Medidas de deslocamento em 2D e 3D utilizando câmera digital como sensor sem contato

Abstract

The use of sensors with no contact have a wide range of applications in various fields of knowledge. Image sensors such as digital cameras, have been widely used for this kind of applications due to its high adaptability. Thus, this work proposes the use of digital cameras as contactless sensor, for analysis in two (2D) and three dimensions (3D). 2D measurement were performed, knowing the background length of the image, in order to evaluate the pixel size in the plan studied and so it was possible to calculate the displacements of the highlighted points. On the other hand, the 3D measurements was used concepts of stereoscopic images, epipolar geometry and triangulation of points in different images of the same scene, so it has become possible to determine the position of predefined points in three dimensional space. For the separation of the targets in the image, it was used image processing methods such as thresholding, erosion and dilatation. The experiment performed in two dimensions was a modal analysis using the output-only data with the use of a camera which has high acquisition rate, the results were compared with a numerical analysis, as well as analysis done with accelerometers of known input and also based only in the output. Otherwise in three dimensions, two cameras were used to recognize the same movements made by a tool controlled by computer (CNC). The results were consistent, and bring great possibilities for using the methodologies proposed.