A New Variable Stiffness Series Elastic Actuator for the Next Generation Collaborative Robot

Date of Award


Degree Name

Ph.D. in Engineering


Department of Electrical and Computer Engineering


Advisor: Raúl Ordóñez

Second Advisor

Advisor: George Sutton


Over the past decades industrial robot manipulators have expanded throughout the automation landscape with their high degree of repeatability and accuracy. For safety reasons these robots are not allowed to share their workspace along with humans, which limits the study of various tasks that can be performed by a human-robot collaboration. To circumvent this limitation, a new kind of variable stiffness series elastic actuator (or vSEA) is proposed as a joint actuator. This vSEA has an ability to servo-control its joint stiffness, and provide a measure of the instantaneous joint torque. These unique abilities play a crucial role in an intelligent robot control design that can scale down the risk factors in a field where humans and robots collaborate. The intrinsic soft joint in vSEA provides a higher bandwidth of compliance to better mitigate the effects of collision. This article dissects the use of the vSEA joint in a planar RR robot manipulator, and its potential use in a human-robot collaborative workspace.


Robotics, Collaborative Robot, Control

Rights Statement

Copyright © 2020, author