Design & development of modular compact series elastic actuator for lower limb extremity assistant exoskeleton

Authors

1 Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.

2 Department of Mechanical Engineering, Center of Excellence on Soft Computing and Intelligent Information Processing, Ferdowsi University of Mashhad, Mashhad, Iran.

Abstract

This paper presents a comprehensive process of designing series elastic actuators to be used in active joints of assistive exoskeleton robots. In this process, the stiffness parameter of torsional spring is selected based on two main criteria to satisfy all the requirements of human motions. The first criterion is an appropriate frequency response for the actuator, according to human motion needs. The second criterion is to provide a sufficient protection of actuator hardware against collision and impact. By determining the desired value for the stiffness parameter, spring architecture is designed to have sufficient mechanical strength and provide the desired stiffness in practice while occupying a minimum space. Along with motor and gearbox, the designed spring is assembled in a module to be used in active joints of exoskeleton robots. The module is designed in a way that the spring can be detached easily and the motor and gearbox can be used as a stiff actuator as well. The considerations in the optimization of the spring and in the design of the module has led to a very compact series elastic actuator which can be used in different human motions such as stair ascend and descend, sit to stand and walking.

Keywords

Main Subjects

References

 [1] HAL Exoskeleton, Accessed on 22 December 2018; https://www.cyberdyne.jp/english.
[2] SuitX Exoskeleton, Accessed on 22 December 2018; https://www.suitx.com.
[3] Honda Exoskeleton, Accessed on 22 December 2018; https://world.honda.com/Walking-Assist.
[4] Kardan I, Akbarzadeh A (2017) Agility enhancement using an assistive controller for exoskeleton robots. Modares Mechanical Engineering 17(9): 119-129. (in Persian)
[5] Irmscher C, Woschke E, May E, Daniel C (2018) Design, optimisation and testing of a compact, inexpensive elastic element for series elastic actuators. Med Eng Phys 52: 84-89.
[6] Veneman JF, Ekkelenkamp R, Kruidhof R, van der Helm FCT, van der Kooij H (2006) A series elastic- and bowden-cable-based actuation system for use as torque actuator in exoskeleton-type robots. Int J Robot Res 25(3): 261-281.
[7] Carpino G, Accoto D, Sergi F, Luigi N, Tagliamonte E Guglielmelli (2012) A novel compact torsional spring for series elastic actuators for assistive wearable robots. J Mech Design 134(12); 121002-121002.
[8] Lagoda C, Schouten AC, Stienen AHA, Hekman EEG, Kooij HVD (2010) Design of an electric series elastic actuated joint for robotic gait rehabilitation training. 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics 21-26.
[9] Chen L, Ding H, Fu T, Li J, Shao L (2018) Design and impedance control of the integrated rotary compliant joint. Adv Mech Eng, Springer Singapore 1125-1140.
[10] Byrvan H, Sugar T, Vanderborght B, Hollander  K, Lefeber D (2009) Review of actuators with passive adjustable compliance/controllable stiffness for robotic applications. Ieee Robot Autom Mag 81-94.
[11] Accoto D, Carpino G, Sergi F, Tagliamonte NL, Zollo L, Guglielmelli E (2013) Design and characterization of a novel high-power series elastic actuator for a lower limb robotic orthosis. Int J Adv Robot Syst 10(10): 359.
[12] Taherifar A, Vossoughi G, Selk Ghafari A (2017) Identification and torque control of series elastic actuator of lower limb extremity exoskeleton. Modares Mechanical Engineering 17(8): 1-8. (in Persian)
[13] dos Santos WM, Caurin GAP, Siqueira AAG (2017) Design and control of an active knee orthosis driven by a rotary series elastic actuator. Control Eng Pract 58: 307-318.
[14] Paine N, Mehling Joshua S, Holley J, Radford A Johnson NG, Fok CL, Sentis L (2015) Actuator control for the NASA‐JSC valkyrie humanoid robot: A decoupled dynamics approach for torque control of series elastic robots. J Field Robot 32(3): 378-396.
[15] Choi W, Won J, Lee J, Park J (2017) Low stiffness design and hysteresis compensation torque control of SEA for active exercise rehabilitation robots. Auton Robot 41(5): 1221-1242.
[16] Bing C, Xuan Z, Hao M, Ling Q, Wei-Hsin L (2017) Design and characterization of a magneto-rheological series elastic actuator for a lower extremity exoskeleton. Smart Mater Struct 26(10): 105008.
[17] Bovi G, Rabuffetti M, Mazzoleni P, Ferrarin M (2011) A multiple-task gait analysis approach: Kinematic, kinetic and EMG reference data for healthy young and adult subjects. Gait Posture 33(1): 6-13.
[18] Maxonmotor, Accessed on 22 December 2018; https://www.maxonmotor.com/maxon/view/content/index.
[19] HarmonicDrive, Accessed on 22 December 2018; http://www.harmonicdrive.net/.
[20] Au S, Berniker M, Herr H (2008) Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits. Neural Networks 21(4): 654-666.
Journal of Solid and Fluid Mechanics
Volume 9, Issue 3
October 2019
Pages 109-123

Files

Share

How to cite

Statistics