Close Range Photogrammetry for Direct Multiple Feature Positioning Measurement without Targets

Abstract

The main objective of this study is to present a new method to carry out measurements so as to improve the positioning verification step in the wind hub part dimensional validation process. This enhancement will speed up the measuring procedures for these types of parts. An industrial photogrammetry based system was applied to take advantage of its results, and new functions were added to existing capabilities. In addition to a new development based on photogrammetry modelling and image processing, a measuring procedure was defined based on optical and vision system considerations. A validation against a certified procedure by means of a laser-tracker has also been established obtaining deviations of ±0.125 μm/m.

Application of Optimal Ellipsoid Fitting for Curvature Change Tracking in Main Reflector of Complex Antenna Structures

“…Close-range photogrammetry is a technique for determining the 3D geometry (location, size, and shape) of physical objects by measuring and analyzing their 2D photographs obtained from the ground; it has been frequently applied to measure the displacement and deformation of facilities. (21)(22)(23)(24) The technological advances of close-range photogrammetry have matured to the point that they can now be implemented as measurement tools to obtain a detailed understanding of the mechanical deformations and full-field strain distribution of large scale composite structures. This technique is a noncontact measurement technique that uses images captured simultaneously by a pair of digital cameras to track prescribed targets placed on a structure.…”

Analysis and implementation of an artificial vision method for micropositioning based on a camera-screen system

“…Diversos autores han buscado enfoques distintos para conseguir optimizar la precisión y exactitud de la medición mediante visión artificial utilizando cámaras. Así, Bosemann [24] recoge, en su tiempo, losúltimos avances desarrollados para la medición mediante fotogrametría que otros autores más recientes han utilizado para nuevos procesos [25][26][27][28]. Desde los inicios de los desarrollos de correlación de imagen digital (DIC) estudiados por, entre otros, Sutton et al [29], una de las aplicaciones más avanzadas es la medida de los desplazamientos 3D utilizando imágenes 2D.…”