Planning and Acting with Temporal and Hierarchical Decomposition Models

This paper reports on FAPE (Flexible Acting and Planning Environment), a framework integrating acting and planning on the basis of the ANML modeling language. ANML is a recent proposal motivated by combining the expressiveness of the timeline representation with decomposition methods of Hierarchical Task Networks (HTN). Our current focus is not efficient temporal planning per se, but the tight integration of acting and planning. This integration is addressed by: (i) extending HTN methods with the refinement of planned actions with skills, expressed in PRS, to map actions into low-level commands, (ii) interleaving the planning process with acting, the former performs plan repair and replanning, while the latter implements the skill-based refinements, and (iii) executing commands with a dispatching mechanism that synchronizes observed time points of action effects and events with planned time. FAPE has been integrated to a PR2 robot and experimented in a home-like environment. The paper presents how planning is performed and integrated with acting and describes briefly the robotics experiments.