Robots Pre-train Robots: Manipulation-Centric Robotic Representation
  from Large-Scale Robot Dataset
Authors: name: Guangqi Jiang, name: Yifei Sun, name: Tao Huang, name: Huanyu Li, name: Yongyuan Liang, name: Huazhe Xu

The pre-training of visual representations has enhanced the efficiency of
robot learning. Due to the lack of large-scale in-domain robotic datasets,
prior works utilize in-the-wild human videos to pre-train robotic visual
representation. Despite their promising results, representations from human
videos are inevitably subject to distribution shifts and lack the dynamics
information crucial for task completion. We first evaluate various pre-trained
representations in terms of their correlation to the downstream robotic
manipulation tasks (i.e., manipulation centricity). Interestingly, we find that
the "manipulation centricity" is a strong indicator of success rates when
applied to downstream tasks. Drawing from these findings, we propose
Manipulation Centric Representation (MCR), a foundation representation learning
framework capturing both visual features and the dynamics information such as
actions and proprioceptions of manipulation tasks to improve manipulation
centricity. Specifically, we pre-train a visual encoder on the DROID robotic
dataset and leverage motion-relevant data such as robot proprioceptive states
and actions. We introduce a novel contrastive loss that aligns visual
observations with the robot's proprioceptive state-action dynamics, combined
with a behavior cloning (BC)-like actor loss to predict actions during
pre-training, along with a time contrastive loss. Empirical results across 4
simulation domains with 20 tasks verify that MCR outperforms the strongest
baseline method by 14.8%. Moreover, MCR boosts the performance of
data-efficient learning with a UR5e arm on 3 real-world tasks by 76.9%. Project
website: https://robots-pretrain-robots.github.io/.