Neural Morphogenetic Evolution System (NMES)

Low-Fidelity Bio-Inspired Design for Evolving 2D and 3D Robotic Structures and Neural Controllers


Table of Contents


1. Introduction

Welcome to the Neural Morphogenetic Evolution System (NMES) documentation. NMES is an innovative engineering framework designed to co-evolve the physical structures (morphology) and neural control systems of agents within 2D and 3D environments. Inspired by biological processes, NMES employs low-fidelity, abstracted models to facilitate the automated design and optimization of intelligent agents tailored for practical applications in robotics, gaming, biomedical engineering, and more. By integrating neuroevolution, neural architecture search (NAS), and procedural content generation, NMES provides a versatile platform for evolving diverse and adaptive structures alongside their neural controllers.


2. System Overview

NMES is a comprehensive engineering framework that combines several advanced artificial intelligence methodologies to create adaptive and intelligent agents in 2D and 3D spaces. The framework consists of four primary components:

  • Morphogenetic Decoder (DNA → Structure): Converts DNA-like structures into actionable instructions to generate 2D or 3D components forming the agent's body, inspired by simplified biological morphogenesis.
  • DNA Generation System: Generates new DNA sequences that can be fed into the Morphogenetic Decoder to produce diverse and optimized structures tailored for practical applications.
  • Neural Controller Evolution: Designs and evolves neural networks that control the behavior and interactions of the generated structures, ensuring functional and adaptive behaviors.
  • Meta-Optimization Layer: Manages the incremental improvement process using evolutionary optimization and neural architecture search techniques, optimizing both morphology and neural controllers.

This modular architecture ensures that each component can be developed, tested, and optimized independently, facilitating scalability and flexibility for real-world engineering projects.


3. Architecture

The architecture of NMES is modular, allowing each component to interact seamlessly while maintaining separation of concerns. This design facilitates easier testing, debugging, and future enhancements.

Note: For a detailed view of the system architecture, please refer to the GitHub repository.


4. Components

Blueprint

The Blueprint is the core component encapsulating the entire neural network. It manages neurons, quantum neurons, input and output nodes, and activation functions.

  • Neurons: Represent individual processing units within the network.
  • QuantumNeurons: Specialized neurons that may leverage quantum computing principles.
  • InputNodes & OutputNodes: Define the entry and exit points for data within the network.
  • ScalarActivationMap: Maps activation function names to their corresponding functions.

Key Functionalities:

  • Initialization: Sets up the foundational structure of the network.
  • Loading Neurons: Imports neuron configurations from JSON data.
  • Adding Nodes: Facilitates the dynamic addition of input and output nodes.
  • Activation Application: Applies specified activation functions to neuron outputs.
  • Forward Propagation: Processes inputs through the network over defined timesteps.
  • Mutation: Evolves the network structure by inserting new neurons and altering connections.

Model Metadata

ModelMetadata holds comprehensive information about each AI model within NMES, including:

  • Basic Information: Model ID, project name, descriptions, parent and child model relationships, creation and modification timestamps.
  • Neuronal Structure: Total number of neurons and layers, range of layers and neurons per layer.
  • Performance Metrics: Training and testing accuracies, error counts, forgiveness thresholds, etc.
  • Session Information: (Planned) Details about training and testing sessions.
  • Optimization Settings: Possible mutations, bias and weight adjustment increments.
  • Advanced Metadata: Optimization targets, compatible environments, tags, neuron types, attention mechanisms, dropout usage.
  • Resource Requirements: Estimated memory usage and compute time.

This metadata is crucial for tracking the evolution and performance of models over time. For more detailed information, refer to the GitHub repository.

Neuron

A Neuron represents a single processing unit within the network, capable of various functionalities based on its type. Key attributes include:

  • ID: Unique identifier for the neuron.
  • Type: Defines the neuron's role (e.g., Dense, RNN, LSTM, CNN, Dropout, BatchNorm, Attention, NCA).
  • Value: Current activation value of the neuron.
  • Bias: Offset applied during activation.
  • Connections: Links to other neurons, each with associated weights.
  • Activation: Specifies the activation function used.
  • Additional Fields: Depending on the type, neurons may have specialized attributes such as GateWeights for LSTM, BatchNormParams for Batch Normalization, AttentionWeights for Attention mechanisms, Kernels for CNNs, and state vectors for NCA neurons.

Neuron Processing:

Neurons process inputs based on their type, applying appropriate activation functions and handling specialized behaviors like gating in LSTMs or convolution operations in CNNs. For implementation details, please visit the GitHub repository.

