Fly by hand

Start the drone

./launch_as2.bash

The tmux session opens on the alphanumeric viewer. Its summary tab shows the drone connected, disarmed and not in offboard, at the origin. Leave it where you can see it.

Open the ground station with the keyboard

In a second terminal, start the ground station with -t for the keyboard teleoperation:

./launch_ground_station.bash -t

RViz opens with the drone at the origin, and so does the keyboard teleoperation window. The window only reads keys while it has focus, so click it before pressing anything.

Take off

Press t. The window arms the drone, switches it to offboard and takes off to 1 m. In the viewer, armed and offboard turn on, and the status changes to taking off and then to flying. In RViz the drone rises and starts drawing its trail.

Take off is a behavior. The window asked the take-off behavior to climb, and the behavior sent references to the motion controller until the drone reached the height.

Move in steps

The window opens in Pose mode. Each arrow moves the drone 1 m along the earth axes, w and s move it 1 m up or down, and a and d turn it.

Fly a few steps and watch the viewer. The controller's mode reads position, because every key sends a new position to reach. These moves don't go through a behavior. The window sends them straight to the motion controller, on motion_reference/pose.

Move at a speed

Click Speed on the left of the window. Now each key sends a velocity, and the drone moves for as long as you hold the key. Let go and it stops.

The controller's mode in the viewer changes to speed, and the references now go out on motion_reference/twist. Before sending the first one, the window asked the motion controller to switch modes, since a controller in position mode ignores speeds.

Look underneath

With the drone flying, open a third terminal in the project folder. With Pixi, start each command with pixi run.

The state estimator publishes where the drone is. This is the pose the viewer and RViz show:

ros2 topic echo /drone0/self_localization/pose

The platform reports whether the drone is connected, armed and in offboard, and its status:

ros2 topic echo --once /drone0/platform/info

Each behavior is a ROS 2 action server in the drone's namespace:

ros2 action list

/drone0/FollowPathBehavior
/drone0/GoToBehavior
/drone0/LandBehavior
/drone0/TakeoffBehavior

Everything the drone runs lives under /drone0. That's how several drones share one ROS 2 network, as you'll see in Several drones.

Land

Press l. The land behavior brings the drone down and disarms it, and the viewer shows it disarmed again.

The space bar hovers the drone where it is. Delete is the emergency stop. It sends the kill switch, which stops the motors in mid-air, so keep it for emergencies and restart the window after using it.

Stop everything

./stop.bash