Sensors

This page describes the predefined sensors and their parameters.

Sensor definition and common parameters

A sensor is attached to a vehicle by adding an XML block with the tag name <sensor>.... </sensor> inside:

the <vehicle>...</vehicle> that instantiates a particular robot, or
the <vehicle:class> to have all vehicles of that type with the same sensors installed.

All sensors, via the common base C++ class mvsim::SensorBase, have the common parameters below, with their meaning explained in the XML comments.

<!--
 ``class``: One of the registered sensor classes.
 ``name``: A name for the sensor, must be unique for each robot. If not provided,
           an automatic name will be generated. The name is important since it is
           used when publishing the sensor ROS or ZMQ topics.
-->
<sensor class="camera" name="camera1">
        <!-- Period (in seconds) between each sensor observation.
             Mathematical expressions can be used with $f{} to specify rates in Hz.
         -->
        <sensor_period>0.1</sensor_period>
        <!-- <sensor_period>$f{1/20.0}</sensor_period> -->

        <!-- See notes below -->
        <visual>
                ...
        </visual>

        <!-- Publish sensor on MVSIM ZMQ topic? (Note, **not** related to ROS at all) -->
        <!-- <publish>
                <publish_topic>/${PARENT_NAME}/${NAME}</publish_topic>
        </publish> -->
</sensor>

The <visual> tag is explained in the World XML definition of VisualObject, and the <publish> tag in World XML definition of Simulable entities, since those tags are common to sensors and many other entities.

Also, note that you can use the XML-level variables ${PARENT_NAME} and ${NAME} anywhere inside the sensor definition tag to refer to the parent vehicle and own sensor names, respectively.

Each sensor class has its own additional parameters, listed in the next sections.

3D LiDARs

HELIOS 32 (26 deg FOV)

HELIOS 32 (31 deg FOV)

HELIOS 32 (70 deg FOV)

OUSTER OS1

Velodyne VLP-16

RGB camera

A regular RGB (color) pin-hole camera (without lens distortion at present). The user must provide the camera intrinsic and extrinsic parameters:

IMU

An inertial sensor that measures (in the current version of MVSim):

3D linear proper acceleration.
3D angular velocity.

2D laser scanner

“Classical” lidars that scan obstacles in a plane only. These includes are available for these sensors:

Generic 2D LIDAR

RPLidar A2

Just like the generic Lidar above, but with a custom visualization for this particular commercial model.

Depth (RGBD) camera

GNSS sensor (“GPS”)

A “GPS sensor” can be attached to a robot with the code shown below. For it to work, the world XML needs to have a georeference tag.