Design and control of an exoskeleton system for gait rehabilitation capable of natural pelvic movement

This paper introduces a novel exoskeleton system for gait rehabilitation, which allows natural pelvic movements. The developed lower extremity exoskeleton system, COWALK, has 14 degrees of freedom including four degrees of freedom for pelvic motion. From 113 healthy human subjects, 3D motion capture data were collected to determine mechanical design parameters and to generate gait patterns for the COWALK system. In order to reduce the affect of the weight of the robot, a gravity compensator was installed to support the weight of the robot. The performance of the COWALK system was validated by experiments. The experimental results from joint trajectories and pelvis movements show that the developed exoskeleton system can produce natural gait movements by augmenting the degrees of freedom for pelvic motion.