【摘要】 对于大跨度桥梁的结构健康监测,传统的人工检测方法存在主观性强,整体性、时效性差等不足.目前广泛使用的有线健康监测在应用中也存在着布线难,系统易受环境影响等困难.利用无线传感器网络技术对桥梁结构健康状态进行监测,不仅保留了有线健康监测的优点,而且弥补了其在应用中的不足.文章首先对整个系统的组成进行了说明,接着分别对无线传感器网络节点以及基站的组成和作用进行了说明.在此基础上,提出温度漂移对无线传感器网络节点的加速度传感器输出的影响,并对如何利用温度补偿技术来校准加速度传感器的输出值进行了探讨,且给出了数据校准前和数据校准后的对比图.接下来,提出节点时钟同步的必要性,并对网络的时钟同步原理进行了探讨.在润扬长江大桥锚索上安装无线传感器网络节点,利用节点采集锚索的振动信息,并将其发送到基站节点.经数据分析可以得出锚索的振动频率,根据振动频率,便可以分析其受力情况,最终可以判断桥梁的结构健康状态.更多还原

【Abstract】 For structural health monitoring of large bridges,the traditional manual detection is inadequate because of its strong subjectivity,bad entirety and bad timeliness.The widely used wired health monitoring system also has some problems in the actual applications.For example,it is hard to wire in some area and it is easy to be affected by environment.Using wireless sensor networks in bridge structural health monitoring not only retains the advantage of wired health monitoring system but also makes up for its deficiencies in the applications.The paper describes the composition of the whole system,and discusses the composition of wireless sensor nodes in the monitoring area of the system.Through studying the composition of base station,the paper gives the role of base station in the health monitoring system.On the basis of the composition of wireless sensor nodes,the paper addresses the mean value drift of the accelerometer output resulting from temperature changes.It gives a method to calibrate the output value of using temperature compensation technology.In order to verify this method,we give a comparison between uncorrected accelerometer readings and corrected accelerometer readings.Then,through proposing the necessity of time synchronization of all nodes before data collection,the paper discusses the principle of time synchronization.At last,we built a health monitoring system which was composed by data collection,data transmission,data reception and data analysis.And we tested the system in the anchor cable of Runyang Yangtze River Bridge.We installed the wireless sensor node in the anchor cable and obtained its vibration information through accelerometer.Then these data was sent to the base station,and to monitoring center in final.By analyzing these data,the vibration frequency spectrum of anchor cables could be obtained.Through analyzing the frequency,the strength of bridge’s cables would be figured out.It is useful to identify if the bridge is in a healthy status.If the data deviates from the normal range,the monitoring center will respond in time.At last,the paper gives a conclusion that the wireless system is suitable for bridge structural health monitoring field and useful for actual application.更多还原