Vision-Language Foundation Models as Effective Robot Imitators

TL;DR

RoboFlamingo leverages open-source VLMs for robot control, achieving 96.4% success rate, outperforming SOTA by a large margin.

cs.RO 🔴 Advanced 2023-11-03 36 views
Xinghang Li Minghuan Liu Hanbo Zhang Cunjun Yu Jie Xu Hongtao Wu Chilam Cheang Ya Jing Weinan Zhang Huaping Liu Hang Li Tao Kong
robot control vision-language models imitation learning multimodal learning robot manipulation

Key Findings

Methodology

RoboFlamingo builds on open-source VLM OpenFlamingo, employing single-step vision-language comprehension, sequence history modeling, and a dedicated policy head. It fine-tunes only on language-conditioned manipulation datasets via imitation learning, requiring minimal data. The visual encoder combines ViT with perceiver resampling, while the feature fusion decoder (from OpenFlamingo) integrates visual and language features. The policy head (LSTM/Transformer/MLP) predicts robot actions based on fused embeddings and historical states. This design decouples perception from control, enabling efficient training and deployment on low-resource platforms, and generalizes well to unseen tasks.

Key Results

  • On the CALVIN benchmark, RoboFlamingo achieves a success rate of 96.4%, nearly doubling the performance of previous methods like HULC and RT-1. It maintains high success over long sequences with an average length of 4.09 steps, demonstrating strong generalization. In zero-shot settings, it exceeds 85% success on unseen objects and instructions. The model requires only a small amount of demonstration data for fine-tuning, making it accessible for research and industry applications. Ablation studies confirm the importance of sequence modeling and multi-scale visual fusion for performance.
  • Different pre-trained VLMs (G-4B, M-3B) show slight performance variations, with G-4B excelling in visual understanding. Fine-tuning improves success rates by about 20%. The approach is robust across environments and instruction variations, validating its adaptability. The experiments highlight that minimal data and computational resources suffice for high-quality control, paving the way for widespread adoption.
  • The framework excels in multi-task, long-horizon scenarios, maintaining high success rates even under environmental changes. Its low training cost and flexibility make it suitable for real-world deployment, with potential for further enhancement via reinforcement learning integration.

Significance

This work bridges the gap between powerful pre-trained vision-language models and low-level robot control, enabling efficient transfer with minimal data. It addresses longstanding challenges of high training costs and limited generalization in robotic manipulation, offering a scalable, low-cost solution. By decoupling perception and decision-making, RoboFlamingo facilitates flexible deployment and rapid adaptation, fostering progress toward autonomous, multi-task robots in industry and service sectors. Its success demonstrates the potential of multimodal foundation models to revolutionize robotic intelligence and autonomy.

Technical Contribution

The paper introduces a novel framework that combines pre-trained VLMs with sequence history modeling, using a lightweight fine-tuning approach. It innovates by decoupling visual-language understanding from low-level control, employing a feature fusion decoder from OpenFlamingo and flexible policy heads. The approach reduces training complexity and resource requirements, while achieving state-of-the-art results on CALVIN. The method’s modular design allows easy adaptation to various tasks and environments, marking a significant step forward in multimodal robotic control.

Novelty

This is the first work to directly adapt open-source VLMs like OpenFlamingo for low-level robot control via minimal fine-tuning. Unlike prior methods relying on large models or web-scale data, RoboFlamingo leverages the single-step understanding ability of pre-trained models, combined with sequence history, to achieve high performance with limited data. Its decoupled architecture and lightweight training process set it apart, offering a practical, scalable solution for robotic manipulation.

Limitations

  • The model struggles with highly dynamic or cluttered environments, where visual perception and sequence modeling may be insufficient. Its performance diminishes under severe occlusion or rapid scene changes, due to limitations in visual encoding and history integration.
  • Dependence on demonstration quality means that poor or biased data can impair generalization, especially in complex tasks requiring precise control.
  • While training is resource-efficient, real-time inference in complex scenes may still face latency issues. Further integration with reinforcement learning could improve autonomy and robustness.

Future Work

Future directions include combining reinforcement learning to enhance autonomous exploration, extending perception capabilities for dynamic scenes, and deploying on real robots to validate robustness. Exploring multi-modal sensor fusion and continual learning could further improve adaptability and performance in diverse real-world scenarios.

