Low-cost Structural Health Monitoring System for Smart Buildings

Structural Health Monitoring (SHM) is a discipline that aims to implement damage identification strategies through the measurement and processing of various data collected from systems under investigation, such as acceleration, temperature, displacement, force, strain, and many others. The identification of damages is strictly related to the change of dynamic properties of the structure such as natural frequency, damping rate, and mode-shapes. Synchronized measurements are mandatory to calculate these parameters, and for such reason most of the monitoring systems nowadays consist of single or multiple acquisition nodes surrounded by analog transducer networks. However, this strategy has two drawbacks, the high cost of the equipment and the usage of long dedicated cables. To solve these problems, a full-digital system has been developed. It makes use of digital MEMS accelerometers connected in daisy-chain through a digital bus implemented on an Unshielded Twisted Pair cable. The proposed solution simplifies the cabling, reduces the cost of the system, and provides accurately synchronized signals.