ROS 2 Workflow

Environments of the Space Robotics Bench can be integrated with ROS 2 to enable control of the robots and data collection over the middleware communication.

Single Environment

The ros2.py script is the primary entry point for interfacing with the environments through ROS 2. This script spawns a single ROS node that maps inputs and outputs for the environment and provides miscellaneous functionalities such as resetting the simulation. Here is an example using the Ingenuity demo:

.docker/run.bash ros2 run space_robotics_bench ros2.py --env ingenuity

Once the environment is initialized, open a new terminal to inspect the available ROS topics. You can either use your ROS setup or join the running Docker container with the .docker/join.bash script:

.docker/join.bash

Now, list the available ROS topics:

ros2 topic list
# Expected output:
# /clock
# /env/info
# /env/reward
# /env/terminated
# /env/truncated
# /parameter_events
# /robot/cmd_vel
# /rosout
# /tf

To control the robot, publish a Twist message to the /robot/cmd_vel topic:

ros2 topic pub --once /robot/cmd_vel geometry_msgs/msg/Twist '{linear: {x: 1.0}}'

You can reset the simulation by calling the /sim/reset service:

ros2 service call /sim/reset std_srvs/srv/Empty

Parallel Environments

You can run multiple environments in parallel by using the --num_envs argument. Each environment will map to its own ROS namespace. For example, try running the Ingenuity demo with 4 environments:

.docker/run.bash ros2 run space_robotics_bench ros2.py --env ingenuity --num_envs 4

List the available ROS topics again:

ros2 topic list
# Expected output:
# /clock
# /env0/reward
# /env0/robot/cmd_vel
# /env0/terminated
# /env0/truncated
# /env1/reward
# /env1/robot/cmd_vel
# /env1/terminated
# /env1/truncated
# /env2/reward
# /env2/robot/cmd_vel
# /env2/terminated
# /env2/truncated
# /env3/reward
# /env3/robot/cmd_vel
# /env3/terminated
# /env3/truncated
# /envs/info
# /envs/robot/cmd_vel
# /parameter_events
# /rosout
# /tf

Each environment has its own namespace, allowing individual control. For example:

ros2 topic pub --once /env0/robot/cmd_vel geometry_msgs/msg/Twist '{linear: {x: -1.0}}'
ros2 topic pub --once /env1/robot/cmd_vel geometry_msgs/msg/Twist '{linear: {x: 1.0}}'
ros2 topic pub --once /env2/robot/cmd_vel geometry_msgs/msg/Twist '{linear: {y: -1.0}}'
ros2 topic pub --once /env3/robot/cmd_vel geometry_msgs/msg/Twist '{linear: {y: 1.0}}'

Launch with rviz2 and teleop_twist_keyboard

For convenience, you can launch rviz2 alongside ros2.py and teleop_twist_keyboard for visualization and control via keyboard:

.docker/run.bash ros2 launch space_robotics_bench demo.launch.py task:=ingenuity_visual num_envs:=4