A Multi-Axis FBG-Based Tactile Sensor for Gripping in Space
Samuel Frishman, Julia Di, Zulekha Karachiwalla, Richard J. Black, Kian Moslehi, Trey Smith, Brian Coltin, Bijan Moslehi
Abstract
Tactile sensing can improve end-effector control and grasp quality, especially for free-flying robots where target approach and alignment present particular challenges. However, many current tactile sensing technologies are not suitable for the harsh environment of space. We present a tactile sensor that measures normal and biaxial shear strains in the pads of a gripper using a single optical fiber with Bragg grating (FBG) sensors. Compared to conventional wired solutions, the encapsulated optical fibers are immune to electromagnetic interference — critical in the harsh environment of space. Sampling is possible at over 1 kHz to detect dynamic events. We mount sensor pads on a custom two-fingered gripper with independent control of the distal and proximal phalanges, allowing for grip readjustment based on sensing data. Calibrated sensor data for forces match those from a commercial multiaxial load cell with an average 96.2% RMS for all taxels. We demonstrate the gripper on tasks motivated by the Astrobee free-flying robots in the International Space Station (ISS): gripping corners, detecting misaligned grasps, and improving load sharing over the contact areas in pinch grasps.
BibTeX
@inproceedings{iros2021_amultiaxisfbgbas,
title = {A Multi-Axis FBG-Based Tactile Sensor for Gripping in Space},
author = {Samuel Frishman and Julia Di and Zulekha Karachiwalla and Richard J. Black and Kian Moslehi and Trey Smith and Brian Coltin and Bijan Moslehi and Mark R. Cutkosky},
booktitle = {IROS 2021},
year = {2021}
}