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A Study on Weight Support and Balance Control Method for Assisting Squat Movement with a Wearable Robot, Angel-suit

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Abstract

An exoskeletal robot can assist the movement of target joints effectively, but the eccentricity in the center of gravity caused by wearing an exoskeletal robot causes an imbalance problem. Such a side effect causes unnatural posture and additional effort for the wearer to maintain the body balance. To minimize the side effect, this paper proposes a control method of an exoskeletal robot to assist a certain target motion with body weight support and balance maintenance functions at the same time. The exoskeletal robot used in this study measures the center of pressure on the wearer’s feet in real-time using air pressure sensors embedded in the soles of the shoes. Then the proposed control method determines the direction of the assistive force to assist the wearers balancing. The desired assistance torque required for realizing the proposed assistance method is precisely generated by series elastic actuators installed at the hip and knee joints of the exoskeletal robot. In the experiments, an assistance effect is verified by measuring the EMG signals of the six lower-limb muscles that are mainly involved in the target movement. This paper also introduces the experimental results that show the proposed assistive method reduces the EMG signal in five muscles, and reduces the variation of the COP movement compared to the case where only the body weight support method is applied in the control of the exoskeletal robot. These demonstrate that the proposed assistance method effectively assists in balancing and body weight supporting effectively.

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Authors and Affiliations

  1. Department of Mechanical Engineering, Sogang University, Seoul, 04107, Korea

    Mingoo Jeong

  2. Department of Mechanical Engineering, KAIST, Daejeon, 34141, Korea

    Hanseung Woo & Kyoungchul Kong

Authors
  1. Mingoo Jeong
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  2. Hanseung Woo
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  3. Kyoungchul Kong
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Correspondence to Kyoungchul Kong.

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Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Recommended by Guest Editors Doo Yong Lee (KAIST) and Jaesoon Choi (Asan Medical Center). This research was supported by the ICT R&D program of MSIP/IITP. [2017-0-01724, Development of A soft wearable suit using intelligent information and meta-material/structure technology for fall prediction and prevention]. This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(2016R1D1A1B03934338 and 2019R1I1A1A01064032).

Mingoo Jeong received his B.S. degree in Division of Robotics from Kwangwoon University, Seoul, Korea, in 2018. He is currently working toward an M.S. degree in mechanical engineering from Sogang University, Seoul, Korea. His research interests include wearable robotics for assistance, control theory, and general mechatronics.

Hanseung Woo received his B.S., M.S., and Ph.D. degrees in mechanical engineering from Sogang University, Seoul, Korea, in 2012, 2014, and 2019, respectively. He is currently a Postdoctoral Researcher at Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea. His current interests include mechanical design, physical human-robot interaction, wearable robot for human power augmentation and robotic rehabilitation.

Kyoungchul Kong received his B.Eng. (summa cum laude) degree in mechanical engineering and a B.S. degree in physics from Sogang University, Seoul, Korea, in 2004, an M.S. degree in mechanical engineering from Sogang University in 2006, and a Ph.D. degree in mechanical engineering from the University of California at Berkeley, Berkeley, CA, USA, in 2009. In 2011, he joined the Department of Mechanical Engineering, Sogang University, as an assistant and associate professor. Since 2019, he has been working at Korea Advanced Institute of Science and Technology (KAIST) as an associate professor. He has authored or co-authored more than 100 technical articles in journals and conference proceedings in the area of mechatronics, including locomotive robotics and human-robot interactive systems. His current research interests include design, modeling, and control of mechatronic systems with an emphasis on locomotion and mobility of robotic systems. Dr. Kong received the Best Innovation Award from the President of Korea in 2017, the Commendation by the Minister of Commerce, Industry and Energy in 2017, the Bronze Medal of Cybathlon in 2016, and the Young Researcher Award from the IFAC Mechatronics TC in 2016.

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Jeong, M., Woo, H. & Kong, K. A Study on Weight Support and Balance Control Method for Assisting Squat Movement with a Wearable Robot, Angel-suit. Int. J. Control Autom. Syst. 18, 114–123 (2020). https://doi.org/10.1007/s12555-019-0243-x

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  • DOI: https://doi.org/10.1007/s12555-019-0243-x

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