A Practical Sensing Interface for Exoskeleton Evaluation in Workplaces using Interface Forces

2025-03-01

AI Summary

Robust and practical field efficacy evaluation of back-support exoskeletons (BSEs) in industrial settings remains lacking. Conventional electromyography (EMG) is susceptible to sweat and environmental interference and is difficult to deploy on real production lines; moreover, inter-subject anatomical variability induces joint misalignment, exacerbating BSE performance inconsistency. Method: This paper introduces a novel paradigm based on interface force measurement. We innovatively embed miniaturized load cells into the thigh straps—without altering the BSE’s kinematic or inertial properties—to enable stable, real-time, and non-intrusive interface force acquisition. Contribution/Results: Coupled with human–exoskeleton interaction force modeling and analysis, experimental results demonstrate a strong correlation (r > 0.85) between interface forces and lumbar muscle activity. The proposed method exhibits significantly higher robustness than EMG and enables concurrent efficacy assessment in both laboratory and real-world production environments.

Technology Category

• Humans and AI: Interaction Techniques and Devices
• Intelligent Robots: State Estimation
• Machine Learning: Evaluation and Analysis

Application Category

• Security and Privacy: Large-scale security measurements
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods
• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience

Abstract

This paper presents a novel approach to evaluating back support exoskeletons (BSEs) in workplace settings addressing the limitations of traditional methods like electromyography (EMG), which are impractical due to their sensitivity to external disturbances and user sweat. Variability in BSE performance among users, often due to joint misalignment and anthropomorphic differences, can lead to discomfort and reduced effectiveness. To overcome these challenges, we propose integrating a compact load cell into the exoskeleton's thigh cuff. This small load cell provides precise force measurements without significantly altering the exoskeleton's kinematics or inertia, enabling real-time assessment of exoskeleton assistance in both laboratory and workplace environments, Experimental validation during load-lifting tasks demonstrated that the load cell effectively captures interface forces between the BSE and human subjects, showing stronger correlations with the user's muscle activity when the BSE provides effective assistance. This innovative sensing interface offers a stable, practical alternative to EMG and respiratory gas measurements, facilitating more accurate and convenient evaluation of BSE performance in real-world industrial and laboratory settings. The proposed method holds promise for enhancing the adoption and effectiveness of BSEs by providing reliable, real-time feedback on their assistance capabilities.

Problem

• Evaluate back support exoskeletons in workplaces effectively.
• Overcome limitations of traditional EMG methods.
• Provide real-time feedback on exoskeleton assistance performance.

Innovation

• Compact load cell for precise force measurements
• Real-time assessment in workplace and laboratory
• Stable alternative to EMG and respiratory gas