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:
ros
as sensor_msgs/Imu (morse.middleware.ros.imu.ImuPublisher
)socket
as straight JSON serialization (morse.middleware.socket_datastream.SocketPublisher
)yarp
as YarpPublisher (morse.middleware.yarp_datastream.YarpPublisher
)text
as key = value format with timestamp and index value (morse.middleware.text_datastream.Publisher
)moos
as IMUNotifier (morse.middleware.moos.imu.IMUNotifier
)
Services for Inertial measurement unit¶
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
get_properties()
(blocking)Returns the properties of a component.
Return value
a dictionary of the current component’s properties
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:
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.)