Mapping with SLAM Toolbox and EasyNav

This guide explains how to map an environment using SLAM Toolbox and then save the map for later use with EasyNav.

SLAM Toolbox belongs to Nav2 and can be installed via:

sudo apt install ros-kilted-slam-toolbox

Or from source at: https://github.com/SteveMacenski/slam_toolbox

SLAM Toolbox publishes a nav_msgs::msg::OccupancyGrid on the /map topic. EasyNav’s Simple MapsManager listens on the topic:

/maps_manager_node/simple/incoming_map

It can directly consume this output. EasyNav also exposes the following service:

/maps_manager_node/simple/savemap (std_srvs/srv/Trigger)

to save the current map (by default to /tmp/default.map).

Step-by-Step Instructions:

1. Launch the simulator (with or without GUI)

ros2 launch easynav_playground_kobuki playground_kobuki.launch.py gui:=false

2. Open RViz2

ros2 run rviz2 rviz2 --ros-args -p use_sim_time:=true

> Note: The /map topic and map frame will not appear until SLAM Toolbox is started.

3. Launch SLAM Toolbox

By default, SLAM Toolbox subscribes to /scan, but in our setup, the laser publishes to /scan_raw. Edit or copy the launcher at:

/opt/ros/kilted/share/slam_toolbox/launch/online_async_launch.py

and add the following remapping:

remappings=[
  ('/scan', '/scan_raw'),
],

Then run:

ros2 launch slam_toolbox online_async_launch.py

4. Teleoperate the robot to build the map

ros2 run teleop_twist_keyboard teleop_twist_keyboard

Observe the map in RViz2 as it builds.

5. Launch EasyNav with MapsManager only

Use the following configuration file (simple.mapping.params.yaml) with all other nodes in dummy mode:

controller_node:
  ros__parameters:
    use_sim_time: true
    controller_types: [dummy]
    dummy:
      rt_freq: 30.0
      plugin: easynav_controller/DummyController
      cycle_time_nort: 0.01
      cycle_time_rt: 0.001

localizer_node:
  ros__parameters:
    use_sim_time: true
    localizer_types: [dummy]
    dummy:
      rt_freq: 50.0
      freq: 5.0
      reseed_freq: 0.1
      plugin: easynav_localizer/DummyLocalizer
      cycle_time_nort: 0.01
      cycle_time_rt: 0.001

maps_manager_node:
  ros__parameters:
    use_sim_time: true
    map_types: [simple]
    simple:
      freq: 10.0
      plugin: easynav_simple_maps_manager/SimpleMapsManager

planner_node:
  ros__parameters:
    use_sim_time: true
    planner_types: [dummy]
    dummy:
      freq: 1.0
      plugin: easynav_planner/DummyPlanner
      cycle_time_nort: 0.2
      cycle_time_rt: 0.001

sensors_node:
  ros__parameters:
    use_sim_time: true
    forget_time: 0.5

system_node:
  ros__parameters:
    use_sim_time: true
    position_tolerance: 0.1
    angle_tolerance: 0.05

Run EasyNav with the following command, remapping the topic to receive the map:

ros2 run easynav_system system_main --ros-args \
  --params-file ~/easynav_ws/src/easynav_indoor_testcase/robots_params/simple.mapping.params.yaml \
  -r /maps_manager_node/simple/incoming_map:=/map

6. Save the generated map

ros2 service call /maps_manager_node/simple/savemap std_srvs/srv/Trigger {{}}

The map will be saved to /tmp/default.map.

7. Rename and move the map to reuse it

For example:

mv /tmp/default.map ~/easynav_ws/src/easynav_indoor_testcase/maps/house_tests.map

Then modify your parameters to use it:

maps_manager_node:
  ros__parameters:
    use_sim_time: true
    map_types: [simple]
    simple:
      freq: 10.0
      plugin: easynav_simple_maps_manager/SimpleMapsManager
      package: easynav_indoor_testcase
      map_path_file: maps/house_tests.map