urROS2Node

Connection to simulated cobot or physical cobot from Universal Robots over ROS 2

Since R2024a

Description

The urROS2Node object represents a connection from the ROS 2 enabled host computer to MATLAB. The ROS 2 enabled host computer is further connected to a simulated collaborative robot (cobot) from Universal Robots (either in the URSim offline simulator from Universal Robots) or to a physical cobot. To interact with the simulated cobot to read robot state data, send joint and cartesian control commands, and follow set of joint-space or task-space waypoints, use this object with the functions listed in Object Functions.

Creation

Syntax

ur = urROS2Node

ur = urROS2Node(Name=Value)

Description

ur = urROS2Node creates a connection, ur, and tries to connect to the ROS 2 node, which is further connected to a simulated cobot or physical cobot from Universal Robots.

ur = urROS2Node(Name=Value) sets the JointStateTopic, FollowJointTrajectoryAction, and RigidBodyTree properties using one or more optional name-value arguments.

Input Arguments

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

DomainID — Domain ID of the ROS 2 node to connect

character vector

Domain ID of the ROS 2 node to connect. By default the DomainID is maintained as 0.

Example: ur = urROS2Node(DomainID = 2)

Properties

JointStateTopic — Name of ROS topic to read robot state

/joint_states (default)

Name of the ROS topic to read robot state, specified as a string scalar or character vector.

Example: ur = urROS2Node(JointStateTopic='/joint_states')

Data Types: char | string

FollowJointTrajectoryAction — Name of the ROS action to move the robot

/arm_controller/follow_joint_trajectory (default)

Name of the ROS action to move the robot, specified as a string scalar or character vector.

Example: ur = urROS2Node(FollowJointTrajectoryAction='/arm_controller/follow_joint_trajectory')

Data Types: char | string

RigidBodyTree — Rigid body tree robot model

object

Rigid body tree robot model, specified as a rigidBodyTree object.

Example: ur = urROS2Node(RigidBodyTree=ur5e), where ur5e is defined using the command ur5e = loadrobot('universalUR5e').

NumberOfJoints — Number of joints in the robot

numeric

This property is read-only.

Number of joints in the robot, specified as a numeric scalar.

Data Types: double

EndEffectorName — End effector body name for frame transformation

character vector

This property is read-only.

End effector body name for frame transformation, specified as a character vector.

Data Types: char

Object Functions

getJointConfiguration	Get current joint configuration from the robot
getCartesianPose	Get current end-effector pose from the robot
getEndEffectorVelocity	Get current end-effector velocities from the robot
getJointVelocity	Get current joint velocities from the robot
getMotionStatus	Get current motion status of the robot
followTrajectory	Command robot to move along the desired joint space waypoints
followWaypoints	Command robot to move along the desired task space waypoints
sendCartesianPose	Command robot to move to desired Cartesian pose
sendCartesianPoseAndWait	Command robot to move to desired Cartesian pose and wait for the motion to complete
sendJointConfiguration	Command robot to move to desired joint configuration
sendJointConfigurationAndWait	Command robot to move to joint configuration and wait for the motion to complete
recordRobotState	Log the key robot state parameters during motion of robot
executePrimaryURScriptCommand	Execute primary URScript command to control cobot over ROS interface
executeSecondaryURScriptCommand	Execute secondary URScript command over ROS interface
handBackControl	Get the control back from the External Control program node in the UR program tree

Examples

Connect to a Cobot Using Auto-detection

Connect to the physical or simulated cobot (either in the URSim offline simulator from Universal Robots or in the Gazebo simulator), in the same host computer, over ROS2.

ur = urROS2Node;

Connect to a Cobot by Specifying Other Optional Arguments

Connect to the physical or simulated cobot (either in the URSim offline simulator from Universal Robots or in the Gazebo simulator), in the host computer, over ROS 2.

ur = urROS2Node;

Connect to a Cobot by Specifying the RBT Object

Connect to the physical or simulated cobot (either in the URSim offline simulator from Universal Robots or in the Gazebo simulator), in the host computer by mentioning the rigid body tree object.

ur5e = loadrobot('universalUR5e')
ur = urROS2Node(RigidBodyTree=ur5e);

ur = 
  urROS2Node with properties:

                  RigidBodyTree: [1×1 rigidBodyTree]
                JointStateTopic: '/joint_states'
    FollowJointTrajectoryAction: '/scaled_pos_joint_traj_controller/follow_joint_trajectory'
                 NumberOfJoints: 6
                EndEffectorName: 'tool0'

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

• During code generation, there can be certain warnings that are expected, similar to the one displayed below. You can ignore them because they do not have any impact on the performance. Warning: The "JointNames" field of the "trajectory_msgs/JointTrajectory" message is a cell string which is not supported in code generation. Do not access the "JointNames" field in your MATLAB code.

Version History

Introduced in R2024a