Evolutionary RoboticsEvolutionary RoboticsTeresa PegorsTeresa Pegors

Importance of EmbodimentImportance of Embodiment

Embodied system includes:Embodied system includes: BodyBody – morphology of system and – morphology of system and

movement capabilities movement capabilities Control ArchitectureControl Architecture – nervous system, – nervous system,

normally adaptive and plastic. normally adaptive and plastic. EnvironmentEnvironment – all things external to the – all things external to the

system but can include system as well.system but can include system as well. All 3 dynamically coupled to each otherAll 3 dynamically coupled to each other Can we synthesize such a system in an Can we synthesize such a system in an

evolutionary context?evolutionary context?

Simulation vs. Real WorldSimulation vs. Real World

Problems with Simulation:Problems with Simulation: Not all physical properties are simulatedNot all physical properties are simulated sensors return perfect values sensors return perfect values Same sensors are considered exactly sameSame sensors are considered exactly same

Problems with Real World:Problems with Real World: Limited resourcesLimited resources Time constraintTime constraint

Makes doubly difficult to evolve both Makes doubly difficult to evolve both controllers controllers andand morphology morphology

General SolutionsGeneral Solutions

((Miglino, Lund, and Nolfi 1996) - evolving neurocontrollersMiglino, Lund, and Nolfi 1996) - evolving neurocontrollers

Look-up TableLook-up Table Sensor readings are taken from large Sensor readings are taken from large

combination of orientations and distancescombination of orientations and distances Allows for intrinsic differences in sensorsAllows for intrinsic differences in sensors Accounts for idiosyncrasies of environmentAccounts for idiosyncrasies of environment

After transfer to real world, run a few more After transfer to real world, run a few more generations generations Allows system to regain lost fitnessAllows system to regain lost fitness

General Solutions (cont’d)General Solutions (cont’d)

““Conservative Position Noise”Conservative Position Noise” Perception is as if farther or closer than really Perception is as if farther or closer than really

are, determined by randomly selected axis are, determined by randomly selected axis Reproduces effects caused by Reproduces effects caused by

illuminations/shadows/etc.illuminations/shadows/etc.NO NOISE CONSERVATIVE POSITION NOISE

Evolving Morphology (Simulation)Evolving Morphology (Simulation)

Karl Sims Karl Sims Recursive, graph based GARecursive, graph based GA Not physically realisticNot physically realistic

Josh Bongard Josh Bongard Physically realistic environment Physically realistic environment ““Artificial Ontogeny (AO)”Artificial Ontogeny (AO)”

Differential gene expressionDifferential gene expression Diffused gene productsDiffused gene products Modular (spheres)Modular (spheres)

(Simulation -> Real World)(Simulation -> Real World)

((Jordan PollackJordan Pollack))

[1] Universal[1] Universal [3]Efficient[3]Efficient

[2] Conservative[2] Conservative [4]Buildable[4]Buildable

1)1) Morphology w/o ControllerMorphology w/o Controller

(Simulation -> Real World)(Simulation -> Real World)

2) 2D modular system from L-System2) 2D modular system from L-System Reduction of dimensionalityReduction of dimensionality Re-usable modules lowers complexityRe-usable modules lowers complexity

(Simulation -> Real World)(Simulation -> Real World)

3) Automatic “design and manufacture” of 3) Automatic “design and manufacture” of 3D systems3D systems Large difference between physical and virtual Large difference between physical and virtual

environment environment Closer to evolving w/o human interventionCloser to evolving w/o human intervention

Relevant LiteratureRelevant Literature

Nolfi S. and Floreano D. (2000). Nolfi S. and Floreano D. (2000). Evolutionary Robotics. Evolutionary Robotics. Cambridge: Cambridge: MIT Press.MIT Press.

H. Lipson and J. B. Pollack (2000), "H. Lipson and J. B. Pollack (2000), "Automatic design and Automatic design and Manufacture of Robotic LifeformsManufacture of Robotic Lifeforms", Nature 406, pp. 974-978. ", Nature 406, pp. 974-978.

Funes, P. and Pollack, J. (1999). “Funes, P. and Pollack, J. (1999). “Computer Evolution of Buildable Computer Evolution of Buildable Objects”Objects”. In . In Evolutionary Design by ComputersEvolutionary Design by Computers. P. Bentley (editor). . P. Bentley (editor). Morgan Kaufmann, San Francisco. pp. 387-403. Morgan Kaufmann, San Francisco. pp. 387-403.

Bongard, J. C. and R. Pfeifer (2003) Bongard, J. C. and R. Pfeifer (2003) Evolving Complete Agents Evolving Complete Agents Using Artificial OntogenyUsing Artificial Ontogeny, in Hara, F. and R. Pfeifer, (eds.), , in Hara, F. and R. Pfeifer, (eds.), Morpho-Morpho-functional Machines: The New Species (Designing Embodied functional Machines: The New Species (Designing Embodied Intelligence)Intelligence) Springer-Verlag, pp. 237-258. Springer-Verlag, pp. 237-258.

Sims K. "Evolving Virtual Creatures" Computer Graphics (Siggraph Sims K. "Evolving Virtual Creatures" Computer Graphics (Siggraph '94 Proceedings), July 1994, pp.15-22. '94 Proceedings), July 1994, pp.15-22.