Auxetic and Holonomic Mobile Robot for Enhanced Navigation in Constrained Terrains

Abstract

ABSTRACT Mobile robots, also known as field robots, perform various tasks practically and effectively on behalf of humans, particularly in inaccessible and/or hazardous environments. In recent years, as the underlying technology has matured remarkably, from hardware to algorithms, the applicability and specialization of mobile robots have gradually expanded. However, robots still present a poor workspace when facing terrains narrower than their size. To address this drawback, we propose a novel mobile robot specialized for operating on narrow terrains, which we call a negative Poisson's ratio robot. Its features include an auxetic body and holonomic locomotion. An auxetic body is a structure based on the theory of a negative Poisson's ratio, in which the lateral width of the robot body decreases as the longitudinal length decreases. This structure enables collision‐free deformation during contraction. The deformability ratio of the auxetic body was 5.13% for the longitudinal length and 30.63% for the lateral width. Holonomic locomotion enables a robot to drive omnidirectionally, and allows the robot to be controlled with a simple, direct, and single command without path planning. This was implemented using Mecanum wheels. To substantiate the efficacy of a robot with a negative Poisson's ratio, we conducted maneuverability experiments including various narrow terrains and path shapes. The proposed robot achieved sufficient maneuverability performance, even in narrow terrains, and outperformed other same‐sized robots. Supporting materials, such as experimental videos, can be accessed on the following website: http://irobot.kumoh.ac.kr/Size-Adjustable-Mobile-Robot .