We present state advantage weighting for offline reinforcement learning (RL). In contrast to action advantage $A(s,a)$ that we commonly adopt in QSA learning, we leverage state advantage $A(s,s^\prime)$ and QSS learning for offline RL, hence decoupling the action from values. We expect the agent can get to the high-reward state and the action is determined by how the agent can get to that corresponding state. Experiments on D4RL datasets show that our proposed method can achieve remarkable performance against the common baselines. Furthermore, our method shows good generalization capability when transferring from offline to online.
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离线增强学习(RL)定义了从静态记录数据集学习的任务,而无需与环境不断交互。学识渊博的政策与行为政策之间的分配变化使得价值函数必须保持保守,以使分布(OOD)的动作不会被严重高估。但是,现有的方法,对看不见的行为进行惩罚或与行为政策进行正规化,太悲观了,这抑制了价值功能的概括并阻碍了性能的提高。本文探讨了温和但足够的保守主义,可以在线学习,同时不损害概括。我们提出了轻度保守的Q学习(MCQ),其中通过分配了适当的伪Q值来积极训练OOD。从理论上讲,我们表明MCQ诱导了至少与行为策略的行为,并且对OOD行动不会发生错误的高估。 D4RL基准测试的实验结果表明,与先前的工作相比,MCQ取得了出色的性能。此外,MCQ在从离线转移到在线时显示出卓越的概括能力,并明显胜过基准。
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博学的无模型离线增强学习(RL)方法的策略通常被限制在数据集的支持范围内,以避免可能的危险危险分发措施或状态,从而使处理不支持的区域挑战。基于模型的RL方法通过使用经过训练的前进或反向动力学模型生成虚构轨迹来提供更丰富的数据集和收益概括。但是,想象的过渡可能不准确,因此降低了基础离线RL方法的性能。在本文中,我们建议通过使用训练有素的双向动力学模型和通过双重检查推出策略来增强离线数据集。我们通过信任前向模型和落后模型一致的样本来介绍保守主义。我们的方法是基于置信度的双向离线模型的想象力,可以生成可靠的样本,并可以与任何无模型的离线RL方法结合使用。 D4RL基准测试的实验结果表明,我们的方法显着提高了现有的无模型离线RL算法的性能,并在基线方法上取得了竞争性或更好的分数。
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在离线强化学习(离线RL)中,主要挑战之一是处理学习策略与给定数据集之间的分布转变。为了解决这个问题,最近的离线RL方法试图引入保守主义偏见,以鼓励在高信心地区学习。无模型方法使用保守的正常化或特殊网络结构直接对策略或价值函数学习进行这样的偏见,但它们约束的策略搜索限制了脱机数据集之外的泛化。基于模型的方法使用保守量量化学习前瞻性动态模型,然后生成虚构的轨迹以扩展脱机数据集。然而,由于离线数据集中的有限样本,保守率量化通常在支撑区域内遭受全面化。不可靠的保守措施将误导基于模型的想象力,以不受欢迎的地区,导致过多的行为。为了鼓励更多的保守主义,我们提出了一种基于模型的离线RL框架,称为反向离线模型的想象(ROMI)。我们与新颖的反向策略结合使用逆向动力学模型,该模型可以生成导致脱机数据集中的目标目标状态的卷展栏。这些反向的想象力提供了无通知的数据增强,以便无模型策略学习,并使远程数据集的保守概括。 ROMI可以有效地与现成的无模型算法组合,以实现基于模型的概括,具有适当的保守主义。经验结果表明,我们的方法可以在离线RL基准任务中产生更保守的行为并实现最先进的性能。
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Offline reinforcement learning (RL) refers to the problem of learning policies entirely from a large batch of previously collected data. This problem setting offers the promise of utilizing such datasets to acquire policies without any costly or dangerous active exploration. However, it is also challenging, due to the distributional shift between the offline training data and those states visited by the learned policy. Despite significant recent progress, the most successful prior methods are model-free and constrain the policy to the support of data, precluding generalization to unseen states. In this paper, we first observe that an existing model-based RL algorithm already produces significant gains in the offline setting compared to model-free approaches. However, standard model-based RL methods, designed for the online setting, do not provide an explicit mechanism to avoid the offline setting's distributional shift issue. Instead, we propose to modify the existing model-based RL methods by applying them with rewards artificially penalized by the uncertainty of the dynamics. We theoretically show that the algorithm maximizes a lower bound of the policy's return under the true MDP. We also characterize the trade-off between the gain and risk of leaving the support of the batch data. Our algorithm, Model-based Offline Policy Optimization (MOPO), outperforms standard model-based RL algorithms and prior state-of-the-art model-free offline RL algorithms on existing offline RL benchmarks and two challenging continuous control tasks that require generalizing from data collected for a different task. * equal contribution. † equal advising. Orders randomized.34th Conference on Neural Information Processing Systems (NeurIPS 2020),
