An Extendable Continuum Robot Arm to Deal with a Confined Space Having Discontinuous Contact Area

Abstract

This paper proposes a concept for constructing a flexible extendable arm by feeding a number of intermediate moving plates along a flexible feed screw and deploying each of them at a certain contactable area. The mechanism is aiming to bear a practical working load to support human’s labor by utilizing a bracing on surrounding walls. Generally, a narrow and confined workspace which human worker’s arms can hardly reach does not provide a continuum and smooth wall surface and is composed of many discontinuous areas instead. Therefore, the mechanism deploys each intermediate plate at a target contactable area, and pushes rest of the plates forward. In order to bend the arm according to the workspace, tendon-driving technique is employed. In this paper, a basic composition of the arm is explained and a simple geometric calculation scheme to obtain a configuration of the arm to avoid insufficient condition is proposed. Finally, several experiments with a prototype setup are performed to demonstrate the feasibility of the proposed concept.