A Novel Variable Stiffness Soft Robotic Gripper

TL;DR

This paper introduces a tri-fingered soft robotic gripper with independently controllable stiffness and shape, enabling adaptive grasping of various objects with improved performance demonstrated through experimental validation.

Contribution

The paper presents a novel soft robotic gripper with decoupled stiffness and shape control, enhancing adaptive grasping capabilities over existing designs.

Findings

The gripper can adapt to different object shapes and sizes.

Decoupled stiffness control improves grasp stability.

Experimental results validate the gripper's performance.

Abstract

We propose a novel tri-fingered soft robotic gripper with decoupled stiffness and shape control capability for performing adaptive grasping with minimum system complexity. The proposed soft fingers adaptively conform to object shapes facilitating the handling of objects of different types, shapes, and sizes. Each soft gripper finger has an inextensible articulable backbone and is actuated by pneumatic muscles. We derive a kinematic model of the gripper and use an empirical approach to map input pressures to stiffness and bending deformation of fingers. We use these mappings to achieve decoupled stiffness and shape control. We conduct tests to quantify the ability to hold objects as the gripper changes orientation, the ability to maintain the grasping status as the gripper moves, and the amount of force required to release the object from the gripped fingers, respectively. The results validate the proposed gripper's performance and show how stiffness control can improve the grasping quality.