Universal Robots Client Library

A C++ library for accessing Universal Robots interfaces. With this library C++-based drivers can be implemented in order to create external applications leveraging the versatility of Universal Robots robotic manipulators.

Requirements

• Polyscope (The software running on the robot controller) version 3.14.3 (for CB3-Series), or 5.9.4 (for e-Series) or higher. If you use an older Polyscope version it is suggested to update your robot. If for some reason (please tell us in the issues why) you cannot upgrade your robot, please see the version compatibility table for a compatible tag.
• The library requires an implementation of POSIX threads such as the pthread library
• Socket communication is currently based on Linux sockets. Thus, this library will require Linux for building and using.
• The master branch of this repository requires a C++17-compatible compiler. For building this library without a C++17-requirement, please use the boost branch instead that requires the boost library.

Build instructions

See Build / installation

License

The majority of this library is licensed under the Apache-2.0 licensed. However, certain parts are licensed under different licenses:

• The queue used inside the communication structures is originally written by Cameron Desrochers and is released under the BSD-2-Clause license.
• The semaphore implementation used inside the queue implementation is written by Jeff Preshing and licensed under the zlib license
• The Dockerfile used for the integration tests of this repository is originally written by Arran Hobson Sayers and released under the MIT license

While the main LICENSE file in this repository contains the Apache-2.0 license used for the majority of the work, the respective libraries of third-party components reside together with the code imported from those third parties.

Library contents

Currently, this library contains the following components:

• Basic primary interface: The primary interface isn’t fully implemented at the current state and provides only basic functionality. See A word on the primary / secondary interface for further information about the primary interface.
• RTDE interface: The RTDE interface is fully supported by this library. See RTDEClient for further information on how to use this library as an RTDE client.
• Dashboard interface: The Dashboard server can be accessed directly from C++ through helper functions using this library.
• Custom motion streaming: This library was initially developed as part of the Universal Robots ROS driver. Therefore, it also contains a mechanism to do data streaming through a custom socket, e.g. to perform motion command streaming.

Example driver

In the examples subfolder you will find a minimal example of a running driver. It starts an instance of the UrDriver class and prints the RTDE values read from the controller. To run it make sure to

• have an instance of a robot controller / URSim running at the configured IP address (or adapt the address to your needs)
• run it from the package’s main folder (the one where this README.md file is stored), as for simplicity reasons it doesn’t use any sophisticated method to locate the required files.

Architecture

See Architecture documentation

A word on the primary / secondary interface

Currently, this library doesn’t support the primary interface very well, as the Universal Robots ROS driver was built mainly upon the RTDE interface. Therefore, there is also no PrimaryClient for directly accessing the primary interface. This may change in future, though.

The comm::URStream class can be used to open a connection to the primary / secondary interface and send data to it. The producer/consumer pipeline structure can also be used together with the primary / secondary interface. However, package parsing isn’t implemented for most packages currently. See the primary_pipeline example on details how to set this up. Note that when running this example, most packages will just be printed as their raw byte streams in a hex notation, as they aren’t implemented in the library, yet.

A word on Real-Time scheduling

As mentioned above, for a clean operation it is quite critical that arriving RTDE messages are read before the next message arrives. Due to this, both, the RTDE receive thread and the thread calling getDataPackage() should be scheduled with real-time priority. See this guide for details on how to set this up.

The RTDE receive thread will be scheduled to real-time priority automatically, if applicable. If this doesn’t work, an error is raised at startup. The main thread calling getDataPackage should be scheduled to real-time priority by the application. See the ur_robot_driver as an example.

Producer / Consumer architecture

Communication with the primary / secondary and RTDE interfaces is designed to use a consumer/producer pattern. The Producer reads data from the socket whenever it comes in, parses the contents and stores the parsed packages into a pipeline queue. You can write your own consumers that use the packages coming from the producer. See the comm::ShellConsumer as an example.

Logging configuration

As this library was originally designed to be included into a ROS driver but also to be used as a standalone library, it uses custom logging macros instead of direct printf or std::cout statements.

The macro based interface is by default using the DefaultLogHandler to print the logging messages as printf statements. It is possible to define your own log handler to change the behavior, see create new log handler on how to.

Change logging level

Make sure to set the logging level in your application, as by default only messages of level WARNING or higher will be printed. See below for an example:

#include "ur_client_library/log.h"

int main(int argc, char* argv[])
{
  urcl::setLogLevel(urcl::LogLevel::DEBUG);

  URCL_LOG_DEBUG("Logging debug message");
  return 0;
}

Create new log handler

The logger comes with an interface LogHandler, which can be used to implement your own log handler for messages logged with this library. This can be done by inheriting from the LogHandler class.

