PC-SHOP: A Probabilistic-Conditional Hierarchical Task Planner

SOMMARIO/ABSTRACT In this paper we report on the extension of the classical HTN planner SHOP to plan in partially observable domains with uncertainty. Our algorithm PC-SHOP uses belief states to handle situations involving incomplete and uncertain information about the state of the world. Sensing and acting are integrated in the primitive actions through the use of a stochastic model. PC-SHOP is showed to scale up well compared to some of the state-of-the-art planners. We outline the main characteristics of the algorithm, and present performance results on some problems found in the literature .