A Novel Control Method of A Soft Exosuit with Plantar Pressure Sensors

Soft Exosuit is a kind of Lower-limb wearable robots to augment and assist the wearer’s performance. Recently, our team developed a cable-driven wearable robot named SIAT Soft Exosuit (SSEX) which can transmit assistive force to wearer’s body. Natural gait feature extraction is the key to control a Soft Exosuit. In this paper, we propose a method to obtain the gait feature by plantar pressure sensors which measure the force load on a shoe insole. The system can detect the gait event accurately and reliably in real time which is the onset time of assistance for hip extension. Then we use IMUs to get the hip joint angle during hip extension which can help us calculate the variation of cable length and motor position profile. There are also two load cells in our system to make a feedback and get us desired assistant force. To achieve a desired active force, the control system adapt a way based on learning iterative control.

[1]  R Wytch,et al.  Instrumentation used in clinical gait studies: a review. , 1989, Journal of medical engineering & technology.

[2]  Hugh M Herr,et al.  Autonomous exoskeleton reduces metabolic cost of human walking during load carriage , 2014, Journal of NeuroEngineering and Rehabilitation.

[3]  Mohammed I. Awad,et al.  Lower limb motion tracking using IMU sensor network , 2014, 2014 Cairo International Biomedical Engineering Conference (CIBEC).

[4]  Conor J. Walsh,et al.  A biologically inspired soft exosuit for walking assistance , 2015, Int. J. Robotics Res..

[5]  Alfred D. Grant Gait Analysis: Normal and Pathological Function , 2010 .

[6]  Gregory S. Sawicki,et al.  Reducing the energy cost of human walking using an unpowered exoskeleton , 2015, Nature.

[7]  Wenlong Zhang,et al.  A Soft-Inflatable Exosuit for Knee Rehabilitation: Assisting Swing Phase During Walking , 2018, Front. Robot. AI.

[8]  Chang-soo Han,et al.  Development of the heavy load transferring task oriented exoskeleton adapted by lower extremity using qausi - Active joints , 2009, 2009 ICCAS-SICE.

[9]  Didier Stricker,et al.  Body-IMU autocalibration for inertial hip and knee joint tracking , 2015, BODYNETS.

[10]  Ruthenberg Bj,et al.  An experimental device for investigating the force and power requirements of a powered gait orthosis. , 1997 .

[11]  Thomas Seel,et al.  IMU-Based Joint Angle Measurement for Gait Analysis , 2014, Sensors.

[12]  Conor J. Walsh,et al.  Biologically-inspired soft exosuit , 2013, 2013 IEEE 13th International Conference on Rehabilitation Robotics (ICORR).

[13]  Wai Yin Wong,et al.  Clinical Applications of Sensors for Human Posture and Movement Analysis: A Review , 2007, Prosthetics and orthotics international.

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

[15]  Simona Crea,et al.  Controlling negative and positive power at the ankle with a soft exosuit , 2016, 2016 IEEE International Conference on Robotics and Automation (ICRA).

[16]  Marko Munih,et al.  Development and validation of a wearable inertial measurement system for use with lower limb exoskeletons , 2011, 2011 11th IEEE-RAS International Conference on Humanoid Robots.

[17]  Alena M. Grabowski,et al.  Leg exoskeleton reduces the metabolic cost of human hopping. , 2009, Journal of applied physiology.

[18]  A. Esquenazi,et al.  The ReWalk Powered Exoskeleton to Restore Ambulatory Function to Individuals with Thoracic-Level Motor-Complete Spinal Cord Injury , 2012, American journal of physical medicine & rehabilitation.

[19]  K. Nakazawa,et al.  A two-degree-of-freedom motor-powered gait orthosis for spinal cord injury patients , 2007, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[20]  B. Ruthenberg,et al.  An experimental device for investigating the force and power requirements of a powered gait orthosis. , 1997, Journal of rehabilitation research and development.

[21]  Isaac Skog,et al.  A note on the limitations of ZUPTs and the implications on sensor error modeling , 2012 .

[22]  Jacob Rosen,et al.  Admittance control of an upper limb exoskeleton - Reduction of energy exchange , 2012, 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.