ROS2 - Advanced Concepts 🚀

Introduction

• How to Follow this Course
• Setup Your Environment (+ Tools)
• Node OOP Template

ROS2 Actions Python 💻

• Why and When to Use ROS 2 Actions
• How do ROS 2 Actions Work?
• Create an Action Definition
• Write a Minimal Python Action Server
• Write a Minimal Python Action Client
• Accept or Reject a Goal
• Goal State Machine Explained
• Set a Goal as Succeeded or Aborted
• Send Goal Feedback
• Cancel a Goal
• Introspect Actions with ros2 action (command line)
• Goal Policy: Multiple Goals in Parallel
• Goal Policy: Refuse New Goal if Current Goal is Active
• Goal Policy: Preempt Current Goal if New Goal Received
• Goal Policy: Queue Goals

ROS2 Actions C++ 💻

• C++ Action Server
• C++ Action Client
• Accept or Reject a Goal (C++)
• Set a Goal as Succeeded or Aborted (C++)
• Send Goal Feedback (C++)
• Cancel a Goal (C++)
• Goal Policy: Multiple Goals in Parallel (C++)
• Goal Policy: Refuse New Goal if Current Goal is Active (C++)
• Goal Policy: Preempt Current Goal if New Goal Received (C++)
• Goal Policy: Queue Goals (C++)

ROS2 Actions - Challenge 💡

• Step 1 - Create and Generate the Action
• Step 2 - Action Server
• Step 3 - Action Client
• Step 4 - Accept Goal and Goal Policy
• Step 5 - Cancel with a Subscriber
• Actions Challenge - C++ Code

ROS2 Lifecycle Nodes 🔄

• What are Lifecycle Nodes, When to Use Them
• Code Setup
• Write a Lifecycle Node in Python
• Transition Between States (with ros2 lifecycle cmd line)
• Processing Errors
• Lifecycle Node Manager (using Lifecycle Services)
• Create a Launch File for Lifecycle Nodes
• Write a Lifecycle Node in C++
• Intro
• Step 1 - Transform the Node Into a Lifecycle Node
• Step 2 - Start Several Nodes (Params + Launch File)
• Step 3 - Lifecycle Manager
• Lifecycle Node Challenge - C++

ROS2 Executors ⚙️

• Understand How Callbacks and Spin Work
• The SingleThreaded Executor
• Multi-Threaded Executor and Callback Groups
• Which Executor/Callback Group Should You Use?
• Going back to the Actions Server Example
• Run Several Nodes in One Executable
• Executors With C++

ROS2 Components 🔧

• Manual Composition with Python
• Manual Composition with C++
• Create a ROS2 Component (plugin)
• Load a Component at Run-Time with ros2 component cmd line
• Load Components From a Launch File

Project 🛠️

• Step 1 - Base Node and Executor
• Step 2 - Action Server
• Step 3 - Lifecycle Node
• Step 4 - Component
• Step 5 - Launch File
• Step 6 - Adapt for Turtlebot3 in Gazebo