优先考虑体验重放是一种强化学习技术,可以通过允许代理商更频繁地重播过去的经验来加速学习。这种有用性被量化为从重播经验的预期增益,并且通常近似为在相应的经验期间观察到的预测误差(TD误差)。但是,预测误差只是一个可能的优先级度量。神经科学的最新作品表明,在生物生物中,通过增益和需求优先考虑重播。需要期限衡量每种经验对目前情况的预期相关性,更重要的是,该术语目前尚未考虑在Q-Network(DQN)等算法中考虑。因此,在本文中,我们提出了一种新方法,以确定重播经验的优先考虑增益和需求。我们通过考虑所需术语,量词,作为继承人表示,进入不同强化学习算法的采样过程来测试我们的方法。我们所提出的算法表现出基准中的性能显着增加,包括Dyna-Q迷宫和一系列Atari Games。
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Experience replay lets online reinforcement learning agents remember and reuse experiences from the past. In prior work, experience transitions were uniformly sampled from a replay memory. However, this approach simply replays transitions at the same frequency that they were originally experienced, regardless of their significance. In this paper we develop a framework for prioritizing experience, so as to replay important transitions more frequently, and therefore learn more efficiently. We use prioritized experience replay in Deep Q-Networks (DQN), a reinforcement learning algorithm that achieved human-level performance across many Atari games. DQN with prioritized experience replay achieves a new stateof-the-art, outperforming DQN with uniform replay on 41 out of 49 games.
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在这项工作中,我们提出并评估了一种新的增强学习方法,紧凑体验重放(编者),它使用基于相似转换集的复发的预测目标值的时间差异学习,以及基于两个转换的经验重放的新方法记忆。我们的目标是减少在长期累计累计奖励的经纪人培训所需的经验。它与强化学习的相关性与少量观察结果有关,即它需要实现类似于文献中的相关方法获得的结果,这通常需要数百万视频框架来培训ATARI 2600游戏。我们举报了在八个挑战街机学习环境(ALE)挑战游戏中,为仅10万帧的培训试验和大约25,000次迭代的培训试验中报告了培训试验。我们还在与基线的同一游戏中具有相同的实验协议的DQN代理呈现结果。为了验证从较少数量的观察结果近似于良好的政策,我们还将其结果与从啤酒的基准上呈现的数百万帧中获得的结果进行比较。
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大多数强化学习算法都利用了经验重播缓冲液,以反复对代理商过去观察到的样本进行训练。这样可以防止灾难性的遗忘,但是仅仅对每个样本都分配了同等的重要性是一种天真的策略。在本文中,我们提出了一种根据样本可以从样本中学到多少样本确定样本优先级的方法。我们将样本的学习能力定义为随着时间的推移,与该样品相关的训练损失的稳定减少。我们开发了一种算法,以优先考虑具有较高学习能力的样本,同时将优先级较低,为那些难以学习的样本,通常是由噪声或随机性引起的。我们从经验上表明,我们的方法比随机抽样更强大,而且比仅在训练损失方面优先排序更好,即时间差损失,这是在香草优先的经验重播中使用的。
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In recent years there have been many successes of using deep representations in reinforcement learning. Still, many of these applications use conventional architectures, such as convolutional networks, LSTMs, or auto-encoders. In this paper, we present a new neural network architecture for model-free reinforcement learning. Our dueling network represents two separate estimators: one for the state value function and one for the state-dependent action advantage function. The main benefit of this factoring is to generalize learning across actions without imposing any change to the underlying reinforcement learning algorithm. Our results show that this architecture leads to better policy evaluation in the presence of many similar-valued actions. Moreover, the dueling architecture enables our RL agent to outperform the state-of-the-art on the Atari 2600 domain.
