Deterministic planning assumes that the planning evolves along a fully predictable path, and therefore it loses the practical value in most real projections. A more realistic view is that planning ought to take into consideration partial observability beforehand and aim for a more flexible and robust solution. What is more significant, it is inevitable that the quality of plan varies dramatically in the partially observable environment. In this paper we propose a probabilistic contingent Hierarchical Task Network (HTN) planner, named High-Quality Contingent Planner (HQCP), to generate high-quality plans in the partially observable environment. The formalisms in HTN planning are extended into partial observability and are evaluated regarding the cost. Next, we explore a novel heuristic for high-quality plans and develop the integrated planning algorithm. Finally, an empirical study verifies the effectiveness and efficiency of the planner both in probabilistic contingent planning and for obtaining high-quality plans.

翻译：确定性规划假设规划过程沿着完全可预测的路径演进，因此在大多数实际场景中丧失了实用价值。更具现实意义的视角是，规划应事先考虑部分可观测性，并致力于寻求更灵活稳健的解决方案。更为关键的是，在部分可观测环境中，规划质量必然存在显著差异。本文提出一种基于概率性权变分层任务网络（HTN）的规划器——高质量权变规划器（HQCP），以在部分可观测环境中生成高质量规划。我们将HTN规划的形式化体系扩展至部分可观测性，并从成本维度进行评估。继而，我们探索了一种面向高质量规划的新启发式方法，并开发了集成规划算法。最终，实证研究验证了该规划器在概率性权变规划及高质量规划获取方面的有效性与高效性。