3D vibrations reconstruction with only one camera

Franck Renaud (1, 2, 3, 4, 5) , Stefania Lo Feudo (1, 3) , Jean-Luc Dion (1, 3) , Adrien Goeller (1, 3)

1 SUPMECA - SUPMECA - Institut supérieur de mécanique de Paris
2 LISMMA - Laboratoire d'Ingénierie des Systèmes Mécaniques et des MAtériaux
3 QUARTZ - Laboratoire QUARTZ
4 ISAE-Supméca - ISAE-Supméca Institut Supérieur de Mécanique de Paris
5 QUARTZ - Laboratoire QUARTZ

In this paper, we propose a new method to measure the vibrations of a 3D mechanical structure. It requires only a video sequence taken by a single camera and a Finite Element model of the structure. First, the intrinsic and extrinsic parameters of the camera are identified. Then, a collection of numerical deflection shapes and normal modes are projected in the image frame of the camera. This is done thanks to a linearization of the perspective projection model. Comparing the motion of targets seen by the camera and the motion of Finite Element model at the same location gives the time evolution of modes amplitude. Finally the motion of the model is reconstructed in 2D in the image frame and in 3D in the world frame. By following this procedure, vibration amplitude can be magnified applying a scale factor on a modal basis covering a large frequency bandwidth. A video graphical abstract can be found on youtube, see [1]. This paper is the preprint of the MSSP article that can be found at https://doi.org/10.1016/j.ymssp.2021.108032

Domaines: Vibrations [physics.class-ph]; Traitement du signal et de l'image [eess.SP]; Vision par ordinateur et reconnaissance de formes [cs.CV]

Franck Renaud, Stefania Lo Feudo, Jean-Luc Dion, Adrien Goeller. 3D vibrations reconstruction with only one camera. Mechanical Systems and Signal Processing, 2022, 162, pp.108032. ⟨10.1016/j.ymssp.2021.108032⟩. ⟨hal-03007332⟩