Dynamic beam deformation measurements with off-the-shelf digital cameras

The physical health monitoring of civil infrastructure systems is an important task that must be performed frequently to ensure their serviceability and sustainability. Part of this process requires fine-scale monitoring of the structural elements that form the infrastructure system. This has traditionally been done with instrumentation, which either requires contact/access to the structural element, performs deformation measurements in only one dimension, or both. In order to avoid the downsides of the commonly used instrumentation systems, this paper proposes the use of a remote sensing approach based on a three dimensional photogrammetric system. The proposed system is low-cost, consists of off-the-shelf components, and is capable of targetless reconstruction. Also, based on the given configuration and the implemented processing techniques, the system yields deformation measurements well below the submillimetre level.