Optimization-based analysis of push recovery during walking motions to support the design of rigid and compliant lower limb exoskeletons

AbstractLower limb exoskeletons provide a promising approach to allow disabled people to walk again in the future. Designing such exoskeletons and tuning the required actuators is challenging, since the full dynamics of the combined human-exoskeleton system have to be taken into account. In particular, it is important to not only consider nominal walking motions but also extreme situations such as the recovery from large perturbations. In this paper, we present an approach based on push recovery experiments while walking, multibody system models, and least-squares optimal control to analyze the required torques to be generated by the exoskeleton, assuming that the human provides no torque. We consider seven different trials with varying push locations and push magnitudes applied on the back of the subject. In a first study, we investigate the dependency of these total joint torques on the exoskeleton mass – and compare the torques required for a human without exoskeleton to the ones for the human with two...

[1]  Martin A. Giese,et al.  Joint torque analysis of push recovery motions during human walking , 2016, 2016 6th IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob).

[2]  Adam Zoss,et al.  Design of an electrically actuated lower extremity exoskeleton , 2006, Adv. Robotics.

[3]  K. Mombaur,et al.  Modeling and Optimal Control of Human-Like Running , 2010, IEEE/ASME Transactions on Mechatronics.

[4]  Johannes P. Schlöder,et al.  An efficient multiple shooting based reduced SQP strategy for large-scale dynamic process optimization: Part II: Software aspects and applications , 2003, Comput. Chem. Eng..

[5]  Jerry E. Pratt,et al.  Learning Capture Points for humanoid push recovery , 2007, 2007 7th IEEE-RAS International Conference on Humanoid Robots.

[6]  S. Robinovitch,et al.  The effect of step length on young and elderly women's ability to recover balance. , 2007, Clinical biomechanics.

[7]  E. T. Hsiao,et al.  Biomechanical influences on balance recovery by stepping. , 1999, Journal of biomechanics.

[8]  Ken Endo,et al.  A Quasi-Passive Leg Exoskeleton for Load-Carrying Augmentation , 2007, Int. J. Humanoid Robotics.

[9]  Jerry Pratt,et al.  Velocity-Based Stability Margins for Fast Bipedal Walking , 2006 .

[10]  Carol O'Sullivan,et al.  Push-recovery stability of biped locomotion , 2015, ACM Trans. Graph..

[11]  Aaron M. Dollar,et al.  Lower Extremity Exoskeletons and Active Orthoses: Challenges and State-of-the-Art , 2008, IEEE Transactions on Robotics.

[12]  Andrey Yatsun,et al.  Motion Control Algorithm for Exoskeleton Push Recovery in the Frontal Plane , 2016, RAAD.

[13]  Hugh Herr,et al.  Exoskeletons and orthoses: classification, design challenges and future directions , 2009, Journal of NeuroEngineering and Rehabilitation.

[14]  Katja D. Mombaur,et al.  Optimization based analysis of push recovery during walking motions to support the design of lower-limb exoskeletons , 2016, 2016 IEEE International Conference on Simulation, Modeling, and Programming for Autonomous Robots (SIMPAR).

[15]  Katja Mombaur,et al.  ExoOpt - A framework for patient centered design optimization of lower limb exoskeletons , 2015, 2015 IEEE International Conference on Rehabilitation Robotics (ICORR).

[16]  Johannes P. Schlöder,et al.  An efficient multiple shooting based reduced SQP strategy for large-scale dynamic process optimization. Part 1: theoretical aspects , 2003, Comput. Chem. Eng..

[17]  Tamim Asfour,et al.  The KIT whole-body human motion database , 2015, 2015 International Conference on Advanced Robotics (ICAR).

[18]  Doyoung Jeon,et al.  A Method to Accurately Estimate the Muscular Torques of Human Wearing Exoskeletons by Torque Sensors , 2015, Sensors.

[19]  Angela C. Boynton,et al.  Exoskeleton Power and Torque Requirements Based on Human Biomechanics , 2002 .

[20]  Katja Mombaur,et al.  Optimal Push Recovery for Periodic Walking Motions , 2016 .

[21]  Albertus Hendrawan Adiwahono,et al.  Push Recovery through walking phase Modification for bipedal locomotion , 2013, Int. J. Humanoid Robotics.

[22]  N. Latif,et al.  TORQUE ANALYSIS OF THE LOWER LIMB EXOSKELETON ROBOT DESIGN , 2015 .

[23]  H. Bock,et al.  A Multiple Shooting Algorithm for Direct Solution of Optimal Control Problems , 1984 .

[24]  Y. Pai,et al.  Minimal step length necessary for recovery of forward balance loss with a single step. , 2007, Journal of biomechanics.

[25]  Shiqian Wang,et al.  Spring uses in exoskeleton actuation design , 2011, 2011 IEEE International Conference on Rehabilitation Robotics.

[26]  Juan Carlos Arevalo,et al.  An Adjustable Compliant Joint for Lower-Limb Exoskeletons , 2015, IEEE/ASME Transactions on Mechatronics.

[27]  Katja D. Mombaur,et al.  Using Spring-Damper Elements to Support Human-Like Push Recovery Motions , 2017, RAAD.

[28]  Benjamin J. Stephens,et al.  Humanoid push recovery , 2007, 2007 7th IEEE-RAS International Conference on Humanoid Robots.

[29]  Martin L. Felis.  RBDL: an efficient rigid-body dynamics library using recursive algorithms , 2017, Auton. Robots.

[30]  Richard W. Longman,et al.  Open-loop stable running , 2005, Robotica.