我们对学习协调的互动代理感兴趣，即$ BUILDER $ - 执行操作但忽略任务的目标 - 以及$架构师$指导建造者以朝着任务的目标指导。我们定义和探索正式的设置，其中人工代理配备了允许它们同时学习任务的机制，同时同时演变共享通信协议。实验符号学领域表明，从先验的未知指示中学习的人类熟练程度。因此，我们从中获取灵感并提出了建筑师构建器问题（ABP）：一个不对称的设置，其中建筑师必须学习指导建设者朝构建特定结构。该架构师知道目标结构，但不能在环境中行动，只能向构建器发送任意消息。另一方面的建筑师可以在环境中采取行动，但没有关于手头的任务的知识，必须学会解决它依赖于架构师发送的消息。至关重要的是，消息的含义最初没有在代理商之间定义，而是必须在整个学习中进行协商。在这些约束下，我们建议建筑师构建器迭代（abig），一个解决方案到架构师 - 建筑师的问题，其中建筑师利用Builder的学习模型指导它，同时构建器使用自模仿学习来加强其导游行为。我们分析ABIG的关键学习机制，并在ABP的二维实例化中测试，其中任务涉及抓取立方体，将它们放在给定位置或构建各种形状。在这种环境中，ABIG导致低级，高频，指导通信协议，不仅使建筑师构建器对能够在手头上解决任务，而且还可以概括到未操作任务。

建立可以探索开放式环境的自主机器，发现可能的互动，自主构建技能的曲目是人工智能的一般目标。发展方法争辩说，这只能通过可以生成，选择和学习解决自己问题的自主和本质上动机的学习代理人来实现。近年来，我们已经看到了发育方法的融合，特别是发展机器人，具有深度加强学习（RL）方法，形成了发展机器学习的新领域。在这个新域中，我们在这里审查了一组方法，其中深入RL算法训练，以解决自主获取的开放式曲目的发展机器人问题。本质上动机的目标条件RL算法训练代理商学习代表，产生和追求自己的目标。自我生成目标需要学习紧凑的目标编码以及它们的相关目标 - 成就函数，这导致与传统的RL算法相比，这导致了新的挑战，该算法设计用于使用外部奖励信号解决预定义的目标集。本文提出了在深度RL和发育方法的交叉口中进行了这些方法的类型，调查了最近的方法并讨论了未来的途径。

Current approaches to multi-agent cooperation rely heavily on centralized mechanisms or explicit communication protocols to ensure convergence. This paper studies the problem of distributed multi-agent learning without resorting to centralized components or explicit communication. It examines the use of distribution matching to facilitate the coordination of independent agents. In the proposed scheme, each agent independently minimizes the distribution mismatch to the corresponding component of a target visitation distribution. The theoretical analysis shows that under certain conditions, each agent minimizing its individual distribution mismatch allows the convergence to the joint policy that generated the target distribution. Further, if the target distribution is from a joint policy that optimizes a cooperative task, the optimal policy for a combination of this task reward and the distribution matching reward is the same joint policy. This insight is used to formulate a practical algorithm (DM$^2$), in which each individual agent matches a target distribution derived from concurrently sampled trajectories from a joint expert policy. Experimental validation on the StarCraft domain shows that combining (1) a task reward, and (2) a distribution matching reward for expert demonstrations for the same task, allows agents to outperform a naive distributed baseline. Additional experiments probe the conditions under which expert demonstrations need to be sampled to obtain the learning benefits.

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。

Exploration in environments with sparse rewards has been a persistent problem in reinforcement learning (RL). Many tasks are natural to specify with a sparse reward, and manually shaping a reward function can result in suboptimal performance. However, finding a non-zero reward is exponentially more difficult with increasing task horizon or action dimensionality. This puts many real-world tasks out of practical reach of RL methods. In this work, we use demonstrations to overcome the exploration problem and successfully learn to perform long-horizon, multi-step robotics tasks with continuous control such as stacking blocks with a robot arm. Our method, which builds on top of Deep Deterministic Policy Gradients and Hindsight Experience Replay, provides an order of magnitude of speedup over RL on simulated robotics tasks. It is simple to implement and makes only the additional assumption that we can collect a small set of demonstrations. Furthermore, our method is able to solve tasks not solvable by either RL or behavior cloning alone, and often ends up outperforming the demonstrator policy.

Deep Reinforcement Learning has been successfully applied to learn robotic control. However, the corresponding algorithms struggle when applied to problems where the agent is only rewarded after achieving a complex task. In this context, using demonstrations can significantly speed up the learning process, but demonstrations can be costly to acquire. In this paper, we propose to leverage a sequential bias to learn control policies for complex robotic tasks using a single demonstration. To do so, our method learns a goal-conditioned policy to control a system between successive low-dimensional goals. This sequential goal-reaching approach raises a problem of compatibility between successive goals: we need to ensure that the state resulting from reaching a goal is compatible with the achievement of the following goals. To tackle this problem, we present a new algorithm called DCIL-II. We show that DCIL-II can solve with unprecedented sample efficiency some challenging simulated tasks such as humanoid locomotion and stand-up as well as fast running with a simulated Cassie robot. Our method leveraging sequentiality is a step towards the resolution of complex robotic tasks under minimal specification effort, a key feature for the next generation of autonomous robots.

