Structured Motion Generation with Predictive Learning: Proposing Subgoal for Long-Horizon Manipulation

For assisting humans in their daily lives, robots need to perform long-horizon tasks, such as tidying up a room or preparing a meal. One effective strategy for handling a long-horizon task is to break it down into short-horizon subgoals, that the robot can execute sequentially. In this paper,we propose extending a predictive learning model using deep neural networks (DNN) with a Subgoal Proposal Module (SPM),with the goal of making such tasks realizable. We evaluate our proposed model in a case-study of a long-horizon task,consisting of cutting and arranging a pizza. This task requires the robot to consider: (1) the order of the subtasks, (2)multiple subtask selection, (3) coordination of dual-arm, and (4)variations within a subtask. The results confirm that the model is able to generalize motion generation to unseen tools and objects arrangement combinations. Furthermore, it significantly reduces the prediction error of the generated motions compared to without the proposed SPM. Finally, we validate the generated motions on the dual-arm robot Nextage Open.