基于Imote2的WSN桥梁结构健康监测系统无线传输研究

无线传输在桥梁结构健康监测系统中的应用有效解决了有线传输的布线问题,但同时也带来了一些数据传输上的问题,例如：数据传输时数据包容易丢失而降低通信的可靠性;节点采集的数据序列很难完全时间同步,因而影响数据的精确度;简单的单跳通信只能满足基站节点与叶节点在可视路径内进行通信,在复杂环境下有障碍物阻挡时会导致通信不良或无法通信。可采取如下措施予以改进：通信时运用ACK机制减少数据包的丢失,从而保证传输的可靠性;采用浮动时间同步协议（FTSP）和重采样使节点之间的时钟同步度提高;采用AODV协议实现多跳传输,使节点在通信不良时通过中间节点与基站节点通信,增加通信可靠性并加大通信距离。

Wireless Transmission of WSN Bridge Health Monitoring System Based on Imote2

The wireless transmission applied to bridge health monitoring system can effectively solve the problem about wiring of wire transmission,but some questions on data transmission are happened.For example： the data packets are very easy to lose during the transmission to reduce the reliability of correspondence,it′s difficult for the dates collected by those nodes to achieve time synchronization completely,the single-hop communication can satisfy the communication between base-node and leaf-node just within a visual path,communications work badly or even can not work in the complex environment and obstacles are existed.Using ACK mechanism can reduce the loss of date packets in order to guarantee the reliability of the transmission,using float time synchronization protocol（FTSP） and re-sampling to improve the time synchronization between nodes.Compared with the single-hop communication,the AODV protocol can offer a ＂multi-hop＂communication,if one node can not communicate with the base-node directly,then it can find a middle-node which can offer a path to connect those two,it can increase the reliability and the potential distance of correspondence in this way.