Mutations

Mutations are evolutionary operations that modify the network's structure to explore new configurations and optimize performance. Key functionalities include:

  • Insertion of Neurons: Adds new neurons of specified types between input and output nodes, adjusting connections accordingly.
  • Initialization of Specialized Fields: Sets up neuron-specific parameters post-insertion, such as GateWeights for LSTM neurons or BatchNormParams for BatchNorm neurons.
  • Evolutionary Strategies: Implements various evolutionary algorithms to guide the mutation process, ensuring a balance between exploration and exploitation.

Mutations are central to the neuroevolutionary aspect of NMES, driving the continuous improvement and diversification of the network. For more information on mutations, visit the GitHub repository.


5. Technical Details

Morphogenetic Decoder

The Morphogenetic Decoder is responsible for transforming DNA-like structures into actionable instructions that generate 2D or 3D components of agents. This process is inspired by biological morphogenesis but employs simplified, abstracted models to facilitate efficient and practical structure generation for engineering applications.

Key Features:

  • Genetic Encoding Interpretation: Decodes genetic information to determine the structure and configuration of agents.
  • Structure Generation: Produces tangible components (e.g., limbs, geometric shapes) that form the agent's body.
  • Integration with Blueprint: Interfaces with the Blueprint to incorporate generated structures into the neural network.

Comparable Systems:

  • Karl Sims' Evolved Virtual Creatures: Pioneering work in evolving virtual organisms with both morphology and control systems.
  • Compositional Pattern Producing Networks (CPPNs): Networks that generate complex patterns and structures based on genetic encoding.
  • L-Systems: Formal grammars used to model the growth processes of plant development and other biological structures.

For implementation specifics, refer to the GitHub repository.

DNA Generation System

The DNA Generation System acts as a generative model, creating new DNA sequences that define the morphology of agents. This system employs various evolutionary algorithms to ensure diversity and optimization.

Potential Implementations:

  • Genetic Algorithms (GAs): Utilize selection, crossover, and mutation to evolve DNA sequences over generations.
  • Evolutionary Strategies (ES): Focus on optimizing continuous parameters within DNA structures.
  • Quality-Diversity Algorithms (e.g., MAP-Elites): Explore and maintain a diverse set of high-quality solutions.
  • Novelty Search: Encourages exploration of novel and unique DNA configurations to prevent premature convergence.

Functionality:

  • Generation of Viable DNA: Ensures that produced DNA sequences are capable of generating functional and diverse agent structures.
  • Diversity Preservation: Maintains a wide variety of DNA configurations to explore a broad search space.
  • Integration with Morphogenetic Decoder: Feeds generated DNA into the Morphogenetic Decoder for structure creation.

Detailed implementation can be found in the GitHub repository.

Neural Controller Evolution

The Neural Controller Evolution component designs and evolves the neural networks that govern the behavior and interactions of the generated structures. This ensures that agents not only have diverse morphologies but also possess optimized control systems to achieve their goals.

Key Implementations:

  • Neural Architecture Search (NAS): Automates the design and optimization of neural network architectures.
  • HyperNEAT-like Indirect Encoding: Encodes neural networks in a way that captures structural patterns and symmetries.
  • Adaptive Topology Evolution: Dynamically adjusts the network topology to better fit the agent's morphology and task requirements.
  • Weight Optimization: Fine-tunes the weights of neural connections to enhance performance.

Functionality:

  • Co-Evolution of Structure and Control: Simultaneously evolves both the physical structure and the neural controllers to achieve synergistic improvements.
  • Performance Evaluation: Assesses the effectiveness of neural controllers based on predefined fitness criteria.
  • Integration with Meta-Optimization Layer: Collaborates with the meta-optimization layer to guide evolutionary strategies and parameter adjustments.

For more details on neural controller evolution, please visit the GitHub repository.

Meta-Optimization Layer

The Meta-Optimization Layer oversees the incremental improvement processes within NMES, ensuring that evolutionary strategies are effectively driving progress toward defined goals.

Potential Implementations:

  • Population-Based Training: Manages multiple populations of agents, facilitating competition and cooperation.
  • Multi-Objective Optimization: Balances multiple fitness criteria, such as speed, efficiency, and adaptability.
  • Surrogate Model-Based Optimization: Uses surrogate models to predict fitness outcomes, reducing computational overhead.
  • Gradient-Free Optimization Methods: Employs optimization techniques that do not rely on gradient information, suitable for complex and non-differentiable fitness landscapes.

Functionality:

  • Management of Evolutionary Processes: Coordinates the selection, mutation, and crossover operations across different components.
  • Incremental Learning: Facilitates the gradual improvement of agents by integrating learning mechanisms over generations.
  • Performance Tracking: Monitors and records the progress of evolutionary processes, providing insights for further optimization.

Explore the Meta-Optimization Layer in detail by visiting the GitHub repository.


6. Installation

Note: Detailed installation instructions are available in the GitHub repository. Please ensure you have the necessary dependencies and a compatible environment to run NMES.

