Towards an objective evaluation of underactuated gripper designs

TL;DR

This study evaluates various underactuated gripper designs on a large set of grasping tasks, revealing that simpler two-fingered designs often outperform more complex multi-fingered hands in generic, unplanned grasping scenarios.

Contribution

It provides the first comprehensive objective comparison of different underactuated hand designs under realistic grasping conditions.

Findings

Two-fingered underactuated hands outperform multi-fingered designs.

Achieved up to 75% success rate in grasping tasks.

Performance varies with object shape, pose, and orientation.

Abstract

In this paper we explore state-of-the-art underactuated, compliant robot gripper designs through looking at their performance on a generic grasping task. Starting from a state of the art open gripper design, we propose design modifications,and importantly, evaluate all designs on a grasping experiment involving a selection of objects resulting in 3600 object-gripper interactions. Interested in non-planned grasping but rather on a design's generic performance, we explore the influence of object shape, pose and orientation relative to the gripper and its finger number and configuration. Using open-loop grasps we achieved up to 75% success rate over our trials. The results indicate and support that under motion constraints and uncertainties and without involving grasp planning, a 2-fingered underactuated compliant hand outperforms higher multi-fingered configurations. To our knowledge this is the first extended objective comparison of various multi-fingered underactuated hand designs under generic grasping conditions.