Series Elasticity and Actuator Power Output

— In this investigation we put forth a simple model to quantify the capacity of series elasticity to increase peak power output from an actuator. Using a linear bandwidth limited force source, we show how series spring stiffness and source stroke length effect power output to an inertial load. We show that an appropriate spring constant increases the the peak power delivered to the inertial load over a limited stroke. The series elasticity changes the actuator operating point along its forcevelocity curve and therefore effects the actuator work output over a fixed stroke length. For single shot motions, the peak power can increase by a factor of √ 2 for appropriate series spring stiffness. We will also present an example of how this work relates to human ankle function and it implies for the design of robotic or prosthetic ankles.

• Type: Conference
• Year: 2006
• Where: ICRA
• Authors: Daniel Paluska, Hugh M. Herr
• Keywords: ICRA 2006, Peak Power, Power Output, Robotics, Series Spring Stiffness