Drone autonomous planning, perception and navigation using ROS, Pixhawk (PX4) and Jetson Nano

Jetson Nano Setup

1. Flash the sd card

• Download the image jetson-nano-2gb-jp461-sd-card-image.zip
• Flash it to the sd card using balena etcher
• Plug the sd card into the jetson nano
• Connect the USB-C port to power supply and the Micro-USB port to the laptop.

2. Login and Setup

• Find the COM port using device manager $\rightarrow$ Ports (usually USB Serial Device - COM12)
• Open Putty and connect to the COM port
• Go through the OEM setup and then reboot. Username = jetson, Password = nano
• Now ssh into the nano with ssh [email protected]
• Connect phone via USB and turn on USB tethering (or) Connect an ethernet cable
• Run the following commands

sudo apt update
sudo apt upgrade -y

3. Install ROS

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt install curl
curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
sudo apt update
sudo apt install ros-melodic-ros-base
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
source ~/.bashrc
sudo apt install -y python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential
sudo rosdep init
rosdep update

4. Pixhawk Setup

sudo apt install ros-melodic-mav* -y
cd Downloads
wget https://raw.githubusercontent.com/mavlink/mavros/master/mavros/scripts/install_geographiclib_datasets.sh
sudo bash ./install_geographiclib_datasets.sh

# Give USB permissions
sudo usermod -a -G tty jetson
sudo usermod -a -G dialout jetson

• Find the vendor and product id.
• To do this first run lsusb and now unplug the pixhawk and run lsusb again.
• See what changed. For example it is Bus 003 Device 005: ID 26ac:0011
• Now vendor id is '26ac' and product id is '0011'
• Create a udev rule

sudo nano /etc/udev/rules.d/99-pixhawk.rules
# Add the following line into the file (remember to change the ids)
SUBSYSTEM=="tty", ATTRS{idVendor}=="26ac", ATTRS{idProduct}=="0011", SYMLINK+="ttyPixhawk"
# Save and close the file. Now Reboot.

• Create a launch file with the changed default parameter

roscd mavros
cd launch
sudo cp px4.launch pixhawk.launch
# Now edit the pixhawk.launch file and change the 'fcu_url' parameter
sudo nano pixhawk.launch
# Set 'fcu_url' to '/dev/ttyPixhawk'
# To run the ROS node, run the above created launch file
roslaunch mavros pixhawk.launch

5. Jetson Inference Installation

sudo apt-get update
sudo apt-get install git cmake libpython3-dev python3-numpy
git clone --recursive https://github.com/dusty-nv/jetson-inference
cd jetson-inference
mkdir build
cd build
cmake ../
make -j$(nproc)
sudo make install
sudo ldconfig

PX4 setup

Environment

mkdir px4
cd px4
# Clone the repository
git clone https://github.com/PX4/PX4-Autopilot.git --recursive
# Install dependencies
bash ./PX4-Autopilot/Tools/setup/ubuntu.sh --no-nuttx --no-sim-tools
# Try the above command again if it fails

Put the following in .bashrc

export GAZEBO_PLUGIN_PATH=$GAZEBO_PLUGIN_PATH:/home/pravardhan/px4/PX4-Autopilot/build/px4_sitl_default/build_gazebo
export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/home/pravardhan/px4/PX4-Autopilot/Tools/sitl_gazebo/models
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/pravardhan/px4/PX4-Autopilot/build/px4_sitl_default/build_gazebo
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:/home/pravardhan/px4/PX4-Autopilot:/home/pravardhan/px4/PX4-Autopilot/Tools/sitl_gazebo

Start the simulation using

roslaunch px4 mavros_posix_sitl.launch

Documentation

Frames

Mavros

Tutorials

Intelligent Quads