Real-time rebar spacing measurement system for quality control in construction

Construction supervision is essential for ensuring structural safety but requires significant labor and expertise. This paper developed a 3D point cloud - RGB projection algorithm to integrate RGB and point cloud data from a depth camera, offering a lightweight and efficient solution for real-time measurements in dynamic construction sites. A real-time rebar spacing measurement system (RSMS) was developed, comprising a portable hardware setup with a depth camera and tablet, and software that overlays depth information as point clouds onto RGB images. The RSMS was tested to evaluate factors influencing measurement accuracy, including distance, angle, and rebar diameter, with results showing improved accuracy at shorter distances and for larger diameters. Laboratory and field validations addressed environmental limitations, such as uneven lighting and partial obstructions, and proposed guidelines to optimize measurement practices. These findings provide practical insights for enhancing rebar spacing measurements in construction scenarios.