If you want to create a new log handler in your application, you can use below example as inspiration:

#include "ur_client_library/log.h"
#include <iostream>

class MyLogHandler : public urcl::LogHandler
{
public:
  MyLogHandler() = default;

  void log(const char* file, int line, urcl::LogLevel loglevel, const char* log) override
  {
    switch (loglevel)
    {
      case urcl::LogLevel::INFO:
        std::cout << "INFO " << file << " " << line << ": " << log << std::endl;
        break;
      case urcl::LogLevel::DEBUG:
        std::cout << "DEBUG " << file << " " << line << ": " << log << std::endl;
        break;
      case urcl::LogLevel::WARN:
        std::cout << "WARN " << file << " " << line << ": " << log << std::endl;
        break;
      case urcl::LogLevel::ERROR:
        std::cout << "ERROR " << file << " " << line << ": " << log << std::endl;
        break;
      case urcl::LogLevel::FATAL:
        std::cout << "ERROR " << file << " " << line << ": " << log << std::endl;
        break;
      default:
        break;
    }
  }
};

int main(int argc, char* argv[])
{
  urcl::setLogLevel(urcl::LogLevel::DEBUG);
  std::unique_ptr<MyLogHandler> log_handler(new MyLogHandler);
  urcl::registerLogHandler(std::move(log_handler));

  URCL_LOG_DEBUG("logging debug message");
  URCL_LOG_INFO("logging info message");
  return 0;
}

Contributor Guidelines

• This repo supports pre-commit e.g. for automatic code formatting. TLDR: This will prevent you from committing falsely formatted code:

  pipx install pre-commit
  pre-commit install
  

• Succeeding pipelines are a must on Pull Requests (unless there is a reason, e.g. when there have been upstream changes).
• We try to increase and keep our code coverage high, so PRs with new features should also have tests covering them.
• Parameters of public methods must all be documented.

Acknowledgment

Many parts of this library are forked from the ur_modern_driver.

Developed in collaboration between:

  and   .

Supported by ROSIN - ROS-Industrial Quality-Assured Robot Software Components. More information: rosin-project.eu

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 732287.

Changelog for package ur_client_library

1.4.0 (2024-09-10)

• Ensure that the targets are reachable within the robots limits (#184)
• Analog domain (#211)
• Fix clang compilation error (#210)
• Moved reset of speed slider to correct teardown function, so that it … (#206) …resets between each test.
• [doc] Fix syntax in example.rst (#207)
• [doc] Migrate documentation to sphinx (#95)
• Contributors: Felix Exner, Mads Holm Peters, Remi Siffert, URJala

1.3.7 (2024-06-03)

• [ci] Update CI
  • Run downstream tests for ICI
  • Correctly name jobs
  • Test Jazzy driver
• [start_ursim] Add program directory at correct location also when no model is provided
• [start_ursim] Always check ursim version for compatibility
• [start_ursim] Use a program folder per model
• [ci] Update distros for prerelease test
• Contributors: Felix Exner, Vincenzo Di Pentima

1.3.6 (2024-04-04)

• Changed spline interpolation to use the last commanded joint velocity… (#195)
• Contributors: Mads Holm Peters, Rune Søe-Knudsen

1.3.5 (2024-02-23)

• Add support for UR30 in start_ursim.sh (#193)
• Add header guard to datatypes.h (#189)
• Remove duplicated entry in clang-format file (#188)
• Wait after docker kill to prevent name conflicts (#187)
• Contributors: Felix Exner, Robert Wilbrandt

1.3.4 (2023-09-22)

• Make depreaction warning for keepalive_counter a warning instead of error (#182)
• Added watchdog configuration for the reverse socket (#178)
• Add support for ur20 in start_ursim script (#179)
• Use pre-commit for clang-format (#175)
• Make tcp_server retry binding the socket (#176)
• Contributors: Felix Exner, Mads Holm Peters

1.3.3 (2023-09-05)

• Add support for setting socket max num tries and reconnect timeout (#172)
• Unify socket open (#174)
• Added handling of spline interpolation with end point velocities (#169)
• Throws exception if the URScript file doesn't exists (#173)
• Added check to ensure receive timeout isn't overwritten (#171)
• Added RTDEClient constructor with vector recipes (#143)
• Only warn if system is not setup for FIFO scheduling (#170)
• Ensuring that the Timestamp is always in the output recipe (#168)
• CI: Add Iron to CI tests (#167)
• Add issue templates for bugs and features (#166)
• Updated license (#164)

• Bugfixes for spline interpolation (#162)

  • Add separate rounding in the conversion from float to int32
  • Add more debug printout for splines
  • Add Copying flight reports if CI fails
  • Update ursim mininum version in start_ursim.sh

