Wrapped Haptic Display for Communicating Physical Robot Learning

TL;DR

This paper introduces a soft haptic display wrapped around a robot arm to improve human-robot interaction by providing tangible feedback, enhancing the transparency of robot learning processes during physical collaboration.

Contribution

The work presents a novel soft haptic device that conforms to robot arms, enabling effective physical communication of robot uncertainty during learning tasks.

Findings

Users can accurately distinguish inflation levels of the haptic display.

Haptic feedback improves user understanding of robot training needs.

The device enhances human-robot collaboration in learning scenarios.

Abstract

Physical interaction between humans and robots can help robots learn to perform complex tasks. The robot arm gains information by observing how the human kinesthetically guides it throughout the task. While prior works focus on how the robot learns, it is equally important that this learning is transparent to the human teacher. Visual displays that show the robot's uncertainty can potentially communicate this information; however, we hypothesize that visual feedback mechanisms miss out on the physical connection between the human and robot. In this work we present a soft haptic display that wraps around and conforms to the surface of a robot arm, adding a haptic signal at an existing point of contact without significantly affecting the interaction. We demonstrate how soft actuation creates a salient haptic signal while still allowing flexibility in device mounting. Using a psychophysics experiment, we show that users can accurately distinguish inflation levels of the wrapped display with an average Weber fraction of 11.4%. When we place the wrapped display around the arm of a robotic manipulator, users are able to interpret and leverage the haptic signal in sample robot learning tasks, improving identification of areas where the robot needs more training and enabling the user to provide better demonstrations. See videos of our device and user studies here: https://youtu.be/tX-2Tqeb9Nw