Armature Pose Sensor

Returns the joint state of a MORSE armature

The sensor streams the joint state (ie, the rotation or translation value of each joint belonging to the armature) of its parent armature.

Note

This sensor must be added as a child of the armature you want to sense. See the Examples section below for an example.

This component only allows to read armature configuration. To change the armature pose, you need an armature actuator.

Important

To be valid, special care must be given when creating armatures. If you want to add new one, please carefully read the armature creation documentation.

Note

The data structure on datastream exported by the armature sensor depends on the armature. It is a dictionary of pair (joint name, joint value). Joint values are either radians (for revolute joints) or meters (for prismatic joints)

See also: armature actuator

Configuration parameters for Armature Pose Sensor

No configurable parameter.

Data fields

This sensor exports these datafields at each simulation step:

• timestamp (float, initial value: 0.0)

  number of seconds in simulated time

Interface support:

• ros as sensor_msgs/JointState (morse.middleware.ros.jointstate.JointStatePublisher)
• socket as straight JSON serialization (morse.middleware.socket_datastream.SocketPublisher)
• yarp as YarpPublisher (morse.middleware.yarp_datastream.YarpPublisher)
• moos as StringPublisher (morse.middleware.moos.abstract_moos.StringPublisher)
• text as key = value format with timestamp and index value (morse.middleware.text_datastream.Publisher)

Services for Armature Pose Sensor

• get_configurations() (blocking)

  Returns the configurations of a component (parsed from the properties).

  • Return value

    a dictionary of the current component’s configurations

• get_joint(joint) (blocking)

  Returns the value of a given joint, either: - its absolute rotation in radian along its rotation axis, or - it absolute translation in meters along its translation axis.

  Throws an exception if the joint does not exist.

  • Parameters
    • joint: the name of the joint in the armature.

• get_joints() (blocking)

  Returns the list of joints of the armature.

  • Return value

    the (ordered) list of joints in the armature, from root to tip.

• get_joints_length() (blocking)

  Returns a dict with the armature joints’ names as key and and the corresponding bone length as value (in meters).

• get_local_data() (blocking)

  Returns the current data stored in the sensor.

  • Return value

    a dictionary of the current sensor’s data

• get_properties() (blocking)

  Returns the properties of a component.

  • Return value

    a dictionary of the current component’s properties

• get_state() (blocking)

  Returns the joint state of the armature, ie a dictionnary with joint names as key and the corresponding rotation or translation as value (respectively in radian or meters).

• set_property(prop_name, prop_val) (blocking)

  Modify one property on a component

  • Parameters

    • prop_name: the name of the property to modify (as shown the documentation)
    • prop_val: the new value of the property. Note that there is no checking about the type of the value so be careful

  • Return value

    nothing

Examples

The following examples show how to use this component in a Builder script:

robot = ATRV()

arm = KukaLWR()
robot.append(arm)
arm.translate(z=0.9)

arm_pose = ArmaturePose()
# the sensor is appended to the armature, *not* to the robot
arm.append(arm_pose)

Other sources of examples

• Source code
• Unit-test

(This page has been auto-generated from MORSE module morse.sensors.armature_pose.)