A resource enhanced HTN planning approach for emergency decision-making

Hierarchical resource reasoning is one of the key issues to successfully apply Hierarchy Task Network (HTN) planning into emergency decision-making. This paper proposes a Resource Enhanced HTN (REHTN) planning approach for emergency decision-making with the objective to enhance the expressive power and improve the processing speed of hierarchical resource reasoning. In the approach, resource timelines are defined to describe various resource variables and constraints. Top-down resource reasoning is used for decomposing the resource constraints of upper-level tasks into those of lower-level tasks. Meanwhile, resource and temporal constraints of tasks in different branches are processed by causal links. After the tasks are decomposed into primitive tasks, resource profiles of consumable resources and reusable resources are checked by separate resource allocation processes. Furthermore, a constraint propagation accelerator is designed to speed up hierarchal resource reasoning. The effectiveness and practicability of REHTN are confirmed with some experiments from emergency logistics distribution problems.