Robust Control of a Multi-Axis Shape Memory Alloy-Driven Soft Manipulator

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Patterson, Zach J., Sabelhaus, Andrew P., Majidi, Carmel
Format: Preprint
Published: 2021
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917816695783424
author Patterson, Zach J.
Sabelhaus, Andrew P.
Majidi, Carmel
author_facet Patterson, Zach J.
Sabelhaus, Andrew P.
Majidi, Carmel
contents Control of soft robotic manipulators remains a challenge for designs with advanced capabilities and novel actuation. Two significant limitations are multi-axis, three-dimensional motion of soft bodies alongside actuator dynamics and constraints, both of which are present in shape-memory-alloy (SMA)-powered soft robots. This article addresses both concerns with a robust feedback control scheme, demonstrating state tracking control for a soft robot manipulator of this type. Our controller uses a static beam bending model to approximate the soft limb as an LTI system, alongside a singular-value-decomposition compensator approach to decouple the multi-axial motion and an anti-windup element for the actuator saturation. We prove stability and verify robustness of our controller, with robustness intended to account for the unmodeled dynamics. Our implementation is verified in hardware tests of a soft SMA-powered limb, showing low tracking error, with promising results for future multi-limbed robots.
format Preprint
id arxiv_https___arxiv_org_abs_2110_10022
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Robust Control of a Multi-Axis Shape Memory Alloy-Driven Soft Manipulator
Patterson, Zach J.
Sabelhaus, Andrew P.
Majidi, Carmel
Robotics
Control of soft robotic manipulators remains a challenge for designs with advanced capabilities and novel actuation. Two significant limitations are multi-axis, three-dimensional motion of soft bodies alongside actuator dynamics and constraints, both of which are present in shape-memory-alloy (SMA)-powered soft robots. This article addresses both concerns with a robust feedback control scheme, demonstrating state tracking control for a soft robot manipulator of this type. Our controller uses a static beam bending model to approximate the soft limb as an LTI system, alongside a singular-value-decomposition compensator approach to decouple the multi-axial motion and an anti-windup element for the actuator saturation. We prove stability and verify robustness of our controller, with robustness intended to account for the unmodeled dynamics. Our implementation is verified in hardware tests of a soft SMA-powered limb, showing low tracking error, with promising results for future multi-limbed robots.
title Robust Control of a Multi-Axis Shape Memory Alloy-Driven Soft Manipulator
topic Robotics
url https://arxiv.org/abs/2110.10022