Technical Report No. 169 - Abstract

Joerg Hoffmann
Extending FF to Numerical State Variables

The FF system obtains a heuristic estimate for each state during a forward search by solving a relaxed version of the planning task, where the relaxation is to assume that all delete lists are empty. We show how this relaxation, and FF's heuristic function, can naturally be extended to planning tasks with constraints and effects on numerical state variables. First results show that the implementation, Metric-FF, is competitive with other approaches to numerical planning, performing well against one of the most recent approaches on a numerical version of the Logistics domain.