DeltaHands: A Synergistic Dexterous Hand Framework Based on Delta Robots

Dexterous robotic manipulation in unstructured environments can aid in everyday tasks such as cleaning and caretaking. Anthropomorphic robotic hands are highly dexterous and theoretically well-suited for working in human domains, but their complex designs and dynamics often make them difficult to control. By contrast, parallel-jaw grippers are easy to control and are used extensively in industrial applications, but they lack the dexterity for various kinds of grasps and in-hand manipulations. In this work, we present DeltaHands, a synergistic dexterous hand framework with Delta robots. The DeltaHands are soft, easy to reconfigure, simple to manufacture with low-cost off-the-shelf materials, and possess high degrees of freedom that can be easily controlled. By leveraging hand synergies, DeltaHands’ dexterity can be adjusted for different applications with further reduced control complexity. We characterize the Delta robots' kinematics accuracy, force profiles, and workspace range to assist with hand design. Finally, we evaluate the versatility of DeltaHands by grasping a diverse set of objects and by using teleoperation to complete three dexterous manipulation tasks: cloth folding, cap opening, and cable arrangement.

I. Introduction

As Robots advance closer to assisting humans at home, the design of their end-effectors becomes crucial in ensuring safety and functionality for complex household manipulation tasks. While parallel jaw grippers are widely used for industrial tasks due to their simple one degree of freedom (DoF) control, many household tasks require hands that are dexterous and can safely adapt to various objects. Anthropomorphic robotic hands [1], [2], [3] possess dexterous fingers capable of accomplishing complex in-hand manipulation tasks; however, they tend to be difficult to control, bulky, and costly to manufacture. We aim to introduce a framework for developing hands that are easy to configure, build, and control for dexterous manipulation.