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Deep reinforcement learning (RL) has achieved several high profile successes in difficult decision-making problems. However, these algorithms typically require a huge amount of data before they reach reasonable performance. In fact, their performance during learning can be extremely poor. This may be acceptable for a simulator, but it severely limits the applicability of deep RL to many real-world tasks, where the agent must learn in the real environment. In this paper we study a setting where the agent may access data from previous control of the system. We present an algorithm, Deep Q-learning from Demonstrations (DQfD), that leverages small sets of demonstration data to massively accelerate the learning process even from relatively small amounts of demonstration data and is able to automatically assess the necessary ratio of demonstration data while learning thanks to a prioritized replay mechanism. DQfD works by combining temporal difference updates with supervised classification of the demonstrator's actions. We show that DQfD has better initial performance than Prioritized Dueling Double Deep Q-Networks (PDD DQN) as it starts with better scores on the first million steps on 41 of 42 games and on average it takes PDD DQN 83 million steps to catch up to DQfD's performance. DQfD learns to out-perform the best demonstration given in 14 of 42 games. In addition, DQfD leverages human demonstrations to achieve state-of-the-art results for 11 games. Finally, we show that DQfD performs better than three related algorithms for incorporating demonstration data into DQN.
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The deep reinforcement learning community has made several independent improvements to the DQN algorithm. However, it is unclear which of these extensions are complementary and can be fruitfully combined. This paper examines six extensions to the DQN algorithm and empirically studies their combination. Our experiments show that the combination provides state-of-the-art performance on the Atari 2600 benchmark, both in terms of data efficiency and final performance. We also provide results from a detailed ablation study that shows the contribution of each component to overall performance.
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Efficient exploration remains a major challenge for reinforcement learning (RL). Common dithering strategies for exploration, such as -greedy, do not carry out temporally-extended (or deep) exploration; this can lead to exponentially larger data requirements. However, most algorithms for statistically efficient RL are not computationally tractable in complex environments. Randomized value functions offer a promising approach to efficient exploration with generalization, but existing algorithms are not compatible with nonlinearly parameterized value functions. As a first step towards addressing such contexts we develop bootstrapped DQN. We demonstrate that bootstrapped DQN can combine deep exploration with deep neural networks for exponentially faster learning than any dithering strategy. In the Arcade Learning Environment bootstrapped DQN substantially improves learning speed and cumulative performance across most games.
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在探索中,由于当前的低效率而引起的强化学习领域,具有较大动作空间的学习控制政策是一个具有挑战性的问题。在这项工作中,我们介绍了深入的强化学习(DRL)算法呼叫多动作网络(MAN)学习,以应对大型离散动作空间的挑战。我们建议将动作空间分为两个组件,从而为每个子行动创建一个值神经网络。然后,人使用时间差异学习来同步训练网络,这比训练直接动作输出的单个网络要简单。为了评估所提出的方法,我们在块堆叠任务上测试了人,然后扩展了人类从Atari Arcade学习环境中使用18个动作空间的12个游戏。我们的结果表明,人的学习速度比深Q学习和双重Q学习更快,这意味着我们的方法比当前可用于大型动作空间的方法更好地执行同步时间差异算法。
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Off-policy reinforcement learning (RL) using a fixed offline dataset of logged interactions is an important consideration in real world applications. This paper studies offline RL using the DQN Replay Dataset comprising the entire replay experience of a DQN agent on 60 Atari 2600 games. We demonstrate that recent off-policy deep RL algorithms, even when trained solely on this fixed dataset, outperform the fully-trained DQN agent. To enhance generalization in the offline setting, we present Random Ensemble Mixture (REM), a robust Q-learning algorithm that enforces optimal Bellman consistency on random convex combinations of multiple Q-value estimates. Offline REM trained on the DQN Replay Dataset surpasses strong RL baselines. Ablation studies highlight the role of offline dataset size and diversity as well as the algorithm choice in our positive results. Overall, the results here present an optimistic view that robust RL algorithms used on sufficiently large and diverse offline datasets can lead to high quality policies. To provide a testbed for offline RL and reproduce our results, the DQN Replay Dataset is released at offline-rl.github.io.
