Design of Lightweight Modular Units for Tendon-Driven Continuum Robots in Industrial Applications

Abstract

Tendon-driven continuum robots (TDCRs) offer flexibility for maneuvering through confined spaces. However, this high flexibility leads to significant tip deflection due to the trade-off between stiffness and flexibility, particularly in long TDCRs, hindering precise movement. To address this, a novel unit design employing compliant mechanisms is introduced. Three distinct unit designs are proposed, offering modularity to tailor the TDCR's structure and showcase enhanced stiffness without compromising flexibility. To enable customization for various applications, the relationship between stiffness and unit dimensions is analyzed, resulting in a mathematical framework for modular unit parametrization. A structured workflow is provided to guide the development of TDCRs, from task objective definition to experimental validation. As a demonstration, a 3-segment TDCR with a total length of \SI{816}{\mm} was prototyped using this approach for aircraft wing inspection. The TDCR successfully inspected all target areas in a 1:3 scaled Cessna 172 wing model, yielding a 100% coverage rate.