Design, Analysis, and Control of A User-Adaptive

Abstract

This paper presents the design and preliminary evaluation of a user-adaptive ankle foot orthosis (AFO). To begin with, according to the foot dimensions of an able-bodied subject, the structures of the ankle orthotic device are conceived. Then, based on a common two-degree-of-freedom (DOF) foot model, the AFO-human system is set up; its kinematic model and the device's mechanism of user adaptation are analyzed. After that, the layout of a portable orthotic system, as well as a smart insole that detects gait phases, is illustrated. Finally, the orthotic system is tested on the aforementioned subject. Results show that, when assistive torque of the AFO is applied, the foot's plantarflexion magnitude before the swing stage and dorsiflexion magnitude during the swing stage approximately increase by 3 and 4 degrees, respectively. Therefore, the orthosis has the potential to aid propulsion motions and control toe clearance.