A new ankle foot orthosis: Modeling and control

摘要

This paper studies the derivation of kinematic and dynamic models of a newly developed active ankle foot orthosis (AFO) that was designated for testing gait-assistive compliance control algorithms. The AFO is characterized with a closed-loop chain structure and powered by a linear ServoTube motor making it very fast and responsive. The paper first derives kinematic and dynamic models for the AFO. Then, a torque controller is developed based on the dynamic model of the AFO and it is shown that the AFO is able to track the position and velocity of the desired trajectory with a satisfactory accuracy.