Overworld Documentation

Getting Start

Overview

Launchers

Overworld is quite easy to launch as it consists of only one executable and only has one mandotory argument. However, Overworld uses the Ontologenius knowledge base. Here we explain the minimal setup to launch both software.

Overworld launcher

Overworld can be launched with a ROS launch file containing the following:

<launch>
<arg name="configuration_file" default="$(find overworld)/config/config_example.yaml"/>
<node name="overworld" pkg="overworld" type="overworld_node" output="screen" args="-c $(arg configuration_file)"> </node>
</launch>

The configuration_file (-c or --config) parameter is used to defined the perception modules to be loaded and to parametrized them. See the configuration page to setup your file.

The robot_name (-n or --name) optional parameter is (quite logically) the identifier of your robot. This parameter is not mandatory if the root parameter of Ontologenius has been defined.

The simulate (-s or --simulate) is an optional boolean ("true" or "false") parameter. It can be set to activate or deactivate the physics simulation in the reasoning process. By default, this parameter is set to true.

The assessment frequency (-af or --assessment-frequency) is an optional double parameter. It can be set to change the assessment loop frequency. By default, this parameter is set to 20hz.

The simulation substepping (-sub or --simulation-substepping) is an optional integer parameter. It can be set to change the physical simulation frequency by substepping the assessment frequency. By default, this parameter is set to 3, meaning a frequency of 20Hz for the default assessment frequency.

The display frequency (-df or --display-frequency) is an optional double parameter. It can be set to change the rendering frequency. By default, this parameter is set to 30hz. Changing this parameter has an impact both on the CPU and GPU usage.

The publish debug (-d or --debug) is an optional boolean parameter to publish debug marker on Rviz. By default, this parameter is set to false.

Ontologenius launcher

Here we propose the simplest launch file to use Ontologenius with Overworld. Advanced use can is explain on Ontologenius website.

Ontologenius has to be used in its multi-mode. The only mandatory parameters are the ontologies to be loaded and the root name representing the robot to be considered.

<launch>
<arg name="root" default="my_robot_name"/>
<arg name="files" default="
$(find common_ground_ontology)/CG_root.owl
$(find overworld)/ontologies/adream_building.owl
"/>
<node name="ontologenius_core" pkg="ontologenius" type="ontologenius_multi" output="screen" args="--root $(arg root) -d false $(arg files)"> </node>
<node name="ontologenius_gui" pkg="ontologenius" type="overworldGUI" output="screen" > </node>
</launch>

The common ground ontology defines the basic vocabulary. It contains some classes and properties used by Overworld. Further descriptions of the ontology are presented in the tutorials.

With this basic launch file, we also launch the Ontologenius graphical interface to ease debugging.