5.1.2. ROS 2

5.1.2.1. Ubuntu packages

Install ROS 2 following instructions from www.ros.org. The following packages might not be installed along the ROS desktop but are needed for all ROS distributions:

sudo apt install python-is-python3 # set Python 3 as default Python
sudo apt install python3-vcstool python3-colcon-common-extensions # for colcon
sudo apt install python3-pykdl # for the CRTK Python client library

For cisst/SAW and dVRK, you will also need the following Ubuntu packages:

Ubuntu 24.04 (recommended)Ubuntu 22.04Ubuntu 20.04

Ubuntu 24.04 with ROS Jazzy:

sudo apt install libraw1394-dev libncurses5-dev qtcreator swig sox espeak cmake-curses-gui cmake-qt-gui git subversion libcppunit-dev libqt5xmlpatterns5-dev libbluetooth-dev libhidapi-dev python3-pyudev libgraphviz-dev # dVRK
sudo apt install ros-jazzy-joint-state-publisher* ros-jazzy-xacro ros-jazzy-camera-info-manager ros-jazzy-image-transport ros-jazzy-image-transport-plugins # ROS
sudo apt install libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libcairo2-dev libjsoncpp-dev python3-opencv python3-numpy libgtk-3-dev libgtkmm-3.0-dev # stereo viewer & data collection

5.1.2.2. Colcon workspace, clone and build

Create your ROS 2 workspace and clone all repositories using vcs:

# this depends on the ROS version you're using
source /opt/ros/jazzy/setup.bash
mkdir -p ~/ros2_ws/src
cd ~/ros2_ws/src
# make sure you use the correct vcs file
vcs import --input https://raw.githubusercontent.com/jhu-saw/vcs/main/ros2-dvrk-main.vcs --recursive

Warning

If you get some errors related to access denied, it is possible GitHub blocks you because vcs uses multiple threads. If this is the case, try something like: vcs import --input https://raw.githubusercontent.com/jhu-saw/vcs/main/ros2-dvrk-main.vcs --recursive --retry 10 --workers 1.

Note

If you forgot the --recursive option, go in ~/ros2_ws/src/cisst-saw/sawRobotIO1394 and run git submodule init; git submodule update (this is to pull the “AmpIO” code).

Hint

To update an existing source directory, simply go in the directory (cd ~/ros2_ws/src) and call vcs pull. This will update all the repositories checked out under src.

To use a specific release, replace the vcs line with:

vcs import --input https://raw.githubusercontent.com/jhu-saw/vcs/main/ros2-dvrk-2.4.0.vcs --recursive

Compile using colcon:

cd ~/ros2_ws
colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release --symlink-install
source ~/ros2_ws/install/setup.bash

Note

colcon build is not as smart as catkin build: you need to be in the top directory of your workspace to build (for example ~/ros2_ws). Do not try to build in a subdirectory in your workspace, colcon will create a new set of build, install and log directories. catkin build recursively look in parent directories until it finds the workspace root, colcon doesn’t.

5.1.2.3. Testing

Environment variables

If you have a single ros2 workspace for a given user account, you might want to automatically source the setup.bash when you log in. To do so, you should add the following lines at the end of your ~/.bashrc (hidden file in your home directory):

# for ROS
if [ -f ~/ros2_ws/install/setup.bash ]; then
  . ~/ros2_ws/install/setup.bash
fi

Note

There is no need to source cisstvars.sh for ROS 2. It is added as a hook in the cisst colcon.pkg file.

Examples

Use a ROS launch file to start the dVRK in simulated mode with the patient cart only:

source ~/ros2_ws/install/setup.bash
ros2 launch dvrk_model patient_cart.launch.py generation:=Classic

dVRK with Classic patient cart simulated in RViz

In the dVRK GUI, open the Arm PSM1 tab and select an instrument to use.

In a second terminal, use a Python test script to make an arm move:

source ~/ros2_ws/install/setup.bash
ros2 run dvrk_python dvrk_arm_test.py -a PSM1

The main dVRK ROS node is dvrk_system from the dvrk_robot. This node requires configuration files specific to your system.

You can also find more launch examples in the Usage/Simulation section.

Notes

• ROS2 will broadcast on your subnet. That means that other computers on the same subnet might send ROS messages you don’t want. Reciprocally, your topics will be broadcasted to others. To prevent this, you can use the environment variables ROS_AUTOMATIC_DISCOVERY_RANGE or ROS_DOMAIN_ID. These are documented on docs.ros.org.