Parallel robots for autonomous climbing along tubular structures

This paper proposes the application of the Gough-Stewart (G-S) platform as a climbing robot. The idea of using the parallel G-S platform as a climbing robot is a novel solution to carry out tasks that imply a high risk for workers who have to climb on tubular structures. Some mechanical adaptations allow to convert the G-S platform in an autonomous and teleoperated robot capable to move autonomously along tubular structures (posts, steel wires of bridges, trunks of palms, pipes, etc.) or inside of fluid conducting pipes. To show the capacity of using this G-S platform as climbing robot we propose several mechanical designs capable of climbing through these tubular structures. Taking into account these designs and their functionality, we study the dynamics of some different configurations of these robots. In the second part of the paper we present a first prototype used as a climbing robot, developed to climb on palm trunks. Technical specifications of the system are presented and the control scheme is analyzed. Finally several experiments show the capability of this parallel robot to climb on tubular structures. (C) 2002 Elsevier Science B.V. All rights reserved.