Two Degree-of-Freedom Vibratory Transport in a Grasp

2026-05-28

AI Summary

This work achieves two-dimensional dexterous manipulation—specifically, in-plane translation and rotation about the normal axis—of objects held by a parallel-jaw gripper. By designing asymmetric stick-slip vibration waveforms and integrating closed-loop position control with adjustable gripping force, the study extends stick-slip actuation for the first time to two degrees of freedom. The research elucidates how accelerations during the stick and slip phases influence the object’s average translational velocity. Using high-resolution encoders, the authors experimentally validate that diverse objects exhibit motion trends in bidirectional translation and rotation that closely align with theoretical predictions, thereby demonstrating both the efficacy and generality of the proposed approach.

Abstract

In this paper, we use asymmetric vibrations to demonstrate two degree-of-freedom (DoF) in-hand manipulation of grasped parts. The asymmetric vibrations are achieved through closed-loop position control of a moving surface, which applies a periodic stick-slip waveform to the part to be manipulated. We show analytically how two vibratory waveform parameters, the sticking acceleration and the slipping acceleration, affect average part velocity when moving against gravity. The theoretical trends are then validated using an experimental setup where the squeeze force is controlled and part motion is recorded by a high-resolution encoder. We also develop a 2-DoF vibratory surface capable of translation in one direction and rotation about the surface normal. Using two of these 2-DoF surfaces in a parallel jaw gripper configuration, we bidirectionally translate and rotate a variety of grasped parts, as well as demonstrate that the same waveform trends for translation also persist for in-plane rotation.

Problem

• in-hand manipulation
• two degree-of-freedom
• vibratory transport
• grasped parts
• asymmetric vibrations

Innovation

• two degree-of-freedom manipulation
• asymmetric vibration
• stick-slip waveform
• in-hand manipulation
• vibratory transport