深度加强学习（RL）算法是解决Visuomotor决策任务的强大工具。然而，训练有素的型号往往难以解释，因为它们被代表为端到端的深神经网络。在本文中，我们通过分析他们在任务执行期间参加的像素来阐明这种训练有素的模型的内部工作，并将它们与执行相同任务的人类参加的像素进行比较。为此，我们调查以下两个问题，以至于我们以前尚未研究过。 1）RL代理商和人类在执行相同的任务时如何相似是如何？ 2）这些学习的陈述中的相似性和差异如何解释RL代理人对这些任务的表现？具体而言，我们在学习玩Atari Games时比较RL代理人的显着图，反对人类专家的视觉模型。此外，我们分析了深度RL算法的超参数如何影响培训代理的学习的表示和显着性图。所提供的见解有可能通知新的算法来关闭人类专家和RL代理商之间的性能差距。

Current learning machines have successfully solved hard application problems, reaching high accuracy and displaying seemingly "intelligent" behavior. Here we apply recent techniques for explaining decisions of state-of-the-art learning machines and analyze various tasks from computer vision and arcade games. This showcases a spectrum of problem-solving behaviors ranging from naive and short-sighted, to wellinformed and strategic. We observe that standard performance evaluation metrics can be oblivious to distinguishing these diverse problem solving behaviors. Furthermore, we propose our semi-automated Spectral Relevance Analysis that provides a practically effective way of characterizing and validating the behavior of nonlinear learning machines. This helps to assess whether a learned model indeed delivers reliably for the problem that it was conceived for. Furthermore, our work intends to add a voice of caution to the ongoing excitement about machine intelligence and pledges to evaluate and judge some of these recent successes in a more nuanced manner.

自2015年首次介绍以来，深入增强学习（DRL）方案的使用已大大增加。尽管在许多不同的应用中使用了使用，但他们仍然存在缺乏可解释性的问题。面包缺乏对研究人员和公众使用DRL解决方案的使用。为了解决这个问题，已经出现了可解释的人工智能（XAI）领域。这是各种不同的方法，它们希望打开DRL黑框，范围从使用可解释的符号决策树到诸如Shapley值之类的数值方法。这篇评论研究了使用哪些方法以及使用了哪些应用程序。这样做是为了确定哪些模型最适合每个应用程序，或者是否未充分利用方法。

深度加强学习（RL）代理在一系列复杂的控制任务中变得越来越精通。然而，由于引入黑盒功能，代理的行为通常很难解释，使得难以获得用户的信任。虽然存在一些基于视觉的RL的有趣的解释方法，但大多数人都无法发现时间因果信息，提高其可靠性的问题。为了解决这个问题，我们提出了一个时间空间因果解释（TSCI）模型，以了解代理人的长期行为，这对于连续决策至关重要。 TSCI模型构建了颞会因果关系的制定，这反映了连续观测结果与RL代理的决策之间的时间因果关系。然后，采用单独的因果发现网络来识别时间空间因果特征，这被限制为满足时间因果关系。 TSCI模型适用于复发代理，可用于发现培训效率高效率的因果特征。经验结果表明，TSCI模型可以产生高分辨率和敏锐的关注掩模，以突出大多数关于视觉的RL代理如何顺序决策的最大证据的任务相关的时间空间信息。此外，我们还表明，我们的方法能够为从时刻视角提供有价值的基于视觉的RL代理的因果解释。

可视化优化景观导致了数字优化的许多基本见解，并对优化技术进行了新的改进。但是，仅在少数狭窄的环境中生成了增强学习优化（“奖励表面”）的目标的可视化。这项工作首次介绍了27个最广泛使用的增强学习环境的奖励表面和相关的可视化。我们还探索了政策梯度方向上的奖励表面，并首次表明许多流行的强化学习环境经常出现“悬崖”（预期回报中突然下降）。我们证明，A2C经常将这些悬崖“脱落”到参数空间的低奖励区域，而PPO避免了它们，这证实了PPO对PPO的流行直觉，以改善以前的方法。我们还引入了一个高度可扩展的库，该库使研究人员将来可以轻松地生成这些可视化。我们的发现提供了新的直觉，以解释现代RL方法的成功和失败，我们的可视化构成了以新颖方式进行强化学习剂的几种失败模式。

In this article we introduce the Arcade Learning Environment (ALE): both a challenge problem and a platform and methodology for evaluating the development of general, domain-independent AI technology. ALE provides an interface to hundreds of Atari 2600 game environments, each one different, interesting, and designed to be a challenge for human players. ALE presents significant research challenges for reinforcement learning, model learning, model-based planning, imitation learning, transfer learning, and intrinsic motivation. Most importantly, it provides a rigorous testbed for evaluating and comparing approaches to these problems. We illustrate the promise of ALE by developing and benchmarking domain-independent agents designed using well-established AI techniques for both reinforcement learning and planning. In doing so, we also propose an evaluation methodology made possible by ALE, reporting empirical results on over 55 different games. All of the software, including the benchmark agents, is publicly available.

