Overview

CI status	Debian package

Multi-drone PX4 SITL setup using Gazebo and ROS2. Generally follows https://docs.px4.io/main/en/sim_gazebo_gz/, but uses custom bringup scripts which serve as a showcase of https://github.com/asherikov/cdinit.

Workspace documentation is at http://www.sherikov.net/px4ws/.

Usage

Building

• Build px4sitl master package. Workspace is designed to be used with https://github.com/asherikov/ccws, but basic colcon build should work too.

• Dependencies can be installed with rosdep except a few PX4 python dependencies that are installed with cmake during build step.

Binary package

• Go to cloudsmith package repo, add new apt source, and run apt update.
• sudo apt install px4ws--reldebug--all
• source /opt/px4ws/px4ws__reldebug__all/setup.bash
• Launch as explained below.

Running

• Start services, QGroundControl-x86_64.AppImage has to be present in an execution path:

cdinit.sh start px4sitl_ros@gui px4sitl_drone_x500@px4sitl_px4_gui PX4SITL_WORLD_SDF_NAME=walls

• Start multiple drones:

cdinit.sh start px4sitl_ros@gui px4sitl_drone_x500@px4sitl_px4_gui px4sitl_drone_vtol@px4sitl_px4_headless PX4SITL_WORLD_SDF_NAME=default

• Start without gui and ROS:

cdinit.sh start px4sitl_gz_sim_headless px4sitl_drone_x500@px4sitl_px4_headless PX4SITL_WORLD_SDF_NAME=default

• Terminate by closing Gazebo gui, or with cdinit.sh shutdown. Since all processes are required, termination can also be performed by stopping a particular service, e.g., cdinit.sh stop --force px4sitl_gz_clock.

cdinit services

All components are started using dinit service files located in px4sitl/cdinit_services/, see https://github.com/asherikov/cdinit for more information.

Example

• Start services as described above.
• List services cdinit.sh list | sort to get something like

# dummy "boot" service
[[+]     ] cdinit_main
# brings up a x500 drone
[[+]     ] px4sitl_drone_x500@gui
# brings up gazebo (with gui) and ROS bridge
[[+]     ] px4sitl_ros@gui
# logging services
[{+}     ] cdinit_log@px4sitl_gz_sim_gui
[{+}     ] cdinit_log@px4sitl_gz_sim_headless
[{+}     ] cdinit_log@px4sitl_gz_wait
[{+}     ] cdinit_log@px4sitl_px4_gui@.../px4sitl/config/x500.drone
[{+}     ] cdinit_log@px4sitl_px4_headless@.../px4sitl/config/x500.drone
[{+}     ] cdinit_log@px4sitl_ros_dds_agent
[{+}     ] cdinit_log@px4sitl_ros_gz_clock
[{+}     ] cdinit_sessionsync
# brings up Gazebo
[{+}     ] px4sitl_gz_sim@gui
# Gazebo gui
[{+}     ] px4sitl_gz_sim_gui
# Gazebo simulation core
[{+}     ] px4sitl_gz_sim_headless
# Helper service which waits for Gazebo to start
[{+}     ] px4sitl_gz_wait
# QGroundControl
[{+}     ] px4sitl_px4_gui@.../px4sitl/config/x500.drone
# PX4 instance with corresponding configuration file
[{+}     ] px4sitl_px4_headless@.../px4sitl/config/x500.drone
# Micro-XRCE-DDS-Agent bridging PX4 and ros2
[{+}     ] px4sitl_ros_dds_agent
# Gazebo -> ROS2 simulation clock bridge
[{+}     ] px4sitl_ros_gz_clock

• Logs are located in cdinit session root directory printed on startup, it depends on environment variables, e.g., ROS_LOG_DIR.

Service dependency graph

Troubleshooting

• protobuf errors like the following could be caused by multiple Gazebo versions installed in parallel: [libprotobuf ERROR google/protobuf/descriptor_database.cc:121] File already exists in database: gz/msgs/pointcloud.proto
• PX4 fails during automatic takeoff with "Disarmed by auto preflight disarming": make sure that unused parameters in vehicle command message are set to NaN.

TODO

• Is installation of px4/build/ intentional?
• CMakeLists.txt, package.xml should not be installed.