Learning Latent Plans from Play

Corey Harrison Lynch
Mohi Khansari
Vikash Kumar
Sergey Levine
Google Scholar


We propose a self-supervised approach to learning a wide variety of manipulation skills from unlabeled data collected through playing in and interacting within a playground environment. Learning by playing offers three main advantages: 1) Collecting large amounts of play data is cheap and fast as it does not require staging the scene nor labeling data, 2) It relaxes the need to have a discrete and rigid definition of skills/tasks during the data collection. This allows the agent to focus on acquiring a continuum set of manipulation skills as a whole, which can then be conditioned to perform a particular skill such as grasping. Furthermore, this data already includes ways to recover, retry or transition between different skills, which can be used to achieve a reactive closed-loop control policy, 3) It allows to quickly learn a new skill from making use of pre-existing general abilities. Our proposed approach to learning new skills from unlabeled play data decouples high-level planning prediction from low-level action prediction by: first self-supervise learning of a latent planning space, then self-supervise learning of an action model that is conditioned on a latent plan. This results in a single task-agnostic policy conditioned on a user-provided goal. This policy can perform a variety of tasks in the environment where playing was observed. We train a single model on 3 hours of unlabeled play data and evaluate it on 18 tasks simply by feeding a goal state corresponding to each task. The baseline model reaches an accuracy of 65\% using 18 specialized policies in 100-shot per task and trained on 1800 expensive demonstrations. Our model completes the tasks with an average of 85\% accuracy using a single policy in zero shots (having never been explicitly trained on these tasks) using cheap unlabeled data. Videos of the performed experiments are available at https://sites.google.com/view/sslmp