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Module 1: ROS 2 Foundations for Humanoid Robotics

Welcome to Module 1 of the Physical AI & Humanoid Robotics curriculum. This module provides a comprehensive introduction to ROS 2 (Robot Operating System 2), the industry-standard middleware for building sophisticated robot applications.

Module Overview​

By the end of this module, you will be able to:

  • Set up and configure a complete ROS 2 development environment
  • Create and manage ROS 2 packages for humanoid robot applications
  • Implement communication patterns using topics, services, and actions
  • Define robot bodies using URDF (Unified Robot Description Format)
  • Bridge AI systems with robot control through custom interfaces

Prerequisites​

Before starting this module, you should have:

  • Programming: Intermediate Python skills (classes, async, decorators)
  • Linux: Basic command-line familiarity (navigation, file operations)
  • Math: Understanding of 3D coordinate systems and transformations
  • Hardware: Computer capable of running Ubuntu 24.04 or WSL2

Module Structure​

Chapters​

Chapter 1: Introduction to ROS 2​

Understand the fundamental architecture of ROS 2 and set up your development environment.

Key Topics:

  • ROS 2 design philosophy and DDS middleware
  • Installation on Ubuntu 24.04 (native, WSL2, Docker)
  • Workspace creation with colcon
  • Your first ROS 2 node

Time Estimate: 2-3 hours

Chapter 2: Nodes, Topics, Services, and Actions​

Master ROS 2's powerful communication patterns for building modular robot systems.

Key Topics:

  • Publishers and Subscribers for streaming data
  • Services for synchronous request-response
  • Actions for long-running tasks with feedback
  • Launch files for multi-node systems

Time Estimate: 4-5 hours

Chapter 3: URDF for Humanoid Robot Bodies​

Define and visualize humanoid robot physical structures using URDF.

Key Topics:

  • URDF file format and XML structure
  • Links (bodies) and their visual/collision/inertial properties
  • Joints (connections) and motion constraints
  • Building a complete humanoid model
  • RViz2 visualization and joint control

Time Estimate: 3-4 hours

Chapter 4: Bridging AI and ROS 2 Control​

Connect AI systems to robot control through custom interfaces and command interpretation.

Key Topics:

  • Custom message, service, and action definitions
  • Command interpreter architecture
  • Behavior action servers
  • State machines for complex behaviors
  • Introduction to Module 4 VLA integration

Time Estimate: 4-5 hours

Code Examples​

All code examples for this module are available in the repository:

docs/code-examples/module-1/
├── chapter-01/
│   └── hello_ros2.py              # First ROS 2 node
├── chapter-02/
│   ├── publisher_node.py          # Topic publisher
│   ├── subscriber_node.py         # Topic subscriber
│   ├── service_server.py          # Service server
│   ├── service_client.py          # Service client
│   ├── action_server.py           # Action server
│   ├── action_client.py           # Action client
│   └── sensor_pipeline.launch.py  # Launch file example
├── chapter-03/
│   ├── humanoid_urdf/
│   │   └── humanoid.urdf          # Complete humanoid model
│   └── launch/
│       └── display.launch.py      # URDF visualization
└── chapter-04/
    ├── custom_msgs/               # Message definitions
    │   ├── msg/
    │   ├── srv/
    │   └── action/
    ├── command_interpreter.py     # NL command parsing
    └── behavior_action_server.py  # Behavior execution

Learning Path​

  1. Week 1: Chapters 1-2 (ROS 2 basics and communication)
  2. Week 2: Chapter 3 (URDF and visualization)
  3. Week 3: Chapter 4 (AI integration patterns)

Hands-On Exercises​

Each chapter includes exercises at three difficulty levels:

  • Basic: Reinforce core concepts (~30 minutes)
  • Intermediate: Apply knowledge to new scenarios (~1 hour)
  • Advanced: Extend and innovate (~2+ hours)

Complete at least the Basic and Intermediate exercises before moving to the next chapter.

Connection to Other Modules​

  • Module 2: Uses ROS 2 for Gazebo simulation integration
  • Module 3: Builds perception pipelines using ROS 2 topics and services
  • Module 4: Deploys VLA models through the AI-ROS bridge from Chapter 4

Resources​

Official Documentation​

Community​

Books​

  • A Gentle Introduction to ROS by Jason O'Kane
  • Programming Robots with ROS by Morgan Quigley et al.
  • Robot Operating System (ROS): The Complete Reference by Anis Koubaa

Assessment​

After completing this module, you should be able to:

SkillAssessment Criteria
Environment SetupCreate and build ROS 2 workspace
Node DevelopmentCreate nodes with proper lifecycle
CommunicationImplement pub/sub, services, and actions
URDFDefine robot with correct joint/link structure
AI IntegrationCreate custom interfaces for AI systems

Next Steps​

After completing Module 1:

  1. Review: Ensure all exercises are completed
  2. Practice: Build a simple robot application combining all concepts
  3. Proceed: Move to Module 2 (Simulation) or Module 3 (Perception)

Ready to begin? Start with Chapter 1: Introduction to ROS 2!