Controlling Synapticon Devices Using the ROS2 Package

Description

This repository provides an example of how to use Synapticon drives (SOMANET Node, SOMANET Circulo and SOMANET Integro) in CSP (Cyclic Sync Position), CSV (Cyclic Sync Velocity), and CST (Cyclic Sync Torque) modes using the ROS2 package. It utilizes SOEM Ethercat Master. The ROS 2 package was originally developed by Andy Zelenak. Synapticon GmbH added examples, simulation, and extended instructions for easier installation, as well as support for containerization using Docker.

Table of Contents

1. Intention
2. Overview
   • 2.1. Hardware
   • 2.2. Software
     • 2.2.1. Ubuntu with ROS2
       • 2.2.1.1. ROS2 Installation
       • 2.2.1.2. Synapticon Package Installation
       • 2.2.1.3. Demo
       • 2.2.1.4. Running Without Sudo (Optional)
     • 2.2.2. Isolated Environment (Docker)
       • 2.2.2.1. Docker Installation
       • 2.2.2.2. Synapticon Package Installation
       • 2.2.2.3. Demo
3. Disclaimer

1. Intention

The intention of this document is to provide instructions on how to quickly begin Synapticon Devices with the ROS2 package using the Synapticon library. Additionally, in order to make it compatible with other Linux distributions, corresponding Docker images are provided.

2. Overview

The following subsections briefly demonstrate hardware and software required for using Synapticon devices with this package.

2.1. Hardware

In the figure below, a block diagram of the wiring used in this setup is provided. Drives can be used once the parameters are configured with OBLAC tools. Detailed instructions and wiring diagrams for all the devices are available on the Synapticon Web site documentation. The package allows daisy chaining of all the Synapticon drives in any order as indicated in the image below.

2.2. Software

In this demo, two scenarios are considered:

• Ubuntu 22.04 or 24.04 is installed on the system and ROS2 (humble, rolling or jazzy) together with the Synapticon package will be installed on that system
• The user wants to run the package in an isolated environment (Docker)

2.2.1. Ubuntu with ROS2

To install ROS2 on your Ubuntu machine, follow the steps from ros.org and install the full version. The minimal version can also be installed; however, if simulation is desired, RViZ must additionally be installed. After the installation, some configuration steps as described here are required. For the completeness of the demo, the commands in the following subsection are copied from the above website and should be executed for the ROS2 installation.

2.2.1.1. ROS2 Installation

To ensure that locale supports UTF-8, run the following commands:

sudo apt update && sudo apt install locales
sudo locale-gen en_US en_US.UTF-8
sudo update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
export LANG=en_US.UTF-8

Enable Ubuntu Universe repository:

sudo apt install software-properties-common
sudo add-apt-repository universe

Add GPG key:

sudo apt update && sudo apt install curl -y
sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg

Add repository to the sources:

echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/ros-archive-keyring.gpg] http://packages.ros.org/ros2/ubuntu $(. /etc/os-release && echo $UBUNTU_CODENAME) main" | sudo tee /etc/apt/sources.list.d/ros2.list > /dev/null

Update apt cache:

sudo apt update

This command updates the packages on your system. Note that if the commands after this work, skip this step.

sudo apt upgrade

Finally, install ROS and compilers (replace ROS_DISTRO with the desired ROS distribution - humble, jazzy or rolling):

sudo apt install ros-ROS_DISTRO-desktop
sudo apt install ros-dev-tools

After the installation is complete, add the following line to the end of /home/USER/.bashrc file (replace ROS_DISTRO with the desired ROS distribution - humble, jazzy or rolling):

source /opt/ros/ROS_DISTRO/setup.bash

In order for ROS2 to not interfere with the communication on other ports, we set the Domain ID (detailed information is available here). For this demo, we just used ROS_DOMAIN_ID=1. To do so, add the following at the end of /home/$USER/.bashrc:

export ROS_DOMAIN_ID=1

After this, close and reopen all your terminals. To verify the installation, open two terminals and run:

ros2 run demo_nodes_cpp talker
ros2 run demo_nodes_py listener

If the nodes are communicating, the installation was successful.

