PX4: Fixed-Wing UAV Formation Flight

A customized PX4-Autopilot for fixed-wing UAVs formation flight.

Key features:

1. Enable airspeed command under offboard mode.
2. Control pitch ($\theta$) and heading ($\psi$) angle of a fixed-wing UAV at the same time.
3. Receive true wind velocity from Gazebo to calculate the true airspeed (Bug fixed)

Contents

• Requirements
• Installation
• Joysticks Control
• Formation Control
  • Single-UAV
  • Multi-UAV
• Data Visualization
• Tools

Requirements

• Ubuntu 22.04 LTS
• Gz sim Garden 7.9.0
• ROS2 humble

Installation

• Install PX4 formation simulation package

• Install PX4 Autopilot

  cd ~/
  git clone git@github.com:TigerWuu/Formation-PX4.git --recursive
  mv ~/Formation-PX4 ~/PX4-Autopilot
  bash ./PX4-Autopilot/Tools/setup/ubuntu.sh
  cd PX4-Autopilot/
  make px4_sitl
  

• Install QGroundControl

Joysticks Control

For Xbox one

• Run

  ros2 launch control joy.xml

• Joystick command mapping

  

Formation Control

Open QGroundControl

./QGroundControl.AppImage

Single-UAV

1. Terminal 1

   cd ~/PX4-Autopilot

• w/ Gazebo gui

  make px4_sitl gz_standard_vtol{world}

• w/o Gazebo gui

  HEADLESS=1 make px4_sitl gz_standard_vtol{world}

  world lists :

  _default : w/o wind field

  _windyGust : w/ wind field

2. Terminal 2

   MicroXRCEAgent udp4 -p 8888

3. Terminal 3

   ros2 launch commander formation.xml wind_com:=w2 L_dir:=0.0 trajectory:=C L:=1.0 L2:=0.1 radii:=400.0

   Arguments :

   • wind_com: w1, w2, none. wind compensation setting.
   • L_dir: straight line formation flight heading angle [rad].
   • trajectory : C, L. C means circular orbit, L means straight line.
   • L: observer gain L1.
   • L2: observer gain L2.
   • radii: circular orbit formation flight radius [m].

Multi-UAV

1. Terminal 1

   cd ~/PX4-Autopilot

• w/ Gazebo gui

  ./px4_multi_uav.sh {world}

  world lists :

  default : w/o wind field

  windyGust : w/ wind field

2. Terminal 5

   ros2 launch commander formation_multi.xml wind_com:=w2 L_dir:=0.0 trajectory:=C L:=1.0 L2:=0.1 radii:=400.0 leader:=0

   Arguments :

   • leader: 0, 1. 0 means all three follower UAVs will maintain a certain configuration with the virtual leader. 1 means only the first follower UAV maintain a configuration with virtual leader, and the other followers maintain the configuration with the first follower UAV, that is, the first follower UAV will be designated as a real leader.

Data Visualization

1. Plot with Matlab

   See https://github.com/TigerWuu/Fixed-Wing-Formation-Control

2. Plot with real time

   ros2 run plotjuggler plotjuggler

Tools

1. ros2 bag
2. Plotjuggler