Performance Verification of a Motorized Prosthetic Leg

초록

The present study emphasized on the optimal design of a motorized prosthetic leg and evaluation of its performance for stair walking. Developed prosthetic leg includes two degrees of freedom on the knee and ankle joint designed using a virtual product development process for better stair walking. AC motor system was introduced to imitate gait motion in the knee joint, and a spring system was applied at the ankle joint to create torque and flexion angle. Weight and dimensions of prosthetic leg were designed not to exceed human body data. Weight is one of the most important design factors with respect to the comfort and fatigue of the user. In order to design better motorized prosthetic leg, unnecessary mass was eliminated via a topology optimization process under a complex walking condition in a boundary considered condition and aluminum alloy for lower limb and plastic nylon through 3D printing foot were used. The structural safety of a developed prosthetic leg was validated via finite element analysis under a variety of walking conditions. A prosthetic leg was designed to follow natural human gait data. In conclusion, the motorized prosthetic leg was optimally designed while maintaining structural safety under boundary conditions based on human walking data, and its knee motions were synchronized with normal human gait via a PD controller. The results of this study about powered transfemoral prosthesis might help amputees in their rehabilitation process. Furthermore, this research can be applied to the area of biped robots that try to mimic human motion.