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离线增强学习吸引了人们对解决传统强化学习的应用挑战的极大兴趣。离线增强学习使用先前收集的数据集来训练代理而无需任何互动。为了解决对OOD的高估(分布式)动作的高估,保守的估计值对所有输入都具有较低的价值。以前的保守估计方法通常很难避免OOD作用对Q值估计的影响。此外,这些算法通常需要失去一些计算效率,以实现保守估计的目的。在本文中,我们提出了一种简单的保守估计方法,即双重保守估计(DCE),该方法使用两种保守估计方法来限制政策。我们的算法引入了V功能,以避免分发作用的错误,同时隐含得出保守的估计。此外,我们的算法使用可控的罚款术语,改变了培训中保守主义的程度。从理论上讲,我们说明了该方法如何影响OOD动作和分布动作的估计。我们的实验分别表明,两种保守的估计方法影响了所有国家行动的估计。 DCE展示了D4RL的最新性能。
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Behavioural cloning (BC) is a commonly used imitation learning method to infer a sequential decision-making policy from expert demonstrations. However, when the quality of the data is not optimal, the resulting behavioural policy also performs sub-optimally once deployed. Recently, there has been a surge in offline reinforcement learning methods that hold the promise to extract high-quality policies from sub-optimal historical data. A common approach is to perform regularisation during training, encouraging updates during policy evaluation and/or policy improvement to stay close to the underlying data. In this work, we investigate whether an offline approach to improving the quality of the existing data can lead to improved behavioural policies without any changes in the BC algorithm. The proposed data improvement approach - Trajectory Stitching (TS) - generates new trajectories (sequences of states and actions) by `stitching' pairs of states that were disconnected in the original data and generating their connecting new action. By construction, these new transitions are guaranteed to be highly plausible according to probabilistic models of the environment, and to improve a state-value function. We demonstrate that the iterative process of replacing old trajectories with new ones incrementally improves the underlying behavioural policy. Extensive experimental results show that significant performance gains can be achieved using TS over BC policies extracted from the original data. Furthermore, using the D4RL benchmarking suite, we demonstrate that state-of-the-art results are obtained by combining TS with two existing offline learning methodologies reliant on BC, model-based offline planning (MBOP) and policy constraint (TD3+BC).
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Model-based reinforcement learning (RL) methods are appealing in the offline setting because they allow an agent to reason about the consequences of actions without interacting with the environment. Prior methods learn a 1-step dynamics model, which predicts the next state given the current state and action. These models do not immediately tell the agent which actions to take, but must be integrated into a larger RL framework. Can we model the environment dynamics in a different way, such that the learned model does directly indicate the value of each action? In this paper, we propose Contrastive Value Learning (CVL), which learns an implicit, multi-step model of the environment dynamics. This model can be learned without access to reward functions, but nonetheless can be used to directly estimate the value of each action, without requiring any TD learning. Because this model represents the multi-step transitions implicitly, it avoids having to predict high-dimensional observations and thus scales to high-dimensional tasks. Our experiments demonstrate that CVL outperforms prior offline RL methods on complex continuous control benchmarks.
