ROS & ROS2: Command the robot

Stop the robot

Stop the current motion

Default topic name	Message type (msg)
`/iiwa/command/stop`	std_msgs/Empty

Example

$ rostopic pub -1 /iiwa/command/stop std_msgs/Empty "{}"

import rospy
import std_msgs.msg

# create a publisher
pub = rospy.Publisher('/iiwa/command/stop', std_msgs.msg.Empty, queue_size=1)

# initialize the ROS node
rospy.init_node('test')

# publish the message
pub.publish(std_msgs.msg.Empty())

$ ros2 topic pub -1 /iiwa/command/stop std_msgs/msg/Empty "{}"

import rclpy
import std_msgs.msg
from rclpy.node import Node
from rclpy.qos import QoSPresetProfiles

# initialize the ROS node
rclpy.init()
node = Node('test')

# create a publisher
pub = node.create_publisher(std_msgs.msg.Empty, '/iiwa/command/stop', QoSPresetProfiles.SYSTEM_DEFAULT.value)

# publish the message
pub.publish(std_msgs.msg.Empty())

try:
    rclpy.spin_once(node)
except KeyboardInterrupt:
    pass
finally:
    # shutdown the node
    node.destroy_node()
    rclpy.shutdown()

Joint space

Move the robot to the specified joint position

Default topic name	Message type (msg)	Units
`/iiwa/command/joint`	sensor_msgs/JointState	\(radians\)

Implementation details

Joint names are the same as those of the iiwa_description URDF model (iiwa_joint_1, iiwa_joint_2, iiwa_joint_3, iiwa_joint_4, iiwa_joint_5, iiwa_joint_6, iiwa_joint_7)

Joint names, and their respective positions, can appear in any order

No need to specify message name if all joint positions are specified

A subset of the joints can be controlled by specifying only the joint names and the corresponding positions, or by setting the other joints positions to nan. In this case, the excluded joints will keep their current position

Example

Move all joints to their respective goal positions

Joint names: [iiwa_joint_1, iiwa_joint_2, iiwa_joint_3, iiwa_joint_4, iiwa_joint_5, iiwa_joint_6, iiwa_joint_7]
Joint positions: [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]

# name are specified
$ rostopic pub -1 /iiwa/command/joint sensor_msgs/JointState "{name: ['iiwa_joint_1', 'iiwa_joint_2', 'iiwa_joint_3', 'iiwa_joint_4', 'iiwa_joint_5', 'iiwa_joint_6', 'iiwa_joint_7'], position: [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]}"

# no need to specify message name if all joint positions are specified
$ rostopic pub -1 /iiwa/command/joint sensor_msgs/JointState "{position: [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]}"

import rospy
import sensor_msgs.msg

# create a publisher
pub = rospy.Publisher('/iiwa/command/joint', sensor_msgs.msg.JointState, queue_size=1)

# initialize the ROS node
rospy.init_node('test')

# build a message
msg = sensor_msgs.msg.JointState()
msg.position = [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]
# or
msg = sensor_msgs.msg.JointState()
msg.name = ['iiwa_joint_1', 'iiwa_joint_2', 'iiwa_joint_3', 'iiwa_joint_4', 'iiwa_joint_5', 'iiwa_joint_6', 'iiwa_joint_7']
msg.position = [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]

# publish the message
pub.publish(msg)

# name are specified
$ ros2 topic pub -1 /iiwa/command/joint sensor_msgs/msg/JointState "{name: ['iiwa_joint_1', 'iiwa_joint_2', 'iiwa_joint_3', 'iiwa_joint_4', 'iiwa_joint_5', 'iiwa_joint_6', 'iiwa_joint_7'], position: [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]}"

# no need to specify message name if all joint positions are specified
$ ros2 topic pub -1 /iiwa/command/joint sensor_msgs/msg/JointState "{position: [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]}"

import rclpy
import sensor_msgs.msg
from rclpy.node import Node
from rclpy.qos import QoSPresetProfiles

