Proposal and Feasibility Evaluation of a Quasi-Static Omni-Directional Mobility Robot Using Multiple Elastic Telescopic Arms

Mobile robots capable of operating in environ- ments where human work is difficult, such as elevated locations or rough terrain, have been developed, including rough-terrain mobile robots capable of three-dimensional locomotion by fixing end of a tether to the environment and winching it in. However, such robots still face issues, for example, automation of tether end fixation and release. To address these issues, we consider Elastic Telescopic Arm (ETA) as an effective solution. In this paper, we propose a robot capable of three-dimensional movement using multiple ETAs. The proposed robot extends several ETAs mounted on its body, grips rigid environmental structures with grippers at their tips, and moves the body to arbitrary positions in three-dimensional space by controlling extension and contraction of the arms. To verify the feasibility of this principle, we conducted contraction experiments on the arm while under tensile load. Furthermore, to demonstrate the usefulness of the ETA in rough-terrain traversal, we performed a proof-of-concept experiment using a prototype equipped with a single ETA mounted on a four-wheeled mobile robot. The experiment confirmed that the use of the ETA enabled the robot to climb stairs that it could not climb on its own.