ROS-explorer is a ROS module that implements some algorithms in robotics, using turtlebot, stage and gazebo.

Docker (optional)

The provided Dockerfile installs all required ROS dependencies.

To run it, first pull the docker image (about 1GB):

docker pull atilaromero/ros-kinetic

The following bash function makes easier to launch a container able to display graphics:

dkr ()
{
  xhost +                                             # allows containers to access host's display
  docker run --rm -it \
          -w "`pwd`" -v "`pwd`":"`pwd`":Z            `# share current dir` \
          -e DISPLAY                                 `# share display` \
          -v /tmp/.X11-unix/:/tmp/.X11-unix/         `# share display` \
          -v /etc/localtime:/etc/localtime:ro        `# share timezone` \
          "$@"                                        # function arguments (atilaromero/ros-kinetic for example)
}
export -f dkr

Using this bash function, starting a ros-kinetic container can be done this way:

dkr atilaromero/ros-kinetic

Or, without the function:

  xhost +                                             # allows containers to access host's display
  docker run --rm -it \
          -w "`pwd`" -v "`pwd`":"`pwd`":Z            `# share current dir` \
          -e DISPLAY                                 `# share display` \
          -v /tmp/.X11-unix/:/tmp/.X11-unix/         `# share display` \
          -v /etc/localtime:/etc/localtime:ro        `# share timezone` \
          atilaromero/kinetic

Depending on acceleration card, it may be necessary to install inside the container the same version of graphic drivers running on the host and to add the options "--device /dev/dri" and "--privileged" to the "docker run" call.

This docker image is a generic environment and does not contains the ros-explorer module, which can be installed following the next section.

Instalation

The following instructions can used both with or without docker.

To install ros-explorer:

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/src
git clone https://github.com/atilaromero/ros-explorer.git
cd ~/catkin_ws/
catkin_make
source devel/setup.bash
echo $'source ~/catkin_ws/devel/setup.bash' >> ~/.bashrc

Usage

to start a turtlebot simulation:

roslaunch turtlebot_stage turtlebot_in_stage.launch

To go to the ros-explorer folder:

roscd ros-explorer

To move the robot using coodenates (without obstacle avoidance):

rosrun ros-explorer move.py 1 0

Exploration

The main functionality of ROS-explorer is a program that controls the robot and uses the laser scanner readings to build a map. It can be started with:

rosrun ros-explorer explore.py

It uses a single ROS topic as input, "/scan". It then builds a map using harmonic potential fields and moves the robot to an unexplored area.

It publishes the map in the topic "/mymap" and the potential field in the topic "/myfield".

When the program is interrupted with Ctrl-C, it saves the current map in a file named worldmap-DATE-TIME.png.