# initialize the ROS node
rclpy.init()
node = Node('test')

# create a publisher
pub = node.create_publisher(sensor_msgs.msg.JointState, '/iiwa/command/joint', QoSPresetProfiles.SYSTEM_DEFAULT.value)

# build a message
msg = sensor_msgs.msg.JointState()
msg.position = [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]
# or
msg = sensor_msgs.msg.JointState()
msg.name = ['iiwa_joint_1', 'iiwa_joint_2', 'iiwa_joint_3',
            'iiwa_joint_4', 'iiwa_joint_5', 'iiwa_joint_6', 'iiwa_joint_7']
msg.position = [0.0, 0.0, 0.0, -1.57, 0.0, 1.57, 0.0]

# publish the message
pub.publish(msg)

try:
    rclpy.spin_once(node)
except KeyboardInterrupt:
    pass
finally:
    # shutdown the node
    node.destroy_node()
    rclpy.shutdown()

Move only the specified joints to their respective goal positions

Joint names: [iiwa_joint_4, iiwa_joint_6]
Joint positions: [-1.57, 1.57]
Other joints will keep their current position

# all names and positions are specified
$ rostopic pub -1 /iiwa/command/joint sensor_msgs/JointState "{name: ['iiwa_joint_1', 'iiwa_joint_2', 'iiwa_joint_3', 'iiwa_joint_4', 'iiwa_joint_5', 'iiwa_joint_6', 'iiwa_joint_7'], position: [.nan, .nan, .nan, -1.57, .nan, 1.57, .nan]}"

# all positions are specified
$ rostopic pub -1 /iiwa/command/joint sensor_msgs/JointState "{position: [.nan, .nan, .nan, -1.57, .nan, 1.57, .nan]}"

# only target joint names and positions are specified
$ rostopic pub -1 /iiwa/command/joint sensor_msgs/JointState "{name: ['iiwa_joint_4', 'iiwa_joint_6'], position: [-1.57, 1.57]}"

import math
import rospy
import sensor_msgs.msg

# create a publisher
pub = rospy.Publisher('/iiwa/command/joint', sensor_msgs.msg.JointState, queue_size=1)

# initialize the ROS node
rospy.init_node('test')

# build a message
# math.nan, float("nan"), np.nan and np.NaN are all equivalent
msg = sensor_msgs.msg.JointState()
msg.position = [math.nan, math.nan, math.nan, -1.57, math.nan, 1.57, math.nan]
# or
msg = sensor_msgs.msg.JointState()
msg.name = ['iiwa_joint_4', 'iiwa_joint_6']
msg.position = [-1.57, 1.57]

# publish the message
pub.publish(msg)

# all names and positions are specified
$ ros2 topic pub -1 /iiwa/command/joint sensor_msgs/msg/JointState "{name: ['iiwa_joint_1', 'iiwa_joint_2', 'iiwa_joint_3', 'iiwa_joint_4', 'iiwa_joint_5', 'iiwa_joint_6', 'iiwa_joint_7'], position: [.nan, .nan, .nan, -1.57, .nan, 1.57, .nan]}"

# all positions are specified
$ ros2 topic pub -1 /iiwa/command/joint sensor_msgs/msg/JointState "{position: [.nan, .nan, .nan, -1.57, .nan, 1.57, .nan]}"

# only target joint names and positions are specified
$ ros2 topic pub -1 /iiwa/command/joint sensor_msgs/msg/JointState "{name: ['iiwa_joint_4', 'iiwa_joint_6'], position: [-1.57, 1.57]}"

import math
import rclpy
import sensor_msgs.msg
from rclpy.node import Node
from rclpy.qos import QoSPresetProfiles

# initialize the ROS node
rclpy.init()
node = Node('test')

# create a publisher
pub = node.create_publisher(sensor_msgs.msg.JointState, '/iiwa/command/joint', QoSPresetProfiles.SYSTEM_DEFAULT.value)

