Design of a Novel Torsional Spring for the Next Generation Compliant Actuators

Series Elastic Actuators (SEA) are one of the most widely studied compliant actuators in anthropomorphic robots and prostheses. However, due to the nature of its unique configuration, an unavoidable trade-off has to be made between compliance and bandwidth performance. In this paper, we show that by adopting a hypocycloid mechanism in rotary actuator designs, compliance and high force control bandwidth can be achieved at the same time, while reaping all the benefits of energy storage and shock absorption characteristics of mechanical springs.