Inertial measurement unit
=========================


This sensor emulates an Inertial Measurement Unit (IMU), measuring
the angular velocity and linear acceleration including acceleration
due to gravity.

If the robot has a physics controller, the velocities are directly
read from it's properties ``localAngularVelocity`` and
``worldLinearVelocity``. Otherwise the velocities are calculated by
simple differentiation. Linear acceleration is always computed by
differentiation of the linear velocity. The measurements are given
in the IMU coordinate system, so the location and rotation of the
IMU with respect to the robot is taken into account.


.. cssclass:: properties morse-section

Configuration parameters for inertial measurement unit
------------------------------------------------------

*No configurable parameter.*

.. cssclass:: fields morse-section

Data fields
-----------


This sensor exports these datafields at each simulation step:

- ``timestamp`` (float, initial value: ``0.0``)
	number of milliseconds in simulated time
- ``angular_velocity`` (vec3<float>, initial value: ``[0.0, 0.0, 0.0]``)
	rates in IMU x, y, z axes (in radian . sec ^ -1)
- ``linear_acceleration`` (vec3<float>, initial value: ``[0.0, 0.0, 0.0]``)
	acceleration in IMU x, y, z axes (in m . sec ^ -2)

*Interface support:*

- :tag:`text`  as key = value format with timestamp and index value (:py:mod:`morse.middleware.text_datastream.Publisher`)
- :tag:`ros`  as ImuPublisher (:py:mod:`morse.middleware.ros.imu.ImuPublisher`)
- :tag:`moos`  as db entries (:py:mod:`morse.middleware.moos.imu.IMUNotifier`)
- :tag:`socket`  as straight JSON serialization (:py:mod:`morse.middleware.socket_datastream.SocketPublisher`)
- :tag:`yarp`  as yarp::Bottle (:py:mod:`morse.middleware.yarp_datastream.YarpPublisher`)


.. cssclass:: services morse-section

Services for Inertial measurement unit
--------------------------------------

- ``get_properties()`` (blocking)
    Returns the properties of a component.
    
    
  - Return value

    a dictionary of the current component's properties  

- ``get_configurations()`` (blocking)
    Returns the configurations of a component (parsed from the properties).
    
    
  - Return value

    a dictionary of the current component's configurations  

- ``get_local_data()`` (blocking)
    Returns the current data stored in the sensor.
    
    
  - Return value

    a dictionary of the current sensor's data 



.. cssclass:: examples morse-section

Examples
--------


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

.. code-block:: python


    from morse.builder import *
    
    robot = ATRV()
    
    # creates a new instance of the sensor
    imu = IMU()

    # place your component at the correct location
    imu.translate(<x>, <y>, <z>)
    imu.rotate(<rx>, <ry>, <rz>)
    
    robot.append(imu)
    
    # define one or several communication interface, like 'socket'
    imu.add_interface(<interface>)

    env = Environment('empty')
    

.. cssclass:: files morse-section

Other sources of examples
+++++++++++++++++++++++++

- `Source code <../../_modules/morse/sensors/imu.html>`_
- `Unit-test <../../_modules/base/imu_testing.html>`_




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