# build a message
# math.nan, float("nan"), np.nan and np.NaN are all equivalent
msg = sensor_msgs.msg.JointState()
msg.position = [math.nan, math.nan, math.nan, -1.57, math.nan, 1.57, math.nan]
# or
msg = sensor_msgs.msg.JointState()
msg.name = ['iiwa_joint_4', 'iiwa_joint_6']
msg.position = [-1.57, 1.57]

# publish the message
pub.publish(msg)

try:
    rclpy.spin_once(node)
except KeyboardInterrupt:
    pass
finally:
    # shutdown the node
    node.destroy_node()
    rclpy.shutdown()

Cartesian space

Move the robot to the specified Cartesian pose

Default topic name	Message type (msg)	Units
`/iiwa/command/cartesian`	geometry_msgs/Pose	position (\(m\)), orientation as quaternion

Implementation details

Values set to nan will keep their current position/orientation

Example

Move to the specified Cartesian pose (position and orientation)

Cartesian position: X, Y, Z = (0.65, 0.0, 0.2)
Cartesian orientation: x, y, z, w = (0.0, 1.0, 0.0, 0.0) \(\; \rightarrow \;\) A, B, C = (-180.0º, 0.0º, 180.0º)

$ rostopic pub -1 /iiwa/command/cartesian geometry_msgs/Pose "{position: {x: 0.65, y: 0.0, z: 0.2}, orientation: {x: 0.0, y: 1.0, z: 0.0, w: 0.0}}" 

import rospy
import geometry_msgs.msg

# create a publisher
pub = rospy.Publisher('/iiwa/command/cartesian', geometry_msgs.msg.Pose, queue_size=1)

# initialize the ROS node
rospy.init_node('test')

# build a message
msg = geometry_msgs.msg.Pose()
msg.position.x = 0.65
msg.position.y = 0.0
msg.position.z = 0.2
msg.orientation.x = 0.0
msg.orientation.y = 1.0
msg.orientation.z = 0.0
msg.orientation.w = 0.0

# publish the message
pub.publish(msg)

$ ros2 topic pub -1 /iiwa/command/cartesian geometry_msgs/msg/Pose "{position: {x: 0.65, y: 0.0, z: 0.2}, orientation: {x: 0.0, y: 1.0, z: 0.0, w: 0.0}}" 

import rclpy
import geometry_msgs.msg
from rclpy.node import Node
from rclpy.qos import QoSPresetProfiles

# initialize the ROS node
rclpy.init()
node = Node('test')

# create a publisher
pub = node.create_publisher(geometry_msgs.msg.Pose, '/iiwa/command/cartesian', QoSPresetProfiles.SYSTEM_DEFAULT.value)

# build a message
msg = geometry_msgs.msg.Pose()
msg.position.x = 0.65
msg.position.y = 0.0
msg.position.z = 0.2
msg.orientation.x = 0.0
msg.orientation.y = 1.0
msg.orientation.z = 0.0
msg.orientation.w = 0.0

# publish the message
pub.publish(msg)

try:
    rclpy.spin_once(node)
except KeyboardInterrupt:
    pass
finally:
    # shutdown the node
    node.destroy_node()
    rclpy.shutdown()

Move to the specified Cartesian position or orientation

Case 1
- Cartesian position: X, Y, Z = (0.65, 0.0, 0.3)
- Keep the current orientation
Case 2
- Move in Z-axis only: Z = 0.4
- Keep the current position in X, Y and orientation
Case 3
- Cartesian orientation: x, y, z, w = (0.0, -0.7071, 0.7071, 0.0) \(\; \rightarrow \;\) A, B, C = (90.0º, 0.0º, 180.0º)
- Keep the current position

# case 1
$ rostopic pub -1 /iiwa/command/cartesian geometry_msgs/Pose "{position: {x: 0.65, y: 0.0, z: 0.3}, orientation: {x: .nan, y: .nan, z: .nan, w: .nan}}" 

# case 2
$ rostopic pub -1 /iiwa/command/cartesian geometry_msgs/Pose "{position: {x: .nan, y: .nan, z: 0.4}, orientation: {x: .nan, y: .nan, z: .nan, w: .nan}}"

