Human-Exoskeleton Interaction Force Estimation Based on Quasi-Direct Drive Actuators

Seiler J, Schafer N, Zhao G, Latsch B, Grimmer M, Beckerle P, Kupnik M (2024)


Publication Language: English

Publication Type: Conference contribution

Publication year: 2024

Publisher: IEEE Computer Society

Series: Proceedings of the IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics

Pages Range: 1132-1139

Conference Proceedings Title: 2024 10th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob)

Event location: Heidelberg DE

ISBN: 9798350386523

DOI: 10.1109/BioRob60516.2024.10719722

Abstract

Exoskeletons have emerged as a promising tech-nological solution to provide functional compensation, training support, physical enhancement, and rehabilitation for an aging population. High torque density and control bandwidth are essential for exoskeleton actuation. In addition, monitoring and control of human-exoskeleton interaction forces is essential for the effectiveness, safety, and comfort of exoskeletons. Quasi-direct drives (QDD) have the potential to address the actuation requirements by enabling proprioceptive actuation with low mechanical output impedance. We present a test bench system to identify and validate the system dynamics, including torque constant, inertia, and friction properties of the QDD Cube-Mars AK10-9 V1.1. The actuator is employed in a hip exoskeleton to evaluate open-loop torque tracking and interaction force estimation in an assisted gait scenario with one participant walking on a treadmill. The model estimates interaction forces with a mean absolute error (MAE) of 2.78±0.58N (6.4% of rated force output). Model-based open-loop control improves the torque tracking MAE by 23%. Our analysis indicates that considering the soft coupling between human and exoskeleton has the potential to further improve the torque tracking and interaction force estimation accuracy. Altogether, the findings demonstrate that QDD actuation enables backdrivability, re-liable force estimation and controllable assistance, thereby providing an effective solution for exoskeleton actuation.

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APA:

Seiler, J., Schafer, N., Zhao, G., Latsch, B., Grimmer, M., Beckerle, P., & Kupnik, M. (2024). Human-Exoskeleton Interaction Force Estimation Based on Quasi-Direct Drive Actuators. In 2024 10th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob) (pp. 1132-1139). Heidelberg, DE: IEEE Computer Society.

MLA:

Seiler, Julian, et al. "Human-Exoskeleton Interaction Force Estimation Based on Quasi-Direct Drive Actuators." Proceedings of the 10th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics, BioRob 2024, Heidelberg IEEE Computer Society, 2024. 1132-1139.

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