Planning with OWL-DL Ontologies (Extended Version)

TL;DR

This paper presents a novel ontology-mediated planning framework that supports the full expressive power of OWL DL, enabling the use of existing planning systems through ontology rewriting into PDDL, with practical evaluation on benchmarks.

Contribution

It introduces a formalism with a loose coupling between planning and ontologies, and a black-box algorithm supporting OWL DL, surpassing previous limited description logic approaches.

Findings

The approach supports full OWL DL expressivity in planning.

Rewriting into PDDL enables use of existing planning tools.

Performance depends on tailored reasoning optimizations.

Abstract

We introduce ontology-mediated planning, in which planning problems are combined with an ontology. Our formalism differs from existing ones in that we focus on a strong separation of the formalisms for describing planning problems and ontologies, which are only losely coupled by an interface. Moreover, we present a black-box algorithm that supports the full expressive power of OWL DL. This goes beyond what existing approaches combining automated planning with ontologies can do, which only support limited description logics such as DL-Lite and description logics that are Horn. Our main algorithm relies on rewritings of the ontology-mediated planning specifications into PDDL, so that existing planning systems can be used to solve them. The algorithm relies on justifications, which allows for a generic approach that is independent of the expressivity of the ontology language. However, dedicated optimizations for computing justifications need to be implemented to enable an efficient rewriting procedure. We evaluated our implementation on benchmark sets from several domains. The evaluation shows that our procedure works in practice and that tailoring the reasoning procedure has significant impact on the performance.