arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2512.20173cs.AI
收藏

基于异质反馈的离线安全策略优化

Offline Safe Policy Optimization From Heterogeneous Feedback

Shenzhen Institute of Advanced Technology (SIAT), CAS(深圳先进技术研究院(SIAT)、中国科学院);Singapore Management University(新加坡管理学院)

Ze Gong, Pradeep Varakantham, Akshat Kumar

AI总结:

本文提出PreSa方法,通过直接学习基于偏好和安全性的策略,解决离线安全强化学习中的性能下降问题。

摘要:

离线偏好强化学习(PbRL)无需大量奖励工程和直接与人类标注者交互,即可学习与人类偏好一致的奖励和策略。然而,在许多领域和任务中,确保安全性仍是一个关键挑战。先前基于人类反馈的安全强化学习(RLHF)方法首先从离线数据中学习奖励和成本模型,然后使用约束强化学习优化安全策略。然而,在长时间连续控制任务中,奖励和成本的误差会累积,导致在使用约束强化学习方法时性能下降。为了解决这些挑战,(a)我们引入了一种框架,该框架直接基于对代理行为的奖励配对偏好学习策略,同时结合二元标签指示轨迹段的安全性;(b)我们提出PreSa(偏好与安全性对齐)方法,该方法在约束优化问题中结合偏好学习模块与安全性对齐。该优化问题在拉格朗日范式中直接学习最大化奖励的安全策略,而无需显式学习奖励和成本模型,从而避免了约束强化学习的需要;(c)我们在具有合成和真实人类反馈的连续控制任务上评估了我们的方法。实验表明,我们的方法成功学习了具有高奖励的安全策略,优于最先进的基线方法和具有真实奖励和成本的离线安全强化学习方法。

英文摘要:

Offline Preference-based Reinforcement Learning (PbRL) learns rewards and policies aligned with human preferences without the need for extensive reward engineering and direct interaction with human annotators. However, ensuring safety remains a critical challenge across many domains and tasks. Previous works on safe RL from human feedback (RLHF) first learn reward and cost models from offline data, then use constrained RL to optimize a safe policy. While such an approach works in the contextual bandits settings (LLMs), in long horizon continuous control tasks, errors in rewards and costs accumulate, leading to impairment in performance when used with constrained RL methods. To address these challenges, (a) instead of indirectly learning policies (from rewards and costs), we introduce a framework that learns a policy directly based on pairwise preferences regarding the agent's behavior in terms of rewards, as well as binary labels indicating the safety of trajectory segments; (b) we propose \textsc{PreSa} (Preference and Safety Alignment), a method that combines preference learning module with safety alignment in a constrained optimization problem. This optimization problem is solved within a Lagrangian paradigm that directly learns reward-maximizing safe policy \textit{without explicitly learning reward and cost models}, avoiding the need for constrained RL; (c) we evaluate our approach on continuous control tasks with both synthetic and real human feedback. Empirically, our method successfully learns safe policies with high rewards, outperforming state-of-the-art baselines, and offline safe RL approaches with ground-truth reward and cost.

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。

↑