Startup the driver

Prepare the robot

If you want to use a real robot, or a URSim simulator, with this driver, you need to prepare it, first. Make sure that you complete all steps from the setup instructions, installed the External Control URCap and created a program as explained here.

Launch files

For starting the driver it is recommended to start the ur_control.launch.py launchfile from the ur_robot_driver package. It starts the driver, a set of controllers and a couple of helper nodes for UR robots. The only required arguments are the ur_type and robot_ip parameters.

$ ros2 launch ur_robot_driver ur_control.launch.py ur_type:=ur5e robot_ip:=192.168.56.101

Allowed ur_type strings: ur3, ur3e, ur5, ur5e, ur10, ur10e, ur16e, ur20, ur30.

Other important arguments are:

  • use_mock_hardware (default: false ) - Use simple hardware emulator from ros2_control. Useful for testing launch files, descriptions, etc.

  • headless_mode (default: false) - Start driver in Headless mode.

  • launch_rviz (default: true) - Start RViz together with the driver.

  • initial_joint_controller (default: scaled_joint_trajectory_controller) - Use this if you want to start the robot with another controller.

    Note

    When the driver is started, you can list all loaded controllers using the ros2 control list_controllers command. For this, the package ros2controlcli must be installed (sudo apt-get install ros-${ROS_DISTRO}-ros2controlcli).

For all other arguments, please see

$ ros2 launch ur_robot_driver ur_control.launch.py --show-args

Also, there are predefined launch files for all supported types of UR robots.

Finish startup on the robot

Unless Headless mode is used, you will now have to start the External Control URCap program on the robot that you have created earlier.

Depending on the robot control mode do the following:

  • In local control mode, load the program on the robot and press the “Play” button play_button on the teach pendant.

  • In remote control mode load and start the program using the following dashboard calls:

    $ ros2 service call /dashboard_client/load_program ur_dashboard_msgs/srv/Load "filename: my_robot_program.urp"``
$ ros2 service call /dashboard_client/play std_srvs/srv/Trigger {}

  • When the driver is started with headless_mode:=true nothing is needed. The driver is running already.

Continuation after interruptions

Whenever the External Control URCap program gets interrupted, it has to be unpaused / restarted.

If that happens, you will see the output Connection to reverse interface dropped.

This can happen, e,g, when

  • The running program is actively stopped.

  • The robot goes into a protective stop / EM stop. (The program will be paused, then)

  • The communication is stopped, since the external source did not receive a command in time.

  • There was another script sent for execution e.g.

    • Script code was sent to the robot via its primary interface

    • Robot motion is performed using the Teach pendant

Depending on the operation mode, perform one of the following steps:

  • In local control mode, simply press the “Play” button play_button on the teach pendant.

  • In remote control mode start the program using the following dashboard call:

    $ ros2 service call /dashboard_client/play std_srvs/srv/Trigger {}

  • When the driver is started with headless_mode:=true perform the following service call:

    $ ros2 service call /io_and_status_controller/resend_robot_program std_srvs/srv/Trigger {}