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离线强化学习在利用大型预采用的数据集进行政策学习方面表现出了巨大的希望,使代理商可以放弃经常廉价的在线数据收集。但是,迄今为止,离线强化学习的探索相对较小,并且缺乏对剩余挑战所在的何处的了解。在本文中,我们试图建立简单的基线以在视觉域中连续控制。我们表明,对两个基于最先进的在线增强学习算法,Dreamerv2和DRQ-V2进行了简单的修改,足以超越事先工作并建立竞争性的基准。我们在现有的离线数据集中对这些算法进行了严格的评估,以及从视觉观察结果中进行离线强化学习的新测试台,更好地代表现实世界中离线增强学习问题中存在的数据分布,并开放我们的代码和数据以促进此方面的进度重要领域。最后,我们介绍并分析了来自视觉观察的离线RL所独有的几个关键Desiderata,包括视觉分散注意力和动态视觉上可识别的变化。
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Deep reinforcement learning (DRL) provides a new way to generate robot control policy. However, the process of training control policy requires lengthy exploration, resulting in a low sample efficiency of reinforcement learning (RL) in real-world tasks. Both imitation learning (IL) and learning from demonstrations (LfD) improve the training process by using expert demonstrations, but imperfect expert demonstrations can mislead policy improvement. Offline to Online reinforcement learning requires a lot of offline data to initialize the policy, and distribution shift can easily lead to performance degradation during online fine-tuning. To solve the above problems, we propose a learning from demonstrations method named A-SILfD, which treats expert demonstrations as the agent's successful experiences and uses experiences to constrain policy improvement. Furthermore, we prevent performance degradation due to large estimation errors in the Q-function by the ensemble Q-functions. Our experiments show that A-SILfD can significantly improve sample efficiency using a small number of different quality expert demonstrations. In four Mujoco continuous control tasks, A-SILfD can significantly outperform baseline methods after 150,000 steps of online training and is not misled by imperfect expert demonstrations during training.
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离线增强学习(RL)提供了一个有希望的方向,可以利用大量离线数据来实现复杂的决策任务。由于分配转移问题,当前的离线RL算法通常被设计为在价值估计和行动选择方面是保守的。但是,这种保守主义在现实情况下遇到观察偏差时,例如传感器错误和对抗性攻击时会损害学习政策的鲁棒性。为了权衡鲁棒性和保守主义,我们通过一种新颖的保守平滑技术提出了强大的离线增强学习(RORL)。在RORL中,我们明确地介绍了数据集附近国家的策略和价值函数的正则化,以及对这些OOD状态的其他保守价值估计。从理论上讲,我们表明RORL比线性MDP中的最新理论结果更紧密地构成。我们证明RORL可以在一般离线RL基准上实现最新性能,并且对对抗性观察的扰动非常强大。
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离线强化学习(RL)定义了从固定批次的数据学习的任务。由于来自分发超出操作的值估计的错误,大多数脱机RL算法采用数据集中包含的动作来计算或正规化策略的方法。构建在预先存在的RL算法上,修改使RL算法正常工作的额外复杂性的成本为代价。离线RL算法引入了新的超参数,通常利用辅助组件,例如生成模型,同时调整底层RL算法。在本文中,我们的目标是在实现最小变化的同时进行深度RL算法。我们发现我们可以通过简单地将行为克隆术语添加到在线RL算法的策略更新并归一化数据的策略更新来匹配最先进的离线RL算法的性能。生成的算法是一种简单的实现和曲线基线,而通过去除先前方法的附加计算开销来大于缩短整个运行时间。
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Deep reinforcement learning algorithms have succeeded in several challenging domains. Classic Online RL job schedulers can learn efficient scheduling strategies but often takes thousands of timesteps to explore the environment and adapt from a randomly initialized DNN policy. Existing RL schedulers overlook the importance of learning from historical data and improving upon custom heuristic policies. Offline reinforcement learning presents the prospect of policy optimization from pre-recorded datasets without online environment interaction. Following the recent success of data-driven learning, we explore two RL methods: 1) Behaviour Cloning and 2) Offline RL, which aim to learn policies from logged data without interacting with the environment. These methods address the challenges concerning the cost of data collection and safety, particularly pertinent to real-world applications of RL. Although the data-driven RL methods generate good results, we show that the performance is highly dependent on the quality of the historical datasets. Finally, we demonstrate that by effectively incorporating prior expert demonstrations to pre-train the agent, we short-circuit the random exploration phase to learn a reasonable policy with online training. We utilize Offline RL as a \textbf{launchpad} to learn effective scheduling policies from prior experience collected using Oracle or heuristic policies. Such a framework is effective for pre-training from historical datasets and well suited to continuous improvement with online data collection.
