Beyond the Majority: Long-tail Imitation Learning for Robotic Manipulation

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhu, Junhong, Zhang, Ji, Song, Jingkuan, Gao, Lianli, Shen, Heng Tao
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915779767697408
author Zhu, Junhong
Zhang, Ji
Song, Jingkuan
Gao, Lianli
Shen, Heng Tao
author_facet Zhu, Junhong
Zhang, Ji
Song, Jingkuan
Gao, Lianli
Shen, Heng Tao
contents While generalist robot policies hold significant promise for learning diverse manipulation skills through imitation, their performance is often hindered by the long-tail distribution of training demonstrations. Policies learned on such data, which is heavily skewed towards a few data-rich head tasks, frequently exhibit poor generalization when confronted with the vast number of data-scarce tail tasks. In this work, we conduct a comprehensive analysis of the pervasive long-tail challenge inherent in policy learning. Our analysis begins by demonstrating the inefficacy of conventional long-tail learning strategies (e.g., re-sampling) for improving the policy's performance on tail tasks. We then uncover the underlying mechanism for this failure, revealing that data scarcity on tail tasks directly impairs the policy's spatial reasoning capability. To overcome this, we introduce Approaching-Phase Augmentation (APA), a simple yet effective scheme that transfers knowledge from data-rich head tasks to data-scarce tail tasks without requiring external demonstrations. Extensive experiments in both simulation and real-world manipulation tasks demonstrate the effectiveness of APA. Our code and demos are publicly available at: https://mldxy.github.io/Project-VLA-long-tail/.
format Preprint
id arxiv_https___arxiv_org_abs_2602_06512
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Beyond the Majority: Long-tail Imitation Learning for Robotic Manipulation
Zhu, Junhong
Zhang, Ji
Song, Jingkuan
Gao, Lianli
Shen, Heng Tao
Robotics
While generalist robot policies hold significant promise for learning diverse manipulation skills through imitation, their performance is often hindered by the long-tail distribution of training demonstrations. Policies learned on such data, which is heavily skewed towards a few data-rich head tasks, frequently exhibit poor generalization when confronted with the vast number of data-scarce tail tasks. In this work, we conduct a comprehensive analysis of the pervasive long-tail challenge inherent in policy learning. Our analysis begins by demonstrating the inefficacy of conventional long-tail learning strategies (e.g., re-sampling) for improving the policy's performance on tail tasks. We then uncover the underlying mechanism for this failure, revealing that data scarcity on tail tasks directly impairs the policy's spatial reasoning capability. To overcome this, we introduce Approaching-Phase Augmentation (APA), a simple yet effective scheme that transfers knowledge from data-rich head tasks to data-scarce tail tasks without requiring external demonstrations. Extensive experiments in both simulation and real-world manipulation tasks demonstrate the effectiveness of APA. Our code and demos are publicly available at: https://mldxy.github.io/Project-VLA-long-tail/.
title Beyond the Majority: Long-tail Imitation Learning for Robotic Manipulation
topic Robotics
url https://arxiv.org/abs/2602.06512