Dynamic Modelling and Real-Time Fuzzy Hybrid Control of an HD-sEMG-Driven Elbow Exoskeleton Using Deep Learning-Based Intention Estimation

Document Type : Research Paper

Authors
Faculty of Science and Technology, University of Canberra, Canberra, ACT 2617, Australia
Abstract
An intelligent hybrid fuzzy control framework is proposed in this study to enable real-time tracking of elbow exoskeleton motion intention based on high-density surface electromyography (HD-sEMG) signals. The procedure involves the following steps: (I) elbow joint torque is estimated in real time using a deep convolutional-bidirectional long short-term memory (Conv-BiLSTM) regression network. (II) The estimated torque serves as the reference for a closed-loop system, where a Sugeno fuzzy inference engine adaptively tunes the parameters of three controllers: proportional–integral–derivative (PID), impedance, and sliding mode. Results show that the fuzzy impedance controller provides compliant and safe interaction, while fuzzy PID proves inadequate under realistic noise, exhibiting large oscillations and negative R2 values. The Conv-BiLSTM significantly improves torque estimation accuracy over traditional statistical methods, and fuzzy-adaptive control reduces tracking error by 50–60% compared to classic strategies. This hybrid deep-fuzzy approach offers strong potential for myoelectric exoskeletons in rehabilitation.
Keywords
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