MARS - ROS

ROS packages for the Mechatronics and Robotics Society at the University of Virginia.

These packages are installed on the team's robot.

Package Descriptions

• actions: handles motor routines like raising bucket ladder, digging, etc.
• hero_board: communication between the hero board and the jetson
• navigation: used for autonomous navigation

Usage on Robot

To run ROS nodes on the robot and connect to them from the control station, navigate to the root directory of this project and run source start1.sh in one terminal and source start2.sh in another. Note that you must run start2.sh with source instead of via ./start2.sh in order to connect to the ROS core on the Jetson after the script runs.

Direct Usage: Launch Files

Once these ROS packages are built and sourced, any nodes in them can be run like any other ROS node. However, we recommend using the code via the launch files we have created.

Main launch file

The navigation/launch/malvi_config.launch launch file is used to start the robot. Refer to the launch file for possible parameters.

roslaunch navigation malvi_config.launch

Additional launch files

We have provided several other launch files for running other ROS nodes outside the typical robot-control use case.

lidar-and-tracking-branch

Runs nodes to start an RP LiDAR and Intel Realsense Tracking Camera T265 that will be mounted on the robot.

roslaunch navigation lidar-and-tracking.launch

Containerized Usage: Docker

For a consistent production environment, we deploy our ROS code in Docker containers. These containers install ROS, set up required packages, and run one of the aforementioned launch files.

Main image

The main Docker image (which can be built using Dockerfile) runs our main launch file, navigation/launch/malvi_config.launch.
Build:

docker build . -t mars-ros

Run:

docker run --rm -it --network host mars-ros

Lidar and tracking camera image

Runs the navigation/launch/lidar-and-tracking.launch launch file.
Build:

docker build . -t mars-lidar-and-tracking -f Docker.lidar_and_tracking

Run:

docker run --rm -it --network host --volume=/dev:/dev --privileged mars-lidar-and-tracking

The USB devices for the camera and LiDAR must be passed through to the container. Due to a quirk of the tracking camera where it is only recognized after its ROS node is started, we must mount /dev on the host to /dev in the container.

Cloning and Pulling

Because this repository uses submodules, care must be taken when pulling/pushing. To clone this repository, you need to add the --recursive flag:

git clone --recursive https://github.com/MARS-UVA/mars-ros.git

If you forgot the --recursive flag, you need to run submodule init manually after cloning

git submodule update --init

To pull changes from the remote, you need to run two commands

git pull
git submodule update --init

Note for Development

When developing for specific packages, you do not need to compile all other packages. You can specify the name of the packages you want to build as arguments.

VSCode Remote Development on Jetson

VSCode remote development works well. However, for the Python/C++ language extension to work, you need to tweak some settings.

Python:

Microsoft Python Language Server does not support arm64. Therefore, you need to add "python.jediEnabled": true to the workspace settings

C++:

Microsoft C++ extension does not support arm64. You need to install the vscode-clangd plugin from llvm instead. Follow the plugin README to get started?

Compiling All Packages

If you need to compile all packages, refer to the compile guide

Managing package dependencies

All performed in ~/catkin_ws/

1. Generate a dependency list with rosinstall_generator: rosinstall_generator $(cat ~/mars-ros/packages.txt) --rosdistro noetic --deps --wet-only --tar > wet1.rosinstall
2. Install ROS dependencies with wstool
   • If it's the first time running wstool, use wstool init -j4 -t src wet1.rosinstall
   • If you're updating the list of packages, use wstool merge -t src wetX.rosinstall then wstool update -j4 -t src
3. Install system dependencies: rosdep install -y --from-paths src --ignore-src --rosdistro noetic -r --os=ubuntu:bionic
4. Build packages: sudo src/catkin/bin/catkin_make_isolated --install -DCMAKE_BUILD_TYPE=Release --install-space /opt/ros/noetic -j4 -DPYTHON_EXECUTABLE=/usr/bin/python3
   • To build specific packages, add on --pkg package1 package2