Chinese Journal of Mechanical Engineering

, Volume 28, Issue 5, pp 878–887 | Cite as

Structure design of lower limb exoskeletons for gait training

  • Jianfeng Li
  • Ziqiang Zhang
  • Chunjing Tao
  • Run Ji


Due to the close physical interaction between human and machine in process of gait training, lower limb exoskeletons should be safe, comfortable and able to smoothly transfer desired driving force/moments to the patients. Correlatively, in kinematics the exoskeletons are required to be compatible with human lower limbs and thereby to avoid the uncontrollable interactional loads at the human-machine interfaces. Such requirement makes the structure design of exoskeletons very difficult because the human-machine closed chains are complicated. In addition, both the axis misalignments and the kinematic character difference between the exoskeleton and human joints should be taken into account. By analyzing the DOF(degree of freedom) of the whole human-machine closed chain, the human-machine kinematic incompatibility of lower limb exoskeletons is studied. An effective method for the structure design of lower limb exoskeletons, which are kinematically compatible with human lower limb, is proposed. Applying this method, the structure synthesis of the lower limb exoskeletons containing only one-DOF revolute and prismatic joints is investigated; the feasible basic structures of exoskeletons are developed and classified into three different categories. With the consideration of quasi-anthropopathic feature, structural simplicity and wearable comfort of lower limb exoskeletons, a joint replacement and structure comparison based approach to select the ideal structures of lower limb exoskeletons is proposed, by which three optimal exoskeleton structures are obtained. This paper indicates that the human-machine closed chain formed by the exoskeleton and human lower limb should be an even-constrained kinematic system in order to avoid the uncontrollable human-machine interactional loads. The presented method for the structure design of lower limb exoskeletons is universal and simple, and hence can be applied to other kinds of wearable exoskeletons.


