ROS2 migration

[daisukes]

Current CaBot consists of ROS, ROS2, and the bridge between them. ROS noetic's support (Ubuntu 20.04 LTS support) will end in May 2025, so we still have two and a half years, but it may be a good time to move to ROS2 as it has matured enough. However, most of the components, except for the navigation stack (Nav2), need to be migrated to ROS2, so we may need to assess that all components can be migrated. If not, we need to consider keeping the bridge for the features that cannot be moved to ROS2. This migration can benefit the project through performance increase (TF and pointcloud2 related), complexity reduction related to navigation, and expansion of its life by 2027 (if we complete the second phase).

Migration phases

• Phase 1
  • Ubuntu20.04, noetic, galactic Ubuntu20.04 - noetic + Ubuntu22.04 - humble / Ubuntu20.04 Host
  • migrate group by group, keeping the bridge active until all migrations are completed
  • need to rearrange topic flows
  • the following groups does not include full consideration of topic flow rearrangement
  • need to migrate nav2 custom code to humble branch
  • not optimized (not using composable node and type adapter)
• Phase 2
  • optimization
  • Ace version support
    • Jetson
    • cabot_serial.py

Migration order by group

• cabot_debug (Done)
• arduino (Done)
• people/queue (Done)
• motor_controller (Done)
• cabot (Done)
• cabot_ui (Done)
• localization (Done)
• mapping
• jetson
• migrate additional changes to dev branch since Dec. 2022
• clean unused (ROS1) packages / lint
• description (gtm, ace)
• cabot_sites
• cabot-arduino-ace (ace)
• cabot-app-server

Packages Status

package	ROS2 migration	category	Migration group	Status
pcl_ros (external)	Yes	ros1	cabot	WIP
cartographer (external)	Yes	localization	localization	Done
cabot-arduino	Yes	Arduino	arduino	Done
WiFiScan	Yes	Arduino	esp32	Done
cabot-arduino-ace	Yes	Arduino	arduino	@aksgibm
cabot-ble-server	Yes	Standalone	ble	@aksgibm
cabot_debug	Yes	host ros1	cabot_debug	Done
cabot_msgs	Yes	ros1	cabot_ui	Done
mf_localization_msgs	Yes	localization	cabot_ui	Done
cabot_ros_backpack	Yes	ros1	cabot_ui	Pending
cabot_description	Yes	ros1	cabot	Partial
cabot_ui	Yes	ros1	cabot_ui	Done
cabot	Yes	ros1	cabot, cabot_ui	Done
cabot_description2	Merge	ros2	cabot_ui	Partial (cabot2-gt1)
cabot_sites	Yes	ros1	cabot_ui	Partial
cabot_wireless_simulator	Yes	localization	gazebo	Done
cabot_gazebo	Yes	ros1	gazebo	Done
mf_localization	Yes	localization	localization	Done
mf_localization_gazebo	Yes	localization	localization	Done
mf_localization_mapping	Yes	localization	localization	Done
wireless_scanner_ros	Yes	localization	localization	Done
mf_localization_rviz	Yes	localization	localization	Done
cabot_mf_localization	Merge	localization	localization	Done
motor_controller	Yes	ros1	motor_controller, cabot	Done
nav2_action_bridge	Remove	bridge	N/A	N/A
cabot_util	ROS2	ros2	N/A	N/A
cabot_bt	ROS2	ros2	N/A	N/A
cabot_navigation	Remove	ros1	N/A	N/A
predict_people_py	Yes	people	people	Done
track_people_py	Yes	people	people	Done
track_people_cpp	Yes	people	people	Done
cabot_people	Merge	people	people/queue	Done
queue_people_py	Yes	people	queue	WIP (check)
queue_utils_py	Yes	people	queue	Done

[daisukes]

Gazebo migration tips

1. if you want to remap gazebo sensor plugin topic, you need to add ros tag into the plugin description like following instead of add remapping to the gzserver launch

        <plugin filename="libgazebo_ros_imu_sensor.so" name="imu">
          <topicName>${prefix}/data</topicName>
          <bodyName>${frame}</bodyName>
          <updateRateHZ>100.0</updateRateHZ>
          <gaussianNoise>0.0</gaussianNoise>
          <xyzOffset>0 0 0</xyzOffset>
          <rpyOffset>0 0 0</rpyOffset>
          <frameName>${frame}</frameName>
	  <initial_orientation_as_reference>0</initial_orientation_as_reference>

	  <!-- remapping /imu/out, 'imu' is the plugin's name, 'out' is hard coded -->
	  <ros>
	    <argument>--ros-args</argument>
	    <argument>-r</argument>
	    <argument>/imu/out:=/cabot/imu/data</argument>
	  </ros>
        </plugin>

2. To publish /gazebo/model_state, you need to add plugin description in each world file

• this is not practical because we need to update all the world files, so I will write a code to append plugin description when the world file is specified for gazebo

  <world name='default'>
    <plugin name="gazebo_ros_state" filename="libgazebo_ros_state.so">
      <ros>
        <namespace>/gazebo</namespace>
      </ros>
      <update_rate>1.0</update_rate>
    </plugin>  

Related forum thread and issue
ros-simulation/gazebo_ros_pkgs#1157
https://answers.ros.org/question/360161/ros2-dashing-service-get_entity_state-is-missing/
ros-simulation/gazebo_ros_pkgs#1157

[daisukes]

Tried to keep using galactic, but there were some issues, so changed it to humble during porting.

[daisukes]

Public cabot_sites have been ported. Private cabot_sites should be ported too, but will not track here.