Prerequisites

  • Go Programming Language: Ensure Go is installed on your system. You can download it from golang.org.
  • JSON Data: Prepare JSON files containing neuron configurations as per the system's requirements.
  • Development Environment: Set up an IDE or code editor of your choice (e.g., VS Code, GoLand).

Installation Steps

  • Clone the Repository:
  • Install Dependencies:

    Follow the instructions provided in the GitHub repository.

  • Build the Project:

    Refer to the build instructions in the GitHub repository.

  • Run Tests:

    Execute the test suites as outlined in the GitHub repository.

Note: Replace placeholders with actual repository details if applicable.


7. Usage

This section provides a step-by-step guide on how to utilize the NMES framework to create, evolve, and optimize neural morphogenetic systems. For comprehensive examples and usage scenarios, please refer to the GitHub repository.

Initializing the Blueprint

The Blueprint serves as the foundation of the neural network within NMES. To initialize a new Blueprint, follow the instructions in the GitHub repository.

Loading Neurons

Neurons are essential building blocks of the neural network. To load neurons from a JSON string, refer to the code examples provided in the GitHub repository.

Adding Input and Output Nodes

Defining input and output nodes is crucial for establishing data flow within the network. Detailed instructions and code snippets are available in the GitHub repository.

Running the Network

To execute the neural network and propagate inputs through it, follow the guidelines and examples provided in the GitHub repository.

Mutating the Network

Evolving the network structure is facilitated through mutations. To insert new neurons and evolve the network, refer to the mutation strategies outlined in the GitHub repository.


8. Examples

Example 1: Basic Network Initialization and Execution

This example demonstrates the basic steps to initialize a Blueprint, load neurons, add input and output nodes, run the network, and mutate the network. For the complete implementation, please visit the GitHub repository.

Example 2: Evolving a CNN Neuron

This example illustrates how to evolve a Convolutional Neural Network (CNN) neuron within the network. Detailed steps and code snippets are available in the GitHub repository.


9. Potential Applications

NMES's ability to co-evolve both morphology and neural controllers makes it versatile across various practical domains:

  • Robotics

    • Evolutionary Robotics: Design robots with optimized physical structures and control systems tailored for specific tasks.
    • Soft Robotics Design: Create adaptable and flexible robots capable of navigating complex environments.
    • Modular Robot Optimization: Develop modular robots that can reconfigure their parts dynamically to perform diverse functions.
  • Engineering Design

    • Generative Design: Automate the creation of complex structures optimized for specific performance criteria.
    • Topology Optimization: Optimize the material layout within a given design space for strength and weight.
    • Adaptive Structures: Develop structures that can adapt their shape and functionality in response to environmental changes.
  • Artificial Life Research

    • Digital Organism Evolution: Simulate the evolution of digital organisms with complex behaviors and structures.
    • Emergence of Complex Behaviors: Study how simple evolutionary rules can lead to the emergence of sophisticated behaviors.
    • Morphological Computation Studies: Explore how physical structures contribute to computational processes within agents.
  • Gaming and Virtual Environments

    • Intelligent Agents: Create game agents with diverse and optimized morphologies and behaviors, enhancing realism and challenge.
    • Procedural Content Generation: Generate dynamic and varied game environments and objects based on evolved structures.
    • Adaptive Game Mechanics: Implement game mechanics that evolve alongside agents, providing a continually changing gameplay experience.
  • Biomedical Engineering

    • Prosthetics Design: Develop prosthetic devices that adapt to user needs and movements through evolutionary optimization.
    • Biomechanical Simulations: Simulate and study the evolution of biological structures and their control systems.


11. Technical Challenges

Search Space Complexity

Description: The combined search space for both morphology and neural architectures is vast and highly complex.

Solutions:

  • Implement efficient exploration strategies: Such as Novelty Search to explore diverse configurations.
  • Utilize dimensionality reduction techniques: To manage and navigate the search space effectively.

Fitness Landscape

Description: The fitness landscape is highly non-linear with numerous local optima, making optimization difficult.

Solutions:

  • Employ diversity preservation mechanisms: To maintain a varied population of solutions.
  • Use multi-objective optimization: To balance different fitness criteria and avoid premature convergence.

Implementation Challenges

  • Physics Simulations: Accurately simulating physical interactions for evolved morphologies requires robust and efficient simulation environments.
  • Computational Intensity: Neuroevolution and NAS are computationally demanding, necessitating optimized algorithms and possibly distributed computing resources.
  • Scalability: As the system evolves, maintaining performance and managing increasing complexity is essential.

Integration Complexity

Description: Seamlessly integrating multiple AI methodologies (neuroevolution, NAS, procedural generation) is inherently complex.

