Robot

Directory Structure

Underneath AirStack/robot, there are these directories: - docker/: Contains files related to building and launching the robot Docker container. - installation/: Contains files related to installing the robot software on a physical robot (TODO). - ros_ws/: Contains the ROS 2 workspace for the robot.

Launch Structure

Each high-level module under ros_ws/ has a [module]_bringup package that contains the launch files for that module. The launch files are located in the launch directory of the [module]_bringup package. The launch files are named *.launch.(xml/yaml/py) and can be launched with ros2 launch <module_name>_bringup <module_name>.launch.(xml/yaml/py).

At a high level, the launch files are organized as follows:

- robot_bringup/: robot.launch.xml
    - autonomy_bringup/: autonomy.launch.xml
        - interface_bringup/: interface.launch.xml
        - sensors_bringup/: sensors.launch.xml
        - perception_bringup/: perception.launch.xml
        - local_bringup/: local.launch.xml
        - global_bringup/: global.launch.xml
        - behavior_bringup/: behavior.launch.xml

Configuration

Desktop vs Jetson

If you look at the robot/docker/docker-compose.yaml file, you'll see it contains two services. robot is meant for x86-64 desktop development whereas robot_l4t is meant to run on NVIDIA Jetson devices. Both extend a base service in robot/docker/robot-base-docker-compose.yaml.

Environment Variables

Environment variables are used to configure the robot Docker container. The top level AirStack/.env file points to a ROBOT_ENV_FILE_NAME (default: robot.env), that in turn is used to load environment variables for the robot Docker container. The file that ROBOT_ENV_FILE_NAME points to gets added into the container under robot/docker/robot-base-docker-compose.yaml.

The environment variables can be used to trigger nodes to launch. For example, the USE_MACVO environmental variable is checked by perception.launch.xml to determine whether to launch the macvo node.

The file robot.env is reproduced below:

# These become environment variables in the robot container
USE_MACVO="false"

Common Topics

Topic	Type	Description
/$ROBOT_NAME/odometry	nav_msgs/Odometry	Best estimate of robot odometry
/$ROBOT_NAME/global_plan	nav_msgs/Path	Current target global trajectory for the robot to follow. See global planning for more details.

Rough System Diagram