Nav2 (ROS2 Navigation Stack)

What is Nav2 (ROS2 Navigation Stack)?

Nav2 is the official ROS2 navigation stack — a collection of packages that together let a mobile robot autonomously move from point A to point B safely. It includes planners, controllers, costmaps, behaviour trees, localisation, and recovery behaviours.

How It Works

Nav2 is structured as a set of ROS2 servers wired together by a top-level behaviour tree. The Planner Server runs a global planner (Smac, NavFn) over a costmap; the Controller Server runs a local planner (DWB, MPPI, Regulated Pure Pursuit); the Behaviour Server runs recovery actions when stuck; the BT Navigator orchestrates everything as a behaviour tree. Costmap layers provide static maps, dynamic obstacles, inflation, and voxels. AMCL provides localisation.

Real-World Example

Almost every Nav2-based mobile robot starts with the TurtleBot3 demo. GreyOrange Butler, ROBOTIS, Clearpath Husky, hospital delivery robots, and Indian warehouse robots all build on Nav2. Foxconn's smart factories use Nav2 in dozens of AMR designs.

Why It Matters for Robotics

Without Nav2 you would write a complete navigation stack from scratch — months of work. Nav2 fluency is non-negotiable for any AMR or service-robot engineering role in India. It is the most-asked-about stack in ROS2 interviews.

Try It Yourself

Launch the nav2_bringup tb3_simulation_launch.py demo in Gazebo + RViz2. Use RViz's '2D Pose Estimate' and '2D Goal Pose' tools to drive a TurtleBot3 across the simulated map. Then change a costmap parameter live and watch the behaviour change.

Quick Quiz

🧠
Quick Quiz
3 questions
1.Nav2 orchestrates its components with:
A.Shell scripts
B.A behaviour tree (BT Navigator)
C.A spreadsheet
D.Email
2.Which is NOT a typical Nav2 component?
A.Planner Server
B.Controller Server
C.Behaviour Server
D.Photo Editor Server
3.A common local planner used in Nav2 is:
A.MPPI or DWB
B.Excel
C.Microsoft Word
D.Photoshop

Further Reading

• Ros2
• Amcl
• Costmap
• Behavior Trees
• Path Planning

Ask R2 About This

Open the R2 Co-pilot (press ⌘K anywhere on R2BOT) and ask: "Explain Nav2 (ROS2 Navigation Stack) for a Class 9 student in India, with one real-world Indian example." You'll get a tailored, sourced answer in seconds.