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离线强化学习用于在实时访问环境昂贵或不可能的情况下培训策略。作为这些恶劣条件的自然后果,在采取行动之前,代理商可能缺乏完全遵守在线环境的资源。我们配备了这种情况资源受限的设置。这导致脱机数据集(可用于培训)的情况可以包含完全处理的功能(使用功能强大的语言模型,图像模型,复杂传感器等)在实际在线时不可用。此断开连接导致离线RL中的有趣和未开发的问题:是否可以使用丰富地处理的脱机数据集来培训可访问在线环境中的更少功能的策略?在这项工作中,我们介绍并正式化这一新颖的资源受限的问题设置。我们突出了使用有限功能培训的完整脱机数据集和策略培训的策略之间的性能差距。我们通过策略传输算法解决了这种性能缺口,该策略传输算法首先使用功能完全可用的脱机数据集列举教师代理,然后将此知识传输到仅使用资源约束功能的学生代理。为了更好地捕获此设置的挑战,我们提出了一个数据收集过程:RL(RC-D4RL)的资源受限数据集。我们在RC-D4RL和流行的D4RL基准测试中评估传输算法,并观察到基线上的一致性改进(无需传输)。实验的代码在https://github.com/jayanthrr /rc-offlinerl上获得。
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保守主义的概念导致了离线强化学习(RL)的重要进展,其中代理从预先收集的数据集中学习。但是,尽可能多的实际方案涉及多个代理之间的交互,解决更实际的多代理设置中的离线RL仍然是一个开放的问题。鉴于最近将Online RL算法转移到多代理设置的成功,可以预期离线RL算法也将直接传输到多代理设置。令人惊讶的是,当基于保守的算法应用于多蛋白酶的算法时,性能显着降低了越来越多的药剂。为了减轻劣化,我们确定了价值函数景观可以是非凹形的关键问题,并且策略梯度改进容易出现本地最优。自从任何代理人的次优政策可能导致不协调的全球失败以来,多个代理人会加剧问题。在这种直觉之后,我们提出了一种简单而有效的方法,脱机多代理RL与演员整流(OMAR),通过有效的一阶政策梯度和Zeroth订单优化方法为演员更好地解决这一关键挑战优化保守值函数。尽管简单,奥马尔显着优于强大的基线,在多售后连续控制基准测试中具有最先进的性能。
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如何在演示相对较大时更加普遍地进行模仿学习一直是强化学习(RL)的持续存在问题。糟糕的示威活动导致狭窄和偏见的日期分布,非马洛维亚人类专家演示使代理商难以学习,而过度依赖子最优轨迹可以使代理商努力提高其性能。为了解决这些问题,我们提出了一种名为TD3FG的新算法,可以平稳地过渡从专家到学习从经验中学习。我们的算法在Mujoco环境中实现了有限的有限和次优的演示。我们使用行为克隆来将网络作为参考动作发生器训练,并在丢失函数和勘探噪声方面使用它。这种创新可以帮助代理商从示威活动中提取先验知识,同时降低了糟糕的马尔科维亚特性的公正的不利影响。与BC +微调和DDPGFD方法相比,它具有更好的性能,特别是当示范相对有限时。我们调用我们的方法TD3FG意味着来自发电机的TD3。
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强化学习(RL)已在域中展示有效,在域名可以通过与其操作环境进行积极互动来学习政策。但是,如果我们将RL方案更改为脱机设置,代理商只能通过静态数据集更新其策略,其中脱机强化学习中的一个主要问题出现,即分配转移。我们提出了一种悲观的离线强化学习(PESSORL)算法,以主动引导代理通过操纵价值函数来恢复熟悉的区域。我们专注于由分销外(OOD)状态引起的问题,并且故意惩罚训练数据集中不存在的状态的高值,以便学习的悲观值函数下限界限状态空间内的任何位置。我们在各种基准任务中评估Pessorl算法,在那里我们表明我们的方法通过明确处理OOD状态,与这些方法仅考虑ood行动时,我们的方法通过明确处理OOD状态。
