ArduPilot-Gazebo-ROS SITL Guide

A guide for setting up ArduPilot, Gazebo and ROS.

An example project: https://github.com/yanhwee/helium

Software Covered

• ArduPilot
• ArduPilot Gazebo Plugin (khancyr)
• Gazebo 9
• ROS Melodic
• MAVROS (ROS package)

Requirements

Tested on Native Ubuntu 18.04.4.

Quick Installation

Script defaults to the home directory as the initial working directory, modifiable in the script. Script will use this working directory to git clone ArduPilot & ArduPilot Gazebo Plugin repositories.

wget -O - https://raw.githubusercontent.com/yanhwee/ardupilot-gazebo-ros-guide/master/install.bash | bash

Script will refresh the sudo timeout every 10 mins so intallation will not be interrupted. Please do not sudo bash. This will run as root and script will not work.

Please restart after the installation is done.

The guide below walks through the steps found in the script.

References

1. ROS Melodic Ubuntu Installation
   http://wiki.ros.org/melodic/Installation/Ubuntu

2. ArduPilot
   https://ardupilot.org/dev/docs/building-setup-linux.html

3. khancyr ArduPilot Gazebo Plugin
   https://github.com/khancyr/ardupilot_gazebo

4. ROS package: MAVROS
   https://github.com/mavlink/mavros/tree/master/mavros

Installation Guide

0. Prerequisites

1. Git
   • sudo apt install git

1. ROS (and Gazebo)

1. Follow all steps:
   http://wiki.ros.org/melodic/Installation/Ubuntu
   • Install: ros-<distro>-desktop-full
   • For our case: ros-melodic-desktop-full
   • Gazebo will be installed alongside ROS

2. ArduPilot

1. Git clone:
   https://ardupilot.org/dev/docs/building-setup-linux.html#cloning-with-the-command-line

2. Install required packages:
   https://ardupilot.org/dev/docs/building-setup-linux.html#install-some-required-packages

3. ArduPilot Gazebo Plugin (khancyr)

1. Git clone:
   https://github.com/khancyr/ardupilot_gazebo#usage-

   • Skip directly to
     git clone https://github.com/khancyr/ardupilot_gazebo

2. Build:
   https://github.com/khancyr/ardupilot_gazebo#usage-

   • Continue after the git clone
   • Set the paths as well

4. MAVROS

1. Binary Installation
   https://github.com/mavlink/mavros/tree/master/mavros#binary-installation-deb

   • Replace 'kinetic' with 'melodic'
   • sudo apt-get install ros-melodic-mavros ros-melodic-mavros-extras

2. Install GeographicLib
   https://github.com/mavlink/mavros/tree/master/mavros#binary-installation-deb

5. Recommended

1. catkin_tools
   https://ardupilot.org/dev/docs/ros-install.html#installing-mavros
   • sudo apt-get install python-catkin-tools

6. Optional

1. RQT (ROS package)
   https://ardupilot.org/dev/docs/ros-install.html#installing-mavros
   • Replace 'kinetic' with 'melodic'
   • sudo apt-get install ros-melodic-rqt ros-melodic-rqt-common-plugins ros-melodic-rqt-robot-plugins

Quick Test

1. Without ROS

   1. https://ardupilot.org/dev/docs/using-gazebo-simulator-with-sitl.html#start-the-simulator
   2. https://ardupilot.org/dev/docs/copter-sitl-mavproxy-tutorial.html

2. With ROS

   • Check out Intelligent Quad Videos
   • Or look at Learning Resources (Connecting to ROS) & continue with Quick Test (Without ROS step 2)

Software Architecture Overview

These psuedo-diagrams are for you to get an idea of how the whole thing works.

