querying.To verify validity and liability of the proposed BHM system, we carried out a serial of experiments on a certain bridge, whose results showed that the WSN based intelligent BHM system achieved on-line data acquisition, and could monitor the health condition of bridges.Finally, the paper summarized the flaws in the currently designed system, and proposed the aspects need to improve.