Inertial measurement unit

This sensor emulates an Inertial Measurement Unit (IMU), measuring the angular velocity and linear acceleration including acceleration due to gravity. For the magnetic field part, refer to the documentation of Magnetometer.

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.

Configuration parameters for Inertial measurement unit

You can set these properties in your scripts with <component>.properties(<property1>=..., <property2>=...).

  • ComputationMode (string, default: "Automatic")

    Kind of computation, can be one of [‘Velocity’, ‘Position’]. Only robot with dynamic and Velocity control can choose Velocity computation. Default choice is Velocity for robot with physics, and Position for others

Data fields

This sensor exports these datafields at each simulation step:

  • timestamp (float, initial value: 0.0)

    number of seconds 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)

  • magnetic_field (vec3<float>, initial value: [0.0, 0.0, 0.0])

    magnetic field along x, y, z axes (in nT)

Interface support:

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_local_data() (blocking)

    Returns the current data stored in the sensor.

    • Return value

      a dictionary of the current sensor’s data

  • 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

  • get_configurations() (blocking)

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

    • Return value

      a dictionary of the current component’s configurations

Examples

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

from morse.builder import *

# adds a default robot (the MORSE mascott!)
robot = Morsy()

# 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')

Other sources of examples

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