多进球的增强学习最近吸引了大量的研究兴趣。通过允许在相关培训任务之间共享经验，只要在被考虑的目标空间中存在某些平滑度时，这种设置有利于测试时间的新任务的概括。但是，在州或目标空间不连续的环境（例如迷宫中的墙壁）中，由于缺乏专家知识的稀疏性，大多数目标都难以实现。这意味着必须发现一些艰苦的探索，必须发现一些目标课程，以通过使培训任务适应其当前功能来帮助代理商学习。我们以最新的自动课程学习技术为目标政策，我们提出了一种新颖的方法：Stein变化目标生成（SVGG），该方法通过利用一种学识渊博的模型来寻求在代理的近端开发区域中的新目标，以寻求新的目标它的能力和目标分布在勘探空间中以颗粒为模型。我们的方法依靠Stein变分梯度下降来动态吸引适当难度领域的目标采样分布。与最近最新的RL方法相比，我们证明了该方法的性能，即目标领域的成功覆盖范围。

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。

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。

在本文中，我们介绍了潜在的探索（LGE），这是一种基于探索加固学习（RL）的探索范式的简单而通用的方法。最初引入了Go-explore，并具有强大的域知识约束，以将状态空间划分为单元。但是，在大多数实际情况下，从原始观察中汲取域知识是复杂而乏味的。如果细胞分配不足以提供信息，则可以完全无法探索环境。我们认为，可以通过利用学习的潜在表示，可以将Go-explore方法推广到任何环境，而无需细胞。因此，我们表明LGE可以灵活地与学习潜在表示的任何策略相结合。我们表明，LGE虽然比Go-explore更简单，但在多个硬探索环境上纯粹的探索方面，更强大，并且优于所有最先进的算法。 LGE实现可在https://github.com/qgallouedec/lge上作为开源。

与一组复杂的RL问题有关的目标条件加固学习（GCRL）训练代理在特定情况下实现不同的目标。与仅根据州或观察结果了解政策的标准RL解决方案相比，GCRL还要求代理商根据不同的目标做出决策。在这项调查中，我们对GCRL的挑战和算法进行了全面的概述。首先，我们回答该领域研究的基本问题。然后，我们解释了如何代表目标并介绍如何从不同角度设计现有解决方案。最后，我们得出结论，并讨论最近研究重点的潜在未来前景。

通过稀疏奖励的环境中的深度加强学习学习机器人操纵是一项具有挑战性的任务。在本文中，我们通过引入虚构对象目标的概念来解决这个问题。对于给定的操纵任务，首先通过物理逼真的模拟训练感兴趣的对象以达到自己的目标位置，而不会被操纵。然后利用对象策略来构建可编征物体轨迹的预测模型，该轨迹提供具有逐步更加困难的对象目标的机器人来达到训练期间的课程。所提出的算法，遵循对象（FO），已经在需要增加探索程度的7个Mujoco环境中进行评估，并且与替代算法相比，取得了更高的成功率。在特别具有挑战性的学习场景中，例如当物体的初始和目标位置相隔甚远，我们的方法仍然可以学习政策，而竞争方法目前失败。

Designing agents, capable of learning autonomously a wide range of skills is critical in order to increase the scope of reinforcement learning. It will both increase the diversity of learned skills and reduce the burden of manually designing reward functions for each skill. Self-supervised agents, setting their own goals, and trying to maximize the diversity of those goals have shown great promise towards this end. However, a currently known limitation of agents trying to maximize the diversity of sampled goals is that they tend to get attracted to noise or more generally to parts of the environments that cannot be controlled (distractors). When agents have access to predefined goal features or expert knowledge, absolute Learning Progress (ALP) provides a way to distinguish between regions that can be controlled and those that cannot. However, those methods often fall short when the agents are only provided with raw sensory inputs such as images. In this work we extend those concepts to unsupervised image-based goal exploration. We propose a framework that allows agents to autonomously identify and ignore noisy distracting regions while searching for novelty in the learnable regions to both improve overall performance and avoid catastrophic forgetting. Our framework can be combined with any state-of-the-art novelty seeking goal exploration approaches. We construct a rich 3D image based environment with distractors. Experiments on this environment show that agents using our framework successfully identify interesting regions of the environment, resulting in drastically improved performances. The source code is available at https://sites.google.com/view/grimgep.