尽管深度强化学习（RL）最近取得了许多成功，但其方法仍然效率低下，这使得在数据方面解决了昂贵的许多问题。我们的目标是通过利用未标记的数据中的丰富监督信号来进行学习状态表示，以解决这一问题。本文介绍了三种不同的表示算法，可以访问传统RL算法使用的数据源的不同子集使用：（i）GRICA受到独立组件分析（ICA）的启发，并训练深层神经网络以输出统计独立的独立特征。输入。 Grica通过最大程度地减少每个功能与其他功能之间的相互信息来做到这一点。此外，格里卡仅需要未分类的环境状态。 （ii）潜在表示预测（LARP）还需要更多的上下文：除了要求状态作为输入外，它还需要先前的状态和连接它们的动作。该方法通过预测当前状态和行动的环境的下一个状态来学习状态表示。预测器与图形搜索算法一起使用。 （iii）重新培训通过训练深层神经网络来学习国家表示，以学习奖励功能的平滑版本。该表示形式用于预处理输入到深度RL，而奖励预测指标用于奖励成型。此方法仅需要环境中的状态奖励对学习表示表示。我们发现，每种方法都有其优势和缺点，并从我们的实验中得出结论，包括无监督的代表性学习在RL解决问题的管道中可以加快学习的速度。

强化学习的最新工作集中在学习的几个特征上，这些政策超出了最大化的奖励。这些特性包括公平，解释性，概括和鲁棒性。在本文中，我们定义了介入的鲁棒性（IR），这是一种通过培训程序的偶然方面（例如训练数据的顺序或代理商采取的特定探索性动作）引入了多变异性的量度。尽管培训程序的这些附带方面有所不同，但在干预下采取非常相似的行动时，培训程序具有很高的IR。我们开发了一种直观的，定量的IR度量，并在数十个干预措施和状态的三个atari环境中对八种算法进行计算。从这些实验中，我们发现IR随训练和算法类型的量而变化，并且高性能并不意味着高IR，正如人们所期望的那样。

Recent progress in artificial intelligence (AI) has renewed interest in building systems that learn and think like people. Many advances have come from using deep neural networks trained end-to-end in tasks such as object recognition, video games, and board games, achieving performance that equals or even beats humans in some respects. Despite their biological inspiration and performance achievements, these systems differ from human intelligence in crucial ways. We review progress in cognitive science suggesting that truly human-like learning and thinking machines will have to reach beyond current engineering trends in both what they learn, and how they learn it. Specifically, we argue that these machines should (a) build causal models of the world that support explanation and understanding, rather than merely solving pattern recognition problems; (b) ground learning in intuitive theories of physics and psychology, to support and enrich the knowledge that is learned; and (c) harness compositionality and learning-to-learn to rapidly acquire and generalize knowledge to new tasks and situations. We suggest concrete challenges and promising routes towards these goals that can combine the strengths of recent neural network advances with more structured cognitive models.

Inspired by progress in large-scale language modeling, we apply a similar approach towards building a single generalist agent beyond the realm of text outputs. The agent, which we refer to as Gato, works as a multi-modal, multi-task, multi-embodiment generalist policy. The same network with the same weights can play Atari, caption images, chat, stack blocks with a real robot arm and much more, deciding based on its context whether to output text, joint torques, button presses, or other tokens. In this report we describe the model and the data, and document the current capabilities of Gato.

