Abstract
When a linear actuator is used for rotation motion by a knee joint of an exoskeleton, the specifications of the joint range of motion (ROM) and joint torque change according to how the linear actuator are attached. Moreover, while the linear actuator generates a constant amount of force, the joint torque generated by the actuator changes according to the joint angle, which causes the torque contraction. This makes it difficult to meet the required torque and ROM for walk and stand-to-sit and sit-to-stand (STS) motions while carrying a load. To solve these problems we propose a novel knee joint for an exoskeleton with good energy efficiency during walk and STS motions while carrying a load. The mechanism is composed of a four-bar linkage and an elastic element. Based on an analysis of human motion, the design variables of the joint were optimized and the feasibility of the optimized variables was verified through the simulation. The findings from the simulation results suggest that combining a four-bar linkage with a linear actuator allows a large ROM and good torque performance of the knee joint for walk and STS motions. Moreover, the energy efficiency can be improved because the spring mounted parallel to the actuator can store the energy dissipated as negative work and recycle the energy as positive work.
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A. B. Zoss, H. Kazerooni and A. Chu, Biomechanical design of the Berkeley lower extremity exoskeleton (BLEEX), Mechatronics, IEEE/ASME Transactions on, 11 (2) (2006) 128–138.
K. N. Gregorczyk, L. Hasselquist, J. M. Schiffman, C. K. Bensel, J. P. Obusek and D. J. Gutekunst, Effects of a lowerbody exoskeleton device on metabolic cost and gait biomechanics during load carriage, Ergonomics, 53 (10) (2010) 1263–1275.
K. W. Hollander, R. Ilg, T. G. Sugar and D. Herring, An efficient robotic tendon for gait assistance, Journal of Biomechanical Engineering, 128 (5) (2006) 788–791.
S. H. Collins and A. D. Kuo, Recycling energy to restore impaired ankle function during human walking, PLoS one, 5 (2) (2010) e9307.
S. Wang, W. van Dijk and H. van der Kooij, Spring uses in exoskeleton actuation design, In Rehabilitation Robotics (ICORR), IEEE international Conference on (2011) 1–6.
V. T. Inman, H. J. Ralston and F. Todd, Human walking, Williams & Wilkins (1981).
P. DeVita, J. Helseth and T. Hortobagyi, Muscles do more positive than negative work in human locomotion, Journal of Experimental Biology, 210 (19) (2007) 3361–3373.
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This paper was presented at the ISR-2013, KINTEX, Seoul, Korea, October 24–26, 2013. Recommended by Guest Editor Byung Kyu Kim
Hyo-gon Kim received the B.S. degree with 2nd major in control and instrumentation engineering and M.S. degree in Mechanical Design & Manufacturing Engineering from Changwon National University, Korea, in 2005 and 2008, respectively. He is currently a Ph.D. candidate at the Department of Mechatronics Engineering in Hanyang University, and also a research assistant in the Robotics R&BD Group at the Korea Institute of Industrial Technology (KITECH). His research interests include compliance control for hydraulic robots, design and control for exoskeleton systems.
Sangdeok Park received his B.S. degree in Mechanical Design at Yeungnam University in 1998 and M.S. and Ph.D. degrees from the department of Mechanical Engineering at Pohang University of Science and Technology (POSTECH) in 1990 and 2000, respectively. He is a principal researcher with a chief officer of Robotics R&BD group of KITECH. His research interests include the design and control of quadruped walking robots, wearable robots and hydraulically driven robots.
Changsoo Han received the Ph.D. in Mechanical Engineering from the University of Texas at Austin, USA, in 1989. He is a Professor of Robotics in the Department of Robot Engineering, Hanyang University, South Korea. His research interests include exoskeleton systems, biomechanical rehabilitation systems and automation in construction.
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Kim, Hg., Park, S. & Han, C. Design of a novel knee joint for an exoskeleton with good energy efficiency for load-carrying augmentation. J Mech Sci Technol 28, 4361–4367 (2014). https://doi.org/10.1007/s12206-014-1003-8
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DOI: https://doi.org/10.1007/s12206-014-1003-8