With the development of deep representation learning, the domain of reinforcement learning (RL) has become a powerful learning framework now capable of learning complex policies in high dimensional environments. This review summarises deep reinforcement learning (DRL) algorithms and provides a taxonomy of automated driving tasks where (D)RL methods have been employed, while addressing key computational challenges in real world deployment of autonomous driving agents. It also delineates adjacent domains such as behavior cloning, imitation learning, inverse reinforcement learning that are related but are not classical RL algorithms. The role of simulators in training agents, methods to validate, test and robustify existing solutions in RL are discussed.

本文解决了逆增强学习（IRL）的问题 - 从观察其行为中推断出代理的奖励功能。 IRL可以为学徒学习提供可概括和紧凑的代表，并能够准确推断人的偏好以帮助他们。 ％并提供更准确的预测。但是，有效的IRL具有挑战性，因为许多奖励功能可以与观察到的行为兼容。我们专注于如何利用先前的强化学习（RL）经验，以使学习这些偏好更快，更高效。我们提出了IRL算法基础（通过样本中的连续功能意图推断行为获取行为），该算法利用多任务RL预培训和后继功能，使代理商可以为跨越可能的目标建立强大的基础，从而跨越可能的目标。给定的域。当仅接触一些专家演示以优化新颖目标时，代理商会使用其基础快速有效地推断奖励功能。我们的实验表明，我们的方法非常有效地推断和优化显示出奖励功能，从而准确地从少于100个轨迹中推断出奖励功能。

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.

The reinforcement learning paradigm is a popular way to address problems that have only limited environmental feedback, rather than correctly labeled examples, as is common in other machine learning contexts. While significant progress has been made to improve learning in a single task, the idea of transfer learning has only recently been applied to reinforcement learning tasks. The core idea of transfer is that experience gained in learning to perform one task can help improve learning performance in a related, but different, task. In this article we present a framework that classifies transfer learning methods in terms of their capabilities and goals, and then use it to survey the existing literature, as well as to suggest future directions for transfer learning work.

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.

Adversarial imitation learning (AIL) has become a popular alternative to supervised imitation learning that reduces the distribution shift suffered by the latter. However, AIL requires effective exploration during an online reinforcement learning phase. In this work, we show that the standard, naive approach to exploration can manifest as a suboptimal local maximum if a policy learned with AIL sufficiently matches the expert distribution without fully learning the desired task. This can be particularly catastrophic for manipulation tasks, where the difference between an expert and a non-expert state-action pair is often subtle. We present Learning from Guided Play (LfGP), a framework in which we leverage expert demonstrations of multiple exploratory, auxiliary tasks in addition to a main task. The addition of these auxiliary tasks forces the agent to explore states and actions that standard AIL may learn to ignore. Additionally, this particular formulation allows for the reusability of expert data between main tasks. Our experimental results in a challenging multitask robotic manipulation domain indicate that LfGP significantly outperforms both AIL and behaviour cloning, while also being more expert sample efficient than these baselines. To explain this performance gap, we provide further analysis of a toy problem that highlights the coupling between a local maximum and poor exploration, and also visualize the differences between the learned models from AIL and LfGP.

有效的探索是深度强化学习的关键挑战。几种方法，例如行为先验，能够利用离线数据，以便在复杂任务上有效加速加强学习。但是，如果手动的任务与所证明的任务过度偏离，则此类方法的有效性是有限的。在我们的工作中，我们建议从离线数据中学习功能，这些功能由更加多样化的任务共享，例如动作与定向之间的相关性。因此，我们介绍了无国有先验，该先验直接在显示的轨迹中直接建模时间一致性，并且即使在对简单任务收集的数据进行培训时，也能够在复杂的任务中推动探索。此外，我们通过从政策和行动之前的概率混合物中动态采样动作，引入了一种新颖的集成方案，用于非政策强化学习中的动作研究。我们将我们的方法与强大的基线相提并论，并提供了经验证据，表明它可以在稀疏奖励环境下的长途持续控制任务中加速加强学习。

我们研究了设计AI代理商的问题，该代理可以学习有效地与潜在的次优伴侣有效合作，同时无法访问联合奖励功能。这个问题被建模为合作焦论双代理马尔可夫决策过程。我们假设仅在游戏的Stackelberg制定中的两个代理中的第一个控制，其中第二代理正在作用，以便在鉴于第一代理的政策给出预期的效用。第一个代理人应该如何尽快学习联合奖励功能，因此联合政策尽可能接近最佳？在本文中，我们分析了如何在这一交互式的两个代理方案中获得对奖励函数的知识。我们展示当学习代理的策略对转换函数有显着影响时，可以有效地学习奖励功能。

