• To start relaxed_ik_ros2: refer to README.md in relaxed_ik_ros2. For detailed directions, see below.
• Note. When adding new nodes within the scripts folder, make sure to add filename under relaxed_ik_ros2 > CMakeLists.txt > install, or else when launch, the node file mentioned in the launch file will not be found and hence throw an error.

Running cartesian_to_joint.py and cartesian_to_joint_multi.py

First start RelaxedIK by running the single_converter.launch.py launch file. Then at a new terminal, run either the cartesian_to_joint.py ROS node or the multi-version of that (i.e., running multiple coordinate csv files sequentially), cartesian_to_joint_multi.py. Make sure the modify the launch file accordingly to your choice of cartesian_xx ROS node file.

Starting relaxed_ik_ros2

For the bulk of the instructions, follow the README in the relaxed_ik_ros2 folder. The UR description files are already in there, so you just have to install it. Installation: https://automaticaddison.com/how-to-create-a-urdf-file-of-the-ur3e-robotic-arm-ros-2/

# Intall python packages
pip3 install -r requirements.txt

# install the required packages
sudo apt-get update
sudo apt install python3-pykdl
sudo apt-get install ros-${ROS_DISTRO}-urdfdom-py
sudo apt-get install ros-${ROS_DISTRO}-ur-description

# verify installation via rviz (for example, UR3e)
source /opt/ros/${ROS_DISTRO}/setup.bash
ros2 launch ur_description view_ur.launch.py ur_type:=ur3e

Whenever you are building the relaxed_ik_ros2 package, use colcon build. Specifically, make sure you are in your workstation and not in src and run

colcon build --packages-select relaxed_ik_ros2 --symlink-install # will take about 3 ~ 8 seconds
. install/setup.bash

Troubleshooting build error

colcon build sometimes yield no rosidl_typesupport_c found error, even though the CMakeLists.txt includes finding the appropriate rosidl packages. You can clear out the previous cmake caches using the option --cmake-clean-cache however, this leads to a libexec error, where the ROS nodes in the install folder are not executable, hence build may be successful however not work when running the ROS node. You should instead try colcon bulid --cmake-clean-cache --symlink-install --packages-select relaxed_ik_ros2 so that the symlink correctly forms the files in the install folder as executable. An ament-package-folder already exists error that is yielded from this command can then be easily fixed by rm -rf-ing the existing install folders, and running colcon build --symlink-install --packages-select relaxed_ik_ros2 subsequently.

ROS2 Iron Installation

# Follow general instructions from [the official ROS2 website](https://docs.ros.org/en/iron/Installation/Ubuntu-Install-Debians.html)

## Setup locale
locale  # check for UTF-8

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

locale  # verify settings

## Ensure that the Ubuntu Universal Repository is enabled
sudo apt install software-properties-common
sudo add-apt-repository universe
sudo apt update && sudo apt install curl -y

## Skip the ROS2 GPG key adding part in the instructions. Instead, refer to post [here](https://answers.ros.org/question/410123/ubuntu-2204-ros2-humble-installing-error-gpg-libc-bin/).
rm /etc/apt/sources.list.d/ros2.list # if exists
curl http://repo.ros2.org/repos.key | sudo apt-key add -
sudo apt-key list # find key name
sudo cp /etc/apt/trusted.gpg /usr/share/keyrings/ros-archive-keyring.gpg

## go back to general instructions
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

sudo apt update && sudo apt install ros-dev-tools

sudo apt update

sudo apt upgrade

sudo apt install ros-iron-desktop

source /opt/ros/iron/setup.bash