An experimental comparison of four different structures for continuum manipulators

Abstract

Continuum manipulators can exhibit behaviors similar to snakes, elephant's trunks, and octopus tentacles, which possess incredible dexterity and intrinsic compliance for safe interaction with unstructured environments. However, the lack of enough stiffness limits their scope and application. In this paper, we introduce four different structures of continuum manipulators, including a simple structure with three elastic actuated rods, a structure with a passive rigid kinematic chain, a structure with a hyperelastic notochord and a segmental structure inspired from the spine without articular structure. This paper presents an experimental comparison of four continuum manipulators and aims to explore approaches to enhance the stiffness of a continuum manipulator and maintain the simple constant curvature kinematics as far as possible simultaneously. Results of this paper contribute to guiding the design of a continuum manipulator for achieving desired stiffness properties.