FHP: Functional Heuristic Planning

Most of the real world problems involve numerical handling. New planning systems such as FF-Metric [9], MIPS [4] and SAPA [3] are able to handle numerical resources, but in most cases the resources are only used as auxiliary numerical constraints added to the symbolic planning domains. Furthermore the numerical update in all of these planning systems is limited to the arithmetic operations. In this paper we present a new planning system FHP (Functional Heuristic Planning) that is able to solve totally numerical and/or symbolic planning domains. We propose a new action representation to support numerical conditions and effects, where we allow a non-restricted function application for numerical update. FHP guides its search using a heuristic derived from a relaxed problem by using the planning graph of GraphPlan-style [1]. Allowing functions application gives the possibility to solve a larger class of problems where the planning process requires a complex calculation instead of simple arithmetic operations.