Platform usage

Overview

The ROS 2 code for Henry is stored in the private henry_ros2 repository.` The repository is cloned on the Henry PC, which has its own Github access. Ask for access from AMLab if you need it.

A separate repository is set up for this online documentation at https://github.com/autonomymobilitylab/HenryRTD. It is also cloned at the Henry PC. Please update it (there or with your own credentials at your laptop) any time changes are made or something seems to be missing!

First time setup

Instructions for setting up the Henry platform. If first-time setup has already been completed, skip to step 5.

Create a folder named henry_platform_ws in home repository.
Run the following command inside the folder to clone the henry_ros2 repository:

git clone https://github.com/autonomymobilitylab/henry_ros2.git
Build the ROS2 package using the following command:

colcon build --symlink-install
Source the bash file. To do this automatically when opening a terminal, add the following line to the ~/.bashrc file:

source ~/henry_platform_ws/install/setup.bash
The Henry platform is ready! To launch the master launch file, execute the following command in a new terminal:

ros2 launch henry_launch henry_bringup_launch.py

Making changes to the code

If you make changes to the code in the workspace, remember to rebuild the package using the following command:

colcon build --symlink-install

and source the bash file again:

source ~/henry_platform_ws/install/setup.bash

After adding code to the repository, you might want to commit the changes to the repository, either in main or in a separate branch. You can also link the changes you made to your Github account by setting the committer and author name and email while committing by adding the following to ~/.gitconfig under [alias]:

commit_yourname = !"GIT_COMMITTER_NAME='Your Name' GIT_COMMITTER_EMAIL='your.email@example.com' GIT_AUTHOR_NAME=$GIT_COMMITTER_NAME GIT_AUTHOR_EMAIL=$GIT_COMMITTER_EMAIL git commit"

And then using git commit_yourname (or whichever alias you choose) to commit like you would use git commit. Github will link to your account based on the email.

Launch files

Master launch file

Henry has a master launch file named henry_bringup_launch.py. This launches all the sensor ros nodes, along with the transforms and Rviz launch files.

To launch the master launch file, run:

ros2 launch henry_launch henry_bringup_launch.py

Configuration files

The sensors use separate configuration files for their parameters. These files are located in the config folder of the henry_launch package, and the launch files use these configuration files to set the parameters for the sensors at start-up.

Rviz

There is a custom configuration and launch file for Rviz in the henry_launch package. To launch Rviz with the custom configuration, run:

ros2 launch henry_launch rviz.launch.py config_file:=config.rviz

To use your own Rviz configuration file, place it in ~/henry_platform_ws/src/henry_launch/config/ and replace config.rviz with the name of to your configuration file in the command above.

Rviz text overlays

The rviz_2d_overlay_plugins package is used to display text overlays in Rviz. It’s installed with the following command:

sudo apt install ros-${ROS_DISTRO}-rviz-2d-overlay-plugins

The package allows text to be displayed in the Rviz window. Any overlayed text must be published as a TextOverlay message in its own topic. The text overlay messages are constructed in rviz_text_overlay_publishers.py in the henry_launch package. See the already published overlays for examples to create your own. Note that the publishers have been written to publish the text immediately when a subscribed message comes in, which means that writing many different messages for frequently-updated topics will be heavy on the car’s CPU - be mindful of what you display.

Recording data

When recording rosbags, place them in the folder ~/rosbags/. Having a subfolder under your own name (or a project’s name) is a good idea, since it allows others to easily see whose data it is.

There is a helper bash function in ~/henry_platform_ws/utils/ for recording all sensor data except raw images:

bash ~/henry_platform_ws/utils/record_sensors.sh

Warning

Do not store data long-term on the Henry PC! The drive will quickly fill up, and there is no backup if anything happens to the PC.