最近的自主代理和机器人的应用，如自动驾驶汽车，情景的培训师，勘探机器人和服务机器人带来了关注与当前生成人工智能（AI）系统相关的至关重要的信任相关挑战。尽管取得了巨大的成功，基于连接主义深度学习神经网络方法的神经网络方法缺乏解释他们对他人的决策和行动的能力。没有符号解释能力，它们是黑色盒子，这使得他们的决定或行动不透明，这使得难以信任它们在安全关键的应用中。最近对AI系统解释性的立场目睹了可解释的人工智能（XAI）的几种方法;然而，大多数研究都专注于应用于计算科学中的数据驱动的XAI系统。解决越来越普遍的目标驱动器和机器人的研究仍然缺失。本文评论了可解释的目标驱动智能代理和机器人的方法，重点是解释和沟通代理人感知功能的技术（示例，感官和愿景）和认知推理（例如，信仰，欲望，意图，计划和目标）循环中的人类。审查强调了强调透明度，可辨与和持续学习以获得解释性的关键策略。最后，本文提出了解释性的要求，并提出了用于实现有效目标驱动可解释的代理和机器人的路线图。

强化学习者必须推广其培训经验。先前的工作主要集中在相同的培训和评估环境上。从最近引入的Crafter Benchmark（一个2D开放世界生存游戏）开始，我们引入了一套新的环境，适合评估某些代理商对以前看不见的（数量）对象的概括并快速适应（元学习）的能力。在Crafter中，通过培训1M步骤时，通过未锁定成就（例如收集资源）来评估代理商。我们表明，当前的代理商努力概括，并引入新颖的以对象为中心的代理，从而改善了强大的基准。我们还通过多个实验为未来在手工艺品上的工作提供了一般兴趣的关键见解。我们表明，仔细的超参数调整可以通过大幅度提高PPO基线代理，即使是前馈代理也可以通过依靠库存显示来解锁所有成就。我们在原始的手工环境中实现了新的最新性能。此外，当经过100万步的​​培训时，我们的调整代理几乎可以解锁所有成就。我们表明，即使删除了库存信息，复发性PPO代理也比进发料剂改进了。我们介绍Crafterood，这是一组15个新的环境，可以评估OOD概括。在Crafterood上，我们表明目前的代理无法概括，而我们的新颖中心的代理人实现了最新的OOD概括，同时也可以解释。我们的代码是公开的。

Deep reinforcement learning is poised to revolutionise the field of AI and represents a step towards building autonomous systems with a higher level understanding of the visual world. Currently, deep learning is enabling reinforcement learning to scale to problems that were previously intractable, such as learning to play video games directly from pixels. Deep reinforcement learning algorithms are also applied to robotics, allowing control policies for robots to be learned directly from camera inputs in the real world. In this survey, we begin with an introduction to the general field of reinforcement learning, then progress to the main streams of value-based and policybased methods. Our survey will cover central algorithms in deep reinforcement learning, including the deep Q-network, trust region policy optimisation, and asynchronous advantage actor-critic. In parallel, we highlight the unique advantages of deep neural networks, focusing on visual understanding via reinforcement learning. To conclude, we describe several current areas of research within the field.

Reinforcement Learning (RL) is a popular machine learning paradigm where intelligent agents interact with the environment to fulfill a long-term goal. Driven by the resurgence of deep learning, Deep RL (DRL) has witnessed great success over a wide spectrum of complex control tasks. Despite the encouraging results achieved, the deep neural network-based backbone is widely deemed as a black box that impedes practitioners to trust and employ trained agents in realistic scenarios where high security and reliability are essential. To alleviate this issue, a large volume of literature devoted to shedding light on the inner workings of the intelligent agents has been proposed, by constructing intrinsic interpretability or post-hoc explainability. In this survey, we provide a comprehensive review of existing works on eXplainable RL (XRL) and introduce a new taxonomy where prior works are clearly categorized into model-explaining, reward-explaining, state-explaining, and task-explaining methods. We also review and highlight RL methods that conversely leverage human knowledge to promote learning efficiency and performance of agents while this kind of method is often ignored in XRL field. Some challenges and opportunities in XRL are discussed. This survey intends to provide a high-level summarization of XRL and to motivate future research on more effective XRL solutions. Corresponding open source codes are collected and categorized at https://github.com/Plankson/awesome-explainable-reinforcement-learning.

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.

