Non-invasive calibration for volumetric flow measurements in confined spaces

Abstract

AbstractThe calibration of a multi-camera system is a crucial step of volumetric flow measurements with photogrammetric methods. Conventional calibration methods are based on recording hardware targets, which are placed in the cameras fields of view. Calibrating in confined spaces with those methods is associated with an increased technical or mechanical effort. This work presents a calibration method without the use of a hardware target. Instead, crossing laser beams are introduced into the volume for creating unique calibration points. The underlying algorithms discussed in this paper for detecting the laser beams are: Ransac algorithm, Template Matching (via cross correlation) and Probabilistic Hough Transformation. The algorithms are tested with experimental data and synthetic data.