Design, implementation and test results of a robust control method for a powered ankle foot orthosis (AFO)

There are various methods to control a powered AFO. As different as they are in their approach each of them has certain advantages as well as difficulties. What is still needed is a robust control concept that meets the requirements for ankle gait assistance. A new, stiffness-control model has been developed that divides the stance phase of gait into five zones using either velocity or stiffness control for each zone. The design and implementation of this new control algorithm as well as some first test results are presented.