Hierarchical Task Network Planning with Task Insertion and State Constraints

Hierarchical Task Network Planning with Task Insertion and State Constraints

Zhanhao Xiao, Andreas Herzig, Laurent Perrussel, Hai Wan, Xiaoheng Su

Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence
Main track. Pages 4463-4469. https://doi.org/10.24963/ijcai.2017/623

We extend hierarchical task network planning with task insertion (TIHTN) by introducing state constraints, called TIHTNS. We show that just as for TIHTN planning, all solutions of the TIHTNS planning problem can be obtained by acyclic decomposition and task insertion, entailing that its plan-existence problem is decidable without any restriction on decomposition methods. We also prove that the extension by state constraints does not increase the complexity of the plan-existence problem, which stays 2-NEXPTIME-complete, based on an acyclic progression operator. In addition, we show that TIHTNS planning covers not only the original TIHTN planning but also hierarchy-relaxed hierarchical goal network planning.
Keywords:
Planning and Scheduling: Theoretical Foundations of Planning
Planning and Scheduling: Hierarchical planning