This article provides an overview of existing structural solutions for in-line robots designed for inspection work. The main attention is paid to the analysis of various motion mechanisms and chassis types used in such robots, as well as to the identification of their advantages and disadvantages in relation to the task of scanning a longitudinal weld. Such types of robots as tracked, wheeled, helical and those that move under the influence of pressure inside the pipe are considered. Special attention is paid to the problem of ensuring stable and accurate movement of the robot along the weld, minimizing lateral displacements and choosing the optimal positioning system. Based on the analysis, recommendations are offered for choosing the most appropriate type of motion and chassis to perform the task of constructing a 3D model of a weld using a laser triangulation sensor (hereinafter referred to as LTD).
Keywords: in-line work, inspection work, 3D scanning, welds, structural solutions, types of movement, chassis, crawler robots, wheeled robots, screw robots, longitudinal welds, laser triangulation sensor