Development of a kind of multi-variable wireless sensor for structural health monitoring in civil engineering

In recent years, structural health monitoring (SHM) has been an important research area for designing and evaluating reliability of civil engineering structures. With the development of the technologies in sensing, wireless communication, and micro electro mechanical systems (MEMS), wireless sensing technique has been caused much more attentions and used gradually in the SHM. The wireless sensors and network has low capital and installation costs as well as ensures more reliability in the communication of sensor measurements, but there exists a key problem of the finite energy and this is a primary design constraint. Therefore, some measures must be adopted to make wireless sensor work more effectively. In this paper, a kind of wireless sensor with 3 variables, temperature- acceleration- strain, is proposed. Such several modules as sensing unit, micro-processing unit, power unit and wireless transceiver are constructed using commercially available parts, and integrated into a complete wireless sensor. The fusion arithmetic of the temperature-acceleration is embedded in the wireless sensor so that the measured acceleration values are more accurate. Measures are also adopted to reduce the energy consumption. Experimental results show that, the wireless sensor can monitor the temperature-acceleration-strain of the structures at real time and precisely, and pre-process and pack the measured data to reduce the data volume to be transmitted and save energy.