System identification and monitoring by using low-cost MEMS sensors

Low cost sensors, based on the MEMS (Micro Electro-Mechanical Systems) technology, are of interest for the structural testing and modal identification of existing buildings or bridges, when irregularly monitoring is required over a long stretch of time since the structure at study can be fitted with an adequate amount of permanently in place sensing devices. Compliance with the sensor specifications, however, it is often guaranteed by design since the low price tag is an advantage that would be lost if each single sensor should be experimentally certified or cali-brated; the "exact" characteristics of each sensor, consequently, are unknown or known in a statistical sense only. In this context, this work examines the possible adoption of low cost, un-calibrated, MEMS accelerometers for the modal identification and the monitoring of a reduced-scale prototype of a building, assessing the effects of sensor parameters uncertainty on the estimation of the structural response.