Development of 3D camera-based robust bolt-hole detection system for bolting cabin

At high-rise building construction sites, construction workers still climb dangerous vertical steel beams. Hence, the bolting cabin helps construction workers to assemble bolts safely. In order to automatically assemble bolts to steel frame, the bolting cabin must estimate bolt-hole location. To do this, precise bolt-hole detection algorithms are important. Generally, a 2D camera is used for visual servoing in industrial fields. However, a construction site is an outdoor environment that does not have constant illumination. Recently, a 3D camera that provides depth images has been used in industrial fields. However, this 3D camera provides a low resolution image with strong noise around the edges. To overcome these problems, an edge detection filter that is robust to strong noise is needed for precise bolt-hole detection. Therefore, we propose a Modified Discrete Gaussian-Hermite Moments (MDGHM) filter based on moment information to detect edges precisely. Using the MDGHM filter, the results show that the proposed method can be effectively applied to bolt-hole detection better than wavelet filter and mixed matching method.