Self-Replicating Machines Source: NASA Conference Publication 2255 (1982), based on the Advanced Automation for Space Missions NASA/ASEE summer study Held at the University of Santa Clara in Santa Clara, California, from June 23-August 29, Original idea: John von Neumann, 1948; often referred to as “von Neumann machines” (different from von Neumann architecture)

CS295/CS395/CSYS395Evolutionary Robotics The Golem Project Lipson, H., Pollack J. B., (2000), "Automatic Design and Manufacture of Artificial Lifeforms", Nature 406, pp

CS295/CS395/CSYS395Evolutionary Robotics The Golem Project Step 1: Step 2: Step 3:

The Golem ProjectGenotype encoding:

The Golem ProjectGenotype encoding: Initial population: 200 null genotypes. Fitness: Displacement of the center of mass Evaluation period:“Fixed number (12) of cycles of its neural control”?

The Golem ProjectGenotype encoding: Mutations:1. Change the length of a bar (10%) 2. Change a synaptic weight (10%) 3. add or 4. remove a dangling bar (1%) 5. add or 6. remove unconnected neuron (1%) 7. split vertex into two and add a small bar (3%) 8. split bar into two and add vertex (3%) 9. attach or 10. detach neuron to bar (3%) One mutation was applied to new newly-created genome. Q: Mutation sequence:

Samples from one generation.

Samples from one evolutionary run.

Another way of visualizing artificial evolution: phylogenetic trees Node = individual; link = parent-child relationship Horizontal distance between two nodes = similarity of ancestry ab c d

Samples from two evolutionary runs. “Snakes” “Crabs” The Golem Project

Samples from several evolutionary runs. The Golem Project

Crossing the reality gap: Arrow: Virtual distance Physical distance Pusher: Virtual distance Physical distance Tetrahedron: Virtual distance Physical distance

The Golem ProjectCrossing the reality gap: Step 1: Evolve a robot to locomote in simulation (evolve body and brain). Step 2: Manufacture robot using 3D printer Step 3: Snap in motors and electronics

Crossing the reality gap: Step 1: Evolve a robot to locomote in simulation (evolve body and brain). Step 2: Manufacture robot using 3D printer Step 3: Snap in motors and electronics

Crossing the reality gap: Reduce, Reuse, Recycle… Reduce, Reuse, Recycle…

Open source 3D printing technology, revolutionizing manufacturing

Rep Rap: A machine that makes a machine that makes a machine that makes… Q: How could evolutionary algorithms be used to expand the capabilities of this technology?