Graspar: a flexible, easily controllable robotic hand

TLDR

The Graspar robotic hand achieves secure grasping of diverse objects with only one motor per finger and a simple mechanical structure, minimizing computation. The study presents the mechanical structure and antagonistic tendoning system of the Graspar robotic hand. The hand’s mechanism uses an antagonistic tendoning system with pulley diameters optimized for maximal finger workspace and collision avoidance, and a control algorithm based on simple mechanical switches to enable compliant motion.

Abstract

With only one motor per finger and a simple, easy to maintain, mechanical structure, the Graspar robotic hand uses minimal computation to provide secure grasping of objects ranging from eggs and light bulbs to tennis rackets, coffee pots and stuffed toys. We first discuss currently developed hands, and show the motivation for our work. Next, we present the mechanical structure of our robotic hand and the antagonistic tendoning system. We then show how this structure moves and complies to the object surface. We discuss how we chose the pulley diameters for our tendoning system by maximizing the workspace of the fingers while mechanically insuring that the hand cannot collide with itself. Our control algorithm which uses simple mechanical switches is presented.