A wireless sensor network for building structural health monitoring and seismic detection

Abstract

AbstractThe aim of this work is to develop a wireless sensor network for both structural health monitoring of civil infrastructure and seismic event detection and recording. The network is consisted of a small number of nodes, on which high resolution ADXL accelerometers are connected. The nodes are placed within the building in pre‐determined locations, in order to acquire and record data generated by seismic activity. A massive installation of such networks could monitor the seismic activity of wide areas within a city, allowing civil safeguard to act quickly in case of serious earthquakes events. The nodes are stationary and the network is self‐organized and self‐configured. We mainly focus on the routing protocol of the network and the time synchronization of the data. Since all data are gathered to a master node placed at the base of the building, successful transmission to that node is of great importance. Therefore, the developed routing protocol emphasizes at the delivery robustness of the transmitted data, trading off latency. Data travel through a multi‐hop order and no periodic routing advertisement is required. Regarding the time synchronization, the desired accuracy is on the order of 1ms. In order to achieve such accuracy, a time synchronization protocol has been developed. Clock differences and drifts between the nodes are calculated and taken into account when synchronizing the acquired data, thus accomplishing even better accuracy (tens of μs). Experimental evaluation in laboratory specially designed set‐up, proved that the performance of both protocols meet the needs of the propose application. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)