A Temporal Planning System for Level 3 Durative Actions of PDDL
António Garrido · 2002
Many planning domains have temporal features that can be expressed as durations associated with actions. Unfortu-nately, the conservative model of actions of most temporal planners is not appropriate for some domains which require richer models. Level 3 of PDDL2.1 introduces a model of durative actions which includes local conditions and effects to be satisfied at different times during the execution of the actions, thereby giving the planner freedom to plan concur-rent actions. This paper presents a temporal planning sys-tem (TPSYS), which combines the ideas of Graphplan and TGP, to plan with such durative actions. The approach neces-sitates the modification of some aspects of the basic planning algorithm: the mutex reasoning, the generation of the tempo-ral graph and the search for an optimal plan. Although the algorithm becomes more complex, the experimental results demonstrate it remains feasible as a way to deal with durative actions.