A unified dynamic approach for dealing with temporal uncertainty and conditional planning
Thierry Vidal · International Conference on Artificial Intelligence Planning Systems · 2000
In temporal planning, Temporal Constraint Networks allow to check the temporal consistency of a plan, but it has to be extended to deal with tasks which effective duration is uncertain and will only be observed during execution. The Contingent TCN models it, in which Dynamic controllability has to be checked, i.e.: during execution, will the system be able to consistently release tasks according to the observed durations of already completed tasks? This behaviour is a reactive one suggesting the plan is conditional in some sense. A Timed Game Automaton model has been specifically designed to check the Dynamic controllability. This paper furthermore discusses the use of such a model with respect to conditional and reactive planning, and its strength with respect to execution supervision needs, and suggests improving efficiency by partitioning the plan into subparts, introducing so-called waypoints with fixed time of occurrence. Last we show that the expressive power of automata might allow to address more elaborate reactive planning features, such as preprocessed subplans, information gathering, or synchronization constraints.