Design of a low cost and high performance wireless sensor network for structural health monitoring

Structural health monitoring systems often requires a large number of accelerometers, so the cost of each sensor and the architecture of the acquisition system become determining elements when evaluating the feasibility of this kind of studies. The flexibility of the monitoring system is fundamental, especially in case of existing buildings, where the use of a considerable quantity of cable could compromise the normal exercise, could affect the quality of acquired signal and finally be too expensive. For these reasons, the adoption of wireless sensor networks able to manage several accelerometers nodes is desirable. Wireless sensor networks have several critical aspects to solve: most important are the synchronism and the high determinism in data sampling required in this kind of applications, and the possible loss of data during the wireless transmission. The purpose of this work is to show and discuss the results obtained with a wireless sensors system for structural health monitoring of buildings or infrastructures placed in seismic zones. The first six prototypes of sensors have been assembled and tested, in order to state floor noise, the performances and the synchronization method.