MORE | Spring 2022

Variable Stiffness as Control Scheme for Enhancing Active Ankle Foot Orthosis

During walking, the human ankle accommodates for surface irregularities during the stance phase by changing its mechanical impedance to a stiffness dominant joint. To prevent discomfort to an ankle-foot orthosis (AFO) device user, it is crucial for AFO controllers to closely follow foot trajectory while constantly changing stiffness properties. This study aims to compare the effectiveness of different control schemes with the goal of restoring the kinematics and dynamics of unperturbed walking. This effort would aid the research community with valuable insight into variable stiffness controller performances and approaches to controlling human assistive robotics.