Designing an Active Ankle-Foot Prosthesis: Digital Prototype, Modeling and Control

Foot amputation can happen due to several factors and cause severe changes in the individual’s gait pattern, reduces mobility and generates injuries. Over the past two decades, researchers have dedicated efforts to develop transtibial pros-theses capable of reproducing healthy foot movement to help the amputee rehabilitation process. This work presents the digital prototype, dynamic modeling and preliminary control of an active ankle-foot prosthesis. The powertrain of the devices is composed of a EC 60 flat 200 W motor coupled to a CPL-20A-50-2 51:1 harmonic drive to generate active torque for the user. Results indicate that the projected prosthesis is promising for the proposed function, with 1.633 kg, a height of 168.57 mm and capable of generating up to 1.02 N.m/kg of torque and 5.39 rad/s of angular velocity, considering a time span of 1 second for the gait cycle on level ground.