Heads Up Jazzy TurtleBots: If No Costmaps

[slowrunner]

Credit @aharshac #501 (comment) for the tip

If you are running Jazzy on your Raspberry Pi (and Iron I.0.0.FastDDS on your Create3) and not seeing global and local costmaps when you run navigation, try:

1. in your ROS 2 workspace, mkdir params
2. cp /opt/ros/jazzy/share/turtlebot4_navigation/config/nav2.yaml params/
   cp /opt/ros/jazzy/share/turtlebot4_navigation/config/localization.yaml params/
3. edit params/nav2.yaml

• remove all use_sim_time: true
• and comment or remove:

# robot_state_publisher:
#   ros__parameters:
#      use_sim_time: true

• save

4. edit params/localization.yaml - remove all use_sim_time: true
5. launch localization with:

ros2 launch turtlebot4_navigation localization.launch.py map:=/home/ubuntu/<full_path_to>/my.map.yaml params:=/home/ubuntu/<full_path_to>/params/localization.yaml

6. launch navigation with:

ros2 launch turtlebot4_navigation nav2.launch.py params_file:=/home/ubuntu/<full_path_to_your_ros2_ws/params/nav2.yaml

You should see the purple and blue costmaps after setting the initial pose:

[hilary-luo]

@slowrunner When you run that launch file the use_sim_time parameter defaults to false (

turtlebot4/turtlebot4_navigation/launch/nav2.launch.py

Line 34 in dc744fe

DeclareLaunchArgument('use_sim_time', default_value='false',

) and gets passed to the nav2 node. Even if it did default to true then this should be simply modified by passing the parameter in when you launch, like so:

ros2 launch turtlebot4_navigation nav2.launch.py use_sim_time:=false

If the use_sim_time parameter is false and this isn't getting propagated through to the nav2 node properly then that is an issue that should be flagged as a bug and needs to be addressed in the launch file so that that parameter works properly.

[slowrunner]

@hilary-luo Indeed the launch argument/parameter is not being handled properly

If the use_sim_time parameter is false and this isn't getting propagated through to the nav2 node properly then that is an issue that should be flagged as a bug and needs to be addressed in the launch file so that that parameter works properly.

Basic Issue:

• Turtlebot4 documentation is targeted to physical robot (assumes all use_sim_time launch arguments default to false)
• The Turtlebot4 navigation parameter file: turtlebot4_navigation/config/nav2.yaml contains use_sim_time: true for each node configured by the parameter file
• The Turtlebot4 navigation launch uses the nav2_bringup/launch/navigation_launch.py
  • which assumes the nav2.yaml param_file does not contain any use_sim_time specifications.
• Resulting in navigation nodes listed in the nav2.yaml file improperly configured to use sim clock

Using the documented invocation:

ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 launch turtlebot4_navigation nav2.launch.py

Resulting node parameter values:

ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /behavior_server  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /bt_navigator  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /collision_monitor  use_sim_time
Boolean value is: True

ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /controller_server  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /docking_server  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /global_costmap/global_costmap  use_sim_time
Boolean value is: True


ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /local_costmap/local_costmap  use_sim_time
Boolean value is: True

ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /planner_server  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /smoother_server  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /velocity_smoother  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /waypoint_follower  use_sim_time
Boolean value is: True

These are not configured in the nav2.yaml file and thus are correctly configured per the launch argument:

ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /analyzers  use_sim_time
Boolean value is: False
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /lifecycle_manager_localization  use_sim_time
Boolean value is: False
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /lifecycle_manager_navigation  use_sim_time
Boolean value is: False

Note localization is also not configured correctly:

ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /amcl  use_sim_time
Boolean value is: True
ubuntu@TB5WaLI:~/TB5-WaLI/wali_ws$ ros2 param get /map_server  use_sim_time
Boolean value is: True

The suggested fix is to remove all use_sim_time: xxxx stanzas from:

• turtlebot4_navigation/config/nav2.yaml
  • and comment or remove:

# robot_state_publisher:
#   ros__parameters:
#      use_sim_time: true

• turtlebot4_navigation/config/localization.yaml

to follow the convention of the nav2_bringup dependency

I only tested the Jazzy branch, but it appears the prior branch nav2.yaml and localization.yaml contain these stanzas also.

I have the feeling this will also improve the reliability of launching navigation issue #543

[mdxtinkernick]

We are having the same issues with a class set of robots - nav2 works around 30% sounds about right. Checking on one of the robots now and get the same results for use sim time for nodes - set to true if not specified, set to true even when using the command suggested passing false for the prameter. Will try removing from launch file tomorrow if I have time.

[hilary-luo]

@slowrunner @mdxtinkernick I will look into replicating this and seeing why it is not being passed through properly. Definitely continue to use that fix though until I am able to get back to you about it.

[mdxtinkernick]

all working here now - thanks for digging this out @slowrunner would never have thought of looking for that - was at the point where we going to start do network traffic analysis as I had reached the point where I thought all the timing issues were being caused by network congestion - just had the most productive class with the TurtleBots since we bought them nearly 3 years ago

[slowrunner]

class with the TurtleBots

@mdxtinkernick You have my curiosity up. I am aware of the mechanical engineering classes @brianabouchard was doing at Tufts with the Create3 before with iRobotEducation - have not found any GitHub detritus from classes using the TB4 yet.