A Lookahead Strategy for Heuristic Search Planning

The planning as heuristic search framework, initiated by the planners ASP from Bonet, Loerincs and Geffner, and HSP from Bonet and Geffner, lead to some of the most performant planners, as demonstrated in the two previous editions of the International Planning Competition. We focus in this paper on a technique introduced by Hoffmann and Nebel in the FF planning system for calculating the heuristic, based on the extraction of a solution from a planning graph computed for the relaxed problem obtained by ignoring deletes of actions. This heuristic is used in a forward-chaining search algorithm to evaluate each encountered state. As a side effect of the computation of this heuristic, more information is derived from the planning graph and its solution, namely the helpful actions which permit FF to concentrate its efforts on more promising ways, forgetting the other actions in a local search algorithm. We introduce a novel way for extracting information from the computation of the heuristi...

• Type: Conference
• Year: 2004
• Where: AIPS
• Authors: Vincent Vidal
• Keywords: AIPS 2004, Artificial Intelligence, Helpful Actions, Heuristic, Planning