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Legless Locomotion
Head: Matthew Mason
Contact: Alfred Rizzi (arizzi@bostondynamics.com)

Mailing address:
Carnegie Mellon University
Robotics Institute
5000 Forbes Avenue
Pittsburgh, PA 15213

Associated lab/group: Manipulation Lab

This page last updated - January 2006.

A flipped turtle is stuck because it's feet do not touch the ground. One way of escape is to rock itself on it's shell so that it rights itself. Alternately, can the turtle locomote in it's flipped configuration merely by swinging the legs and rocking back and forth? Similarly, what happens when a robot is high-centered? How can it move in such a situation? My doctoral work has "discovered" this novel locomotion technique for high-centered robots, a locomotion we call \emph{legless locomotion}. The high-level goal of this project is to investigate escape/recovery strategies when robots get stuck (mobile-robot errors).

To simplify the high-centered-robot problem, we built a prototype called Rocking and Rolling Robot (RRRobot). It is "high-centered for life", that is, its legs don't touch the ground in its nominal position. We show in a recent paper that it is possible to locomote RRRobot in the plane just by wiggling its short legs, i.e., the robot locomotes by transferring energy and momentum to produce a rocking and rolling body motion. This rocking motion when coupled with the nonholonomic contact constraints produces incremental translation. An important aspect of this locomotion is that RRRobot's inertia varies with leg configuration.

Name - Title <Email Address>
• [Home] Matthew Mason - Director, Robotics Institute, RI/CS <matt.mason@cs.cmu.edu>

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

• Toward Legless Locomotion Control
  R. Balasubramanian, A. Rizzi, and M. Mason
  2006 IEEE/RSJ International Conference on Intelligent Robots and Systems, October, 2006, pp. 5594 - 5599. [Abstract]
  Download: pdf [968 KB] copyrighted

• Kinematic reduction and planning using symmetry for a variable inertia mechanical system
  R. Balasubramanian and A. Rizzi
  Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, Vol. 4, October, 2004, pp. 3829 - 3834. [Abstract]
  Download: pdf [337 KB] copyrighted

• Legless Locomotion: Models and Experimental Demonstration
  R. Balasubramanian, A. Rizzi, and M. Mason
  Proceedings of the IEEE International Conference on Robotics and Automation, Vol. 2, April, 2004, pp. 1803 - 1808. [Abstract]
  Download: pdf [653 KB] copyrighted

• Legless Locomotion for Legged Robots
  R. Balasubramanian, A. Rizzi, and M. Mason
  tech. report CMU-RI-TR-04-05, Robotics Institute, Carnegie Mellon University, January, 2004. [Abstract]
  Download: pdf [973 KB] copyrighted

• Legless Locomotion for Legged Robots
  R. Balasubramanian, A. Rizzi, and M. Mason
  Proceedings of the International Conference on Robotics and Intelligent Systems, Vol. 1, October, 2003, pp. 880 - 885. [Abstract]
  Download: pdf [473 KB] copyrighted