我们提出了贝叶斯团队模仿学习者（BTIL），这是一种模仿学习算法，以模拟马尔可夫域中执行顺序任务的团队的行为。与现有的多机构模仿学习技术相反，BTIL明确模型并渗透了团队成员的时间变化的心理状态，从而从次优的团队合作的演示中实现了分散的团队政策的学习。此外，为了允许从小型数据集中进行样本和标签有效的政策学习，Btil采用了贝叶斯的角度，并且能够从半监督的示范中学习。我们证明并基准了BTIL在合成多代理任务以及人类代理团队工作的新型数据集上的性能。我们的实验表明，尽管团队成员（随时间变化且可能未对准）精神状态对其行为的影响，BTIL可以成功地从示威中学习团队政策。

部署后，AI代理会遇到超出其自动解决问题能力的问题。利用人类援助可以帮助代理人克服其固有的局限性，并坚决应对陌生的情况。我们提出了一个通用的交互式框架，该框架使代理商能够从对任务和环境有知识的助手那里请求和解释丰富的上下文有用的信息。我们在模拟的人类辅助导航问题上证明了框架的实用性。在我们的方法中学到的援助要求政策的帮助下，导航代理与完全自主行为相比，在以前看不见的环境中发生的任务上的成功率提高了7倍。我们表明，代理商可以根据上下文来利用不同类型的信息，并分析学习援助要求政策的好处和挑战，当助手可以递归地将任务分解为子任务。

Safe Reinforcement Learning can be defined as the process of learning policies that maximize the expectation of the return in problems in which it is important to ensure reasonable system performance and/or respect safety constraints during the learning and/or deployment processes. We categorize and analyze two approaches of Safe Reinforcement Learning. The first is based on the modification of the optimality criterion, the classic discounted finite/infinite horizon, with a safety factor. The second is based on the modification of the exploration process through the incorporation of external knowledge or the guidance of a risk metric. We use the proposed classification to survey the existing literature, as well as suggesting future directions for Safe Reinforcement Learning.

从演示方法中学习通常利用接近最佳示范的方法来加速培训。相比之下，在展示任务时，人类教师会偏离​​最佳示威活动，并通过提供最佳歧视他们想要展示的目标的演示来改变其行为。类似地，人类的学习者在务实地推断老师的意图方面表现出色，从而促进了两个代理商之间的沟通。在少数示威制度中，这些机制至关重要，在少数示威制度中，推断目标更加困难。在本文中，我们通过利用示威活动的贝叶斯推断贝叶斯模型来实施教学法和实用主义机制。我们在多进球教师学习者的设置中强调了该模型的好处，并使用两个人工代理人通过目标条件的强化学习来学习。我们表明，将教学老师和务实的学习者结合起来会导致学习速度更快，并减少了从演示中进行标准学习的目标歧义，尤其是在少数示威制度中。

由于部分可观察性，高维视觉感知和延迟奖励，在MINECRAFT等开放世界游戏中的学习理性行为仍然是挑战，以便对加固学习（RL）研究造成挑战性，高维视觉感知和延迟奖励。为了解决这个问题，我们提出了一种具有代表学习和模仿学习的样本有效的等级RL方法，以应对感知和探索。具体来说，我们的方法包括两个层次结构，其中高级控制器学习控制策略来控制选项，低级工作人员学会解决每个子任务。为了提高子任务的学习，我们提出了一种技术组合，包括1）动作感知表示学习，其捕获了行动和表示之间的基础关系，2）基于鉴别者的自模仿学习，以实现有效的探索，以及3）合奏行为克隆一致性筛选政策鲁棒性。广泛的实验表明，Juewu-MC通过大边缘显着提高了样品效率并优于一组基线。值得注意的是，我们赢得了神经脂溢斯矿业锦标赛2021年研究竞赛的冠军，并实现了最高的绩效评分。

增强学习（RL）研究领域非常活跃，并具有重要的新贡献；特别是考虑到深RL（DRL）的新兴领域。但是，仍然需要解决许多科学和技术挑战，其中我们可以提及抽象行动的能力或在稀疏回报环境中探索环境的难以通过内在动机（IM）来解决的。我们建议通过基于信息理论的新分类法调查这些研究工作：我们在计算上重新审视了惊喜，新颖性和技能学习的概念。这使我们能够确定方法的优势和缺点，并展示当前的研究前景。我们的分析表明，新颖性和惊喜可以帮助建立可转移技能的层次结构，从而进一步抽象环境并使勘探过程更加健壮。