Example Universal Robots

webots_ros2_universal_robot

This package provides an interface between ROS2 and the UR3e, UR5e, and UR10e simulation models of the Universal Robots running in Webots. It includes several simulations of these robots.

universal_robot Node

This node acts as a Webots robot controller. It publishes the /joint_states topic that represents the state of all the joints of the robot. And it provides the /follow_joint_trajectory action server that allows you to send joint trajectory action to the robot.

Samples Simulations

The following simulations are provided within this package:

universal_robot

This simulation can be started with the following launch file:

ros2 launch webots_ros2_universal_robot universal_robot.launch.py

This simulation contains one UR5e robot in a very simple environment.

universal_robot_rviz_dynamic

This simulation uses a new Webots feature to export URDF. Therefore, you will be able to change the robot model in Webots and to see the changes in RViz.

ros2 launch webots_ros2_universal_robot universal_robot_rviz_dynamic.launch.py

Note that the visual elements are still not supported, only the transforms will be shown.

universal_robot_multiple

This simulation can be started with the following launch file:

ros2 launch webots_ros2_universal_robot universal_robot_multiple.launch.py

This simulation contains a UR3e and a UR5e robot in a simple factory environment. This is a very good example showcasing how to use the multi-robots support with the Webots-ROS2 interface.

universal_robot_lidar

This world contains UR5e robot with 3D LiDAR.

ros2 launch webots_ros2_core robot_launch.py \
    executable:=webots_robotic_arm_node \
    world:=$(ros2 pkg prefix webots_ros2_universal_robot --share)/worlds/universal_robot_lidar.wbt

Interact with the Robot

Move the Robot

The /follow_joint_trajectory action server can be tested directly using the ROS2 action CLI interface to move the robot (if more than one robot is present in the simulation, the action name should be changed, e.g. /UR3e/follow_joint_trajectory):

ros2 action send_goal /follow_joint_trajectory control_msgs/action/FollowJointTrajectory "{
  trajectory: {
    joint_names: [shoulder_pan_joint, shoulder_lift_joint, elbow_joint, wrist_1_joint, wrist_2_joint, wrist_3_joint],
    points: [
      { positions: [3.02, -1.63, -1.88, 1.01, 1.51, 1.13], velocities: [0.1, 0.1, 0.1, 0.1, 0.1, 0.1], accelerations: [0.1, 0.1, 0.1, 0.1, 0.1, 0.1], time_from_start: { sec: 5, nanosec: 500 } },
      { positions: [-1.01, 0.38, -0.63, -0.88, 0.25, -1.63], velocities: [0.1, 0.1, 0.1, 0.1, 0.1, 0.1], accelerations: [0.1, 0.1, 0.1, 0.1, 0.1, 0.1], time_from_start: { sec: 6, nanosec: 500 } },
      { positions: [-1.01, 0.38, -0.63, -0.88, 0.25, 6.2], velocities: [0.1, 0.1, 0.1, 0.1, 0.1, 0.1], accelerations: [0.1, 0.1, 0.1, 0.1, 0.1, 0.1], time_from_start: { sec: 50, nanosec: 500 } }
    ]
  },
  goal_tolerance: [
    { name: shoulder_pan_joint, position: 0.01 },
    { name: shoulder_lift_joint, position: 0.01 },
    { name: elbow_joint, position: 0.01 },
    { name: wrist_1_joint, position: 0.01 },
    { name: wrist_2_joint, position: 0.01 },
    { name: wrist_3_joint, position: 0.01 }
  ]
}"

Display the Joint State

The joint state (/joint_states topic) can be displayed directly using the ROS2 topic CLI interface (if more than one robot is present in the simulation, the action name should be changed, e.g. /UR3e/joint_states):

ros2 topic echo /joint_states