2.2.1.2. Synapticon Package Installation

OPTION 1: Installing from Source

Create an ROS2 workspace:

mkdir -p ~/ros2_ws/src
cd ~/ros2_ws/src

Clone the Synapticon package:

git clone https://github.com/synapticon/synapticon_ros2_control

Install build tools:

sudo apt install python3-colcon-common-extensions

Build the package:

cd ~/ros2_ws
rosdep install --from-paths src -y --ignore-src
colcon build

Additionally, you can source the workspace by adding the following line to the /home/USER/.bashrc file above the line where the ROS installation was sourced (above this line: source /opt/ros/ROS_DISTRO/setup.bash:

source /home/USER/ros2_ws/install/setup.bash

OPTION 2: Binary Installation

If required, add the ROS repository (this occurs only once):

sudo apt install software-properties-common 
sudo add-apt-repository universe 
sudo apt update

Install the Synapticon package (replace ROS_DISTRO with the ROS distribution you want - humble, jazzy or rolling):

sudo apt install ros-ROS_DISTRO-synapticon-ros2-control

Make sure rosdep is initialized and updated:

sudo rosdep init 
rosdep update

Install its dependencies:

rosdep install synapticon_ros2_control

The package will get installed to /opt/ros/ROS_DISTRO/share/synapticon_ros2_control/.

VERIFICATION

The ethernet device name, to which the drive is connected, is required. This could be checked with the ifconfig command. Ethernet adapters usually start with en. To check if the master could be run and if the slaves are found, execute the following in the terminal (replace YOUR_ETHERNET_INTERFACE with the one found with ifconfig). If you installed from source:

sudo ./home/$USER/ros2_ws/install/synapticon_ros2_control/bin/torque_control_executable YOUR_ETHERNET_INTERFACE

or if you installed using the binary installation (replace ROS_DISTRO with the desired ROS distribution - humble, jazzy or rolling):

sudo ./opt/ros/ROS_DISTRO/share/synapticon_ros2_control/bin/torque_control_executable YOUR_ETHERNET_INTERFACE

Before running other scripts, stop this one by CTRL+C (or wait - it will shutdown automatically after a while).

2.2.1.3. Demo

For turning the motor in different modes, five terminals are required and in all of them execute:

sudo -i
source /home/YOUR_USER/.bashrc

• Terminal 1:

If you are running the demo with one motor:

ros2 launch synapticon_ros2_control elevated_permissions_1_dof.launch.py

If you are running the demo with two motors:

ros2 launch synapticon_ros2_control elevated_permissions_2_dof.launch.py

• Terminal 2:

If you are running the demo with one motor:

ros2 launch synapticon_ros2_control single_dof.launch.py eth_device:=YOUR_ETHERNET_DEVICE

If you are running the demo with two motors:

ros2 launch synapticon_ros2_control two_dof.launch.py eth_device:=YOUR_ETHERNET_DEVICE

• Terminal 3 - to show the running controllers

ros2 control list_controllers

(Information does not automatically refresh - it can be refreshed each M seconds using watch -n M ros2 control list_controllers)

• Running motors with different controllers:

CSV (Cyclic Sync Velocity) mode:

Terminal 4 to turn on the controller :

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['forward_velocity_controller'], deactivate_controllers: []}"

Terminal 5 to create a publisher:

If you are running the demo with one motor:

ros2 topic pub /forward_velocity_controller/commands std_msgs/msg/Float64MultiArray data:\ [100]

If you are running the demo with two motors:

ros2 topic pub /forward_velocity_controller/commands std_msgs/msg/Float64MultiArray data:\ [100,100]

Stopping it: CTRL+C on Terminal 5 and in Terminal 4:

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['quick_stop_controller'], deactivate_controllers: ['forward_velocity_controller']}"

• CSP (Cyclic Sync Position) mode:

Terminal 4 to turn on the controller :

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['forward_position_controller'], deactivate_controllers: [quick_stop_controller]}"

Terminal 5 to create a publisher:

If you are running the demo with one motor:

ros2 topic pub /forward_position_controller/commands std_msgs/msg/Float64MultiArray data:\ [140]

If you are running the demo with two motors:

ros2 topic pub /forward_position_controller/commands std_msgs/msg/Float64MultiArray data:\ [140, 140]

Stopping it: CTRL+C on Terminal 5 and in Terminal 4:

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['quick_stop_controller'], deactivate_controllers: ['forward_position_controller']}"

• CST (Cyclic Sync Torque) mode:

Terminal 4 to turn on the controller :

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['forward_torque_controller'], deactivate_controllers: [quick_stop_controller]}"	

Terminal 5 to create a publisher (value is in per mille of torque):

