Repository logo
 

Closing the Control Loop with Time-Variant Embedded Soft Sensors and Recurrent Neural Networks

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

George Thuruthel, Thomas  ORCID logo  https://orcid.org/0000-0003-0571-1672
Gardner, Paul 

Abstract

Embedded soft sensors can significantly impact the design and control of soft-bodied robots. Al-though, there have been considerable advances in technology behind these novel sensing materials, their application in real-world tasks, especially in closed-loop control tasks have been severely limited. This is mainly because of the challenge involved with modelling a nonlinear time-variant sensor embedded in a complex soft-bodied system. This paper presents a learning-based approach for closed-loop force control with embedded soft sensors and recurrent neural networks. We present learning protocols for training a class of recurrent neural networks called long-short term memory (LSTMs) that allows us to develop accurate and robust state estimation models of these complex dynamical systems within a short period of time. Using this model, we develop a simple feedback force controller for a soft anthropomorphic finger even with significant drift and hysteresis in our feedback signal. Simulation and experimental studies are conducted to analyze the capabilities and generalizability of the control architecture. Experimentally, we are able to develop a closed-loop controller with a control frequency of25Hz and an average accuracy of 0.17 N. Our results indicate that current soft sensing technologies can already be employed in real-world applications with the aid of machine learning techniques and an appropriate training methodology

Description

Keywords

closed-loop control, force control, machine learning, recurrent neural networks, soft sensors, Neural Networks, Computer, Computer Simulation, Machine Learning, Feedback, Memory, Long-Term

Journal Title

Soft Robotics

Conference Name

Journal ISSN

2169-5172
2169-5180

Volume Title

Publisher

Mary Ann Liebert
Sponsorship
European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (828818)

Version History

Now showing 1 - 2 of 2
VersionDateSummary
2023-10-12 13:35:42
Published version added
1*
2022-01-12 00:30:21
* Selected version