arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.09024cs.LG
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将扩散行为与Q函数对齐以实现高效连续控制

Aligning Diffusion Behaviors with Q-functions for Efficient Continuous Control

Tsinghua University(清华大学);Institute for AI(人工智能研究院);Pazhou Lab(琶洲实验室)

Huayu Chen, Kaiwen Zheng, Hang Su, Jun Zhu

AI总结:

该研究借鉴大语言模型对齐思路,提出两阶段离线强化学习框架EDA,用标量网络导数表示扩散策略以适配对齐理论,扩展DPO实现扩散行为与Q函数对齐,在D4RL基准上性能超基线,且低标注数据下仍保持优异表现。

摘要:

借鉴语言模型对齐领域的最新进展,我们将离线强化学习建模为一个两阶段优化问题:首先在无奖励行为数据集上预训练具有强表达能力的生成式策略,随后微调这些策略,使其与Q值这类任务特定标注对齐。该策略让我们能够利用丰富多样的行为数据提升泛化能力,且仅需极少标注就能快速适配下游任务。我们特别提出了用于解决连续控制问题的Efficient Diffusion Alignment(高效扩散对齐,EDA)。EDA采用扩散模型进行行为建模,但与现有方法不同的是,我们将扩散策略表示为一个标量神经网络对动作输入的导数。这一表示至关重要,因为它支持扩散模型的直接密度计算,使其与现有大语言模型对齐理论兼容。在策略微调阶段,我们扩展了Direct Preference Optimization(直接偏好优化,DPO)等基于偏好的对齐方法,让扩散行为与连续Q函数对齐。我们在D4RL基准上的评估显示,EDA的整体性能超过所有基线方法。值得注意的是,微调阶段仅使用1%的Q标注数据时,EDA仍能保持约95%的性能,且表现优于多个基线。

英文摘要:

Drawing upon recent advances in language model alignment, we formulate offline Reinforcement Learning as a two-stage optimization problem: First pretraining expressive generative policies on reward-free behavior datasets, then fine-tuning these policies to align with task-specific annotations like Q-values. This strategy allows us to leverage abundant and diverse behavior data to enhance generalization and enable rapid adaptation to downstream tasks using minimal annotations. In particular, we introduce Efficient Diffusion Alignment (EDA) for solving continuous control problems. EDA utilizes diffusion models for behavior modeling. However, unlike previous approaches, we represent diffusion policies as the derivative of a scalar neural network with respect to action inputs. This representation is critical because it enables direct density calculation for diffusion models, making them compatible with existing LLM alignment theories. During policy fine-tuning, we extend preference-based alignment methods like Direct Preference Optimization (DPO) to align diffusion behaviors with continuous Q-functions. Our evaluation on the D4RL benchmark shows that EDA exceeds all baseline methods in overall performance. Notably, EDA maintains about 95\% of performance and still outperforms several baselines given only 1\% of Q-labelled data during fine-tuning.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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