If you are running the demo with one motor:

ros2 topic pub /forward_torque_controller/commands std_msgs/msg/Float64MultiArray data:\ [100]	

If you are running the demo with two motors:

ros2 topic pub /forward_torque_controller/commands std_msgs/msg/Float64MultiArray data:\ [100, 100]	

Stopping it: CTRL+C on Terminal 5 and in Terminal 4:

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['quick_stop_controller'], deactivate_controllers: ['forward_torque_controller']}"

2.2.1.4. Running Without Sudo (Optional)

To run the example without using sudo, create:

sudo touch /etc/systemd/system/ros2_control_node.service

and use the text editor to paste the following into that file. Note that YOUR_USER, ROS_DISTRO, pythonX.XX and elevated_permissions_X_dof.launch.py must be replaced with the correct data.

[Unit]
Description=Launch ros2_control_node with socket permissions

[Service]
Type=simple
User=YOUR_USER
ExecStartPre=/bin/bash -c 'source /opt/ros/ROS_DISTRO/setup.bash; source /home/YOUR_USER/.bashrc; source /home/YOUR_USER/ros2_ws/install/setup.bash'
# Write the user environment to file, for debugging
#ExecStartPre=/bin/bash -c 'env > /home/YOUR_USER/Documents/ros_env_before_start.txt'

# This is essentially a copy of my normal user env
Environment="AMENT_PREFIX_PATH=/home/YOUR_USER/ros2_ws/install/synapticon_ros2_control:/opt/ros/ROS_DISTRO"
Environment="HOME=/home/YOUR_USER"
Environment="LD_LIBRARY_PATH=/opt/ros/ROS_DISTRO/opt/rviz_ogre_vendor/lib:/opt/ros/ROS_DISTRO/lib/x86_64-linux-gnu:/opt/ros/ROS_DISTRO/lib"
Environment="PATH=/opt/ros/ROS_DISTRO/bin:/usr/lib/ccache:/home/YOUR_USER/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/snap/bin"
Environment="PYTHONPATH=/opt/ros/ROS_DISTRO/lib/pythonX.XX/site-packages:/opt/ros/ROS_DISTRO/local/lib/pythonX.XX/dist-packages"
Environment="ROS_DISTRO=ROS_DISTRO"
Environment="ROS_DOMAIN_ID=1"
Environment="ROS_PYTHON_VERSION=3"
Environment="ROS_VERSION=2"
Environment="ROSCONSOLE_FORMAT=[${severity}] - ${node}: [${time}] ${message}"
Environment="USER=YOUR_USER"
Environment="USERNAME=YOUR_USER"

ExecStart=/opt/ros/ROS_DISTRO/bin/ros2 launch synapticon_ros2_control elevated_permissions_X_dof.launch.py
AmbientCapabilities=CAP_NET_RAW

[Install]
WantedBy=multi-user.target

Save the file, restart the daemon:

sudo systemctl daemon-reload

and start the service:

sudo systemctl restart ros2_control_node.service

To check the service status and see the ROS console logging:

sudo systemctl status ros2_control_node.service

Now, the example can be run by these two commands:

sudo systemctl restart ros2_control_node.service

and, if running the demo with one motor:

ros2 launch synapticon_ros2_control single_dof.launch.py eth_device:=YOUR_ETHERNET_DEVICE

If you are running the demo with two motors:

ros2 launch synapticon_ros2_control two_dof.launch.py eth_device:=YOUR_ETHERNET_DEVICE

Changing the controllers and publishing the desired position/velocity/torque can be now executed without sudo. To stop the ros2_control_node:

sudo systemctl stop ros2_control_node.service

2.2.2. Isolated Environment (Docker)

For users with different Linux distributions or those preferring an isolated environment, Docker can be used. Installation steps can be found in the Docker Documentation. Installation instructions are also provided below:

2.2.2.1. Docker Installation

Install Docker and add the user to the Docker group:

sudo apt update
sudo apt install -y docker.io
sudo groupadd docker
sudo usermod -aG docker $USER

2.2.2.2. Synapticon Package Installation

With the following command, the Docker image can be pulled (replace ROS_DISTRO with the desired ROS_distribution - humble, jazzy or rolling):

docker pull ghcr.io/synapticon/synapticon_ros2_control:ROS_DISTRO

To allow Docker containers to output the screen on your system, which is required for RViZ, execute this on the host system:

xhost +

For the first execution of the program, we build container named ros2_container from the downloaded docker image (replace ROS_DISTRO with the desired ROS_distribution - humble, jazzy or rolling):

docker run -it -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket -v /tmp/.X11-unix:/tmp/.X11-unix --ipc=host -e DISPLAY=$DISPLAY  --network=host --env QT_X11_NO_MITSHM=1 --privileged --name ros2_container ghcr.io/synapticon/synapticon_ros2_control:ROS_DISTRO