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Offline reinforcement learning (RL) is suitable for safety-critical domains where online exploration is too costly or dangerous. In safety-critical settings, decision-making should take into consideration the risk of catastrophic outcomes. In other words, decision-making should be risk-sensitive. Previous works on risk in offline RL combine together offline RL techniques, to avoid distributional shift, with risk-sensitive RL algorithms, to achieve risk-sensitivity. In this work, we propose risk-sensitivity as a mechanism to jointly address both of these issues. Our model-based approach is risk-averse to both epistemic and aleatoric uncertainty. Risk-aversion to epistemic uncertainty prevents distributional shift, as areas not covered by the dataset have high epistemic uncertainty. Risk-aversion to aleatoric uncertainty discourages actions that may result in poor outcomes due to environment stochasticity. Our experiments show that our algorithm achieves competitive performance on deterministic benchmarks, and outperforms existing approaches for risk-sensitive objectives in stochastic domains.
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大多数前往离线强化学习(RL)的方法都采取了一种迭代演员 - 批评批评,涉及违规评估。在本文中,我们展示了使用行为政策的政策Q估计来令人惊讶地执行一步的Q估计,从而简单地执行一个受限制/正规化的政策改进的步骤。该一步算法在大部分D4RL基准测试中击败了先前报告的迭代算法的结果。一步基线实现了这种强劲的性能,同时对超公数更简单,更强大而不是先前提出的迭代算法。我们认为迭代方法的表现相对较差是在违反政策评估中固有的高方差,并通过对这些估计的重复优化的政策进行放大。此外,我们假设一步算法的强大性能是由于环境和行为政策中有利结构的组合。
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离线强化学习(RL)任务要求代理从预先收集的数据集中学习,没有与环境进行进一步的交互。尽管有可能超越行为政策,但基于RL的方法通常是不切实际的,因为培训不稳定并引导外推错误,这始终需要通过在线评估进行仔细的超参数调整。相比之下,离线模仿学习(IL)没有这样的问题,因为它直接在不估计值函数的情况下直接了解策略。然而,IL通常限制在行为政策的能力,并且倾向于从政策混合收集的数据集中学习平庸行为。在本文中,我们的目标是利用IL但缓解这种缺点。观察行为克隆能够使用较少的数据模仿邻近的策略,我们提出\ Textit {课程脱机仿制学习(线圈)},它利用具有更高回报的自适应邻近策略的体验挑选策略,并提高了当前策略沿课程阶段。在连续控制基准测试中,我们将线圈与基于仿制的和基于RL的方法进行比较,表明它不仅避免了在混合数据集上学习平庸行为,而且甚至与最先进的离线RL方法竞争。
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