Universal_Robots_ROS2_Description

This repository contains description files and meshes for Universal Robots manipulators.

Build status

ROS2 Distro	Branch	Build status	Released packages
Galactic	galactic		ur_description
Humble	ros2		ur_description
Iron	ros2		ur_description
Rolling	ros2		ur_description

Note that for ROS2 Foxy the description is in the driver's repository. Please do not clone this repository into a Foxy workspace.

Structure of the repository

The most relevant files are: - urdf/ur_macro.xacro - macro file with UR-manipulator description. This file is usually included into external projects to visualize and configure UR manipulators properly. An example how to use this macro is in urdf/ur.urdf.xacro file. - urdf/ur.ros2_control.xacro - definition of manipulator's joints and interfaces for ros2_control framework.

Testing description of a manipulator

To visualize the robot install this repository to you workspace and execute the following:

ros2 launch ur_description view_ur.launch.py ur_type:=ur5e

To test other descriptions change the ur_type argument.

Package / Description structure

This package uses one description for all robots. The different robot variants are configured using four configuration files. These files can also be changed for further customizing a description.

Basically, the description can be modified using configuration values stored in four files: - config/urXX/default_kinematics.yaml - This contains the calibration values as they can be extracted from the robot. Changing these values with the one extracted from a real robot will result in a description matching the real robot exactly (w.r.t the tool0 frame). It is highly recommended to use matching kinematic values in real-world applications. - config/urXX/joint_limits.yaml - If you'd like to further restrict the robot's joint limits, these limits can be modified there. - config/urXX/physical_parameters.yaml - Everything regarding physics simulation parameters (e.g. inertia poses and values) can be tuned here - config/urXX/visual_parameters.yaml - Some users change certain visual aspects, e.g. replacing the cap on the wrist_3_link. This config file specifies which meshes (both, visual and collision) should be used.

The four configuration files have to be passed to ur_macro.urdf (more specific to the macro defined in that file) which is done inside the ur.urdf.macro. Contents of the files are parsed inside ur_common.xacro.

Arguments that have to be passed to the main ur.urdf.xacro file are: - kinematics_params - Filename to the default_kinematics.yaml (or equivalent specific kinematics) file - joint_limit_params - Filename to the joint_limits.yaml file - physical_params - Filename to the physical_parameters.yaml file - visual_params - Filename to the visual_params.yaml file

The launchfile launch/view_ur.launch.py abstracts these four parameters to one ur_type argument which will basically replace the urXX part of the paths as shown in the picture above.

Creating your own description including this description

In real-world applications you will most probably have a more complex description consisting of more objects than just the robot. It is recommended to create a separate ROS package containing this particular description. Inside this description you could also store your robot-specific kinematics parameters file.

As mentioned above, see the urdf/ur.urdf.xacro file as an example to integrate a UR robot into your scene description. Basically, you could create a copy of that file and extend it with the modifications from your specific scene.

Changelog for package ur_description

2.1.0 (2023-06-01)

• added missing handback interface - ros2control mock interface won\'t work otherwise (#68) Co-authored-by: Lennart Nachtigall <lennart.nachtigall@sci-mo.de>
• remove ticks from tf_prefix (#60) Co-authored-by: Lennart Nachtigall <lennart.nachtigall@sci-mo.de>
• Replace duplicated prefix parameter with tf_prefix
• Whitespace fixes
• Update pre-commit workflows to current versions

• This commits adds additional configuration fields which are needed for multiarm support: (#47)

  • Added trajectory_port - Port needed for the trajectory sending interface
  • Added non_blocking_read - Takes control of the update rate from ur interface by immediately returning from the read method

  - Added keep_alive_count field - Configures the amount of allowed reading timeouts on the robot side Additionally it adds the \${prefix} argument for the gpios and the force torque sensor in the ur.ros2_control.xacro file Co-authored-by: Lennart Nachtigall <firesurfer@firesurfer.de>

• Set the default tool voltage in the description to 0 (#41) I am not sure whether this will actually affect something, as I don\'t think we actually set the value initially, but it still makes sense to keep the default tool voltage at 0 to emphasize that by default, this will not be set higher.

• Run prerelease tests on current distros (#44)

• Contributors: Felix Exner, Felix Exner (fexner), Lennart Nachtigall

2.0.1 (2022-11-08)

• Add tool voltage and zero ft sensor to command interface (#38) Added reverse ip and script command interface port as parameters
• use xacro.load_yaml in favor of deprecated version (#43) Co-authored-by: aditya <aditya@nimble.ai>
• Use mock_components instead of fake_components (#37) This has been renamed in ros2_control hardware_interface.
• Prepare for branching out galactic (#39)
  • Add Humble to README and workflows
  • Use galactic branch for galactic stuff
• Contributors: Abishalini Sivaraman, Aditya Agarwal, Felix Exner, Mads Holm Peters

2.0.0 (2022-03-17)

• Migrated the description to ROS2
• Added support for Gazebo and Ignition
• Added ROS2_control definitions
• Contributors: AndyZe, Denis Stogl, Denis