Ground mobile mechanism with a multi-loop reconfigurable trunk

Abstract

In confined spaces, conventional ground mobile robots may be unable to reach the target location because of limited maneuvering space or the inability to overcome obstacles. This study presents a ground mobile mechanism with a multi-loop reconfigurable trunk (GMMRT) designed to enhance mobility in constrained spaces, such as narrow gaps, ditches, and cross-shaped channels. GMMRT can effectively overcome obstacles in confined spaces through the coordinated motion of its wheels and reconfigurable trunk. Its reconfigurable trunk comprises six limbs and four vertex platforms, forming a versatile, adaptable structure. GMMRT supports two topological structures: wheeled mobility and overall rolling. It features three distinct motion modes: (i) adjusting external dimensions, (ii) performing zero-radius steering, and (iii) overall deformation rolling motion. The kinematic model of GMMRT is established, and its parameters are described using Denavit–Hartenberg parameters. The degrees of freedom under the two topological structures are analyzed on the basis of screw theory. Torque analysis of servo motors is conducted through dynamic analysis. An experimental prototype is designed to validate the three motion modes and servo motor selection, and relevant experiments are performed. Through the development and experimental validation of GMMRT, this work advances mobile robot design for confined spaces and provides a promising approach to overcome the limitations of conventional ground robots.

Graphical abstract

Keywords

confined space / ground mobile mechanism / reconfigurable trunk / multi-loop mechanism / multi-mode / dynamic analysis

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