Measurement of Vibration Occurring at Multiple Frequencies Using Target-Less Photogrammetry and Phase-Based Motion Magnification

For the vibration measurement of a structure, contact-type sensors such as gap sensors are used, however, these sensors can add mass-loading to lightweight structures which can result in negative performance. Furthermore, vibrations in a structure caused by multiple factors need to be detected separately to recognize these factors one by one. To solve these problems, in this study, we introduced a target-less photogrammetric vibration measurement technique that measures the vibration by using subpixel-based edge detection and tracking method. Moreover, this technique separates the vibrations occurring in a structure caused by multiple factors by utilizing the phase-based motion magnification technique together with subpixel-based vibration measurement method applied to a video of vibrating structure. The results generated by the proposed method can be used to identify multiple deformations in a structure.