Superhuman神经网络代理如alphazero是什么？这个问题是科学和实际的兴趣。如果强神经网络的陈述与人类概念没有相似之处，我们理解他们的决定的忠实解释的能力将受到限制，最终限制了我们可以通过神经网络解释来实现的。在这项工作中，我们提供了证据表明，人类知识是由alphapero神经网络获得的，因为它在国际象棋游戏中列车。通过探究广泛的人类象棋概念，我们在alphazero网络中显示了这些概念的时间和地点。我们还提供了一种关注开放游戏的行为分析，包括来自国际象棋Grandmaster Vladimir Kramnik的定性分析。最后，我们开展了初步调查，观察alphazero的表现的低级细节，并在线提供由此产生的行为和代表性分析。

背景信息：在过去几年中，机器学习（ML）一直是许多创新的核心。然而，包括在所谓的“安全关键”系统中，例如汽车或航空的系统已经被证明是非常具有挑战性的，因为ML的范式转变为ML带来完全改变传统认证方法。目的：本文旨在阐明与ML为基础的安全关键系统认证有关的挑战，以及文献中提出的解决方案，以解决它们，回答问题的问题如何证明基于机器学习的安全关键系统？'方法：我们开展2015年至2020年至2020年之间发布的研究论文的系统文献综述（SLR），涵盖了与ML系统认证有关的主题。总共确定了217篇论文涵盖了主题，被认为是ML认证的主要支柱：鲁棒性，不确定性，解释性，验证，安全强化学习和直接认证。我们分析了每个子场的主要趋势和问题，并提取了提取的论文的总结。结果：单反结果突出了社区对该主题的热情，以及在数据集和模型类型方面缺乏多样性。它还强调需要进一步发展学术界和行业之间的联系，以加深域名研究。最后，它还说明了必须在上面提到的主要支柱之间建立连接的必要性，这些主要柱主要主要研究。结论：我们强调了目前部署的努力，以实现ML基于ML的软件系统，并讨论了一些未来的研究方向。

我们提出了CX-TOM，简短于与理论的理论，一种新的可解释的AI（XAI）框架，用于解释深度卷积神经网络（CNN）制定的决定。与生成解释的XAI中的当前方法形成对比，我们将说明作为迭代通信过程，即对话框，机器和人类用户之间。更具体地说，我们的CX-TOM框架通过调解机器和人类用户的思想之间的差异，在对话中生成解释顺序。为此，我们使用思想理论（汤姆），帮助我们明确地建模人类的意图，通过人类的推断，通过机器推断出人类的思想。此外，大多数最先进的XAI框架提供了基于注意的（或热图）的解释。在我们的工作中，我们表明，这些注意力的解释不足以增加人类信任在潜在的CNN模型中。在CX-TOM中，我们使用命名为您定义的故障行的反事实解释：给定CNN分类模型M预测C_PRED的CNN分类模型M的输入图像I，错误线识别最小的语义级别特征（例如，斑马上的条纹，狗的耳朵），称为可解释的概念，需要从I添加或删除，以便将m的分类类别改变为另一个指定的c_alt。我们认为，由于CX-TOM解释的迭代，概念和反事本质，我们的框架对于专家和非专家用户来说是实用的，更加自然，以了解复杂的深度学习模式的内部运作。广泛的定量和定性实验验证了我们的假设，展示了我们的CX-TOM显着优于最先进的可解释的AI模型。

Imitation learning techniques aim to mimic human behavior in a given task. An agent (a learning machine) is trained to perform a task from demonstrations by learning a mapping between observations and actions. The idea of teaching by imitation has been around for many years, however, the field is gaining attention recently due to advances in computing and sensing as well as rising demand for intelligent applications. The paradigm of learning by imitation is gaining popularity because it facilitates teaching complex tasks with minimal expert knowledge of the tasks. Generic imitation learning methods could potentially reduce the problem of teaching a task to that of providing demonstrations; without the need for explicit programming or designing reward functions specific to the task. Modern sensors are able to collect and transmit high volumes of data rapidly, and processors with high computational power allow fast processing that maps the sensory data to actions in a timely manner. This opens the door for many potential AI applications that require real-time perception and reaction such as humanoid robots, self-driving vehicles, human computer interaction and computer games to name a few. However, specialized algorithms are needed to effectively and robustly learn models as learning by imitation poses its own set of challenges. In this paper, we survey imitation learning methods and present design options in different steps of the learning process. We introduce a background and motivation for the field as well as highlight challenges specific to the imitation problem. Methods for designing and evaluating imitation learning tasks are categorized and reviewed. Special attention is given to learning methods in robotics and games as these domains are the most popular in the literature and provide a wide array of problems and methodologies. We extensively discuss combining imitation learning approaches using different sources and methods, as well as incorporating other motion learning methods to enhance imitation. We also discuss the potential impact on industry, present major applications and highlight current and future research directions.