This is a documented example of a KnowRob Package.
In the subdirectory OWL we stored an example knowledge base. In 'src' you will find the source code of this package.
To run the package use the launch file
roslaunch knowrob_example knowrob_example.launch
You can then use the following command to send queries:
rosrun rosprolog rosprolog_commandline.py
In 'src/util/pose.pl' we defined get_better_pose, as a simple example of
manipulation of a pose.
?- get_better_pose([[1.0,1.0,1.0],[0.0, 0.0, 0.0, 1.0]],[[XNew,Y,Z],Rotation]).
Rotation: [0.0, 0.0, 0.0, 1.0],
XNew: 2.0,
Y: 1.0,
Z: 1.0.
In 'src/model/objects.pl' we define predicates to query and manipulate knowledge in the knowledge base.
To create new knowledge you can use kb_project (different to assert kb_project will project the knowledge into the mongo database). The simplest way would be to assert a new triple into the knowledge base (e.g. kb_project(triple(a,b,c))). In objects.pl we defined is_pizza that allows to create and query new pizza entities:
Creating:
?- kb_project(is_pizza(P)).
P: http://www.ease-crc.org/ont/knowrob-example#Pizza_IOTQDJZX.
Querying:
?- is_pizza(P).
P: http://www.ease-crc.org/ont/knowrob-example#Pizza_IOTQDJZX.
After creating a Pizza we can query for it's ingredients using has_ingredient:
?- is_pizza(P), has_ingredient(P,Ingredient).
Ingredient: http://www.ease-crc.org/ont/knowrob-example#Cheese,
P: http://www.ease-crc.org/ont/knowrob-example#Pizza_DXLUMEJP ;
Ingredient: http://www.ease-crc.org/ont/knowrob-example#Tomato,
P: http://www.ease-crc.org/ont/knowrob-example#Pizza_DXLUMEJP.