Postural Virtual Fixtures for Ergonomic Physical Interactions with Supernumerary Robotic Bodies

2026-01-30

AI Summary

This study addresses the risk of musculoskeletal discomfort or injury arising from non-ergonomic postures adopted by users during physical interaction with supernumerary robotic bodies (SRBs). To mitigate this issue, the authors propose a virtual fixture control framework that integrates real-time ergonomic assessment. The system provides haptic feedback to actively discourage harmful postures while dynamically repositioning the robot’s floating base to enhance human–robot collaboration. This approach represents the first integration of virtual fixtures with online ergonomic evaluation, simultaneously promoting proper user behavior and optimizing the robot’s base motion strategy. The effectiveness and practicality of the framework were validated through two loco-manipulation tasks involving 14 human participants, demonstrating its capacity to foster ergonomically sound interactions.

Technology Category

• Intelligent Robots: Manipulation
• Humans and AI: Interaction Techniques and Devices
• Computer Vision: Low Level & Physics-based Vision

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Search and Retrieval-Augmented AI: Web learning to rank, online learning, and counterfactual learning for ranking
• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience

Abstract

Conjoined collaborative robots, functioning as supernumerary robotic bodies (SRBs), can enhance human load tolerance abilities. However, in tasks involving physical interaction with humans, users may still adopt awkward, non-ergonomic postures, which can lead to discomfort or injury over time. In this paper, we propose a novel control framework that provides kinesthetic feedback to SRB users when a non-ergonomic posture is detected, offering resistance to discourage such behaviors. This approach aims to foster long-term learning of ergonomic habits and promote proper posture during physical interactions. To achieve this, a virtual fixture method is developed, integrated with a continuous, online ergonomic posture assessment framework. Additionally, to improve coordination between the operator and the SRB, which consists of a robotic arm mounted on a floating base, the position of the floating base is adjusted as needed. Experimental results demonstrate the functionality and efficacy of the ergonomics-driven control framework, including two user studies involving practical loco-manipulation tasks with 14 subjects, comparing the proposed framework with a baseline control framework that does not account for human ergonomics.

Problem

• supernumerary robotic bodies
• ergonomic posture
• physical human-robot interaction
• non-ergonomic postures
• human-robot collaboration

Innovation

• Postural Virtual Fixtures
• Supernumerary Robotic Bodies
• Ergonomic Posture Assessment
• Kinesthetic Feedback
• Human-Robot Collaboration