Designing Underactuated Graspers with Dynamically Variable Geometry Using Potential Energy Map Based Analysis

Abstract

This paper introduces an extension to the energy map method for in-hand manipulation. Energy maps are used to predict how a part will evolve in the grasp given a specific actuation input to the gripper. Previous approaches assumed frictionless contacts, but we show analytically that friction can be included in the energy maps when using two-link underactuated fingers by understanding the evolution of the part-finger contact. These friction-based energy maps were used to evaluate the importance of various tendon-pulley gripper parameters across nearly 6 million simulated grasping scenarios. Specifically, a variable palm width is needed to manipulate parts of varying scales, and a variable transmission ratio, or the ratio of the distal to the proximal pulley radii, is needed to draw parts into a cage or to maintain a tip prehension grasp.

arXiv commentThis is an updated version of my original paper (with the same title) published in IROS 2022. Parts of this work were refined or corrected in Chapter 3 of my dissertation, Good Vibrations: Toward Vibration-Based Robotic In-Hand Manipulation (DOI: 10.25740/mm182vq8220), and many of those changes have been incorporated here