Related Experiment Video
Updated: May 25, 2026

Training Persons with Spinal Cord Injury to Ambulate Using a Powered Exoskeleton
Published on: June 16, 2016
Series elastic actuator control of a powered exoskeleton
Daniel Ragonesi1, Sunil Agrawal, Whitney Sample
1Department of Mechanical Engineering, University of Delaware, Newark, DE 19716, USA. ragonesi@udel.edu
Abstract:
A motorized upper extremity orthosis based on the passive WREX system is being developed. The orthosis is a 4 dof arm controlled by user residual force inputs. The arm is intended for people with neuromuscular weakness due to muscular dystrophy or spinal muscular atrophy. Previous work determined that actuation in parallel with gravity balancing springs required less torque than actuation in series. Compliance is achieved by using a series elastic actuator (SEA) by placing torsional springs between the motors and the WREX. A torque control was implemented on the SEA at the joint level. The response of the control law was characterized without disturbances. The SEAs were then attached to the orthosis to test the response with disturbances, and the control provided accurate joint torques.
More Related Videos
Related Concept Videos
Elastic Potential Energy
Potential energy is also associated with the elastic force exerted by an ideal spring. The work done by this force can be represented as a change in the elastic potential energy of the spring. Thus, the work done by a perfectly elastic spring, in one dimension, depends only...
Power Expended by a Constant Force

