Energy-Efficient Technique for Engineering Structural Monitoring in the Dark

The research investigated the use of low-cost video cameras and low-voltage near-infrared emitter for night-time engineering structural monitoring. The aim of the investigation was to determine whether near-infrared video could be used for night-time continuous engineering structural monitoring. Engineering structural deformation monitoring trials were carried out using wooden, steel and concrete beams. Factory floor floodlights and near-infrared emitters were used to provide light for the video recording during the tests in total darkness. Multi-station photogrammetric image processing techniques were exploited to obtain accurate 3D models of the structural deformation. The results show that near-infrared video and colour video give similar 3D measurement accuracy of around 0.050 mm. Nevertheless, the near-infrared video technique is more suitable for night-time deformation monitoring as it requires less electric power to illuminate objects continuously in the dark.