Validation of MEMS acceleration measurements for seismic monitoring with LVDT and vision system

Recent improvements in Micro-Electro-Mechanical Systems (MEMS) and wireless transmission technologies today allow researchers to overcome some of the limitations of tethered structural monitoring systems, such as their high installation and maintenance costs. This paper presents a new-generation monitoring system based on MEMS and wireless transmission. This is an integrated system consisting of a set of small acceleration and strain sensors, distributed within the structure. The sensors have on-board computational capabilities and can transmit recorded data to a remote acquisition unit. This unit automatically records and interprets the data, and provides the user with a damage index representing the structural safety after a seismic event. Specifically developed algorithms which estimate the displacement time histories based on the accelerations recorded during the earthquake are used to perform this task. The aim of this paper is to assess the reliability of these algorithms, by comparing the output of the prototype monitoring system in terms of displacement with data from other measuring systems, such as linear voltage displacement transducers (LVDT) and multiple cameras.