Landing on an AruCo marker

This is a work in progress and proof of concept of an off-board control that lands an UAV using PX4 on an AruCo marker.

It uses Precision Land flight mode in combination with AruCo marker detection on bottom camera pictures.

A demo is available at:

sim.webm

The sources of inspiration are mostly:

• https://youtu.be/iezU2PR0hBk
• https://github.com/Kenil16/master_project

A lot of work need to be done before running in production!

Dependencies

• Python 3.8 or compatible
• Robot Operating System noetic with cv_bridge, geometry_msgs, mavros, mavros_msgs, rospy and sensor_msgs or compatible
• Pymavlink 2.4 or compatible
• NumPy 1.24 or compatible
• OpenCV-Python 4.2 or compatible

Installation

1. install the dependencies above
2. download the offboard_control package to your PYTHONPATH

Run

1. run the offboard_control package with --help argument to see its usage

Tutorials

Gazebo simulator on Linux Mint

Install ROS:

curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu focal main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt install ros-noetic-desktop ros-noetic-mavros

Install GeographicLib datasets:

# Extracted from https://raw.githubusercontent.com/mavlink/mavros/master/mavros/scripts/install_geographiclib_datasets.sh
sudo geographiclib-get-geoids egm96-5

Install OpenCV-Python:

sudo apt install python3-opencv

Create a workspace and a Python virtual environment:

mkdir precland
python3 -m venv --system-site-packages precland/venv

Install PX4:

git clone --branch=v1.14.2 --recursive --depth=1 https://github.com/PX4/PX4-Autopilot.git precland/PX4-Autopilot
# Extracted from Tools/setup/ubuntu.sh
sudo apt-get --no-install-recommends install libjson-perl cppcheck libxml2-dev shellcheck ninja-build lcov astyle
sudo apt-get --no-install-recommends install libgstreamer-plugins-base1.0-dev
. precland/venv/bin/activate
pip install -r precland/PX4-Autopilot/Tools/setup/requirements.txt
pushd precland/PX4-Autopilot && DONT_RUN=1 make px4_sitl gazebo-classic; popd
deactivate

Download a world:

curl --header "X-GitHub-Api-Version: 2022-11-28" --header "Accept: application/vnd.github+json" --location   https://api.github.com/repos/Kenil16/master_project/tarball/b032d57b9a47796a2e81caebd2f359d79de1d846 | tar --gunzip --extract --directory=precland Kenil16-master_project-b032d57/software/ros_workspace/PX4-software/worlds/optitrack_big_board_onepattern.world Kenil16-master_project-b032d57/software/ros_workspace/PX4-software/models

Install the off-board control:

curl --header "X-GitHub-Api-Version: 2022-11-28" --header "Accept: application/vnd.github+json" --location   https://api.github.com/repos/radekholy24/aruco-landing/tarball/v0.1.0-alpha | tar --gunzip --extract --directory=precland
mv --verbose precland/radekholy24-aruco-landing-* precland/radekholy24-aruco-landing

Run the simulation:

cd precland
. venv/bin/activate
. /opt/ros/noetic/setup.bash
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$(pwd)/PX4-Autopilot/build/px4_sitl_default/build_gazebo-classic
export GAZEBO_MODEL_PATH=${GAZEBO_MODEL_PATH}:$(pwd)/Kenil16-master_project-b032d57/software/ros_workspace/PX4-software/models:$(pwd)/radekholy24-aruco-landing/sim
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)/PX4-Autopilot:$(pwd)/PX4-Autopilot/Tools/simulation/gazebo-classic/sitl_gazebo-classic
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)/radekholy24-aruco-landing
roslaunch $(pwd)/radekholy24-aruco-landing/sim/sim.launch \
    "world:=$(pwd)/Kenil16-master_project-b032d57/software/ros_workspace/PX4-software/worlds/optitrack_big_board_onepattern.world" \
    "vehicle:=gazebo-classic_iris" \
    "vehicle_sdf:=$(pwd)/radekholy24-aruco-landing/sim/gazebo-classic_iris_camera/gazebo-classic_iris_camera.sdf" \
    "vehicle_x:=-3" \
    "vehicle_y:=0" \
    "vehicle_z:=0" \
    "vehicle_R:=0" \
    "vehicle_P:=0" \
    "vehicle_Y:=0" \
    "offboard_control_camera_matrix:=623.680552,0,360,0,623.680552,240,0,0,1" \
    "offboard_control_distortion_coefficients:=0,0,0,0" \
    "offboard_control_search_altitude:=5.5" \
    "offboard_control_bottom_camera_node_name:=mono_cam_bottom" \
    "offboard_control_land_on_aruco_rate:=20" \
    "offboard_control_aruco_markers:=5X5_1000:537:0.2 5X5_1000:467:0.2 5X5_1000:537:0.2"

It is supposed to take off, switch to the Precision Land flight mode, find the given marker and land on it. Then do the same for the other given marker. And then again for the first marker.