Development and control of robotic exoskeleton for walking rehabilitation

Abstract

Robotic exoskeletons see much potential in the field of assisted gait rehabilitation. Particularly with Spinal Cord Injury (SCI) or Stroke patients, many of whom lower limb functions are affected, robotic exoskeletons would allow them to perform basic locomotion such as walking and standing up. However, human-machine interface still remains one of the challenges in designing such a device. This report will be detailing the development of the design and control such an exoskeleton, dividing the approach into three parts. Firstly, a state recognising algorithm is deployed to read the user intentions and input it to the exoskeleton. Next, real-time estimations of the user’s centre of mass and sensory data will be continuously fed back to the control system while impedance control of the robotic orthosis eases the human-machine interface by accounting for the user’s contribution to the gait trajectory. Lastly, a naturalistic gait is achieved by both adapting the movements of the unaffected leg to the active robotic orthosis and gait planning. The results demonstrate proper control of the state machine and natural gait motion from the exoskeleton.