universalrobot

(Not recommended) Connection to simulated cobot or physical cobot from Universal Robots

Since R2022a

universalrobot is not recommended. Use urROS2Node or urROSNode instead. For more information, see Version History.

Description

The universalrobot object represents a connection from the ROS enabled host computer to MATLAB. The ROS master running inside the ROS 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 in the Gazebo simulator) 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 = universalrobot

ur = universalrobot(hostname)

ur = universalrobot(hostname,port)

ur = universalrobot(URI)

ur = universalrobot(hostname,Name=Value)

Description

ur = universalrobot creates a connection, ur, and tries to connect to the ROS master at default URI: http://localhost:11311. The ROS master is further connected to a simulated cobot or physical cobot from Universal Robots.

However, before initiating the connection, the command checks for the value of the standard ROS environmental variable, ROS_MASTER_URI, which defines the ROS master. Therefore, you can use the syntax ur = universalrobot to create connection to simulated cobot in a different host computer if you have already specified a different address for the ROS master using that variable.

example

ur = universalrobot(hostname) creates a connection, ur, to the ROS master at the specified IP address or host name. This syntax assumes that the ROS master is running on the ROS default port number, 11311.

example

ur = universalrobot(hostname,port) creates a connection, ur, to the ROS master at the specified IP address or host name, and the specified port.

example

ur = universalrobot(URI) creates a connection, ur, to the ROS master at the specified URI (Uniform Resource Identifier).

example

ur = universalrobot(hostname,Name=Value) also specifies the IP address if the automatic detection fails (NodeHost), or sets the JointStateTopic, FollowJointTrajectoryAction, and RigidBodyTree properties using one or more optional name-value arguments.

example

Input Arguments

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`hostname` — Host name or IP address
string scalar | character vector

Host name or IP address, specified as a string scalar or character vector.

`port` — Port number
numeric scalar

Port number used to connect to the ROS master, specified as a numeric scalar.

`URI` — URI for ROS master
string scalar | character vector

URI for ROS master, specified as a string scalar or character vector. Standard format for URIs is either http://ipaddress:port or http://hostname:port.

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.

`NodeHost` — Host name or IP address that is advertised
character vector

Host name or IP address that the node uses to advertise itself to the ROS network, specified as the pair consisting of NodeHost and a character vector. This argument is useful if the automatic detection of ROS master fails.

Example: ur = universalrobot('172.19.98.176',11311,NodeHost='172.20.224.1')

Example: ur = universalrobot('172.19.98.176',11311,NodeHost='comp-home')

Properties

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`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 = universalrobot('172.19.98.176',11311,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 = universalrobot('http://172.19.98.176:11311',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 = universalrobot('http://172.19.98.176:11311',RigidBodyTree=loadrobot('universalUR5e','DataFormat','row'))

`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

`universalrobot`	(Not recommended) Connection to simulated cobot or physical cobot from Universal Robots
`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.

ur = universalrobot;

Connect to the physical or simulated cobot (either in the URSim offline simulator from Universal Robots or in the Gazebo simulator), in a different host computer. Specify the address of the ROS master by using the ROS_MASTER_URI environmental variable.

setenv('ROS_MASTER_URI',['http://192.168.58.128:11311']);
ur = universalrobot;

Connect to a Cobot by Specifying the IP Address

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 identified by the IP address in the ROS network.

ur = universalrobot('172.19.98.176');

Connect to a Cobot by Specifying the IP Address and Port Number

ur = universalrobot('172.19.98.176',11312);

Connect to a Cobot by Specifying the URI

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 identified by the URI in the ROS network.

ur = universalrobot('http://172.19.98.176:11311');

Connect to a Cobot by Specifying the Advertised Address and 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 by mentioning the advertised address (for example, 172.20.224.1) of the host computer in the ROS network.

ur = universalrobot('172.19.98.176',NodeHost='172.20.224.1');

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.

ur = universalrobot('172.19.98.176',RigidBodyTree=ur5);

ur = 
  universalrobot 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™.

Usage notes and limitations:

The hostname and port input arguments are redundant in code generation. Therefore, you can either keep them as it is or add an empty char array (‘ ’) as an argument. For example, see the last command line shown below:
```
ur5e = loadrobot('universalUR5','DataFormat','row');
ur = urROSNode('','RigidBodyTree',ur5e);
```
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 R2022a

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R2024a: `universalrobot` object will be removed

The universalrobot function will be removed in a future release. Use urROS2Node or urROSNode instead. Use urROS2Node to connect to UR Series cobot if you selected the ROS 2 option in the Hardware Setup screen. Use urROSNode to connect to UR Series cobot if you selected the ROS option in the Hardware Setup screen.

universalrobot

Description

Creation

Syntax

Description

Input Arguments

`hostname` — Host name or IP address
string scalar | character vector

`port` — Port number
numeric scalar

`URI` — URI for ROS master
string scalar | character vector

`NodeHost` — Host name or IP address that is advertised
character vector

Properties

`JointStateTopic` — Name of ROS topic to read robot state
`/joint_states` (default)

`FollowJointTrajectoryAction` — Name of the ROS action to move the robot
`/arm_controller/follow_joint_trajectory` (default)

`RigidBodyTree` — Rigid body tree robot model
object

`NumberOfJoints` — Number of joints in the robot
numeric

`EndEffectorName` — End effector body name for frame transformation
character vector

Object Functions

Examples

Connect to a Cobot Using Auto-detection

Connect to a Cobot by Specifying the IP Address

Connect to a Cobot by Specifying the IP Address and Port Number

Connect to a Cobot by Specifying the URI

Connect to a Cobot by Specifying the Advertised Address and Other Optional Arguments

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

R2024a: `universalrobot` object will be removed

See Also

Topics

universalrobot

Description

Creation

Syntax

Description

Input Arguments

hostname — Host name or IP address string scalar | character vector

port — Port number numeric scalar

URI — URI for ROS master string scalar | character vector

NodeHost — Host name or IP address that is advertised character vector

Properties

JointStateTopic — Name of ROS topic to read robot state /joint_states (default)

FollowJointTrajectoryAction — Name of the ROS action to move the robot /arm_controller/follow_joint_trajectory (default)

RigidBodyTree — Rigid body tree robot model object

NumberOfJoints — Number of joints in the robot numeric

EndEffectorName — End effector body name for frame transformation character vector

Object Functions

Examples

Connect to a Cobot Using Auto-detection

Connect to a Cobot by Specifying the IP Address

Connect to a Cobot by Specifying the IP Address and Port Number

Connect to a Cobot by Specifying the URI

Connect to a Cobot by Specifying the Advertised Address and Other Optional Arguments

Extended Capabilities

C/C++ Code Generation Generate C and C++ code using MATLAB® Coder™.

Version History

R2024a: universalrobot object will be removed

See Also

Topics

`hostname` — Host name or IP address
string scalar | character vector

`port` — Port number
numeric scalar

`URI` — URI for ROS master
string scalar | character vector

`NodeHost` — Host name or IP address that is advertised
character vector

`JointStateTopic` — Name of ROS topic to read robot state
`/joint_states` (default)

`FollowJointTrajectoryAction` — Name of the ROS action to move the robot
`/arm_controller/follow_joint_trajectory` (default)

`RigidBodyTree` — Rigid body tree robot model
object

`NumberOfJoints` — Number of joints in the robot
numeric

`EndEffectorName` — End effector body name for frame transformation
character vector

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

R2024a: `universalrobot` object will be removed