Computing Abstraction Hierarchies by Numerical Simulation

Abstract

We present a novel method for building ABSTRIPS-style abstraction hierarchies in planning. The aim of this method is to minimize the amount of backtracking between abstraction levels. Previous approaches have determined the criticality of operator preconditions by reasoning about plans directly. Here, we adopt a sim-pler and faster approach where we use numerical sim-ulation of the planning process. We demonstrate the theoretical advantages of our approach by identifying some simple properties lacking in previous approaches but possessed by our method. We demonstrate the empirical advantages of our approach by a set of four benchmark experiments using the ABTWEAK sys-tem. We compare the quality of the abstraction hi-erarchies generated with those built by the ALPINE and HIGHPOINT algorithms.