Experimental investigation of reinforcement inspection using point clouds generated from camera videos attached to a rebar tying machine

Abstract

The efficiency of reinforcement confirmation in reinforced concrete structures was aimed to be enhanced by verifying the effectiveness of a camera attached to a rebar tying machine that automatically moves along the slab-shaped reinforcement and captures videos. The obtained rebar model from the point cloud generated through Structure-from-Motion (SfM) and Multi-View Stereo (MVS) was utilized for confirmation tasks such as checking the spacing of reinforcement. Since the machine can move regularly on the slab, capturing videos from multiple perspectives, it efficiently acquired point clouds of the lower-level rein-forcement behind the upper-level rebar and the point cloud of the stirrups arranged vertically. Additionally, using the generated cylindrical rebar model from the obtained point cloud, it was possible to measure the spacing between all the reinforcements within the target range of the structure.