Relational Learning for Skill Preconditions
This work provides a method for robots to learn skill preconditions, which is crucial for operating in dynamic and unstructured environments, particularly for manipulation tasks involving multiple objects.
This paper addresses the problem of determining if a robot skill can be executed in a given environment by learning skill preconditions. The authors propose an object-relation model that learns continuous representations for pairwise object relations, trained in simulation, and demonstrate significant improvements in predicting preconditions for sweeping, cutting, and unstacking tasks with varying objects in real-world scenarios.
To determine if a skill can be executed in any given environment, a robot needs to learn the preconditions for the skill. As robots begin to operate in dynamic and unstructured environments, precondition models will need to generalize to variable number of objects with different shapes and sizes. In this work, we focus on learning precondition models for manipulation skills in unconstrained environments. Our work is motivated by the intuition that many complex manipulation tasks, with multiple objects, can be simplified by focusing on less complex pairwise object relations. We propose an object-relation model that learns continuous representations for these pairwise object relations. Our object-relation model is trained completely in simulation, and once learned, is used by a separate precondition model to predict skill preconditions for real world tasks. We evaluate our precondition model on $3$ different manipulation tasks: sweeping, cutting, and unstacking. We show that our approach leads to significant improvements in predicting preconditions for all 3 tasks, across objects of different shapes and sizes.