Work

A hybrid admittance control strategy for fluid-driven origami actuators in lower limb exoskeleton

Year: 2026

Type: article

Abstract: This work presents a hybrid admittance control strategy for a lower limb exoskeleton powered by a fluid-driven origami-inspired artificial muscle (FOAM). The proposed approach combines the force-responsive characteristics of conventional admittance control with the adaptive learning capability of neural networks to assist humans during knee rehabilitation. Furthermore, surface electromyography (sEMG) signals are incorporated via fuzzy logic control to determine the appropriate level of assistive force, thereby promoting optimal muscle engagement throughout the recovery process. Experimental results clearly highlight the effectiveness of the proposed system, demonstrating its ability to handle variations in external load as well as changes in user exertion—challenges that are particularly critical when controlling exoskeletons actuated by highly nonlinear mechanisms. Performance evaluation further reports a root mean square error (RMSE) of 0.615 Nm under hybrid admittance control, indicating high stability and adaptability of assistive torque output in response to varying muscular effort. These findings highlight the potential of the proposed system to enhance user–robot interaction and broaden the applicability of exoskeletons in diverse rehabilitation scenarios.

Source: Robotics and Autonomous Systems

DOI: 10.1016/j.robot.2026.105416

Authors: Nonthaphat Prakongpak, Teeranoot Chanthasopeephan

Institution: King Mongkut's University of Technology Thonburi

Language: English

Topic: Prosthetics and Rehabilitation Robotics

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,140