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近年来,已经引入了越来越多的基于模型的强化学习(RL)方法。鉴于其许多潜在的好处,例如更高的样本效率和快速适应环境变化的潜力,对基于深层模型的RL的兴趣并不奇怪。但是,我们证明,使用最近引入的本地变化适应(LOCA)设置的改进版本,众所周知的基于模型的方法(例如Planet和Dreamerv2)在适应本地环境变化的能力方面表现不佳。结合先前的工作,对其他基于模型的方法Muzero进行了类似的观察,似乎出现了一种趋势,这表明当前基于深层模型的方法具有严重的局限性。我们通过识别损害适应性行为并将其与经常在基于DEEP模型的RL中经常使用的基础技术联系起来的元素,深入研究这种绩效不佳的原因。在线性函数近似的情况下,我们通过证明了线性DyNA的修改版本实现有效适应局部变化,从而验证了这些见解。此外,我们通过实验非线性版本的DYNA来提供详细的见解,以了解构建基于自适应非线性模型方法的挑战。
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我们确定和研究政策流失的现象,即基于价值的强化学习中贪婪政策的快速变化。政策流失以惊人的快速步伐运作,改变了少数学习更新(在Atari上的DQN等典型的深层RL设置中)中大量州的贪婪行动。我们从经验上表征了现象,验证它不限于特定算法或环境特性。许多消融有助于削弱关于为什么流失仅与深度学习有关的少数相关的合理解释。最后,我们假设政策流失是一种有益但被忽视的隐性探索形式,它以新鲜的方式铸造了$ \ epsilon $ greedy探索,即$ \ epsilon $ - noise的作用比预期的要小得多。
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We present the first deep learning model to successfully learn control policies directly from high-dimensional sensory input using reinforcement learning. The model is a convolutional neural network, trained with a variant of Q-learning, whose input is raw pixels and whose output is a value function estimating future rewards. We apply our method to seven Atari 2600 games from the Arcade Learning Environment, with no adjustment of the architecture or learning algorithm. We find that it outperforms all previous approaches on six of the games and surpasses a human expert on three of them.
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在时间差异增强学习算法中,价值估计的差异会导致最大目标值的不稳定性和高估。已经提出了许多算法来减少高估,包括最近的几种集合方法,但是,没有通过解决估计方差作为高估的根本原因来表现出样品效率学习的成功。在本文中,我们提出了一种简单的集合方法,将目标值估计为集合均值。尽管它很简单,但卑鄙的(还是在Atari学习环境基准测试的实验中显示出明显的样本效率)。重要的是,我们发现大小5的合奏充分降低了估计方差以消除滞后目标网络,从而消除了它作为偏见的来源并进一步获得样本效率。我们以直观和经验的方式为曲线的设计选择证明了合理性,包括独立经验抽样的必要性。在一组26个基准ATARI环境中,曲线均优于所有经过测试的基线,包括最佳的基线,日出,在16/26环境中的100K交互步骤,平均为68​​%。在21/26的环境中,曲线还优于500k步骤的Rainbow DQN,平均为49%,并使用200K($ \ pm $ 100k)的交互步骤实现平均人级绩效。我们的实施可从https://github.com/indylab/meanq获得。
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已经提出了几种算法,以非均匀地对深钢筋学习(RL)剂的重播缓冲液进行采样,以加速学习,但是几乎没有提供这些抽样方案的理论基础。除其他外,优先的经验重播似乎是一种超级参数敏感的启发式,尽管它可以提供良好的性能。在这项工作中,我们将重播缓冲液抽样问题视为估算梯度的重要性采样。这允许得出理论上最佳的采样分布,从而获得最佳的理论收敛速度。详细阐述了理想抽样方案的知识,我们展示了优先经验重播的新理论基础。最佳采样分布非常棘手,我们进行了几个近似值,可在实践中提供良好的结果,并介绍Laber(大批次经验重播),这是一种易于编码和有效的方法来抽样重播缓冲区。与其他优先级方案相比,Laber可以与深层Q-NETWORKS,分布RL代理或参与者 - 批判性方法结合使用,在各种Atari游戏和Pybullet环境中,可以提高性能。
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深度强化学习(RL)导致了许多最近和开创性的进步。但是,这些进步通常以培训的基础体系结构的规模增加以及用于训练它们的RL算法的复杂性提高,而均以增加规模的成本。这些增长反过来又使研究人员更难迅速原型新想法或复制已发表的RL算法。为了解决这些问题,这项工作描述了ACME,这是一个用于构建新型RL算法的框架,这些框架是专门设计的,用于启用使用简单的模块化组件构建的代理,这些组件可以在各种执行范围内使用。尽管ACME的主要目标是为算法开发提供一个框架,但第二个目标是提供重要或最先进算法的简单参考实现。这些实现既是对我们的设计决策的验证,也是对RL研究中可重复性的重要贡献。在这项工作中,我们描述了ACME内部做出的主要设计决策,并提供了有关如何使用其组件来实施各种算法的进一步详细信息。我们的实验为许多常见和最先进的算法提供了基准,并显示了如何为更大且更复杂的环境扩展这些算法。这突出了ACME的主要优点之一,即它可用于实现大型,分布式的RL算法,这些算法可以以较大的尺度运行,同时仍保持该实现的固有可读性。这项工作提出了第二篇文章的版本,恰好与模块化的增加相吻合,对离线,模仿和从演示算法学习以及作为ACME的一部分实现的各种新代理。
