Machine Metabolism - Truss Structure Manipulation using Robots

Project Members: Jeremy Blum, Franz Nigl, Shuguang Li, David Alan Hjelle, Daniel Lobo, Eric Schweikardt

Biological organisms can metabolize: break down nutrients into basic building blocks and then use those building blocks to create new things. What if we could reproduce this kind of process in a robotic system?

This would allow many useful properties for engineering and manufacturing:

  • Perfect reuse and recycling of modular elements from one object into another.
  • Adaptation and robustness to fluctuations in resource availability.
  • Self-repair.
  • Autonomous design satisfying given functional requirements for the system.

Ultimately, we hope that such work can provide insights into the art and science of design, the process of creativity, and biological metabolism. We also aim for wide-ranging practical applications, in areas as diverse as disaster recovery, design engineering, and space exploration.

We are currently exploring these ideas in several areas. First, we have designed and constructed a robot testbed capable of reconfiguring simple truss structures, as shown in the concept image on the left and in the video below. Second, we are working on devising genetic algorithms that are capable of performing reconfigurations of these such structures to fulfill given functional requirements. Finally, we hope to expand this work into larger fields of exploration: kinematic structures, automated design, and more.



Click each image for a high-res version


Q: How long did this take to create?
A: This robot has been through several design revisions.  The second and third versions, shown in the video above, are a significant departure from the first version, which is described in the papers by Hjelle below.  The primary difference is the co-design of the 3D-printed trusses and gears.  The first version of the robot was developed in 2009, the second version in 2010, and the third version in 2011.

Q: What are some of the implications of this technology?
A: Think big.  One of the most interesting applications is on the international space station.  Imagine that a truss supporting the station's solar panels is damaged by space debris.  Instead of sending astronauts out on a dangerous spacewalk, robots such as the one demonstrated above could be deployed to replace the damaged struss.  Terrestrial applications are possible as well.  Metabolic machines could be used to build or repair cell phone towers, skyscrapers, and more.

Q: What's the next step?
A: One of the most important things to do next will involve developing an improved machanism for the the robot to carry around several trusses at once.  This will greatly increase the number of actions it can perform, and decrease construction time.  Additional plans include implementing genetic algorithms to allow the robot to plan its own paths based on design constrains of the final structure.


Nigl, F., Li, S., Blum, J. E., Lipson, H., (2011) "Autonomous Truss Reconfiguration and Manipulation", IEEE Robotics and Automation Magazine, in press.

Lobo, D., Hjelle, D. A., Lipson, H., (2009) "Reconfiguration Algorithms for Robotically Manipulatable Structures," In Proceedings of ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots (ReMAR 2009), June 2009

Hjelle, D. A., Lipson, H., (2009) "A Robotically Reconfigurable Truss," In Proceedings of ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots (ReMAR 2009), June 2009.