Control Methodologies for Powered Orthoses for People with Ambulatory Disabilities

Abstract

Wearable, powered lower-limb orthoses have begun to emerge as viable assistive devices for individuals with mobility impairments. Control approaches for powered lower-limb orthoses have focused on leg kinematics rather than examining both the kinematics and interactions between the user and the device. This dissertation describes the development and validation of control strategies for powered lower-limb orthoses that improve leg kinematics while providing smoother interactions between the user and orthosis. This work details the first adaptation of a passive, position-based spring-damper controller for overground walking. Afterwards, the development of an active velocity-based controller for overground walking aimed at reducing the disturbance torques to the user is explained. The last chapter of this work details the adaptation of the velocity-based controller to a single degree of freedom knee-ankle-foot orthosis with a powered knee.