• Fix the prerelease ci for Melodic (#163)
• Contributors: Dag-Are Trydal, Felix Exner, Felix Exner (fexner), Mads Holm Peters, Michael Eriksen, RobertWilbrandt, Rune Søe-Knudsen, urmahp, urrsk

1.3.2 (2023-07-13)

• Add a cmake option to activate address sanitizers (#146)
• Install start ursim (#155)
• Add spline interpolation on robot (#151)
• Add codecov.yml to exclude test and examples folders (#152)
• Make URSim log files available as artifacts also for the CI-industrial (#153)
• Remove Foxy from CI
• Add a script to run the examples instead of run-parts
• Add SaveLog command to the Dashboard client
• Make URSim log files available as artifacts
• Specifically set RTDE pipeline producer to FIFO scheduling (#139)
• Added support for force_mode, freedrive and tool contact (#138)
• Docs: Update link to ros_industrial_cmake_boilerplate
• Added tests for the comm classes (#129)
• Changed num_retries from static to an unsigned int (#136)
• Build downstream humble version from humble branch (#132)
• Contributors: Felix Exner, Mads Holm Peters, Rune Søe-Knudsen, Robert Wilbrandt

1.3.1 (2022-11-30)

• CI: Add a prerelease check that calls [bloom-generate]{.title-ref} (#134)
• Contributors: Felix Exner

1.3.0 (2022-11-28)

• Dashboard commands, Docker Image and CI step for running the examples #127
• Added tests for the rtde interface clasess (#125)
• Fix unique_ptr type (#124)
• Fix 'BEGIN_REPLACE' - used in tool_communication (copy #101) (#120) (cherry picked from commit f7ce9f73181848f3957c660647fac0e5325862b9) Co-authored-by: rxjia <<60809735+rxjia@users.noreply.github.com>>
• Contributors: Felix Exner, Mads Holm Peters, RobertWilbrandt, Rune Søe-Knudsen, mergify[bot], urmarp, urrsk

1.2.0 (2022-10-04)

• Initialized receive timeout and changed exception to warning (#118)
• Added tests for the control interface classes (#112)
• Added note about Polyscope version requirement
• Added tcp_offset
• Added interface for forwarding script commands to the robot, that is … (#111)
• Fixed parsing of incomming packages when using rtde protocol v1 (#114) The received rtde packages should be parsed slightly different whether we use protocol v1 or v2.
• Add codecov step (#116)
• Added humble build
• Fixed downstream test instructions
• Update atomicops.h (#117) Fix the url in the comment regarding POSIX semaphores to fix error in the CI
• Make the read during boot depend on the frequency of the robot controller (#102)
• Ignore debian folder in check_links (#100) Otherwise this job raises an error in the release repository.
• Contributors: Felix Exner, Mads Holm Peters, Rune Søe-Knudsen, urmahp, urmarp

1.1.0 (2022-04-22)

• Support starting the driver, before the robot is booted (#98)
• Clear the queue when consumer reads from it (#96)
• Fix build with newer glibc
• Doxygen check (#77)
• Added target_frequency to RTDEClient (#85)
• Removed console_bridge dependency (#74)
• Added "On behalf of Universal Robots A/S" notice (#81) to all files that have been created by FZI
• Always install package.xml file (#78)
• register package with ament index
• Corrected smaller doxygen errors
• Added rosdoc_lite check
• Contributors: Cory Crean, Felix Exner, Jørn Bersvendsen, Mads Holm Peters, Martin Jansa, Stefan Scherzinger

1.0.0 (2021-06-18)

• Added Cartesian streaming interface #75
• Added trajectory forwarding interface #72
• Refactored Reverse interface #70 from fmauch/refactor_reverse_interface
• Added option for robot_ip as runtime argument for rtde_test (#71)
• Added reverse_ip parameter (#52)
• Move calibration check out of constructor. #65 from fmauch/calibration_check_optional
• Install the resources folder instead of the script file directly (#62)
• Use a non-blocking tcp server for the [ReverseInterface]{.title-ref} and [ScriptSender]{.title-ref}. #46 from fmauch/tcp_server
• Added LogHandler #40 from urmahp/logging_feature
• Fixed links in README (#35)
• Contributors: Felix Exner, G.A. vd. Hoorn, JS00000, Lennart Puck, Mads Holm Peters, Tristan Schnell

0.1.1 (2020-09-15)

• readme: missing whitespace
• Further elaborated license statements in README
• Install package.xml when built with catkin support
• Contributors: Felix Exner, G.A. vd. Hoorn

0.1.0 (2020-09-11)

• initial standalone release