AI Executive Summary

The rapid advancement of vision-language models (VLMs) has opened new horizons for robotic manipulation, promising more natural and flexible human-robot interaction. However, translating these powerful models into practical low-level control systems remains challenging due to high data and computational demands. This paper introduces RoboFlamingo, a novel framework that leverages open-source VLMs like OpenFlamingo, enabling efficient and effective robot control with minimal fine-tuning.

RoboFlamingo’s core innovation lies in decoupling visual-language understanding from control decision-making. It employs a visual encoder based on ViT and perceiver resampling to process static images, and a feature fusion decoder (from OpenFlamingo) to generate joint embeddings of visual and linguistic inputs. A lightweight policy head—using LSTM, Transformer, or MLP—predicts robot actions based on these embeddings and sequence history. Fine-tuning involves only a small subset of parameters, primarily the perception modules and policy head, trained on limited demonstration data.

Experimental results on the CALVIN benchmark demonstrate the framework’s superiority, with success rates reaching 96.4%, nearly doubling previous bests. The model generalizes well to unseen objects and instructions, maintaining high performance in zero-shot scenarios. Its ability to perform multi-step, long-horizon tasks with limited data underscores its practicality and scalability.

This approach significantly lowers the barrier for deploying multimodal foundation models in robotics, offering a cost-effective, flexible, and high-performance solution. It paves the way for future integration with reinforcement learning and real-world deployment, promising more autonomous and adaptable robots in industry and daily life. Despite current limitations in dynamic scenes, RoboFlamingo marks a major step toward truly intelligent robotic systems.

Deep Analysis

Background

机器人操控作为人工智能的核心任务之一,经历了从手工规则到深度学习的演变。早期方法依赖强化学习和手工设计的策略,成本高且泛化能力有限。近年来,预训练的视觉-语言模型(如CLIP、Flamingo)在多模态理解中表现出色,推动了机器人自主学习的研究。代表性工作包括RT-1、HULC等,采用大规模数据训练复杂模型,实现多任务操作,但训练成本高、部署困难。尽管如此,将这些模型高效迁移到机器人低层控制中仍面临挑战,主要在于模型复杂度、数据需求和泛化能力不足。

Core Problem

核心问题在于如何利用预训练VLM的理解能力,直接指导机器人低层动作,且训练成本低、易部署。现有方法多依赖庞大模型或海量数据,训练流程复杂,难以普及。此外,模型在长序列、多任务环境中的泛化能力不足,限制了实际应用。如何在保证性能的同时简化训练流程,成为亟待解决的难题。

Innovation

提出RoboFlamingo,创新点包括:1)利用开源VLM OpenFlamingo的单步理解能力,解耦视觉理解与动作决策;2)引入序列历史建模(LSTM/Transformer),增强长序列任务表现;3)微调仅需少量示范数据,极大降低训练成本;4)模型结构支持多种策略头,适应不同任务。这些创新使得模型在长序列、多任务环境中表现优异,且易于部署。

Methodology

  • �� 视觉编码:使用ViT提取图像特征,感知器重采样压缩特征序列;• 特征融合:基于预训练解码器融合视觉和语言信息,生成联合嵌入;• 策略头:采用LSTM/Transformer/MLP模型,结合历史信息预测动作;• 微调:只训练感知器、交叉注意力层和策略头,冻结其他参数,利用示范数据微调;• 训练目标:最大似然模仿学习,优化位置回归(MSE)和状态分类(BCE);• 训练流程:用少量示范数据,快速迁移。

Experiments

在CALVIN基准上,模型训练仅需单GPU,微调少量示范数据。评估指标包括任务成功率、平均成功长度。对比HULC、RT-1等,RoboFlamingo在长序列任务中成功率达96.4%,比前者提升近两倍。消融实验验证序列建模和视觉融合的关键作用。模型在未见对象和指令下表现稳定,具有良好泛化能力。多任务环境中表现优异,验证其实际应用潜力。

Results

模型在CALVIN长序列任务中成功率达96.4%,平均成功长度4.09步,显著优于HULC和RT-1。在零样本环境中,成功率超85%。微调仅需少量示范,训练成本低,适合研究者快速部署。消融实验显示序列建模和多尺度视觉融合是性能关键。模型对指令丰富度和环境变化具有良好适应性,验证其广泛应用潜力。

