On the importance of a motor model for the optimization of SEA-driven prosthetic ankles

Abstract

Several examples in literature demonstrate the potential impact of motor inertia on the electrical energy consumption of actuators. Nevertheless, optimizations of actuated prosthetics are often based on the mechanical energy consumption, disregarding the potential effects of motor inertia. In this short abstract, we simulate the electrical energy consumption of a powered prosthetic ankle actuated by a Series Elastic Actuator. Its compliant element is optimized for mechanical energy consumption, a typical strategy in state-of-the-art prosthetics. Our results confirm the importance of motor inertia. Due to the resulting changes in the operating points of the motor, the average motor efficiency is lowered by 17 %.