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Quadrotor outdoor flight demo

Description: This tutorial describes how to simulate a quadrotor UAV flying in a outdoor scenario using the hector_quadrotor stack.

Tutorial Level: INTERMEDIATE

Next Tutorial: Quadrotor indoor SLAM demo hector_quadrotor/Tutorials/Quadrotor indoor SLAM demo

Overview

This tutorial describes the setup and launch of the outdoor flight scenario shown in the video below. The quadrotor UAV is teleoperated.

Setup

Prerequisites

Install binary packages

The hector_quadrotor, hector_localization, hector_gazebo and hector_models packages are needed to run this demo.

The simplest option is to install the Ubuntu binary packages of hector_quadrotor available in the ROS package repository. To install all required packages for this tutorial run:

sudo apt-get install ros-hydro-hector-quadrotor-demo

Install from source

Alternatively, if you want to build from source in order to edit source or configuration files to suit your needs, all required stacks can be installed with the following commands (requires wstool):

mkdir ~/hector_quadrotor_tutorial
cd ~/hector_quadrotor_tutorial
wstool init src https://raw.github.com/tu-darmstadt-ros-pkg/hector_quadrotor/hydro-devel/tutorials.rosinstall

Build the catkin workspace as usual and source the new setup.bash:

catkin_make
source devel/setup.bash

Launch

Launch the outdoor flight demo:

roslaunch hector_quadrotor_demo outdoor_flight_gazebo.launch

gazebo simulation as well as rviz visualization should start up now, and the quadrotor UAV should be on the ground ready for takeoff.

Control

Depending on the version of the package you use, you might have to enable motors via a service first:

rosservice call /enable_motors "enable: true"

The quadrotor accepts geometry_msgs/Twist messages on the 'cmd_vel' topic, as many other robots do, too. It is recommended to use a gamepad for teleoperation. For this, start the appropriate launch file of the hector_quadrotor_teleop package, in case of an Xbox controller:

roslaunch hector_quadrotor_teleop xbox_controller.launch 

You can also control the UAV using any other method for publishing geometry_msgs/Twist messages. This of course also includes controllers for autonomous flight. If you have installed the teleop_twist_keyboard package, you can for example also use this:

rosrun teleop_twist_keyboard teleop_twist_keyboard.py

Demo

Camera

You can activate the view of the onboard camera by ticking the corresponding entry in rviz (left pane). For teleoperation using the camera, it is recommended to untick the tf and robot_model visualizations as they might block the view occasionally.

GPS

The quadrotor aircraft uses ground truth information from gazebo for localization in this scenario, simulating the availability of GPS signals in outdoor scenarios. In this example, there is no artifical noise added.