RI | Research | Projects | The Electric Cable Differential (ECD) Leg

Text only version of this site

The Electric Cable Differential (ECD) Leg Head: Jonathan W Hurst Contact: Jonathan W Hurst (jhurst@cmu.edu) Mailing address: Carnegie Mellon University Robotics Institute 5000 Forbes Avenue Pittsburgh, PA 15213 Associated lab/group: Microdynamic Systems Laboratory For more information, see this project's homepage.

Jump to: Project Description | Personnel | Sub-projects | Publications

Project Description

The Electric Cable Differential (ECD) Leg is designed for running, walking, jumping, hopping, and generally behaving in a highly dynamic manner. Large fiberglass springs are used for storing the energy of a running gait, much like the springs in a pogo stick or the tendons in a kangaroo. The name "ECD Leg" is derived from the method of actuation and power transmission; we use electric motors, which offer much simpler and more precise computer control than pneumatic or hydraulic actuators. The motors are connected to the leg joints using steel cable wrapped around aluminum pulleys, and there are several mechanical differentials to implement the desired relationship between the electric motors, fiberglass springs, and leg joints.

There are currently two robots built using ECD Legs: A monopod, named Thumper, installed here at the Robotics Institute, and a biped, named MABEL, installed in professor Jessy Grizzle's laboratory at the University of Michigan. Thumper will be used to explore the role of compliance in a running gait, while MABEL will be used to explore control theory for legged locomotion.

Personnel [Past Members]

	Name	Title	Email Address
	Jonathan W Hurst	PhD Student, RI	jhurst@cmu.edu

Current Sub-projects

Actuator with Mechanically Adjustable Series Compliance - We are developing actuation methods for highly dynamic legged locomotion.

Publications

Note: This list may not be comprehensive. It contains only those publications in the RI publications database. Entries are listed in reverse chronological order.

• A Policy for Open-Loop Attenuation of Disturbance Effects Caused by Uncertain Ground Properties in Running
  J.W. Hurst, B. Morris, J. Chestnutt, and A. Rizzi
  IEEE Conference on Robotics and Automation, April, 2007. [Abstract]
  Download: pdf [162 KB], ps.gz [128 KB] copyrighted

• Design and Philosophy of the BiMASC, a Highly Dynamic Biped
  J.W. Hurst, J. Chestnutt, and A. Rizzi
  IEEE Conference on Robotics and Automation, April, 2007. [Abstract]
  Download: pdf [386 KB], ps.gz [928 KB] copyrighted

• Physically Variable Compliance in Running
  J.W. Hurst and A. Rizzi
  CLAWAR, SPRINGER-VERLAG, www.springeronline.com, September, 2004. [Abstract]
  Download: pdf [118 KB], ps.gz [155 KB] copyrighted

• An Actuator with Physically Variable Stiffness for Highly Dynamic Legged Locomotion
  J.W. Hurst, J. Chestnutt, and A. Rizzi
  Proceedings of the 2004 International Conference on Robotics and Automation, Vol. 5, May, 2004, pp. 4662 - 4667. [Abstract]
  Download: pdf [758 KB] copyrighted

• An Actuator with Mechanically Adjustable Series Compliance
  J.W. Hurst, J. Chestnutt, and A. Rizzi
  tech. report CMU-RI-TR-04-24, Robotics Institute, Carnegie Mellon University, April, 2004. [Abstract]
  Download: pdf [663 KB], ps.gz [856 KB] copyrighted