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Example 15: Using multiple controller managers

This example shows how to integrate multiple robots under different controller manager instances.

Note

The commands below are given for a local installation of this repository and its dependencies as well as for running them from a docker container. For more information on the docker usage see Using Docker.

Scenario: Using ros2_control within a local namespace

• Launch file: rrbot_namespace.launch.py

• Controllers yaml: rrbot_namespace_controllers.yaml

• URDF file: rrbot.urdf.xacro

  • Description: rrbot_description.urdf.xacro

  • ros2_control tag: rrbot.ros2_control.xacro

• RViz configuration: rrbot.rviz

• Test nodes goals configuration:

  • rrbot_forward_position_publisher

  • rrbot_joint_trajectory_publisher

• Hardware interface plugin: rrbot.cpp

Note

When running ros2 control CLI commands you have to use additional parameter with exact controller manager node name, i.e., -c /rrbot/controller_manager.

Launch the example with

ros2 launch ros2_control_demo_example_15 rrbot_namespace.launch.py

• Command interfaces:

  • joint1/position

  • joint2/position

• State interfaces:

  • joint1/position

  • joint2/position

Available controllers: (nodes under namespace “/rrbot”)

$ ros2 control list_controllers -c /rrbot/controller_manager
joint_state_broadcaster[joint_state_broadcaster/JointStateBroadcaster] active
forward_position_controller[forward_command_controller/ForwardCommandController] active
position_trajectory_controller[joint_trajectory_controller/JointTrajectoryController] inactive

Commanding the robot using a ForwardCommandController (name: /rrbot/forward_position_controller)

ros2 launch ros2_control_demo_example_15 test_forward_position_controller.launch.py publisher_config:=rrbot_namespace_forward_position_publisher.yaml

Abort the command and switch controller to use JointTrajectoryController (name: /rrbot/position_trajectory_controller):

ros2 control switch_controllers -c /rrbot/controller_manager --deactivate forward_position_controller --activate position_trajectory_controller

Commanding the robot using JointTrajectoryController (name: /rrbot/position_trajectory_controller)

ros2 launch ros2_control_demo_example_15 test_joint_trajectory_controller.launch.py publisher_config:=rrbot_namespace_joint_trajectory_publisher.yaml

Scenario: Using multiple controller managers on the same machine

• Launch file: multi_controller_manager_example_two_rrbots.launch.py

• Controllers yaml: - multi_controller_manager_rrbot_1_controllers.yaml - multi_controller_manager_rrbot_2_controllers.yaml

• URDF file: rrbot.urdf.xacro

  • Description: rrbot_description.urdf.xacro

  • ros2_control tag: rrbot.ros2_control.xacro

• RViz configuration: rrbot.rviz

• Test nodes goals configuration:

  • rrbot_forward_position_publisher

  • rrbot_joint_trajectory_publisher

• Hardware interface plugin: rrbot.cpp

Note

When running ros2 control CLI commands you have to use additional parameter with exact controller manager node name, e.g., -c /rrbot_1/controller_manager or -c /rrbot_2/controller_manager.

Launch the example with

ros2 launch ros2_control_demo_example_15 multi_controller_manager_example_two_rrbots.launch.py

You should see two robots in RViz:

rrbot_1 namespace:

• Command interfaces:

  • rrbot_1_joint1/position

  • rrbot_1_joint2/position

• State interfaces:

  • rrbot_1_joint1/position

  • rrbot_1_joint2/position

rrbot_2 namespace:

• Command interfaces:

  • rrbot_2_joint1/position

  • rrbot_2_joint2/position

• State interfaces:

  • rrbot_2_joint1/position

  • rrbot_2_joint2/position

Available controllers (nodes under namespace /rrbot_1 and /rrbot_2):

$ ros2 control list_controllers -c /rrbot_1/controller_manager
position_trajectory_controller[joint_trajectory_controller/JointTrajectoryController] inactive
joint_state_broadcaster[joint_state_broadcaster/JointStateBroadcaster] active
forward_position_controller[forward_command_controller/ForwardCommandController] active

$ ros2 control list_controllers -c /rrbot_2/controller_manager
joint_state_broadcaster[joint_state_broadcaster/JointStateBroadcaster] active
position_trajectory_controller[joint_trajectory_controller/JointTrajectoryController] inactive
forward_position_controller[forward_command_controller/ForwardCommandController] active

Commanding the robots using the forward_position_controller (of type ForwardCommandController)

ros2 launch ros2_control_demo_example_15 test_multi_controller_manager_forward_position_controller.launch.py

Switch controller to use the position_trajectory_controller (of type JointTrajectoryController) - alternatively start main launch file with argument robot_controller:=position_trajectory_controller:

ros2 control switch_controllers -c /rrbot_1/controller_manager --deactivate forward_position_controller --activate position_trajectory_controller
ros2 control switch_controllers -c /rrbot_2/controller_manager --deactivate forward_position_controller --activate position_trajectory_controller

Commanding the robots using the now activated position_trajectory_controller:

ros2 launch ros2_control_demo_example_15 test_multi_controller_manager_joint_trajectory_controller.launch.py

Controllers from this demo

• Joint State Broadcaster (ros2_controllers repository): doc

• Forward Command Controller (ros2_controllers repository): doc

• Joint Trajectory Controller (ros2_controllers repository): doc