Now, the container is running. For all other occurrences, start the container using:

docker start ros2_container

For opening a new terminal in the running container, use:

docker exec -it ros2_container bash

and, once it opens, source the ROS2 environment using

source /root/.bashrc

To check if the master could be run and if the slaves are found, in the container terminal execute:

./install/synapticon_ros2_control/bin/torque_control_executable

Before running other scripts, stop this one by CTRL+C (or wait, it will shutdown automatically after a while).

2.2.2.3. Demo

Connect the Synapticon device configured with OBLAC Tools to your ethernet port as shown in Figure 1. For the demo, run five terminals in the container (docker exec -it ros2_container bash and source /root/.bashrc)

• Terminal 1 If you are running the demo with one motor:

ros2 launch synapticon_ros2_control elevated_permissions_1_dof.launch.py

If you are running the demo with two motors:

ros2 launch synapticon_ros2_control elevated_permissions_2_dof.launch.py

• Terminal 2 - this one will open RViZ. If it fails, xhost + was not executed on your host machine. By spinning the motor by hand, movement should be seen in RViZ. If you are running the demo with one motor:

ros2 launch synapticon_ros2_control single_dof.launch.py eth_device:=YOUR_ETHERNET_DEVICE

If you are running the demo with two motors:

ros2 launch synapticon_ros2_control two_dof.launch.py eth_device:=YOUR_ETHERNET_DEVICE

• Terminal 3 - to show the running controllers:

ros2 control list_controllers

(Information does not automatically refresh - it can be refreshed each M seconds using watch -n M ros2 control list_controllers)

• Running motors with different controllers: CSV (Cyclic Sync Velocity) mode:

Terminal 4 to turn on the controller :

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['forward_velocity_controller'], deactivate_controllers: []}"

Terminal 5 to create a publisher: If you are running the demo with one motor:

ros2 topic pub /forward_velocity_controller/commands std_msgs/msg/Float64MultiArray data:\ [100]

If you are running the demo with two motors:

ros2 topic pub /forward_velocity_controller/commands std_msgs/msg/Float64MultiArray data:\ [100,100]

Stopping it: CTRL+C on Terminal 5 and in Terminal 4:

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['quick_stop_controller'], deactivate_controllers: ['forward_velocity_controller']}"

• CSP (Cyclic Sync Position) mode:

Terminal 4 to turn on the controller :

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['forward_position_controller'], deactivate_controllers: [quick_stop_controller]}"

Terminal 5 to create a publisher: If you are running the demo with one motor:

ros2 topic pub /forward_position_controller/commands std_msgs/msg/Float64MultiArray data:\ [140]

If you are running the demo with two motors:

ros2 topic pub /forward_position_controller/commands std_msgs/msg/Float64MultiArray data:\ [140, 140]

Stopping it: CTRL+C on Terminal 5 and in Terminal 4:

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['quick_stop_controller'], deactivate_controllers: ['forward_position_controller']}"

• CST (Cyclic Sync Torque) mode:

Terminal 4 to turn on the controller :

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['forward_torque_controller'], deactivate_controllers: [quick_stop_controller]}"	

Terminal 5 to create a publisher (value is in per mille of torque): If you are running the demo with one motor:

ros2 topic pub /forward_torque_controller/commands std_msgs/msg/Float64MultiArray data:\ [100]	

If you are running the demo with two motors:

ros2 topic pub /forward_torque_controller/commands std_msgs/msg/Float64MultiArray data:\ [100, 100]	

Stopping it: CTRL+C on Terminal 5 and in Terminal 4:

ros2 service call /controller_manager/switch_controller controller_manager_msgs/srv/SwitchController "{activate_controllers: ['quick_stop_controller'], deactivate_controllers: ['forward_torque_controller']}"

3. Disclaimer

This repository is an example of how to use SOMANET drives with ROS2 (humble, jazzy and rolling). It does not guarantee compatibility with the latest ROS versions or SOMANET firmware. The included code is for demonstration purposes only. Synapticon GmbH refuses any responsibility for any problem or damage by using the example configuration and code!