Using Temporal Logic to Control Search in a Forward Chaining Planner

Over the years increasingly sophisticated planning algorithms have been developed. These have made for more efficient planners, but unfortunately these planners still suffer from combinatorial explosion. Indeed, recent theoretical results demonstrate that such an explosion is inevitable. It has long been acknowledged that domain independent planners need domain dependent information to help them plan effectively. In this work we describe how natural domain information, of a “strategic” nature, can be expressed in a temporal logic, and then utilized to effectively control a forward-chaining planner. There are numerous advantages to our approach, including a declarative semantics for the search control knowledge; a high degree of modularity (the more search control knowledge utilized the more efficient search becomes); and an independence of this knowledge from the details of the planning algorithm. We have implemented our ideas in the TLPLAN system, and have been able to demonstrate its remarkable effectiveness in a wide range of planning domains.