Solutions:

  • Maintain a modular architecture: To isolate and manage different components.
  • Develop clear interfaces and communication protocols: Between modules to ensure smooth interactions.

For more insights into handling integration complexities, check the GitHub repository.


12. Future Work

To advance NMES and realize its full potential, the following areas are identified for future development:

  • Enhanced Morphogenetic Decoding

    Goal: Improve the fidelity and diversity of generated structures by refining the DNA-to-instruction mapping.

    Approach: Incorporate more complex genetic encoding schemes and leverage advanced pattern generation techniques like CPPNs.

  • Advanced Neural Architecture Search

    Goal: Optimize the efficiency and performance of neural controllers through sophisticated NAS techniques.

    Approach: Integrate state-of-the-art NAS algorithms and explore hybrid approaches combining reinforcement learning with evolutionary strategies.

  • Real-Time Adaptation and Learning

    Goal: Enable agents to adapt and learn in real-time within dynamic environments.

    Approach: Incorporate reinforcement learning and online learning mechanisms into the neural controllers.

  • Distributed and Parallel Computing

    Goal: Address computational intensity by leveraging distributed computing resources.

    Approach: Implement parallel processing and distributed evolutionary algorithms to expedite the evolution process.

  • Enhanced Evaluation Metrics

    Goal: Develop more comprehensive and nuanced fitness metrics to better guide the evolutionary process.

    Approach: Incorporate multi-objective metrics that evaluate both morphological complexity and behavioral performance.

  • User Interface and Visualization

    Goal: Provide intuitive tools for users to interact with, monitor, and visualize the evolution process.

    Approach: Develop graphical interfaces and dashboards that display agent morphologies, neural network structures, and performance metrics in real-time.

  • Application-Specific Customizations

    Goal: Tailor NMES to specific application domains such as robotics, gaming, or biomedical engineering.

    Approach: Develop domain-specific modules and optimization criteria to enhance relevance and performance within targeted fields.

For more information on future development plans, visit the GitHub repository.


13. Contributing

Contributions to NMES are welcome! Whether you're looking to report a bug, suggest an enhancement, or contribute code, your input is valuable to the growth and improvement of the framework.

How to Contribute

  • Fork the Repository: Click the "Fork" button at the top-right corner of the GitHub repository page.
  • Clone Your Fork: Visit your forked repository and follow the cloning instructions.
  • Create a Branch: Create a new branch for your feature or fix as outlined in the GitHub repository.
  • Make Your Changes: Implement your feature or fix in your local repository.
  • Commit Your Changes: Commit your changes with clear and descriptive messages.
  • Push to Your Fork: Push your committed changes to your forked repository on GitHub.
  • Create a Pull Request: Navigate to your fork on GitHub and click the "Compare & pull request" button to submit your changes for review.

Code of Conduct

Please adhere to the Code of Conduct when contributing to NMES to ensure a respectful and productive environment for all contributors. The Code of Conduct can be found in the GitHub repository.


14. License

NMES is released under the [Specify License Here]. For more details, please refer to the LICENSE file in the GitHub repository.
Note: Decide on a suitable license and update this section accordingly.


15. Contact

For questions, suggestions, or support, please contact:


Appendix

Glossary

  • Neuroevolution: The use of evolutionary algorithms to develop and optimize neural networks.
  • Neural Architecture Search (NAS): Automated process of designing neural network architectures.
  • Morphogenesis: Biological process that causes an organism to develop its shape.
  • LSTM: Long Short-Term Memory, a type of recurrent neural network.
  • CNN: Convolutional Neural Network, often used for image processing.
  • Batch Normalization: Technique to normalize the inputs of each layer to improve training speed and stability.
  • Dropout: Regularization technique to prevent overfitting by randomly dropping neurons during training.
  • NCA: Neural Cellular Automata, models that simulate cellular processes using neural networks.

References

  • Stanley, K. O., & Miikkulainen, R. (2002). Evolving Neural Networks through Augmenting Topologies. Evolutionary Computation.
  • Hinton, G. E., Srivastava, N., & Swersky, K. (2012). Neural Networks for Machine Learning. Lecture Notes.
  • Goodfellow, I., Pouget-Abadie, J., Mirza, M., Xu, B., Warde-Farley, D., Ozair, S., ... & Bengio, Y. (2014). Generative Adversarial Nets. Advances in Neural Information Processing Systems.
  • Lehman, J., & Stanley, K. O. (2011). Abandoning Objective Traps: Moving Beyond Single Objective Optimization in Evolutionary Computation. Proceedings of the Genetic and Evolutionary Computation Conference.

Note: Update references with relevant literature as your project progresses.

This documentation is a living document and will be updated as NMES evolves. Contributions to improve the documentation are welcome.