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本文研究了一种使用背景计划的新方法,用于基于模型的增强学习:混合(近似)动态编程更新和无模型更新,类似于DYNA体系结构。通过学习模型的背景计划通常比无模型替代方案(例如Double DQN)差,尽管前者使用了更多的内存和计算。基本问题是,学到的模型可能是不准确的,并且经常会产生无效的状态,尤其是在迭代许多步骤时。在本文中,我们通过将背景规划限制为一组(抽象)子目标并仅学习本地,子观念模型来避免这种限制。这种目标空间计划(GSP)方法更有效地是在计算上,自然地纳入了时间抽象,以进行更快的长胜压计划,并避免完全学习过渡动态。我们表明,在各种情况下,我们的GSP算法比双DQN基线要快得多。
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Adequately assigning credit to actions for future outcomes based on their contributions is a long-standing open challenge in Reinforcement Learning. The assumptions of the most commonly used credit assignment method are disadvantageous in tasks where the effects of decisions are not immediately evident. Furthermore, this method can only evaluate actions that have been selected by the agent, making it highly inefficient. Still, no alternative methods have been widely adopted in the field. Hindsight Credit Assignment is a promising, but still unexplored candidate, which aims to solve the problems of both long-term and counterfactual credit assignment. In this thesis, we empirically investigate Hindsight Credit Assignment to identify its main benefits, and key points to improve. Then, we apply it to factored state representations, and in particular to state representations based on the causal structure of the environment. In this setting, we propose a variant of Hindsight Credit Assignment that effectively exploits a given causal structure. We show that our modification greatly decreases the workload of Hindsight Credit Assignment, making it more efficient and enabling it to outperform the baseline credit assignment method on various tasks. This opens the way to other methods based on given or learned causal structures.
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一种被称为优先体验重播(PER)的广泛研究的深钢筋学习(RL)技术使代理可以从与其时间差异(TD)误差成正比的过渡中学习。尽管已经表明,PER是离散作用域中深度RL方法总体性能的最关键组成部分之一,但许多经验研究表明,在连续控制中,它的表现非常低于参与者 - 批评算法。从理论上讲,我们表明,无法有效地通过具有较大TD错误的过渡对演员网络进行训练。结果,在Q网络下计算的近似策略梯度与在最佳Q功能下计算的实际梯度不同。在此激励的基础上,我们引入了一种新颖的经验重播抽样框架,用于演员批评方法,该框架还认为稳定性和最新发现的问题是Per的经验表现不佳。引入的算法提出了对演员和评论家网络的有效和高效培训的改进的新分支。一系列广泛的实验验证了我们的理论主张,并证明了引入的方法显着优于竞争方法,并获得了与标准的非政策参与者 - 批评算法相比,获得最先进的结果。
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经验重播方法是加固学习(RL)算法的重要组成部分,旨在减轻伪造的相关性和偏见,同时从时间依赖的数据中学习。粗略地说,这些方法使我们能够从大型缓冲液中绘制批处理的数据,从而使这些时间相关性不会妨碍下降算法的性能。在这项实验工作中,我们考虑了最近开发和理论上严格的反向经验重播(RER),该重播已被证明可以消除简化的理论环境中的这种虚假偏见。我们将RER与乐观的经验重播(OER)相结合,以获得RER ++,在神经功能近似下这是稳定的。我们通过实验表明,在各种任务上的优先体验重播(PER)等技术的性能要比计算复杂性明显较小,具有更好的性能。在RL文献中众所周知,选择最大的TD误差(如OER)或形成具有连续数据点(如RER)的迷你批次而贪婪地选择示例。但是,结合这些技术的方法效果很好。
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