Static and Dynamic Monitoring of Bridges by Means of Vision-Based Measuring System

Abstract

AbstractCivil structure static and dynamic monitoring is a key activity for both safety and maintenance purposes. In this paper the use of cameras to monitor a bridge response to train transits is being considered and results are presented and compared with a reference measurement, provided by a laser interferometer. A camera is a non contact measurement device, having mainly two advantages: first of all the effort required to prepare the set-up is very low, because the camera is fixed in the proximity of the structure and the targets to be mounted on the bridge (if required) do not need any cable connection for both power supply and signals. Secondly cameras can measure the displacements of multiple targets in the field of view. The leading idea of the paper is to use image acquisition and processing (Pattern Matching and Edge Detection) not only to measure the displacement of a few targets but also to grab images from a wide structure portion in order to recover displacements of a large number of points in the field of view. The extreme final solution would be having wide area measurements with no targets, to make measurements really easy, with evident advantages, but also with some drawbacks to be fully comprehended.KeywordsVisionBridgesDynamicsMonitoringUncertainty