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The Swing Control of Knee Exoskeleton Based on Admittance Model and Nonlinear Oscillator


It is important to control exoskeleton to act synchronously with the user for movement assistance. A knee exoskeleton was constructed for gait rehabilitation training, and a control method based on adaptive frequency oscillator (AFO) was presented for swing motion of knee exoskeleton. Firstly, during the learning mode, the user flexed and extended with the exoskeleton leg together, and the exoskeleton leg was not actuated. The phase of the exoskeleton angle extracted, and the envelope curve of the user’s EMG is generated based on AFO. Then, during power-assisted mode, the assistive torque is generated according to the angle phase on-line and the restructuring muscle torque. At last, the assistive torque as a feedback signal was input to the admittance model for the swing control of the knee exoskeleton. The experiments of swing control showed that knee exoskeleton can follow the user’s motion well.

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  1. Yan, T., Cempini, M., Oddo, C.M., Vitiello, N.: Review of assistive strategies in powered lower-limb orthoses and exoskeletons, Robotics and Autonomous System. (2014)

  2. Bogue, R.: Exoskeletons and robotic prosthetics: a review of recent developments[J]. Ind Robot. 36(5), 421–427 (2009)

    Article  Google Scholar 

  3. Jiménez-Fabián, R., Verlinden, O.: Review of control algorithms for robotic ankle systems in lower-limb orthoses, prostheses, and exoskeletons[J]. Med Eng Phys. 1–12 (2011)

  4. Quinlivan, B., Asbeck, A., Wagner, D., et al.: Force transfer characterization of a soft exsuitfor gait assistance, Proceedings of the ASME 2015 international design engineering technical conferences & computers and information in engineering conference, 1–7 (2015)

  5. Ding, Y., Galiana, I., Asbeck, A.T., et al.: Biomechanical and Physiological Evaluation of Multi-Joint Assistance with Soft Exosuits, IEEE transactions on neural systems and rehabilitation engineering, (2016).

  6. Griffin, W.B., Provancher, W.R., Cutkosky, M.R.: Feedback strategies for telemanipulation with shared control of object handling forces. Presence. 14(6), 720–731 (2005)

    Article  Google Scholar 

  7. Ronsse, R., Vitiello, N., Lenzi, T., van den Kieboom, J., Carrozza, M.C., Ijspeert, A.J.: Flexible assistance using adaptive oscillators. IEEE transaction on biomedical engineering. 58(4), (2011)

  8. Kawamoto, H., Sankai, Y.: Power assist method for HAL-3 using EMG-based feedback controller, In systems, man and cybernetics, 2003 IEEE international conference on, 2:1648–1653 (2003)

  9. Banala, S.K., Kim, S.H., Agrawal, S.K., Scholz, J.P.: Robot assisted gait training with active leg exoskeleton (ALEX). IEEE Trans Neural Syst Rehabil Eng. 17(1), 2–8 (2009)

    Article  Google Scholar 

  10. Kazerooni, H., Racine, J., Huang, L., Steger, R.: On the control of the Berkeley lower extremity exoskeleton. IEEE international conference on Robotics and Automation. 4, 4353 (2005)

    Google Scholar 

  11. Kawamoto, H., Lee, S., Kanbe, S., Sankai, Y.: Power Assist Method for Hal-3 Using Emg-Based Feedback Controller. IEEE International Conference on Man and Cybernetics Systems. 2, 1648–1653 (2003)

    Google Scholar 

  12. Ronsse, R., Vitiello, N., Lenzi, T., van den Kieboom, J., Carrozza, M., Ijspeert, A.: Human-robot synchrony: flexible assistance using adaptive oscillators. IEEE Trans. Biomed. Eng. 58, 1001–1012 (2011)

    Article  Google Scholar 

  13. Ronsse, R., Vitiello, N., Lenzi, T., van den Kieboom, J., Carrozza, M., Ijspeert, A.: Adaptive oscillators with human-in-the –loop: Proof of concept for assistance and rehabilitation, IEEE RAS and EMBS Internation conference on Biomedical Robotics and Biomechatronics (BioRob) page:668–674, (2010)

  14. Aguirre-Ollinger, G., Colgate, J.E., Peshkin, M.A., Goswami, A.: Design of an Active One-Degree-of-Freedom Lower-Limb Exoskeleton with Inertia Compensation, the International Journal of Robotics Research, 30(4), (2011)

  15. Aguirre-Ollinger, G., Learning muscle activation patterns via nonlinear oscillators: application to lower-limb assistance, IEEE/RSJ international conference on intelligent robots and systems (IROS), Tokyo, Japan, 3-7, 1182–1189 (2013)

  16. Ronses, R., Lenzi, T., Vitiello, N., et al.: Oscillator –based assistance of cyclical movements:model-based and model-free approaches. Med. Bio. Eng. Comput. 49, 1173–1185 (2011)

    Article  Google Scholar 

  17. Gams, A., Ijspeert, A.J., Schaal, S.:, on-line learning and modulation periodic movements with nonlinear dynamical systems. Auton. Robot. 27, 3–23 (2009)

    Article  Google Scholar 

  18. Petric, T., Gams, A., Ijspeert, A.J., et al.: On-line frequency adaptation and movement imitation for rhythmic robotic tasks. Int. J. Robot. Res. 30(14), 1775–1788 (2011)

    Article  Google Scholar 

  19. Righetti, L., Buchli, J., Ijspeert, A.J.: Dynamic hebbian learning in adaptive frequency oscillators. Physica D. 216, 269–281 (2006)

    MathSciNet  Article  Google Scholar 

  20. Gordon, K.E., Ferris, D.P.: Learning to walk with robotic ankle exoskeleton. J. Biomech. 40, 2636–2644 (2007)

    Article  Google Scholar 

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This work is supported by the National Natural Science Foundation of China (Grant No. 51205182),the Innovation Foundation of NJIT(Grant No.CKJA 201605, JXKJ201510), Six talent peaks project in Jiangsu Province(Grant No. JXQC-015), the Natural Science Foundation of Higher Education of Jiangsu province(15KJA46007), Key research & Development plan of Jiangsu Province(Grant No. BE2019724), Humanities and Social Science Youth foundation of Ministry of Education(18YJCZH032).

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Correspondence to Yali Han.

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Han, Y., Zhu, S., Gao, H. et al. The Swing Control of Knee Exoskeleton Based on Admittance Model and Nonlinear Oscillator. J Intell Robot Syst 99, 747–756 (2020).

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  • Exoskeleton
  • Rehabilitation robot
  • Adaptive oscillator
  • Electromyography (EMG)
  • Admittance control