Design and Control of Concentric-Tube Robots

TLDR

A novel approach toward construction of robots is based on a concentric combination of precurved elastic tubes. This paper demonstrates the potential of this technology. The robot uses concentric precurved elastic tubes whose rotation and extension interact elastically to shape the tip and body, with the tubes serving as both links and joints, and a general kinematic model incorporating bending and torsion is derived and used for real‑time position control. The resulting slender, elastically‑shaped robot is well suited for minimally invasive medical procedures, and real‑time position control was experimentally demonstrated using the derived kinematic model.

Abstract

A novel approach toward construction of robots is based on a concentric combination of precurved elastic tubes. By rotation and extension of the tubes with respect to each other, their curvatures interact elastically to position and orient the robot's tip, as well as to control the robot's shape along its length. In this approach, the flexible tubes comprise both the links and the joints of the robot. Since the actuators attach to the tubes at their proximal ends, the robot itself forms a slender curve that is well suited for minimally invasive medical procedures. This paper demonstrates the potential of this technology. Design principles are presented and a general kinematic model incorporating tube bending and torsion is derived. Experimental demonstration of real-time position control using this model is also described.