Landmark-Based Plan Recognition
This addresses the need for quick and accurate plan recognition in applications where incomplete evidence is available, representing a strong incremental improvement over existing methods.
The paper tackles the problem of efficiently recognizing goals and plans from incomplete action evidence by developing a heuristic approach based on planning landmarks. The result shows that their method is substantially more accurate than state-of-the-art approaches across all datasets and an order of magnitude faster.
Recognition of goals and plans using incomplete evidence from action execution can be done efficiently by using planning techniques. In many applications it is important to recognize goals and plans not only accurately, but also quickly. In this paper, we develop a heuristic approach for recognizing plans based on planning techniques that rely on ordering constraints to filter candidate goals from observations. These ordering constraints are called landmarks in the planning literature, which are facts or actions that cannot be avoided to achieve a goal. We show the applicability of planning landmarks in two settings: first, we use it directly to develop a heuristic-based plan recognition approach; second, we refine an existing planning-based plan recognition approach by pre-filtering its candidate goals. Our empirical evaluation shows that our approach is not only substantially more accurate than the state-of-the-art in all available datasets, it is also an order of magnitude faster.