A Continuum Robot With Programmable Tendon Routing for Desired Curve Generation

Abstract

Continuum robots are widely employed in confined environments with narrow passages and spatial constraints. However, achieving general curves with non-constant curvature remains challenging, as existing systems typically rely on multiple flexible segments arranged in series, coupled with complex drive systems requiring numerous actuators. This paper proposes a novel continuum robot design that features a programmable tendon routing capable of generating desired curves. The system integrates modular joints and a single-actuator drive unit, enabling the generation of spatial curves with non-constant curvature. By strategically designing the arrangement of modular joints to control rotational direction and angular deflection at each joint, the system achieves a substantially expanded design workspace compared to conventional continuum robots. Simulation and prototype experiments validate the proposed design methodology. The relative mean distance between simulated and desired curve remains below 3.12<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula>, while the prototype demonstrates a relative mean distance of 6.67<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> from the desired curve. This approach offers a promising pathway to advance continuum robot design by improving configurational adaptability while simultaneously achieving complex curve generation and reduced drive system complexity.