A Low-Cost Photogrammetric System for Structural Deformation Monitoring

Abstract

Abstract:As a remote sensing technique, photogrammetry does not need access to objects beingmeasured. This can be a great advantage when it comes to deformation monitoring. Thispaper proposes a low-cost photogrammetric system for deformation monitoring ofstructural materials. The system design is based on a setup consisting of a projector andmultiple cameras, and it is using a pattern projection. The software necessary to performthe 3D object reconstruction includes modules dealing with epipolar resampling, featureextraction, matching and tracking, and 3D multiple light ray intersection. The systemwas tested by first fitting a point cloud reconstruction of a flat particle board to amathematical plane. Then, the same particle board was artificially deformed, and thenormal distances from the new point cloud reconstruction to the original fitted planewere calculated. The experiment proved that it was possible to detect sub-millimetrelevel deflections.