In this paper we present an interface between a symbolic planner and a geometric task planner, which is different to a standard trajectory planner in that the former is able to perform geometric reasoning on abstract entities—tasks. We believe that this approach facilitates a more principled interface to symbolic planning, while also leaving more room for the geometric planner to make independe...

Ordered Task Decomposition is a new approach to HTN planning that appears to work quite well in a diverse set of real-world planning problems. This paper summarizes what Ordered Task Decomposition is, describes our past and current work on it, and describes our plans for future work.

One big obstacle to understanding the nature of hierarchical task network (HTN) planning has been the lack of a dear theoretical framework. In particular, no one has yet presented a clear and concise HTN algorithm that is sound and complete. In this paper, we present a formal syntax and semantics for HTN planning. Based on this syntax and semantics, we are able to define an algo~thm for HTN pla...

Ill order to scale-up to real-~vorlcl problems, planning systems must be able to rc~)lal) in order to deal with changes i~~ problerll context. In this paper we describe hierarchical task network and operatorbased rc-planning techniclues which allow adaptation of a previous plan to account for problems associated with executing plans in real-world d~ mains with uncertainty, concurrency, changing...

Belief-Desire-Intention (BDI) agent systems and Hierarchical Task Network (HTN) planning systems are two popular approaches to acting and planning, both of which are based on hierarchical and context-based expansion of subgoals. Over the past three decades, various authors have recognised the similarities between the two approaches, and developed methods for making the domain knowledge embedded...

In this paper we introduce a probabilistic relational framework for automated human behavior modeling. This is achieved by observing a human successfully achieving given goals. The proposed modeling algorithm uses commonsense background knowledge analytically to facilitate modeling of complicated human behavior. At the same time it is grounded in physical observations and takes noisy sensory da...

This paper presents some enhancements in the temporal reasoning of a Hierarchical Task Network (HTN) planner, named SIADEX, that, up to authors knowledge, no other HTN planner has. These new features include a sound partial order metric structure, deadlines, temporal landmarking or synchronization capabilities built on top of a Simple Temporal Network and an efficient constraint propagation eng...

In this paper we describe work in progress that aims to develop a domain-independent tool set which supports the creation and analysis of domain descriptions and plans containing continuously changing processes, instantaneous events, and actions. The tools described are (i) a life history editor that enables a designer to create a domain description diagrammatically, automatically generating mu...

Recent research has provided methods for coordinating the individually formed concurrent hierarchical plans (CHiPs) of a group of agents in a shared environment. A reasonable criticism of this technique is that the summary information can grow exponentially as it is propagated up a plan hierarchy. This paper analyzes the complexity of the coordination problem to show that in spite of this expon...

For HTN planning, we formally characterize and classify four kinds of problem spaces in which each node represents a planning problem or subproblem. Two of the problem spaces are searched by current HTN planning algorithms; the other two problem spaces are new. This enables us to provide: • Sufficient (and in one case, necessary) conditions for finiteness of each kind of problem space. The cond...