Landmarks for Numeric Planning Problems

Landmarks for Numeric Planning Problems

Enrico Scala, Patrik Haslum, Daniele Magazzeni, Sylvie Thiébaux

Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence
Main track. Pages 4384-4390. https://doi.org/10.24963/ijcai.2017/612

The paper generalises the notion of landmarks for reasoning about planning problems involving propositional and numeric variables. Intuitively, numeric landmarks are regions in the metric space defined by the problem whose crossing is necessary for its resolution. The paper proposes a relaxation-based method for their automated extraction directly from the problem structure, and shows how to exploit them to infer what we call disjunctive and additive hybrid action landmarks. The justification of such a disjunctive representation results from the intertwined propositional and numeric structure of the problem. The paper exercises their use in two novel admissible LP-Based numeric heuristics, and reports experiments on cost-optimal numeric planning problems. Results show the heuristics are more informed and effective than previous work for problems involving a higher number of (sub)goals.
Keywords:
Planning and Scheduling: Temporal and Hybrid planning
Planning and Scheduling: Search in Planning and Scheduling
Planning and Scheduling: Planning and Scheduling