ROS2 Launch — Complete Guide | R2BOT
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ROS2 launch files start, configure, and monitor multiple nodes from a single command. The backbone of every real ROS2 deployment.
The programming software concept: ROS2 launch files start, configure, and monitor multiple
A ROS2 launch file describes which nodes to start, with which parameters, in which order, and what to do when they exit. Real robots run dozens of nodes — drivers, planners, controllers, recorders — and launch files orchestrate them with one command.
💡 Think of it like…
Think of it like a household object that does the same job — the underlying idea is the same, just adapted for robots.
Why it matters
Without ros2 launch — complete guide | r2bot, many programming software systems in robotics simply couldn't work.
ROS2 Launch
What is ROS2 Launch?
A ROS2 launch file describes which nodes to start, with which parameters, in which order, and what to do when they exit. Real robots run dozens of nodes — drivers, planners, controllers, recorders — and launch files orchestrate them with one command.
How It Works
Launch files are written in Python (ROS2 supports XML and YAML too). You compose a LaunchDescription containing Node() actions, IncludeLaunchDescription() (to compose other launch files), ExecuteProcess() (to run shell commands), and event handlers (OnProcessExit, OnShutdown). The ros2 launch command runs the file, expands all variables, starts every action in the requested order, and tracks lifecycles. Arguments allow the same launch file to be reused across robots and environments.
Real-World Example
Nav2 and MoveIt2 ship dozens of launch files for different robot setups. Spot, TurtleBot, GreyOrange's Butler stack — every real ROS2 robot has a top-level launch file that boots the entire system. CI pipelines use launch files to start sim-test environments.
Why It Matters for Robotics
If ROS2 nodes are the bricks of a robot, launch files are the blueprints that turn the bricks into a house. Writing clean, parametric launch files is one of the most-tested skills in ROS2 interviews.
Try It Yourself
Write a Python launch file that starts (1) a TurtleSim node and (2) a teleop_twist_keyboard node. Run with ros2 launch your_pkg my_demo.launch.py and drive the turtle around — your first multi-node orchestration.
Quick Quiz
Quick Quiz
3 questions
1.ROS2 launch files are most commonly written in:
2.You start a launch file from the terminal with:
3.A great use of launch files is to:
Further Reading
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Open the R2 Co-pilot (press ⌘K anywhere on R2BOT) and ask: "Explain ROS2 Launch for a Class 9 student in India, with one real-world Indian example." You'll get a tailored, sourced answer in seconds.
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Last updated · 2026-05-21
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