On the role of ground actions in refinement planning
Abstract
Less than a decade ago, the focus in refinement planning was on
partial order planners using lifted actions. Today, the currently
most successful refinement planners are all state space planners using
ground actions—i.e. actions where all parameters have been
substituted by objects. In this paper, we address the role of ground
actions in refinement planning, and present empirical results
indicating that their role is twofold. First, planning with ground
actions represents a bias towards early commitment of parameter
bindings. Second, ground actions help enforce joint parameter domain
constraints. By implementing these two techniques in a least
commitment planner such as UCPOP, together with using an informed
heuristic function to guide the search for solutions, we show that we
often need to generate far fewer plans than when planning with ground
action, while the number of explored plans remains about the same. In
some cases a vast reduction can also be achieved in the number of
explored plans.
Sample citation
Håkan L. S. Younes and
Reid G. Simmons. 2002.
On the role of ground actions in refinement planning. In
Proceedings of the Sixth International Conference on Artificial Intelligence Planning and Scheduling Systems, edited by Malik Ghallab, Joachim Hertzberg, and Paolo Traverso, 54–61, Toulouse, France. AAAI Press.
Full paper (8 pages, 18 references)
Copyright © 2002, American Association for Artificial Intelligence. All rights reserved.
Presentation (26 slides)