Typical Drone System (Physical Components)

Software-in-the-Loop (SITL Components)

Learning Resources

1. Intelligent Quad

   1. YouTube
      https://www.youtube.com/playlist?list=PLy9nLDKxDN683GqAiJ4IVLquYBod_2oA6
   2. GitHub
      https://github.com/Intelligent-Quads/iq_tutorials

2. ROS

   1. Tutorials
      http://wiki.ros.org/ROS/Tutorials
   2. Understanding package.xml
      http://wiki.ros.org/roslaunch/XML
   3. IDEs
      http://wiki.ros.org/IDEs

3. Catkin

   1. Workspaces
      http://wiki.ros.org/catkin/workspaces
   2. catkin_tools
      https://catkin-tools.readthedocs.io/en/latest/quick_start.html

4. CMake

   1. Understanding CMakeLists.txt
      https://www.youtube.com/playlist?list=PLK6MXr8gasrGmIiSuVQXpfFuE1uPT615s
   2. Documentation
      https://cmake.org/cmake/help/v3.17/manual/cmake.1.html

5. ArduPilot

   1. Connecting to ROS
      https://ardupilot.org/dev/docs/ros-sitl.html
   2. SITL Architecture
      https://ardupilot.org/dev/docs/sitl-simulator-software-in-the-loop.html#sitl-architecture
   3. Using SITL (sim_vehicle.py & MAVProxy)
      https://ardupilot.org/dev/docs/using-sitl-for-ardupilot-testing.html
   4. SITL Examples
      https://ardupilot.org/dev/docs/sitl-examples.html

6. ArduCopter

   1. Paramters List
      https://ardupilot.org/copter/docs/parameters.html
   2. Flight Modes
      https://ardupilot.org/copter/docs/flight-modes.html

7. MAVLink

   1. MAVLink Messages
      https://mavlink.io/en/messages/common.html
   2. Copter Commands (Guided)
      https://ardupilot.org/dev/docs/copter-commands-in-guided-mode.html#copter-commands-in-guided-mode
   3. Copter Commands (Auto / Mission)
      https://ardupilot.org/copter/docs/common-mavlink-mission-command-messages-mav_cmd.html
   4. Pymavlink (Also applicable to ArduCopter)
      https://www.ardusub.com/developers/pymavlink.html

8. Gazebo

   1. Tutorials
      http://gazebosim.org/tutorials
   2. Digitial Elevation Map (DEM)
      1. Tool for getting real-life DEM
         https://terrain.party/
      2. Heightmap Tutorial
         https://vimeo.com/58409707
   3. SDFormat Specification
      http://sdformat.org/spec

Troubleshooting

1. ArduPilot

1. sim_vehicle.py not found
   • Restart Ubuntu

2. Gazebo

1. Slow Gazebo startup or
   libcurl: (6) Could not resolve host: api.ignitionfuel.org

   • https://bitbucket.org/osrf/gazebo/issues/2607/error-restcc-205-during-startup-gazebo
   • In ~/.ignition/fuel/config.yaml, change to:
     • url: https://fuel.ignitionrobotics.org/1.0/models

2. Bad lighting

   • https://answers.gazebosim.org//question/848/lighting-and-shadow-effect-problems/
   • In world file, set shadow to 0
   • Or in Gazebo >> World >> Scene >> Disable Shadow

3. Visual Studio Code

1. Linting for cpp files
   1. Find ROS cpp path
      1. Can be found by
         cd / && sudo find -name 'ros.h'
   2. Add path to "c_cpp_properties.json' include path

4. Mavproxy

1. Any Problems

   • Try pip install -U mavproxy

2. Re-requesting WPs

   • ArduPilot/MAVProxy#402
   • In the MAVProxy Terminal
     • Type: wp list

Tips

1. QGroundControl

1. Rebooting ArduPilot
   1. Click on the Gear Icon (Vehicle Setup), top-left of the screen.
   2. Click on the Parameter Tab, bottom left of the Vehicle Setup screen.
   3. Click Tools, top-right of the screen.
      • If not found, click on the Clear Button beside the Search Bar first.
   4. Click "Reboot Vehicle"