Planar Cable-Driven Manipulators for Inspection of Large Surfaces

Cable-Driven Parallel Manipulators (CDPM) are a type of parallel robots in which the rigid links connecting the base with the terminal link, also called end-effector, are replaced by cables. This kind of system has been introduced during the last two decades, since then many issues have been addressed, but there are still open problems. Thanks to the nature of the cables, lightweight if compared to the overall structure, and the very large workplace, their possible applications are increasing. Recently, Robotics and Automation have been applied to the inspection of structures and infrastructure; therefore, they are starting to be used to substitute personnel in dangerous or unsafe operations. Related to the inspection, autonomous or tele-operated systems can be used for securing the access to the buildings or infrastructure. In this paper, we propose the application of CDPMs for the inspection of large surfaces, constituted by buildings facades, top roofs, and parts of infrastructures. The development of suitable model of the system, also called Digital Twin, allows the managing of the operation in safe conditions. As new application, we propose the use of a planar CDPM for being applied to the inspection and monitoring. The 3D model acts as a Digital Twin of the real prototype that has been developed and used for experimental testing. Since the purpose is to drive the end-effector to point of interest carrying suitable sensors, tests for trajectory planning and experimental tests are proposed. The inspection of structures and infrastructures has become a very important issue for the security of critical infrastructures, not only at European level but worldwide.