Analysis of the performance of controlled semi-active knee joint with magnetorheological (MR) damper

Because of their short response time and ability to be controlled in real-time, use of MR dampers has been increased in the last decade in every area,. In prosthesis applications, it is important to maintain high levels of comfort and safety for the user. To achieve this objective stiffness of the damper utilized in prosthetics should be adjusted according to the gait phase and gait speed. In this study, to determine the necessary MR cylinder stiffness level, gait data of different users on different gait speeds were recorded. After determining the stiffness level of the prosthesis on different speeds, a Finite State Control algorithm was implemented for an above-knee proteshesis and the performance of this method was evaluated. Finally, performances of controlled and uncontrolled prostheses were compared to each other.