Animal tails

Unusual Appendages:

Novel, multi-modal, or multi-functional uses for
limbs, tails, and other body parts

RSS 2018 Workshop
Friday, June 29th, 2018
Aaron M. Johnson, Amir Patel, and Tom Libby
Assistant Professor of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
Senior Lecturer of Electrical Engineering, University of Cape Town, South Africa
Postdoctoral Fellow in Electrical Engineering, University of Washington, Seattle, WA, USA


Mobile robots locomote by pushing on the environment with appendages: legs and wheels on ground, wings or propellers in the air, etc. Intuitively, appendages are generally optimized for the chosen modality. By contrast, animal appendages are diverse and incredibly versatile, enabling multi-modal utility across many tasks. Robots can also benefit from more creative use of appendages: swinging tails that generate inertial forces, walking on wings, swimming with legs, and more. This workshop will broaden our understanding of appendages by exploring their design for novel, multi-modal or multi-functional interactions with the environment or inertial forces. We will explore diverse appendages in animals and robots including tails, wheels, legs, arms, gyros, tracks, and more. What modalities can be harnessed to aid locomotion, and how is morphology shaped by task performance? Robots are not constrained by evolutionary history, so their appendages should be even more diverse than those found in nature. What new appendages can we imagine that add functionality, agility or robustness? The format will consist of a number of invited and contributed presentations from biologists and roboticists on cutting edge research in the field, as well as an open discussion prompted by the questions listed below. The workshop will also accept submissions from non-invited speakers for consideration.


Robot tails

This workshop falls under the "Mechanisms and Design" special theme for RSS 2018. The organizers will assign a chair to each session who will be responsible for reading in advance the material to be presented. In addition to moderating questions from the workshop participants, the chair will raise specific questions prepared in advance of each speaker after their talk. Beyond these question periods between speakers, a dedicated discussion session in the afternoon will provide a venue to summarize the conclusions of the day's proceedings and consider the future and potential of this line of research. A few discussion questions will be sent to the presenters and listed on the workshop website in advance so that participants can have time to prepare and consider their answers. Presenters will also be encouraged to touch on the following set of overarching topics in their talks:

After the workshop, we hope to have a journal special issue for which the speakers at the workshop will be invited. This special issue, as with the workshop, will aim to bring together the many varied approaches being explored for understanding the design and multi-modal use of appendages.


Schedule of events for Friday, June 29th, 2018 (presenting author marked with a *):

09:00 - 09:10 Welcome: Overview, Prospects, and Challenges
09:10 - 10:00 Session 1: Passive and Quasi-static Appendage Use         Chair: Tom Libby
Jonathan Clark* Passive Limbs for Dynamic Running and Climbing
Haosen Xing, Baxi Chong, Guillaume Sartoretti, Daniel I. Goldman, and Howie Choset* Tail Use in Quadruped Improves Static Stability in Diagonal Sequence Walking Gaits
10:00 - 10:30 Refreshment Break
10:30 - 12:00 Session 2: New Results with Inertial Appendages         Chair: Amir Patel
Avik De* and Daniel E. Koditschek Tail Design and Control for a Tail- and Hip-Energized and -Stabilized Bipedal Hopping Robot
Pinhas Ben-Tzvi* Design and Control of Bioinspired Articulated Robotic Tails for Stabilization and Maneuvering of Legged Robots
James P. Schmiedeler* Reaction Wheels as "Appendages" to aid in Underactuated Biped Walking
Joseph Norby* and Aaron Johnson Towards Energy Optimal Design and Control of Tailed Legged Robot Locomotion
Sean W. Gart, Changxin Yan, Ratan Othayoth*, Zhiyi Ren, and Chen Li Active Tail Helps Legged Robots Dynamically Traverse Large Gap and Bump Obstacles
12:00 - 13:30 Lunch Break
13:30 - 14:30 Session 3: Beyond Legged Locomotion         Chair: Aaron Johnson
Ardian Jusufi*, Daniel Vogt, George Lauder, and Robert Wood Undulatory Locomotion with a Soft Robotic Fishtail: Steps towards Closing the Loop with Soft Sensors for Body Stiffness Modulation
Zachary Manchester* Should Satellites Have Tails?
Qiyuan Fu*, Sean W. Gart, Thomas W. Mitchel, and Chen Li A Novel, Adaptive, Partitioned Gait of Biological Snakes Helps Snake Robots Traverse a Large Step
Richard Parker*, Peter Clinton, and Brionny Hooper Tree-to-Tree Locomotion for Forest Operations
14:30 - 15:00 Refreshment Break
15:00 - 16:15 Session 4: Reimagining the Tail         Chair: Ardian Jusufi
Ratan Othayoth, George Thoms, Qihan Xuan, and Chen Li* Vibration Helps Robots Explore Locomotion Energy Landscapes and Transition to More Favorable Locomotor Modes
Amir Patel*, Philipp Suhrcke, Adam Zeloof, Peter Li, Cameron Selby, and Aaron Johnson Tail Aerodynamics in Cheetahs and Robots
Ronald S. Fearing* Tails for Minimally-Actuated Milli-Robots
16:15 - 17:00 Discussion Session

Invited Speakers

Invited speakers will have 20 minutes for presentation and 5 minutes for questions.

Contributed Speakers

We invite anyone interested to submit contributed abstracts for a our "lightning" (PechaKucha-inspired) talks. This is a great opportunity for students and to share works-in-progress.

Submission of 1-page extended abstracts is now closed.

Speakers for contributed abstracts will have 4 minutes for presentation and 1 minute for questions.