Analysis and Dimensional Synthesis of a Robotic Hand Based on the Stewart-Gough Platform

In this paper, we study the dimensional synthesis of a Stewart-Gough platform-inspired dexterous robotic hand, seeking to optimize the hand’s geometric design parameters to achieve the largest possible 6-degree-of-freedom workspace of a grasped object serving in the place of the “platform.” We present an analysis of the hand mechanism that considers both object stability from frictional contact forces as well as kinematic motion transmissibility, seeking a balance between these two properties. We examine the effect of variations in the kinematic and frictional parameters on both the workspace size of the hand as well as on the motion quality throughout the workspace across a range of grasped object sizes. We then present a spectrum of optimal designs that weight these two performance criteria differently. Most notably, the palm radius of the hand was found to have the greatest effect on the workspace size, with smaller palms exhibiting significantly larger workspaces. Overall, this work serves to inform the design process for dexterous robotic hands based on this common kinematic configuration, with the ultimate goal of increasing the dexterity of robotic manipulators to facilitate more versatile interactions with the environment.