Abstract

Purpose Threedimensional (3D) as-built plant models are required for various purposes, such as plant operation, maintenance, and the expansion of existing facilities. The as-built plant model reconstruction process consists of as-built plant measurement and 3D plant model reconstruction. As-built plant measurement uses 3D laser scanning technology to efficiently acquire data. However, the current method used for 3D as-built plant model reconstruction from laserscanned data is still labor-intensive. The objective of this study is to develop a fully-automated parametric reconstruction of the as-built pipe-line occupying a large portion of the area in an as-built plant. Method The proposed approach consists of three main steps. The first step is to extract the cylindricallyformed pipelines from laser-scanned data based on random sampling consensus (RANSAC). The second step is to segment the extracted pipelines into pipe components, such as straight pipe, elbow, and branch tee, based on medial axis extraction and curve skeletonization. The last step is to surface-model reconstruct the segmented pipe-lines using the parametric modeling method. Results & Discussion The experiment was performed at an operating plant to validate the proposed method. The experimental results revealed that the proposed method could contribute to automation for 3D as-built plant model reconstruction.

Abstract

Purpose An inspection and maintenance system is essential to obtain a proper and stable construction. However, internal inspection and maintenance of the inner parts of pipeline are difficult to conduct. Force effects should be eliminated to accurately inspect the state of a pipeline. This paper suggests a self-growing mechanism (SGM) which focuses on a minimization of force effects compared to previous progress maintenance methods. Method SGM mimicks the motion of amoeba, a protozoan, as a growing unit. It is shaped like a reversed hose. The SGM represents gelation and isolation of the amoeba; the inside skin is fixed outside and fluid is injected. In this way contact force is minimized so as to be negligible. By passing through injected fluid, the SGM acts as a buffer. Nevertheless, there is a limit to the use of this instrument for maintenance due to the drift of the upper section of the growing unit. To overcome this and expand the field application, the SGM was equipped with auxiliary equipment called install-base, this is composed of three rings. Bundling several units was also considered. This can give SGM direction by differential fluid injection to each unit, and facilitates progress through the curved paths. Results & Discussion SGM allows only contact force on the surface, similar to amoeba movement. This can be described as the contact which occurs when a rolled surface unfolds. SGM can help in the maintenance process of highly hazardous or unreachable spots, such as nuclear power plants, pipelines, and so on. It is best suited for highly sensitive environments. SGM is also promising in combination with inspection and maintenance of constructions with field endoscopy; it can provide medical checkups or remedies innovatively. Moreover, it is expected that SGM, unlike previous methods, can more accurately carry out maintenance of gradually downsized applications.