Fast forward planning by guided enforced hill climbing

In recent years a number of new heuristic search methods have been developed in the field of automated planning Enforced hill climbing (EHC) is one such method which has been frequently used in a number of Al planning systems Despite certain weaknesses such as getting trapped in dead-ends in some domains this method is more competitive than several other methods in many planning domains In order to enhance the efficiency of ordinary enforced hill climbing a new form of enforced hill climbing called guided enforced hill climbing is introduced in this paper An adaptive branch ordering function is the main feature that guided enforced hill climbing has added to EHC Guided enforced hill climbing expands successor states in the order recommended by the ordering function Our experimental results in several planning domains show a significant improvement in the efficiency of the enforced hill climbing method especially when applied to larger problems (C) 2010 Elsevier Ltd All rights reserved