Vision-based measurements for slender structures vibration monitoring

Monitoring of structures requires vibration measurements to both estimate structural parameters and early predict potential disasters. The problem is crucial in particular in slender structures, where the use of classic techniques (such as accelerometer-based measurements and the strain estimation using either electric or optical-fibre strain gauges) presents some limitations. In these latter cases contactless measuring techniques would be preferred in order to avoid loading effects and, above all, to measure the vibration in many points contemporarily with a single transducer (a camera). An image-based vibration measurement technique is proposed and qualified in this paper and an application to overhead transmission lines (OHTL) is shown as an example.