../_images/tiagopro-icon.png ../_images/tiago-icon.png ../_images/triago-icon.png ../_images/mobile-bases-icon.png

How to use the dockstation

🏁 Goal of this tutorial

By the end of this tutorial, you will know how to make the robot autonomously dock and undock using the PAL dockstation.

Pre-requisites

Caution

This tutorial requires the robot to be equipped with a dockstation and that the dockstation is properly powered.

Dock the robot using RViz

The easiest way to dock the robot is by using the RViz GUI. This requires that you first establish the communication with the robot as explained in Set up ROS 2 communication with the robot.

Then, in the same terminal that is connected to the robot, you can start RViz with the command:

rviz2 -d /opt/pal/$PAL_DISTRO/share/<ROBOT>_2dnav/config/rviz/navigation.rviz

Attention

Make sure to replace the <ROBOT> placeholder with the name of your robot (e.g. tiago, omni_base, tiago_pro, etc.).

Otherwise, if you want to use the simulation, you can use the following command:

source /opt/pal/${PAL_DISTRO}/setup.bash
ros2 launch <robot>_gazebo <robot>_gazebo.launch.py navigation:=True docking:=True world_name:=pal_office_w_docks

This starts the simulation in a virtual environment with several dockstations available.

../_images/pal_office_w_docks.svg

Once RViz is running and is connected to the robot or to the simulation, you can dock it by following these steps:

  1. If not already available, load the PAL Navigation 2 panel in RViz

../_images/pal_nav2_panel.svg

  1. Go to the Docking tab in the PAL Navigation 2 panel

../_images/docking_manager_rviz_interface.svg

  1. Place the robot in front of the dockstation, as shown in the image below:

Staging Pose for Dock Detection

Staging Pose for Dock Detection

  1. Click on the Dock button in the PAL Navigation 2 panel

This will send a new Action Goal to the /dock_robot Server, which will trigger the Docking detection system and the robot will autonomously navigate to the dockstation and dock itself.

Undock the robot using RViz

The easiest way to undock the robot is by using the RViz GUI through the PAL Navigation 2 RViz panel. To achieve this, the Docking tab in the PAL Navigation 2 panel provides an Undock button that will send a new Action Goal to the /undock_robot Server, which will trigger the undocking maneuver.

Dock the robot using ROS 2 Actions

Alternatively, to trigger the Dock, one can use the /dock_robot Action. By sending an Action Goal to this Server it will make the robot detect a dock and perform the docking maneuver.

Please, refer to the following examples for executing docking:

ros2 action send_goal /dock_robot opennav_docking_msgs/action/DockRobot "use_dock_id: false
dock_id: ''
dock_pose:
  header:
    stamp:
      sec: 0
      nanosec: 0
    frame_id: 'map'
  pose:
    position:
      x: 0.0
      y: 0.0
      z: 0.0
    orientation:
      x: 0.0
      y: 0.0
      z: 0.0
      w: 1.0
dock_type: 'pal_charging_dock'
max_staging_time: 1000.0
navigate_to_staging_pose: false"

Undock the robot using ROS 2 Actions

Similarly, to trigger the Undock, one can use the /undock_robot Action. By sending an Action Goal to this Server it will make the robot perform the undocking maneuver.

ros2 action send_goal /undock_robot opennav_docking_msgs/action/UndockRobot "dock_type: 'pal_charging_dock'
max_undocking_time: 30.0"

Next steps