Overworld Documentation

Getting Start

Overview

Launchers

Overworld is quite easy to launch as it consists of only one executable and only has two mandotory arguments. 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"/>
<arg name="robot_name" default="pr2"/>
<node name="overworld" pkg="overworld" type="overworld_node" output="screen" args="-c $(arg configuration_file) -n $(arg robot_name)"> </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) parameter is (quite logically) the identifier of your robot. This parameter should be the same as the one defined in the configuration file.

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 17hz.

The simulation frequency (-sf or --simulation-frequency) is an optional double parameter. It can be set to change the physical simulation frequency. By default, this parameter is set to 70hz.

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 parameter is the ontologies to be loaded.

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