Gaze-based Task Decomposition for Robot Manipulation in Imitation Learning

In imitation learning for robotic manipulation, decomposing object manipulation tasks into multiple sub-tasks is essential. This decomposition enables the reuse of learned skills in varying contexts and the combination of acquired skills to perform novel tasks, rather than merely replicating demonstrated motions. Gaze plays a critical role in human object manipulation, where it is strongly correlated with hand movements. We hypothesize that an imitating agent's gaze control, fixating on specific landmarks and transitioning between them, simultaneously segments demonstrated manipulations into sub-tasks. In this study, we propose a simple yet robust task decomposition method based on gaze transitions. The method leverages teleoperation, a common modality in robotic manipulation for collecting demonstrations, in which a human operator's gaze is measured and used for task decomposition as a substitute for an imitating agent's gaze. Notably, our method achieves consistent task decomposition across all demonstrations for each task, which is desirable in contexts such as machine learning. We applied this method to demonstrations of various tasks and evaluated the characteristics and consistency of the resulting sub-tasks. Furthermore, through extensive testing across a wide range of hyperparameter variations, we demonstrated that the proposed method possesses the robustness necessary for application to different robotic systems.