Table of contents

• Folder structure
• Manual execution on a companion computer
  • How to run the Raspberry Pi code
• Simulation
  • Setup
  • How to run the simulation
  • Useful coords

Folder structure

• drone-delivery: root folder.
  • vision: code to detect ArUco markers and live stream drone footage.
  • flight: guidance, navigation and control (GNC) folder.
    • aruco_hunter: ROS package to find and land on an ArUco marker.
    • aruco_msgs: ROS package that define message(s) used to communicate ArUco detections from the ArUco detector node to the GNC nodes.
  • scripts: useful instructions, scripts and recipes.

Manual execution on a companion computer

WARNING: don't execute the following commands manually on a vehicle with propeller blades.

How to run the Raspberry Pi code

The instructions suppose the board has 4 CPU cores. Tip: use tmux to run the instructions.

terminal 1

# launch roscore and mavros
taskset -c 3 roslaunch mavros px4.launch

terminal 2

# change the current directory
cd drone-delivery/vision

# run the computer vision code
taskset -c 0,1,2 python3 main.py --stream-video-to-app --detect-aruco --using-ros --frames-per-second 7

# for more info, run
python3 main.py --help

terminal 3

# run the guidance, navigation and control code
taskset -c 3 roslaunch aruco_hunter main.launch

Simulation

Setup

It's not my priority to write better setup instructions right now, but I'm using Ubuntu 20.04, ROS Noetic, Gazebo 11, MAVROS 2.2.0, PX4-Autopilot 1.13.0 and my custom PX4-SITL_gazebo-classic.

How to run the simulation

terminal 1

# set the vehicle startup location (see the next section for useful coords)
export PX4_HOME_LAT=52.171974
export PX4_HOME_LON=4.417091
export PX4_HOME_ALT=0

# launch gazebo, roscore, mavros and px4 sitl with a single command
roslaunch px4 mavros_posix_sitl.launch

# set some parameters to be able to simulate without a RC control
param set NAV_RCL_ACT 0
param set NAV_DLL_ACT 0
param set COM_RCL_EXCEPT 4

terminal 2

# launch qgroundcontrol
./QGroundControl.AppImage

terminal 3

Open the main.launch file for more info. Must open if changing the vehicle default startup location (52.171974, 4.417091).

# run the guidance, navigation and control code
roslaunch aruco_hunter main.launch

terminal 4 (optional)

# change the current working directory
cd drone-delivery/vision

# run the computer vision related code
python3 main.py --stream-video-to-app --detect-aruco --using-ros --receive-video-from-gazebo

# for more info on how to run the computer vision code, run
python3 main.py --help

Useful coords

Tip: calculate altitude from latitude and longitude using https://www.maps.ie/coordinates.html

# default
export PX4_HOME_LAT=28.452386
export PX4_HOME_LON=-13.867138
export PX4_HOME_ALT=36
roslaunch px4 mavros_posix_sitl.launch

# my school soccer field (quadra de futebol da FGA)
export PX4_HOME_LAT=-15.989944
export PX4_HOME_LON=-48.044025
export PX4_HOME_ALT=1217
roslaunch px4 mavros_posix_sitl.launch