Simple Gazebo Example

To install this project, clone the repository:

git clone https://github.com/aerostack2/project_gazebo

To start using this project, please go to the root folder of the project.

Launching

The execution on the project is split into two parts: Aerostack2 components and ground station.

Launching Aerostack2

To launch the Aerostack2 components, execute the following command:

./launch_as2.bash

This will open a Gazebo simulation alongside with a tmux session with an Aerostack2 instance for each drone launched.

Launcher offers a few options to customize the execution. ./launch_as2.bash -h will show option list. Options can be set with the following flags:

  • -m: launch multiagent system simulation. By default not set.

  • -n: select drones namespace to launch, values are comma separated. By default, it launches all drones from world description file.

  • -s: disable launch Gazebo simulator. By default launch simulation.

  • -g: launch using gnome-terminal. By default not set, uses tmux.

Launching Ground Station

To launch the ground station, execute the following command:

./launch_ground_station.bash

Launcher offers a different pool of options to customize the execution. ./launch_ground_station.bash -h will show option list. Options can be set with the following flags:

  • -m: launch multiagent system simulation. By default not set.

  • -t: launch keyboard teleoperation. By default not set.

  • -v: launch rviz. By default not set.

  • -r: record rosbag. By default not set.

  • -n: select drones namespace to launch, values are comma separated. By default, it launches all drones from world description file.

  • -g: launch using gnome-terminal. By default not set, uses tmux.

Closing

Close all nodes (aerostack2 and ground_station) with the following command executing outside the tmux session:

./stop.bash

Note

The command tmux kill-server will have a similar effect but closing all tmux sessions, so be careful if you have other tmux sessions running.

If launcher was executed with the flag -g, closing should be done manually exiting all gnome-terminal tabs.

Mission execution

The project offers a few examples of mission execution.

  • Keyboard Teleoperation control: Using reactive teleoperation control. For both single and multiagent swarms.

  • Python API missions: Using Aerostack2 python API for mission definition. For single drone, using GPS and multiple drones.

  • Behavior Tree missions: Using Behavior Tree as the mission planner. For single drone only.

  • Mission Interpreter: Using Aerostack2 mission interpreter. For single drone only.

Keyboard Teleoperation control

In order to launch the components for a single drone, Aerostack2 launcher does not need any additional flags. Just execute ./launch_as2.bash. This will open a simulation for a single drone alongside the Aerostack2 components necessary for the mission execution.

../../../_images/single_drone_gz1.png

Gazebo simulator

Ground station should be launched with -t flag to enable keyboard teleoperation. Take a look at the keyboard teleoperation user guide for more information. A window containing the teleoperation widget should pop up:

../../../_images/keyboard_teleop_view2.png

Keyboard teleoperation

Note

The teleoperation widget is also available for multi drone missions. To launch a multi drone simulation, use the flag -m in both launch commands.

Python API missions

In order to launch the components for multiple drones, both launchers require the flag -m. This will open a simulation for a swarm of drones alongside the Aerostack2 components necessary for the mission execution.

../../../_images/swarm_gz.png

Gazebo simulator

There are three python scripts available for mission execution in the project. For single drone missions, use python3 mission.py for flying a square. When flying using GPS, use python3 mission_gps.py which will fly a square using GPS waypoints. Here it is what the execution looks like:

For multi drone missions, use python3 mission_swarm.py where a group of drones will fly a swarm coreography. Here it is what the execution looks like:

Note

To understand how missions are built using the Aerostack2 python API, take a look at the Python API reference guide.

Mission Interpreter

Previous missions were defined using python syntaxis. Aerostask2 offers a mission interpreter that allows mission definition using a JSON format. Currently, the mission interpreter script at the project is only available for single drone missions. To launch the mission interpreter, execute python3 mission_interpreter.py. The execution is similar to the python API mission where the drone will fly a square.

Behavior Tree

Missions can also be defined using a behavior tree. The project offers a mission example using a behavior tree for a single drone. To launch the behavior tree mission, execute python3 mission_behavior_tree.py. The execution is similar to the python API mission where the drone will fly a square.

Note

Trees can be defined using GUIs like Groot.