Thumbs up, thumbs down: non-verbal human-robot interaction through real-time EMG classification via inductive and supervised transductive transfer learning

Jhonatan Kobylarz, Jordan J. Bird*, Diego R. Faria, Eduardo Parente Ribeiro, Anikó Ekárt

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review


    In this study, we present a transfer learning method for gesture classification via an inductive and supervised transductive approach with an electromyographic dataset gathered via the Myo armband. A ternary gesture classification problem is presented by states of ’thumbs up’, ’thumbs down’, and ’relax’ in order to communicate in the affirmative or negative in a non-verbal fashion to a machine. Of the nine statistical learning paradigms benchmarked over 10-fold cross validation (with three methods of feature selection), an ensemble of Random Forest and Support Vector Machine through voting achieves the best score of 91.74% with a rule-based feature selection method. When new subjects are considered, this machine learning approach fails to generalise new data, and thus the processes of Inductive and Supervised Transductive Transfer Learning are introduced with a short calibration exercise (15 s). Failure of generalisation shows that 5 s of data per-class is the strongest for classification (versus one through seven seconds) with only an accuracy of 55%, but when a short 5 s per class calibration task is introduced via the suggested transfer method, a Random Forest can then classify unseen data from the calibrated subject at an accuracy of around 97%, outperforming the 83% accuracy boasted by the proprietary Myo system. Finally, a preliminary application is presented through social interaction with a humanoid Pepper robot, where the use of our approach and a most-common-class metaclassifier achieves 100% accuracy for all trials of a ‘20 Questions’ game.

    Original languageEnglish
    Pages (from-to)6021-6031
    Number of pages11
    JournalJournal of Ambient Intelligence and Humanized Computing
    Issue number12
    Early online date7 Mar 2020
    Publication statusPublished - Dec 2020

    Bibliographical note

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    • Electromyography
    • Gesture classification
    • Human-robot interaction
    • Inductive transfer learning
    • Machine learning
    • Myo armband
    • Pepper robot
    • Supervised transductive transfer Learning
    • Transfer learning


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