A three-dimensional range camera is a state-of-the-art imaging technology that has strong potential for various closerange high-precision measurement applications. One such application is the measurement of structural deformation under external loading conditions. Deformation tests have been conducted on two concrete beams with and without steel-reinforced polymer sheets in an indoor testing facility using an SR4000 range camera. The achieved measurement precision and accuracy were both within 1 mm when compared with a terrestrial laser scanner. Further testing on the concrete beam with the steel-reinforced polymer sheets has shown that a deformation as small as 3 mm can be reliably detected with a range camera with a measurement precision of 0.3 mm and an accuracy of 0.4 mm. These results clearly indicate the high metric potential of 3D range cameras in spite of their coarse imaging resolution and low (centimeterlevel) single point accuracy. The high accuracy can be achieved thanks to the differencing scheme used to derive the deflection estimates from two sets of range camera measurements, one at no-load and one of the beam in a loaded state, which eliminates the scene-dependent range biases such as scattering and multi-path errors.

Date Published: 21 June 2011
PDF: 8 pages
Proc. SPIE 8085, Videometrics, Range Imaging, and Applications XI, 80850K (21 June 2011); doi: 10.1117/12.889191

Published in SPIE Proceedings Vol. 8085:
Videometrics, Range Imaging, and Applications XI
Fabio Remondino; Mark R. Shortis, Editor(s)