Kinematic analysis and optimization of a planar parallel compliant mechanism for self-alignment knee exoskeleton

Abstract. Misalignment between the instantaneous center of rotation (ICR) of human joint and the ICR of wearable robotic exoskeleton widely exists among most of exoskeletons widely used in rehabilitation, which results in discomfort, even endangers human safety. In order to alleviate it, this study focuses on the solution of misalignment in knee joint of lower limb exoskeletons, and proposes a compliant five-bar parallel mechanism, which offers two mobility in sagittal plane, as well as the torsional springs mounted on this mechanism, have the potential to automatically adjust the ICR of output link connected to thigh with respect to the basis link connected to shank. To reach this goal, we build the stiffness model of the mechanism and optimize its variables. And the self-alignment of the compliant five-bar parallel mechanism is verified via experimental investigations.

[1]  Jongwon Kim,et al.  Antagonistic Stiffness Optimization of Redundantly Actuated Parallel Manipulators in a Predefined Workspace , 2013, IEEE/ASME Transactions on Mechatronics.

[2]  Yasuhiro Akiyama,et al.  Knee Joint Misalignment in Exoskeletons for the Lower Extremities: Effects on User's Gait , 2015, IEEE Transactions on Robotics.

[3]  D. Tesar,et al.  Analysis of a fully-parallel six degree-of-freedom micromanipulator , 1991, Fifth International Conference on Advanced Robotics 'Robots in Unstructured Environments.

[4]  T P Andriacchi,et al.  A point cluster method for in vivo motion analysis: applied to a study of knee kinematics. , 1998, Journal of biomechanical engineering.

[5]  Jichuan Zhang,et al.  Kinematic and dynamic performance of prosthetic knee joint using six-bar mechanism. , 2003, Journal of rehabilitation research and development.

[6]  Luis Héctor Hernández-Gómez,et al.  Optimization of the Design of a Four Bar Mechanism for a Lower Limb Prosthesis Using the Taboo Search Algorithm , 2013 .

[7]  M. Nordin,et al.  Basic biomechanics of the skeletal system , 1980 .

[8]  Michel Benoit,et al.  MoonWalker, a lower limb exoskeleton able to sustain bodyweight using a passive force balancer , 2010, 2010 IEEE International Conference on Robotics and Automation.

[9]  Herman van der Kooij,et al.  LIMPACT:A Hydraulically Powered Self-Aligning Upper Limb Exoskeleton , 2015, IEEE/ASME Transactions on Mechatronics.

[10]  H. Kazerooni,et al.  Biomechanical design of the Berkeley lower extremity exoskeleton (BLEEX) , 2006, IEEE/ASME Transactions on Mechatronics.

[11]  G. Smidt.  Biomechanical analysis of knee flexion and extension. , 1973, Journal of biomechanics.

[12]  F. Zajac,et al.  A planar model of the knee joint to characterize the knee extensor mechanism. , 1989, Journal of biomechanics.

[13]  Yuanxi Sun,et al.  Design and Evaluation of a Prosthetic Knee Joint Using the Geared Five-Bar Mechanism , 2015, IEEE Transactions on Neural Systems and Rehabilitation Engineering.

[14]  Vincent Hayward,et al.  DESIGN OF SELF-ADJUSTING ORTHOSES FOR REHABILITATION , 2009 .

[15]  Jose L Pons,et al.  Rehabilitation Exoskeletal Robotics , 2010, IEEE Engineering in Medicine and Biology Magazine.

[16]  Takehito Kikuchi,et al.  Development of bio-inspired knee joint for power assist suit , 2015, 2015 IEEE International Conference on Robotics and Biomimetics (ROBIO).

[17]  Yasuhiro Akiyama,et al.  Test method for contact safety assessment of a wearable robot -analysis of load caused by a misalignment of the knee joint- , 2012, 2012 IEEE RO-MAN: The 21st IEEE International Symposium on Robot and Human Interactive Communication.

[18]  Guangbo Hao.  A framework of designing compliant mechanisms with nonlinear stiffness characteristics , 2018 .

[19]  Lauri Bishop,et al.  A wearable robotic knee orthosis for gait training: a case-series of hemiparetic stroke survivors , 2012, Prosthetics and orthotics international.

[20]  Guangbo Hao,et al.  Extended Static Modeling and Analysis of Compliant Compound Parallelogram Mechanisms Considering the Initial Internal Axial Force , 2016 .

[21]  Jay il Jeong,et al.  Experimental verification of antagonistic stiffness planning for a planar parallel mechanism with 2-DOF force redundancy , 2011, Robotica.

[22]  C W Radcliffe.  Four-bar linkage prosthetic knee mechanisms: Kinematics, alignment and prescription criteria , 1994, Prosthetics and orthotics international.

[23]  M. Maležič,et al.  Treadmill training with partial body weight support compared with physiotherapy in nonambulatory hemiparetic patients. , 1995, Stroke.

[24]  D A Hobson,et al.  Optimization of four-bar knee mechanisms--a computerized approach. , 1974, Journal of biomechanics.

[25]  J. Edward Colgate,et al.  Design of an active one-degree-of-freedom lower-limb exoskeleton with inertia compensation , 2011, Int. J. Robotics Res..

[26]  Hyunpyo Shin,et al.  Stiffness enhancement of a redundantly actuated parallel machine tool by dual support rims , 2012 .

[27]  Nevio Luigi Tagliamonte,et al.  Robomorphism: A Nonanthropomorphic Wearable Robot , 2014, IEEE Robotics & Automation Magazine.

[28]  Marco Cempini,et al.  Self-Alignment Mechanisms for Assistive Wearable Robots: A Kinetostatic Compatibility Method , 2013, IEEE Transactions on Robotics.

[29]  C W Radcliffe.  The Knud Jansen Lecture: above-knee prosthetics. , 1977, Prosthetics and orthotics international.

[30]  Dan Zhang,et al.  Multi-objective optimization of stiffness and workspace for a parallel kinematic machine , 2012 .

[31]  M. Yalcin,et al.  Kinematics and design of AssistOn-SE: A self-adjusting shoulder-elbow exoskeleton , 2012, 2012 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob).