Academia.eduAcademia.edu

Outline

Recurrence and Plasticity in Evolved Neural Controllers

2009

Abstract

Mark Ahlstrom. RECURRENCE AND PLASTICITY IN EVOLVED ADAPTIVE NEURAL CONTROLLERS. (Under the direction of Dr. M. H. N. Tabrizi). Department of Computer Science, December 10 2009. Among the more important applications of evolutionary neurocontrollers is the development of systems that are able to dynamically adapt to a changing environment. While traditional approaches to control system design demand that the developer attempt to foresee all possible situations within which the controller may operate, neuroevolutionary approaches can facilitate the design of systems that are capable of operating in unforeseen circumstances. This paper examines two methods that have been used to provide for this adaptivity. The first method is the use of recurrent neural networks that have fixed connection weights. The second develops neurocontrollers with plastic synapses, thus allowing for the adaptation of the connection weights. Previous experimental results have shown that while both approaches can facilitate adaptive behavior, neural plasticity does not necessarily confer the expected benefits. In experiments using the NeuroEvolution of Augmenting Topologies (NEAT) method, discovered that in simple cases, recurrence was sufficient in solving at least some control problems. I examined whether or not these initial results continue to scale upwards into more complex problem spaces. This was done through a series of experiments ranging from controlling a simplified cannon shot to attempting to evolve neural flight controllers capable of flying different airplanes through a series of waypoints. The results of these experiments indicate that the NEAT algorithm itself is unable to scale efficiently to some larger problem spaces.

References (97)

  1. 1 Diagram of the five parts of an artificial neuron. . . . . . . . . . . . .
  2. 2 Hebbian weight update of a neuron. . . . . . . . . . . . . . . . . . . .
  3. 3 Default Sigmoid activation function curve . . . . . . . . . . . . . . .
  4. 4 Sigmoid activation function with large threshold . . . . . . . . . . . .
  5. 5 Single Layer Neural Network . . . . . . . . . . . . . . . . . . . . . . .
  6. 6 Multi Layer Neural Network . . . . . . . . . . . . . . . . . . . . . . .
  7. 7 Recurrent Neural Network . . . . . . . . . . . . . . . . . . . . . . . .
  8. Nonstandard Neural Network . . . . . . . . . . . . . . . . . . . . . .
  9. 9 Nonstandard Functionality in a full network . . . . . . . . . . . . . .
  10. Kohonen SOM for character recognition. . . . . . . . . . . . . . . . .
  11. 11 Reinforcement control . . . . . . . . . . . . . . . . . . . . . . . . . .
  12. 12 Knapsack Problem encoding . . . . . . . . . . . . . . . . . . . . . . .
  13. 13 Initial Fitness Distribution . . . . . . . . . . . . . . . . . . . . . . . .
  14. 14 Knapsack Problem Initial Population . . . . . . . . . . . . . . . . . .
  15. 15 Knapsack Problem Initial Fitness . . . . . . . . . . . . . . . . . . . .
  16. 16 Fitness with poor selection . . . . . . . . . . . . . . . . . . . . . . . .
  17. 17 Single Point Crossover . . . . . . . . . . . . . . . . . . . . . . . . . .
  18. 18 Double Point Crossover . . . . . . . . . . . . . . . . . . . . . . . . . .
  19. 19 Cut and Splice Crossover . . . . . . . . . . . . . . . . . . . . . . . . .
  20. Competing Conventions . . . . . . . . . . . . . . . . . . . . . . . . .
  21. 1 Cannon average fitness . . . . . . . . . . . . . . . . . . . . . . . . . .
  22. 2 Cannon average nodes . . . . . . . . . . . . . . . . . . . . . . . . . .
  23. 3 Cannon best run fitness . . . . . . . . . . . . . . . . . . . . . . . . .
  24. 4 Cannon best run number nodes . . . . . . . . . . . . . . . . . . . . .
  25. 5 Cannon average adaptive fitness . . . . . . . . . . . . . . . . . . . . .
  26. 6 Cannon average number adaptive nodes . . . . . . . . . . . . . . . . .
  27. 7 Cannon best adaptive run fitness . . . . . . . . . . . . . . . . . . . .
  28. 8 Cannon best adaptive run number nodes . . . . . . . . . . . . . . . .
  29. 9 Robot for food foraging . . . . . . . . . . . . . . . . . . . . . . . . . .
  30. 10 Food foraging world . . . . . . . . . . . . . . . . . . . . . . . . . . . .
  31. 11 Food Foraging fitness . . . . . . . . . . . . . . . . . . . . . . . . . . .
  32. 12 Food Foraging average number nodes . . . . . . . . . . . . . . . . . .
  33. 13 Food Foraging best run fitness . . . . . . . . . . . . . . . . . . . . . .
  34. 14 Food Foraging best run number nodes . . . . . . . . . . . . . . . . .
  35. 15 Dangerous Food Foraging fitness . . . . . . . . . . . . . . . . . . . . .
  36. 16 Dangerous Food Foraging average number nodes . . . . . . . . . . . .
  37. 17 Dangerous Food Foraging best run fitness . . . . . . . . . . . . . . .
  38. 18 Dangerous Food Foraging best run number nodes . . . . . . . . . . .
  39. 19 Dangerous Food Foraging adaptive fitness . . . . . . . . . . . . . . .
  40. 20 Dangerous Food Foraging average adaptive number nodes . . . . . . .
  41. 21 Dangerous Food Foraging best adaptive run fitness . . . . . . . . . .
  42. 22 Dangerous Food Foraging best adaptive run number nodes . . . . . .
  43. 23 Safe vs Dangerous foraging fitness comparison . . . . . . . . . . . . .
  44. 24 Safe vs Dangerous foraging node comparison . . . . . . . . . . . . . .
  45. 1 Neural Flight Controller ANN . . . . . . . . . . . . . . . . . . . . . .
  46. 1 Recurrent Flight Controller average fitness . . . . . . . . . . . . . . .
  47. 2 Recurrent Flight Controller average number nodes . . . . . . . . . . .
  48. 3 Recurrent Flight Controller best run fitness . . . . . . . . . . . . . .
  49. 4 Recurrent Flight Controller best run number nodes . . . . . . . . . .
  50. 5 Flight Controller average fitness . . . . . . . . . . . . . . . . . . . . .
  51. 6 Flight Controller average number nodes . . . . . . . . . . . . . . . . .
  52. 7 Flight Controller best adaptive run fitness . . . . . . . . . . . . . . .
  53. 8 Flight Controller best adaptive run number nodes . . . . . . . . . . .
  54. 9 Single Plane Simplified Average Fitness . . . . . . . . . . . . . . . . .
  55. 10 Single Plane Simplified Average number nodes . . . . . . . . . . . . . BIBLIOGRAPHY
  56. Attik, M., Bougrain, L., and Alexandre, F. (2005). Neural network topology opti- mization. Lecture Notes in Computer Science, 3697:53.
  57. Auer, P., Burgsteiner, H., and Maass, W. (2007). A learning rule for very simple universal approximators consisting of a single layer of perceptrons. Neural Networks.
  58. Berndt, J. (2004). Jsbsim: An open source flight dynamics model in c++. AIAA Modeling and Simulation Technologies Conference and Exhibit.
  59. Beyeler, A., Zufferey, J., and Floreano, D. (2009). Vision-based control of near- obstacle flight. Autonomous Robots, pages 1-19.
  60. Chalmers, D. J. (1990). The evolution of learning: An experiment in genetic con- nectionism.
  61. Cybenko, G. (1989). Approximation by superpositions of a sigmoidal function. Math- ematics of Control, Signals, and Systems (MCSS), 2(4):303-314.
  62. Daqi, G. and Shouyi, W. (1998). An optimization method for the topological struc- tures of feed-forward multi-layer neural networks. Pattern recognition, 31(9):1337- 1342.
  63. de Castro, L. (2007). Fundamentals of natural computing: an overview. Physics of Life Reviews, 4(1):1-36.
  64. Emmert-Streib, F. (2006). Influence of the neural network topology on the learning dynamics. Neurocomputing, 69(10-12):1179-1182.
  65. Ferrari, S. and Stengel, R. (2004). Online adaptive critic flight control. Journal of Guidance Control and Dynamics, 27:777-786.
  66. Floreano, D. (1998). Evolutionary re-adaptation of neurocontrollers in changing environments.
  67. Floreano, D. and Nolfi, S. (1997). Adaptive behavior in competing co-evolving species.
  68. Floreano, D. and Urzelai, J. (1999). Evolution of neural controllers with adaptive synapses and compact genetic encoding. Lecture Notes in Computer Science, pages 183-194.
  69. Ge, S., Hang, C., and Zhang, T. (1997). Direct adaptive neural network control of nonlinear systems. American Control Conference, 1997. Proceedings of the 1997, 3.
  70. Gomez, F. and Miikkulainen, R. (2003). Active guidance for a finless rocket using neuroevolution. Lecture Notes in Computer Science, pages 2084-2095.
  71. Hagan, M. and Demuth, H. (1999). Neural networks for control. American Control Conference, 1999. Proceedings of the 1999, 3.
  72. Jansen, T. (2001). On classifications of fitness functions. pages 371-385.
  73. Keane, A. J. (2001). An introduction to evolutionary computing in design search and optimisation. pages 1-11.
  74. Kirkpatrick, S., Gelatt, C., and Vecchi, M. (1983). Optimization by simulated an- nealing. Science, 220:671-680.
  75. Kohl, N. and Miikkulainen, R. (2008). Evolving neural networks for fractured do- mains. GECCO '08: Proceedings of the 10th annual conference on Genetic and evolutionary computation.
  76. Konen, W. and Bartz-Beielstein, T. (2009). Reinforcement learning for games: fail- ures and successes. Proceedings of the 11th annual conference companion . . . .
  77. Linhardt, M. and Butz, M. (2009). Neat in increasingly non-linear control situations. GECCO '09: Proceedings of the 11th annual conference companion on Genetic and evolutionary computation conference.
  78. Luger, G. F. (2001). Artificial Intelligence: Structures and Strategies for Complex Problem Solving. Addison-Wesley Longman Publishing Co., Inc., Boston, MA, USA.
  79. Minsky, M. and Papert, S. (1988). Perceptrons. pages 157-169.
  80. Monroy, G., Stanley, K., and Miikkulainen, R. (2006). Coevolution of neural net- works using a layered pareto archive. Proceedings of the 8th annual conference on Genetic and evolutionary computation, pages 329-336.
  81. Moriarty, D. E. and Miikkulainen, R. (1998). Forming neural networks through efficient and adaptive coevolution.
  82. Noriega, J. and Wang, H. (1995). A direct adaptive neural network control for unknown nonlinearsystems and its application. American Control Conference, 1995. Proceedings of the, 6.
  83. Padhy, N. (2007). Artificial Intelligence and Intelligent Systems. Oxford University Press, New Delhi, India.
  84. Pallett, T. and Ahmad, S. (1993). Adaptive neural network control of a helicopter in vertical flight. Aerospace Control Systems, 1993. Proceedings. The First IEEE Regional Conference on, pages 264-268.
  85. Pardoe, D., Ryoo, M., and Miikkulainen, R. (2005). Evolving neural network en- sembles for control problems. Proceedings of the 2005 conference on Genetic and evolutionary computation, pages 1379-1384.
  86. Pearlmutter, B. A. (1996). Gradient calculations for dynamic recurrent neural net- works: A survey.
  87. Principe, J. C., Euliano, N. R., and Lefebvre, W. C. (1999). Neural and Adaptive Systems: Fundamentals through Simulations with CD-ROM. John Wiley & Sons, Inc., New York, NY, USA.
  88. Reisinger, J. and Miikkulainen, R. (2007). Acquiring evolvability through adaptive representations. GECCO '07: Proceedings of the 9th annual conference on Genetic and evolutionary computation.
  89. Risi, S., Vanderbleek, S., Hughes, C., and Stanley, K. (2009). How novelty search escapes the deceptive trap of learning to learn. GECCO '09: Proceedings of the 11th Annual conference on Genetic and evolutionary computation.
  90. Rojas, R. (1996). Neural networks: A systematic introduction.
  91. Rowe, J. E. (2001). The dynamical systems model of the simple genetic algorithm. pages 31-57.
  92. Soltoggio, A. and Jones, B. (2009). Novelty of behaviour as a basis for the neuro- evolution of operant reward learning. GECCO '09: Proceedings of the 11th Annual conference on Genetic and evolutionary computation.
  93. Stanley, K. (2004). Efficient evolution of neural networks through complexification.
  94. Stanley, K., Bryant, B., and Miikkulainen, R. (2003). Evolving adaptive neural networks with and without adaptive synapses. Evolutionary Computation, 2003. CEC'03. The 2003 Congress on, 4.
  95. Stanley, K. and Miikkulainen, R. (2002). Evolving neural networks through aug- menting topologies. Evolutionary Computation, 10(2):99-127.
  96. Thomson, J., Jha, R., and Pradeep, S. (2004). Neurocontroller design for nonlinear control of takeoff of unmanned aerospace vehicles. Proceedings of the 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV.
  97. Urzelai, J. and Floreano, D. (2001). Evolution of adaptive synapses: Robots with fast adaptive behavior in new environments. Evolutionary Computation, 9(4):495- 524. Valsalam, V. and Miikkulainen, R. (2009). Evolving symmetric and modular neu- ral networks for distributed control. GECCO '09: Proceedings of the 11th Annual conference on Genetic and evolutionary computation.