# case 3
$ rostopic pub -1 /iiwa/command/cartesian geometry_msgs/Pose "{position: {x: .nan, y: .nan, z: .nan}, orientation: {x: 0.0, y: -0.7071, z: 0.7071, w: 0.0}}"

import math
import rospy
import geometry_msgs.msg

# create a publisher
pub = rospy.Publisher('/iiwa/command/cartesian', geometry_msgs.msg.Pose, queue_size=1)

# initialize the ROS node
rospy.init_node('test')

# build a message 
# math.nan, float("nan"), np.nan and np.NaN are all equivalent

# case 1
msg = geometry_msgs.msg.Pose()
msg.position.x = 0.65
msg.position.y = 0.0
msg.position.z = 0.3
msg.orientation.x = math.nan
msg.orientation.y = math.nan
msg.orientation.z = math.nan
msg.orientation.w = math.nan

# case 2
msg = geometry_msgs.msg.Pose()
msg.position.x = math.nan
msg.position.y = math.nan
msg.position.z = 0.4
msg.orientation.x = math.nan
msg.orientation.y = math.nan
msg.orientation.z = math.nan
msg.orientation.w = math.nan

# case 3
msg = geometry_msgs.msg.Pose()
msg.position.x = math.nan
msg.position.y = math.nan
msg.position.z = math.nan
msg.orientation.x = 0.0
msg.orientation.y = -0.7071
msg.orientation.z = 0.7071
msg.orientation.w = 0.0

# publish the message
pub.publish(msg)

# case 1
$ ros2 topic pub -1 /iiwa/command/cartesian geometry_msgs/msg/Pose "{position: {x: 0.65, y: 0.0, z: 0.3}, orientation: {x: .nan, y: .nan, z: .nan, w: .nan}}" 

# case 2
$ ros2 topic pub -1 /iiwa/command/cartesian geometry_msgs/msg/Pose "{position: {x: .nan, y: .nan, z: 0.4}, orientation: {x: .nan, y: .nan, z: .nan, w: .nan}}"

# case 3
$ ros2 topic pub -1 /iiwa/command/cartesian geometry_msgs/msg/Pose "{position: {x: .nan, y: .nan, z: .nan}, orientation: {x: 0.0, y: -0.7071, z: 0.7071, w: 0.0}}"

import math
import rclpy
import geometry_msgs.msg
from rclpy.node import Node
from rclpy.qos import QoSPresetProfiles

# initialize the ROS node
rclpy.init()
node = Node('test')

# create a publisher
pub = node.create_publisher(geometry_msgs.msg.Pose, '/iiwa/command/cartesian', QoSPresetProfiles.SYSTEM_DEFAULT.value)

# build a message 
# math.nan, float("nan"), np.nan and np.NaN are all equivalent

# case 1
msg = geometry_msgs.msg.Pose()
msg.position.x = 0.65
msg.position.y = 0.0
msg.position.z = 0.3
msg.orientation.x = math.nan
msg.orientation.y = math.nan
msg.orientation.z = math.nan
msg.orientation.w = math.nan

# case 2
msg = geometry_msgs.msg.Pose()
msg.position.x = math.nan
msg.position.y = math.nan
msg.position.z = 0.4
msg.orientation.x = math.nan
msg.orientation.y = math.nan
msg.orientation.z = math.nan
msg.orientation.w = math.nan

# case 3
msg = geometry_msgs.msg.Pose()
msg.position.x = math.nan
msg.position.y = math.nan
msg.position.z = math.nan
msg.orientation.x = 0.0
msg.orientation.y = -0.7071
msg.orientation.z = 0.7071
msg.orientation.w = 0.0

# publish the message
pub.publish(msg)

try:
    rclpy.spin_once(node)
except KeyboardInterrupt:
    pass
finally:
    # shutdown the node
    node.destroy_node()
    rclpy.shutdown()

Circular motion

# TODO