Multi-DOF Blower-Powered and Inner Tendon-Driven Soft Inflatable Robotic Arm

Abstract

We propose a soft inflatable robotic arm as a type of inflatable robot that is light and can be made larger. This robotic arm is based on a soft inflatable joint, which is actuated by an internal tendon and constantly supplied with air by a blower. The tendon drive method was unknown, so it was difficult to make the arm articulated. To achieve multiple degrees of freedom, a guide was fabricated to prevent tendon interference and to guide the tendons. This guide was made of a thin plate so that the flexibility and light weight of the inflatable robot would not be compromised. Guide was provided at the joints to derive the relationship between joint angle and amount of wire pulling. It was used to maintain the relationship between the tendon wire intersections and the anchor points between the joints. The function of the guide was fully confirmed through motion experiments on a robot arm using these guides. Based on this, a robot arm over 1-meter long was created, and it was verified that various postures were possible. These results will contribute to expanding the design space for low-pressure, large inflatable robots.