gait training lower limb exoskeleton structure design kinematic compatibility even-constrained kinematic chain 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    HIDLER J, WISMAN W, NECKEL N. Kinematic trajectories while walking within the LOKOMAT robotic gait-orthosis[J]. Clinical Biomechanics, 2008, 23(10): 1251–1259.CrossRefGoogle Scholar
  2. [2]
    ZANOTTO D, STEGALL P, AGRAWAL S K. ALEX III: A novel robotic platform with 12 DOFs for human gait training [C]//Proceeding of IEEE International Conference on Robotics and Automation, Karlsruhe, Germany, May 6–10, 2013: 3914–3919.Google Scholar
  3. [3]
    VENEMAN J F, KRUIDHOF R, HEKMAN E E G, et al. Design and evaluation of the LOPES exoskeleton robot for interactive gait rehabilitation[J]. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2007, 15(3): 379–386.CrossRefGoogle Scholar
  4. [4]
    PERRY J C, ROSEN J, BURNS S. Upper-limb powered exoskeleton design[J]. IEEE/ASME Transactions on Mechatronics, 2007, 12(4): 408–417.CrossRefGoogle Scholar
  5. [5]
    Schiele A, van der Helm F C T. Kinematic design to improve ergonomics in human machine interaction[J]. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2006, 14(4): 456–469.CrossRefGoogle Scholar
  6. [6]
    SCHIELE A. Ergonomics of exoskeletons: sbjective performance metrics[C]//Proceeding of IEEE/RSJ International Conference on Intelligent Robots and Systems, St. Louis, USA, October 11–15, 2009: 480–485.Google Scholar
  7. [7]
    HUSSAIN S, XIE S Q, JAMWAL P K, et al. An intrinsically compliant robotic orthosis for treadmill training[J]. Medical Engineering & Physics, 2012, 34(10): 1448–1453.CrossRefGoogle Scholar
  8. [8]
    WU M, HORNBY T G, LANDRY J M, et al. A cable-driven locomotor training system for restoration of gait in human SCI[J]. Gait and Posture, 2011, 33(2): 256–260.CrossRefGoogle Scholar
  9. [9]
    PARK H S, REN Y, ZHANG L Q. IntelliArm: An exoskeleton for diagnosis and treatment of patients with neurological impairments [C]//Proceeding of the 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, Scottsdale, AZ, USA, October 19–22, 2008: 109–114.Google Scholar
  10. [10]
    STEGALL P, WINFREE K, ZANOTTO D, et al. Rehabilitation exoskeleton design: exploring the effect of the anterior lunge degree of freedom[J]. IEEE Transactions on Robotics, 2013, 29(4): 825–837.CrossRefGoogle Scholar
  11. [11]
    Stienen A H A, Hekman E E G, van der Helm F C T, et al. Self-aligning exoskeleton axes through decoupling of joint rotations and translations[J]. IEEE Transactions on Robotics, 2009, 25(3): 628–633.CrossRefGoogle Scholar
  12. [12]
    CEMPINI M, de ROSSI S M M, LENZI T, et al. Self-alignment mechanisms for assistive wearable robots: a kinetostatic compatibility method[J]. IEEE Transactions on Robotics, 2013, 29(1): 236–250.CrossRefGoogle Scholar
  13. [13]
    DEHEZ B, SAPIN J. ShouldeRO, an alignment-free two-DOF rehabilitation robot for the shoulder complex[C]//Proceeding of IEEE International Conference on Rehabilitation Robotics, Zurich, Switzerland, June 27–July 1, 2011: 1–6.CrossRefGoogle Scholar
  14. [14]
    NEF T, GUIDALI M, RIENER R. Arminarm therapy exoskeleton with an ergonomic shoulder actuation[J]. Applied Bionics and Biomechanics, 2009, 6(2): 127–142.CrossRefGoogle Scholar
  15. [15]
    LEE K M, GUO J. Kinematic and dynamic analysis of an anatomically based knee joint[J]. Journal of Biomechatronics, 2010, 43(7): 1231–1236.CrossRefGoogle Scholar
  16. [16]
    ERGIN M A, PATOGLU V. ASSISTON-SE: A self-aligning shoulder-elbow exoskeleton[C]//Proceeding of IEEE International Conference on Robotics and Automation, Saint Paul, Minnesota, USA, May 14–18, 2012: 2479–2485.Google Scholar
  17. [17]
    COLOMBO G, JOERG M, SCHREIER R, et al. Treadmill training of paraplegic patients using a robotic orthosis[J]. Journal of Rehabilitation Research and Development, 2000, 37(6): 693–700.Google Scholar
  18. [18]
    SCHIELE A. An explicit model to predict and interpret constraint force creation in pHRI with exoskeletons[C]//Proceeding of IEEE International Conference on Robotic And Automation, Pasadena, CA, USA, May 19–23, 2008: 1324–1330.Google Scholar
  19. [19]
    SERGI F, ACCOTO D, TAGLIAMONTE N L, et al. A systematic graph-based method for the kinematic synthesis of nonanthropomorphic wearable robots[C]//Proceeding of IEEE Conference on Robotics, Automation and Mechatronics, Singapore, June 28–30, 2010: 100–105.CrossRefGoogle Scholar
  20. [20]
    SERGI F, ACCOTO D, TAGLIAMONTE N L, et al. Kinematic synthesis, optimization and analysis of a non-anthropomorphic 2-DOFs wearable orthosis for gait assistance[C]//Proceeding of IEEE/RSJ International Conference on Intelligent Robots and Systems, Vilamoura, Algarve, Portugal, October 7–12, 2012: 4303–4308.CrossRefGoogle Scholar
  21. [21]
    JARRASSE N, MOREL G. Connecting a human limb to an exoskeleton[J]. IEEE Transactions on Robotics, 2013, 28(3): 697–709.CrossRefGoogle Scholar
  22. [22]
    WANG Haijie. Anatomy of the human system[M]. 3rd ed. Shanghai: Fudan University Press, 2008. (in Chinese).Google Scholar
  23. [23]
    CENCIARINI M, DOLLAR A M. Biomechanical considerations in the design of lower limb Exoskeletons[C]//Proceeding of IEEE International Conference on Rehabilitation Robotics, Zurich, Switzerland, June 27–July 1, 2011: 1–6.CrossRefGoogle Scholar
  24. [24]
    Cai-Viet-Anh Dung, BIDAUD P, HAYWARD V, et al. Self-adjusting, isostatic exoskeleton for the human knee joint [C]//Proceeding of Annual International Conference of IEEE Engineering in Medicine and Biology Society, Boston, Massachusetts, USA, August 30–September 3, 2011: 612–618.Google Scholar
  25. [25]
    HUANG Zhen, ZHAO Yongsheng, ZHAO Tieshi. Advanced spatial mechanism[M]. Beijing: China Higher Education Press, 2006. (in Chinese)Google Scholar

Copyright information

© Chinese Mechanical Engineering Society and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Jianfeng Li
    • 1
  • Ziqiang Zhang
    • 1
    • 2
  • Chunjing Tao
    • 3
  • Run Ji
    • 3
  1. 1.College of Mechanical Engineering and Applied Electronics TechnologyBeijing University of TechnologyBeijingChina
  2. 2.Robotic InstituteBeihang UniversityBeijingChina
  3. 3.National Research Center for Rehabilitation Technical AidsBeijingChina

Personalised recommendations