ROS 2 Autonomous Navigation Stack

SLAM · Nav2 · Multi-Robot · Frontier Exploration · Fleet Management

Nav2 + SLAM in Gazebo — single command

ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital explore:=true

_{Single-robot SLAM · Nav2 · frontier exploration}

One launch → Gazebo + SLAM/Nav2 + RViz. Scale to a fleet with one arg. Humble/Jazzy params auto-selected from $ROS_DISTRO.

Deep dive → concepts.md · launch args → ros2 launch rosnav_bot <file> --show-args

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1. Install

# Ubuntu 22.04 / Humble — use jazzy on 24.04
sudo apt install -y \
  ros-humble-ros-gz ros-humble-ros-gz-bridge \
  ros-humble-xacro ros-humble-joint-state-publisher \
  ros-humble-nav2-bringup ros-humble-slam-toolbox \
  ros-humble-navigation2 ros-humble-teleop-twist-keyboard \
  ros-humble-laser-filters ros-humble-rviz2

git clone https://github.com/darshmenon/rosnav.git ~/rosnav
cd ~/rosnav && colcon build --symlink-install
source /opt/ros/humble/setup.bash && source install/setup.bash

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2. Map · save · navigate

A — Drive with teleop (build the map)

# Terminal 1 — SLAM only (no frontier). Keep safety:=true so /cmd_vel reaches Gazebo.
ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital

# Terminal 2 — keyboard drive
ros2 run teleop_twist_keyboard teleop_twist_keyboard

Keys: i forward · , back · j/l turn · k stop · q/z speed.
Watch the map in RViz (Map on /map), or:

ros2 topic hz /scan          # ~10 Hz
ros2 topic hz /odom          # ~50 Hz
ros2 topic echo /map --once --field info    # width/height should grow

Or let the robot explore alone: add explore:=true to the launch above.

B — Save the map

ros2 run nav2_map_server map_saver_cli -f src/rosnav_bot/maps/map_hospital

Writes map_hospital.yaml + map_hospital.pgm. Then Ctrl+C the SLAM launch.
(With explore:=true, maps also autosave under src/rosnav_bot/maps/map_<world>.*.)

C — Navigate on the saved map

ros2 launch rosnav_bot robot.launch.py world_name:=hospital \
  map:=src/rosnav_bot/maps/map_hospital.yaml

AMCL localizes on the static map — no more SLAM. Send a goal:

RViz

1. Fixed Frame = map
2. 2D Pose Estimate — seed AMCL if particles are wide
3. 2D Goal Pose — click+drag the goal

CLI

ros2 action send_goal /navigate_to_pose nav2_msgs/action/NavigateToPose \
  "{pose: {header: {frame_id: map}, pose: {position: {x: 2.0, y: -1.0}, orientation: {w: 1.0}}}}"

ros2 run rosnav_bot fleet_manager.py goto '' 2.0 -1.0    # single robot
ros2 run rosnav_bot fleet_manager.py goto robot1 room_a  # named location

Goal accepted but no motion? Keep safety:=true (Nav2 /cmd_vel → Gazebo /cmd_vel_safe).

Multi-SLAM (slam_mode:=multi): save /map_merged with -t /map_merged or fleet_manager.py savemap.

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3. Fleet & explore

ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital explore:=true
ros2 launch rosnav_bot multi_robot.launch.py robot_count:=2
ros2 launch rosnav_bot multi_robot.launch.py fleet_mgmt:=true
ros2 launch rosnav_bot multi_robot.launch.py slam_mode:=multi      # → /map_merged
ros2 launch rosnav_bot multi_robot.launch.py merge_scans:=true     # → /map_fused

ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital safety:=true
ros2 run rosnav_bot mission_server.py patrol robot1 1,2,0 3,4,90
ros2 run rosnav_bot coverage_planner.py

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4. YOLO object detection

Needs: pip install ultralytics. Camera is enabled automatically with enable_yolo:=true.

ros2 launch rosnav_bot slam_nav.launch.py world_name:=warehouse enable_yolo:=true

# Tune
ros2 launch rosnav_bot slam_nav.launch.py world_name:=warehouse enable_yolo:=true \
  yolo_model:=yolov8n.pt yolo_confidence:=0.6 yolo_classes:=person,chair

Topics: yolo/detections · yolo/image_annotated

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_{ArUco visual docking}

5. ArUco docking

Needs: enable_camera:=true and sudo apt install ros-humble-cv-bridge python3-opencv. Hospital world has the dock marker.

ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital enable_camera:=true rviz:=true

ros2 run rosnav_bot fleet_manager.py dock '' charging_dock
ros2 run rosnav_bot fleet_manager.py undock '' 0.5 0.05

# Visual approach only (skip Nav2 staging)
ros2 run rosnav_bot aruco_dock.py --ros-args -p dock_name:=charging_dock

Dock poses / marker IDs → config/docks.yaml. Live view: /tmp/aruco_dock_view.jpg or RViz Image on /camera/image_raw.

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6. LLM voice navigation

Needs: ollama serve and a pulled model (ollama pull llama2). Start the nav stack first.

ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital

ros2 run rosnav_bot llm_nav.py
# type or speak: go to room_b · go to 2.5 1.0 · stop

# Text only (no mic)
ros2 topic pub /llm_nav/command std_msgs/msg/String "data: 'go to room_a'" --once

Named places → config/locations.yaml.

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7. Drive bases & controllers

# Diff (default) · holonomic · car-like
ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital drive_type:=diff explore:=true
ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital drive_type:=mecanum explore:=true
ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital drive_type:=ackermann explore:=true safety:=true

# Fleet-wide
ros2 launch rosnav_bot multi_robot.launch.py drive_type:=mecanum
ros2 launch rosnav_bot multi_robot.launch.py drive_type:=ackermann

# MPPI instead of DWB (Humble; Jazzy already defaults to MPPI)
ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital controller:=mppi explore:=true

# 3D lidar / RTAB-Map · MiR100 visual chassis
ros2 launch rosnav_bot slam_nav.launch.py lidar_type:=3d
ros2 launch rosnav_bot slam_nav.launch.py lidar_type:=3d slam_algo:=3d explore:=true
ros2 launch rosnav_bot slam_nav.launch.py robot_model:=mir100

Strafe example (mecanum):

ros2 topic pub -r 20 /cmd_vel_safe geometry_msgs/msg/Twist \
  "{linear: {x: 0.0, y: 0.3, z: 0.0}, angular: {x: 0.0, y: 0.0, z: 0.0}}"

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8. Open-RMF (experimental)

ros2 launch rosnav_bot multi_robot.launch.py explore:=false robot_count:=2
ros2 launch rosnav_bot rmf_fleet.launch.py robot_count:=2 docking:=noop
ros2 run rosnav_bot rmf_submit_task.py patrol room_a room_b --rounds 2

Details → concepts.md §11b.

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_{Multi-robot coordinated exploration}

9. Fleet CLI

ros2 run rosnav_bot fleet_manager.py list|status|health
ros2 run rosnav_bot fleet_manager.py goto robot1 room_a
ros2 run rosnav_bot fleet_manager.py teleop robot1
ros2 run rosnav_bot fleet_manager.py savemap src/rosnav_bot/maps/map_hospital
ros2 run rosnav_bot fleet_manager.py mission robot1 patrol room_a room_b
ros2 run rosnav_bot fleet_manager.py tasks add 2.0 1.5 0 pickup_A
ros2 run rosnav_bot fleet_gui.py
ros2 run rosnav_bot multi_teleop.py

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10. Worlds

Indoor	hospital house office warehouse maze corridor obstacles
Special	empty · warehouse_depot (scripts/download_depot_model.sh if needed)
No map yet	outdoor multi_terrain — use explore:=true

ros2 launch rosnav_bot slam_nav.launch.py world_name:=warehouse explore:=true
ros2 launch rosnav_bot multi_robot.launch.py world:=house

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_{Dock approach in map / TF view}

11. Update YAML (tuning)

All configs live under src/rosnav_bot/config/. With --symlink-install, edit then relaunch (no rebuild).

Want to change…	Edit
Named places (room_a, goto)	locations.yaml
ArUco dock ID / staging / stand-off	docks.yaml
Nav2 speeds, footprint, costmaps (diff, Humble)	nav2_params.yaml
Same on Jazzy	nav2_params_jazzy.yaml
MPPI / mecanum / ackermann	nav2_params_mppi.yaml · nav2_params_mecanum.yaml · nav2_params_ackermann.yaml
Multi-robot Nav2	nav2_multirobot_params.yaml (+ _jazzy)
SLAM Toolbox	mapper_params_online_async.yaml · mapper_params_per_robot.yaml
RMF lanes / fleet policy	rmf_fleet.yaml
Keep-out zones	no_go_zones.yaml

# locations.yaml — then: ros2 run rosnav_bot fleet_manager.py goto '' kitchen
#   kitchen: {x: 3.0, y: -1.5, yaw: 0.0}

# nav2_params.yaml — raise speed:
#   controller_server → FollowPath → max_vel_x: 0.5

source install/setup.bash
ros2 launch rosnav_bot slam_nav.launch.py world_name:=hospital explore:=true

Maps: src/rosnav_bot/maps/map_<world>.yaml (+ .pgm) · use map:=... on launch.
More → concepts.md.

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12. Fixes

Problem	Try
Plugin FATAL	Source the right $ROS_DISTRO
No motion	ros2 topic hz /cmd_vel · keep safety:=true
Map not saved	explore:=true · multi-SLAM: -t /map_merged
TF / no frontiers	Kill stale gz / ros2 processes
Invisible robots	colcon build --symlink-install && source install/setup.bash
YAML change ignored	Symlink install + relaunch; edit the correct Humble/Jazzy / drive-type file
Dock sees nothing	Set enable_camera:=true
YOLO missing	pip install ultralytics
LLM fails	ollama serve + ollama pull llama2

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Fleet mgmt  →  Nav2 + SLAM/AMCL  →  Gazebo Harmonic + ros-gz bridge

Made by @darshmenon · Blog · concepts.md