Documentation of the challenges

• challenge 1: generate a path
• challenge 2: detect the obstacles
• challenge 3: avoid the obstacles

Installation

Create workspace

You need to install vcstool. You can install it using pip:

pip install vcstool

Clone this project and go to the root:

git clone https://github.com/FiraHackathon/fira_hackathon_workspace.git
cd fira_hackathon_workspace

Then you can execute a script to clone all the ROS packages and download the gazebo models:

./scripts/create_ws

Compiling

Create docker image and compile

A docker image is available to install ROS2 and all the dependencies of the packages. You first need to install a recent version of docker compose by following the instruction on the docker documentation. Then you can build the image and compile the workspace using the following command (from the root of this project):

docker compose up compile --build

Running

You can run the default demo simulation by executing:

docker compose up

This command will start the default docker services named compile and demo. The compile service execute the colcon build command. The demo service is started when the compile service exits successfully and execute ros2 launch fira_hackathon_demo demo.launch.py.

Running a challenge

All the following commands must be run from the root of this project.

The available docker service are the following:

• demo (that starts demo.launch.py)
• challenge1 (that starts challenge1.launch.py)
• challenge2 (that starts challenge2.launch.py)
• challenge3 (that starts challenge3.launch.py)

They are defined in the file docker/compose.yml. You can add your own services if you want to easily execute specific commands in the docker environment.

To execute a specific challenge. You can replace challenge1 by one the previous services and run

docker compose up challenge1

You can save time by avoiding recompiling using --no-deps and you can lighten terminal output using run instead of up

docker compose run --rm --no-deps challenge1

Run other commands in docker

If you want to execute a specific command, it is possible tu specify it after docker compose run. For example, to manually launch demo.launch.py you can execute:

docker compose run --rm --no-deps demo ros2 launch fira_hackathon_demo demo.launch.py

Every ros command is available. For example, it is possible to do ros2 topic list by executing

docker compose run --rm --no-deps demo ros2 topic list

It is also possible to open a shell on the docker to run several commands

docker compose run --rm --no-deps demo bash

The option --rm allows to automatically delete the container when the command finishes.

Architecture of the workspace

Here is a brief presentation of the main directories:

• build contains the files generated by the compilation step
• docker contains the configuration files for docker
• gazebo contains the downloaded gazebo models that are too large to be versioned
• install contains the shared files and executables of the ROS packages
• log contains the logged information of the compilation
• scripts contains some useful tools to prepare the workspace
• src contains all the cloned ROS packages

How the docker image works

The docker image corresponds to an Ubuntu 22.04 image with a complete installation of ROS2 Humble and all the dependencies of the ROS2 packages of this workspace. The image is built from the Dockerfile and can be edited to add other ubuntu or pip packages.

When a docker service is started, this workspace is mounted as a volume inside the docker container and the ROS commands are run using your own Linux user. This makes using the tools in docker similar to using them directly. This means that, if you have ROS Humble on your host system, you should be able to direclty run ros2 commands without using docker commands.

ROS packages for the hackathon

In the src directory, the packages are organized in several sub-folders:

• romea_core contains all packages that are independant of ROS
• romea_ros2 contains all ROS2 packages (in several sub-folders)
• third_party contains packages that are not written by our team

Your developments will focus on the following projects:

• romea_ros2/demos/fira_hackathon_demo containing the main launch files of the challenges
• romea_ros2/demos/fira_minimal_node containing an example node to make the robot follow a trajectory

For more details about this packages, read their README.

Updating

All the ROS packages may evolve during the hackathon. You can update them by using the command

vcs pull -nw6

Some projects may fail to update. This may be due to local modifications. You have to manually handle this projects. However, it is possible to stash your local changes on every project before updating by running

vcs custom -nw6 --args pull --rebase --autostash 

If you want to update projects and re-download the gazebo models, you can re-run the installation script

./scripts/create_ws