Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals

Recognizing applied hand forces using force myography (FMG) biosignals requires adequate training data to facilitate physical human-robot interactions (pHRI). But in practice, data is often scarce, and labels are usually unavailable or time consuming to generate. Synthesizing FMG biosignals can be a...

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Main Authors: Umme Zakia, Arnab Barua, Xianta Jiang, Carlo Menon
Format: Article
Language:English
Published: IEEE 2022-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/9810260/
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author Umme Zakia
Arnab Barua
Xianta Jiang
Carlo Menon
author_facet Umme Zakia
Arnab Barua
Xianta Jiang
Carlo Menon
author_sort Umme Zakia
collection DOAJ
description Recognizing applied hand forces using force myography (FMG) biosignals requires adequate training data to facilitate physical human-robot interactions (pHRI). But in practice, data is often scarce, and labels are usually unavailable or time consuming to generate. Synthesizing FMG biosignals can be a viable solution. Therefore, in this paper, we propose for the first time a dual-phased algorithm based on semi-supervised adversarial learning utilizing fewer labeled real FMG data with generated unlabeled synthetic FMG data. We conducted a pilot study to test this algorithm in estimating applied forces during interactions with a Kuka robot in 1D-X, Y, Z directions. Initially, an unsupervised FMG-based deep convolutional generative adversarial network (FMG-DCGAN) model was employed to generate real-like synthetic FMG data. A variety of transformation functions were used to observe domain randomization for increasing data variability and for representing authentic physiological, environmental changes. Cosine similarity score and generated-to-input-data ratio were used as decision criteria minimizing the reality gap between real and synthetic data and helped avoid risks associated with wrong predictions. Finally, the FMG-DCGAN model was pretrained to generate pseudo-labels for unlabeled real and synthetic data, further retrained using all labeled and pseudo-labeled data and was termed as the self-trained FMG-DCGAN model. Lastly, this model was evaluated on unseen real test data and achieved accuracies of 85&#x0025;&#x003E;R<sup>2</sup> &#x003E; 77&#x0025; in force estimation compared to the corresponding supervised baseline model (89&#x0025;&#x003E;R<sup>2</sup> &#x003E; 78&#x0025;). Therefore, the proposed method can be more practical for use in FMG-based HRI, rehabilitation, and prosthetic control for daily, repetitive usage even with few labeled data.
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spelling doaj.art-5d659fd0656848c783e296ed636912982022-12-22T02:44:25ZengIEEEIEEE Access2169-35362022-01-0110699106992110.1109/ACCESS.2022.31871159810260Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography SignalsUmme Zakia0https://orcid.org/0000-0002-7313-3969Arnab Barua1Xianta Jiang2https://orcid.org/0000-0002-3219-1871Carlo Menon3https://orcid.org/0000-0002-2309-9977Menrva Research Group, School of Mechatronic Systems Engineering, Simon Fraser University, Burnaby, BC, CanadaDepartment of Computer Science, Memorial University of Newfoundland, St. John&#x2019;s, NL, CanadaDepartment of Computer Science, Memorial University of Newfoundland, St. John&#x2019;s, NL, CanadaMenrva Research Group, School of Mechatronic Systems Engineering, Simon Fraser University, Burnaby, BC, CanadaRecognizing applied hand forces using force myography (FMG) biosignals requires adequate training data to facilitate physical human-robot interactions (pHRI). But in practice, data is often scarce, and labels are usually unavailable or time consuming to generate. Synthesizing FMG biosignals can be a viable solution. Therefore, in this paper, we propose for the first time a dual-phased algorithm based on semi-supervised adversarial learning utilizing fewer labeled real FMG data with generated unlabeled synthetic FMG data. We conducted a pilot study to test this algorithm in estimating applied forces during interactions with a Kuka robot in 1D-X, Y, Z directions. Initially, an unsupervised FMG-based deep convolutional generative adversarial network (FMG-DCGAN) model was employed to generate real-like synthetic FMG data. A variety of transformation functions were used to observe domain randomization for increasing data variability and for representing authentic physiological, environmental changes. Cosine similarity score and generated-to-input-data ratio were used as decision criteria minimizing the reality gap between real and synthetic data and helped avoid risks associated with wrong predictions. Finally, the FMG-DCGAN model was pretrained to generate pseudo-labels for unlabeled real and synthetic data, further retrained using all labeled and pseudo-labeled data and was termed as the self-trained FMG-DCGAN model. Lastly, this model was evaluated on unseen real test data and achieved accuracies of 85&#x0025;&#x003E;R<sup>2</sup> &#x003E; 77&#x0025; in force estimation compared to the corresponding supervised baseline model (89&#x0025;&#x003E;R<sup>2</sup> &#x003E; 78&#x0025;). Therefore, the proposed method can be more practical for use in FMG-based HRI, rehabilitation, and prosthetic control for daily, repetitive usage even with few labeled data.https://ieeexplore.ieee.org/document/9810260/FMG signalapplied force estimationunsupervised learninggenerative adversarial networksdomain randomizationtransformation functions
spellingShingle Umme Zakia
Arnab Barua
Xianta Jiang
Carlo Menon
Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals
IEEE Access
FMG signal
applied force estimation
unsupervised learning
generative adversarial networks
domain randomization
transformation functions
title Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals
title_full Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals
title_fullStr Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals
title_full_unstemmed Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals
title_short Unsupervised, Semi-Supervised Interactive Force Estimations During pHRI via Generated Synthetic Force Myography Signals
title_sort unsupervised semi supervised interactive force estimations during phri via generated synthetic force myography signals
topic FMG signal
applied force estimation
unsupervised learning
generative adversarial networks
domain randomization
transformation functions
url https://ieeexplore.ieee.org/document/9810260/
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AT arnabbarua unsupervisedsemisupervisedinteractiveforceestimationsduringphriviageneratedsyntheticforcemyographysignals
AT xiantajiang unsupervisedsemisupervisedinteractiveforceestimationsduringphriviageneratedsyntheticforcemyographysignals
AT carlomenon unsupervisedsemisupervisedinteractiveforceestimationsduringphriviageneratedsyntheticforcemyographysignals