ROS2 Off-board drone control with DDS and PX4

High-level path planning and off-board control of a Pixhawk flight computer running PX4 with a Raspberry Pi 4B. The code is written in C++ and Python in a ROS2 Humble interface.

Custom drone built from scratch

T-Motor motors, ESCs and propellers
Pixhawk 6X Flight computer (PX4 v1.14)
Raspberry Pi 4B (Ubuntu 22.04, ROS2 HUMBLE)
RTK + Base station
Tarot 680 Pro Sport frame

Simple take-off -> hover -> land

IMG_9274.mp4

Prerequisites:

Ubuntu 22.04
Python3
C++
ROS2 Humble

Installation & Setup guide

Ground control station

Install Qgroundcontrol

Pixhawk 6X setup

PX4 v1.14 for new Micro XRCE-DDS capabilities
NOTE version 1.14 is now a stable version so do not have to build from source anymore you can use QGC to install it

Build v1.14 instructions here

  git clone https://github.com/PX4/PX4-Autopilot.git --recursive
  git checkout release/v1.14
  make px4_fmu-v6x_default upload # Plug in Pixhawk before running this

If not using DDS, but serial and mavsdk then PX4 v1.13 -> This enables HITL

Setup on drone control computer (Laptop for SITL or RPi 4 on drone)

Install ROS2 Humble
ROS2 Off-board drone control
```
  git clone git@github.com:Marnonel6/ROS2_offboard_drone_control.git
```
- To clone the ROS2 control package an alias with the deployment key also exists on the Pi. Use:
```
  osprey_code_pull
```

Setup Micro XRCE-DDS Agent

  git clone https://github.com/eProsima/Micro-XRCE-DDS-Agent.git
  cd Micro-XRCE-DDS-Agent
  mkdir build
  cd build
  cmake ..
  make
  sudo make install
  sudo ldconfig /usr/local/lib/

Fields2Cover Fork or Fields2Cover

  sudo apt-get update
  sudo apt-get install --no-install-recommends software-properties-common
  sudo add-apt-repository ppa:ubuntugis/ppa
  sudo apt-get update
  sudo apt-get install --no-install-recommends build-essential ca-certificates cmake \
      doxygen g++ git libeigen3-dev libgdal-dev libpython3-dev python3 python3-pip \
      python3-matplotlib python3-tk lcov libgtest-dev libtbb-dev swig libgeos-dev
  python3 -m pip install gcovr

  git clone git@github.com:Marnonel6/Fields2Cover.git
  cd Fields2Cover
  mkdir -p build;
  cd build;
  cmake -DCMAKE_BUILD_TYPE=Release ..;
  make -j$(nproc);
  sudo make install;

On RPi I have a deployment key with an alias in the .bashrc file to clone the repo. Use: fields2cover_code_pull

PX4 SITL Simulation with (Ignition) Gazebo setup (On Ubuntu Laptop)

Install PX4 development environment

  cd
  git clone https://github.com/PX4/PX4-Autopilot.git --recursive
  bash ./PX4-Autopilot/Tools/setup/ubuntu.sh
  !!! Relogin or reboot computer before proceeding !!!
  cd PX4-Autopilot/
  make px4_sitl

SITL simulation:

Start the simulation (On Ubuntu Laptop):
```
  make px4_sitl gz_x500
```
Start Qgroundcontrol
Start the DDS agent on the drone control computer:
```
  MicroXRCEAgent udp4 -p 8888
```
Running ros2 topic list should now display all the flight computer topics
Alternatively to running the agent you can run the off-board control ROS2 package with:
```
  ros2 launch drone_control offboard_control.launch.py 
```
This will plan a path and then control the drone to follow the path.

Steps to run off-board autonomous mission on drone:

Start Qgroundcontrol

Run the launch file to start the agent and all the nodes:

  ros2 launch drone_control offboard_control.launch.py

This will plan a path and then control the drone to follow the path.

References

PX4 DDS topics
Simple ROS2 sensor reader package here

Marnonel6/ROS2_offboard_drone_control