4.1.3. ROS 2

This code hasn’t been tested extensively. We welcome any feedback. The following has been tested on Ubuntu 20.04 with ROS 2 Galactic, Ubuntu 22.04 with ROS 2 Humble and Ubuntu 24.04 with ROS 2 Jazzy.

4.1.3.1. 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 20.04Ubuntu 22.04Ubuntu 24.04

Ubuntu 20.04 with ROS Galactic:

sudo apt install libxml2-dev libraw1394-dev libncurses5-dev qtcreator swig sox espeak cmake-curses-gui cmake-qt-gui git subversion gfortran libcppunit-dev libqt5xmlpatterns5-dev libbluetooth-dev libhidapi-dev python3-pyudev # dVRK
sudo apt install ros-galactic-joint-state-publisher* ros-galactic-xacro # ROS

4.1.3.2. 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/galactic/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-2.3.1.vcs --recursive

To use the development branches, replace the vcs line with:

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

Warning

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).

Compile using colcon:

cd ~/ros2_ws
colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release
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.

4.1.3.3. 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 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_console_json from the dvrk_robot. This node requires configuration files specific to your system.

Notes

• ROS2 will broadcast on your subnet. That means that other computers on the same subnet might send ROS messages you don’t want. To prevent this, google ROS_LOCALHOST_ONLY or ROS_DOMAIN_ID.