A learning from demonstration framework for adaptive task and motion planning in varying package-to-order scenarios

Abstract

Current advances in Task and Motion Planning (TAMP) framework often rely on a specific and static task structure. A task structure is a sequence of how work pieces should be manipulated towards achieving a goal. Such systems can be problematic when task structures change as a result of human performance during human-robot collaboration scenarios in manufacturing or when redundant objects are present in the workspace, for example, during a Package-To- Order scenario with the same object type fulfilling different package configurations. In this paper, we propose a novel integrated TAMP framework that supports learning from human demonstrations while tackling variations in object positions and product configurations during massive-Package-To-Order (mPTO) scenarios in manufacturing as well as during human-robot collaboration scenarios. We design and apply a Graph Neural Network(GNN) based high-level reasoning module that is capable of handling variant goal configurations and can generalize to different task structures. Moreover, we also built a two-level motion module which can produce flexible and collision-free trajectories based on important features and task labels produced by the reasoning module. Through simulations and physical experiments, we show that our framework holds several advantages when compared with state-of-the-art previous work. The advantages include sample-efficiency and generalizability to unseen goal configurations as well as task structures.