Applications

该方法适用于工业、服务机器人等场景,尤其在缺乏大量标注数据时,能快速迁移预训练模型完成多任务。只需少量示范,便可实现复杂任务自主完成。未来结合强化学习,提升自主探索能力,推动机器人在复杂环境中的自主操作。

Limitations & Outlook

模型在遮挡和动态环境中表现仍有限,尤其在多目标、多动作场景下,视觉编码和历史建模不足以应对复杂变化。示范数据质量影响泛化,极端长序列推理速度和稳定性仍需优化。

Plain Language Accessible to non-experts

想象你在厨房做饭,手里拿着食材和工具,按照食谱一步步操作。传统机器人就像只会机械重复的厨师,不能理解食谱内容,也不能应对突发情况。而RoboFlamingo就像一个聪明的厨师助手,它能看懂你说的“放入碗中”,也能理解厨房里的各种图像和指示,然后根据之前学到的经验,灵活地完成任务。它不用复杂的程序,只需要少量示范,就能学会做各种菜。这个系统就像你身边的智能厨师,能快速学习新菜,适应不同厨房环境,帮你省时省力。

ELI14 Explained like you're 14

想象你在学校里学做菜,你告诉你的机器人朋友“把苹果放到篮子里”,它看着厨房里的苹果和篮子,记住了你的指令,然后用它学到的经验,把苹果放到篮子里。这个机器人就像一个聪明的学生,不需要你教它每一步,只要告诉它目标,它就能自己完成任务。它还可以学会新菜,只要你给它一些示范。这个系统就像你有个超级聪明的帮手,能理解你说的话,看到厨房的样子,然后帮你做饭,非常方便。

Glossary

视觉-语言模型 (Vision-Language Model, VLM)

一种同时理解图像和文字的模型,能将视觉信息和语言信息结合,用于多模态任务。

本文利用VLM实现机器人视觉理解和指令理解。

模仿学习 (Imitation Learning)

通过模仿专家示范,训练模型模仿其行为的学习方法。

用少量示范数据微调模型,实现机器人操控。

特征融合解码器

将视觉和语言特征融合,生成联合表示的神经网络模块。

用于增强视觉和指令的理解能力。

微调 (Fine-tuning)

在预训练模型基础上,用少量任务相关数据调整参数以适应新任务。

本文微调仅涉及少量参数,提升效率。

CALVIN基准

用于评估长序列、多任务语言条件机器人操控性能的模拟平台。

用作模型性能验证的主要数据集。

Open Questions Unanswered questions from this research

  • 1 如何进一步提升模型在极端复杂环境中的鲁棒性仍未解决,尤其是在多目标、多动作场景下的表现仍有限。
  • 2 模型对动态变化和遮挡的适应能力不足,未来需结合动态感知和强化学习优化。

Applications

Immediate Applications

工业自动化

可用于装配线上的机器人,快速适应不同任务,只需少量示范即可部署,降低成本。

家庭服务机器人

帮助家庭完成日常任务,如取物、整理,用户只需用自然语言指令,系统即可自主完成。

Long-term Vision

自主探索与学习

结合强化学习,实现机器人自主探索未知环境,持续优化操控策略,逐步实现自主创新。

Abstract

Recent progress in vision language foundation models has shown their ability to understand multimodal data and resolve complicated vision language tasks, including robotics manipulation. We seek a straightforward way of making use of existing vision-language models (VLMs) with simple fine-tuning on robotics data. To this end, we derive a simple and novel vision-language manipulation framework, dubbed RoboFlamingo, built upon the open-source VLMs, OpenFlamingo. Unlike prior works, RoboFlamingo utilizes pre-trained VLMs for single-step vision-language comprehension, models sequential history information with an explicit policy head, and is slightly fine-tuned by imitation learning only on language-conditioned manipulation datasets. Such a decomposition provides RoboFlamingo the flexibility for open-loop control and deployment on low-performance platforms. By exceeding the state-of-the-art performance with a large margin on the tested benchmark, we show RoboFlamingo can be an effective and competitive alternative to adapt VLMs to robot control. Our extensive experimental results also reveal several interesting conclusions regarding the behavior of different pre-trained VLMs on manipulation tasks. We believe RoboFlamingo has the potential to be a cost-effective and easy-to-use solution for robotics manipulation, empowering everyone with the ability to fine-tune their own robotics policy.

cs.RO cs.AI cs.LG