Design Methodology of Hydraulically-driven Soft Robotic Gripper for a Large and Heavy Object

TL;DR

This paper introduces a hydraulic soft robotic gripper capable of grasping large, heavy objects by developing a design methodology based on mathematical modeling and finite element analysis, with experimental validation.

Contribution

It presents a novel hydraulic actuation design methodology for soft robotic grippers targeting heavy object grasping, including modeling, material selection, and experimental validation.

Findings

Successfully grasped a 20 kg object.

Demonstrated effective closed-loop control of finger bending.

Validated design approach through experimental results.

Abstract

This paper presents a design methodology of a hydraulically-driven soft robotic gripper for grasping a large and heavy object -- approximately 10 - 20 kg with 20 - 30 cm diameter. Most existing soft grippers are pneumatically actuated with several hundred kPa pressure, and cannot generate output force sufficient for such a large and heavy object. Instead of pneumatic actuation, hydraulic actuation has a potential to generate much larger power by several MPa pressure. In this study, we develop a hydraulically-driven soft gripper, in which its basic design parameters are determined based on a mathematical model that represents the relationship among the driving pressure, bending angle, object mass and grasping force. Moreover, we selected materials suitable for grasping a heavier object, based on the finite element analysis result of the detailed design. We report experimental results on a 20 kg object grasping and closed-loop control of the finger bending angle.