Sensing of low-frequency vibration using photogrammetric technique

This paper presents a flexible videogrammetric technique for structural dynamic measurement by commercial-grade digital cameras. It can capture structural three-dimensional (3D) dynamic trajectories at low-cost, to be used for some system identification problems. Some theorems from close-range photogrammetry and computer vision form the foundation of this measurement technique. In order to evaluate the applicability and reliability of the proposed method, three laboratory tests have been performed to characterize structural vibration. The results indicate that this method is capable of providing accepted accuracy for dynamic response measurement, and proved to be a good complement to traditional sensors especially in 3D vibration measurement.