QFoto: Automatic Inline Measurement System for Parabolic Trough Structures: Experiences and Development

Abstract

Digital close range photogrammetry has proven to be a precise and efficient measurement technique for the assessment of shape accuracies of solar concentrators and their components. The flexibility of photogrammetry to provide high accuracy 3d-coordinate measurements over almost any scale resulted in the development of the QFoto system for inline quality control of support structures in parabolic trough collector assembly lines before the mirror panels are attached. The paper gives an overview of the capabilities of the QFoto system, its layout and measurement adapters and a description of the employed in-situ camera calibration. Special attention is given to the internal quality control of the system and features like the statistical process control, and the evaluation of the angles of all mirror brackets within one single measurement using specific measurement adapters.