While reinforcement learning algorithms provide automated acquisition of optimal policies, practical application of such methods requires a number of design decisions, such as manually designing reward functions that not only define the task, but also provide sufficient shaping to accomplish it. In this paper, we view reinforcement learning as inferring policies that achieve desired outcomes, rather than as a problem of maximizing rewards. To solve this inference problem, we establish a novel variational inference formulation that allows us to derive a well-shaped reward function which can be learned directly from environment interactions. From the corresponding variational objective, we also derive a new probabilistic Bellman backup operator and use it to develop an off-policy algorithm to solve goal-directed tasks. We empirically demonstrate that this method eliminates the need to hand-craft reward functions for a suite of diverse manipulation and locomotion tasks and leads to effective goal-directed behaviors.

我们介绍了课程学习算法，变分自动课程学习（VIVL），用于解决具有挑战性的目标条件的合作多功能增强学习问题。我们通过变分的角度激励我们的范式，其中学习目标可以分解为两种术语：任务学习当前任务分发以及新任务分发的课程更新。第二任期内的本地优化表明，课程应该逐步扩展培训任务，易于努力。我们的Vivl算法用两个实际组件，任务扩展和实体进展实现了这种变分的范例，它在任务配置以及任务中的实体数量产生培训课程。实验结果表明，Vacl解决了大量代理商的稀疏奖励问题的集合。特别是，使用单个桌面机器，VACL在简单扩展的基准测试中实现了100个代理的98％覆盖率，并再现最初在Openai隐藏项目中显示的斜坡使用行为。我们的项目网站位于https://sites.google.com/view/vacl-neurips-2021。

大自然的一个迷人方面在于它能够产生大型和多样化的生物体，这些生物都在他们的利基中都很高兴。相比之下，大多数AI算法专注于向给定问题找到一个有效的解决方案。除了表现外，旨在实现多样性是处理勘探开发权衡的便捷方式，在学习中发挥着核心作用。当返回的集合包含对所考虑的问题的几个工作解决方案时，它还允许增加鲁棒性，使其适用于机器人等真实应用。质量 - 多样性（QD）方法是为此目的设计的进化算法。本文提出了一种新颖的QD - PG，它结合了政策梯度算法的强度和质量多样性方法，在连续控制环境中产生了各种和高性能的神经政策的集合。这项工作的主要贡献是引入多样性政策梯度（DPG），该梯度（DPG）利用时刻级别的信息以采样有效的方式培养更多样化的策略。具体而言，QD-PG从地图 - E LITES网格中选择神经控制器，并使用两个基于梯度的突变运算符来提高质量和多样性，从而产生稳定的人口更新。我们的结果表明，QD - PG产生了各种解决方案的集合，解决了具有挑战性的勘探和控制问题，同时是比其进化竞争对手更高的样本效率的两个数量级。

深度强化学习（DRL）和深度多机构的强化学习（MARL）在包括游戏AI，自动驾驶汽车，机器人技术等各种领域取得了巨大的成功。但是，众所周知，DRL和Deep MARL代理的样本效率低下，即使对于相对简单的问题设置，通常也需要数百万个相互作用，从而阻止了在实地场景中的广泛应用和部署。背后的一个瓶颈挑战是众所周知的探索问题，即如何有效地探索环境和收集信息丰富的经验，从而使政策学习受益于最佳研究。在稀疏的奖励，吵闹的干扰，长距离和非平稳的共同学习者的复杂环境中，这个问题变得更加具有挑战性。在本文中，我们对单格和多代理RL的现有勘探方法进行了全面的调查。我们通过确定有效探索的几个关键挑战开始调查。除了上述两个主要分支外，我们还包括其他具有不同思想和技术的著名探索方法。除了算法分析外，我们还对一组常用基准的DRL进行了全面和统一的经验比较。根据我们的算法和实证研究，我们终于总结了DRL和Deep Marl中探索的公开问题，并指出了一些未来的方向。

When searching for policies, reward-sparse environments often lack sufficient information about which behaviors to improve upon or avoid. In such environments, the policy search process is bound to blindly search for reward-yielding transitions and no early reward can bias this search in one direction or another. A way to overcome this is to use intrinsic motivation in order to explore new transitions until a reward is found. In this work, we use a recently proposed definition of intrinsic motivation, Curiosity, in an evolutionary policy search method. We propose Curiosity-ES, an evolutionary strategy adapted to use Curiosity as a fitness metric. We compare Curiosity with Novelty, a commonly used diversity metric, and find that Curiosity can generate higher diversity over full episodes without the need for an explicit diversity criterion and lead to multiple policies which find reward.

代理商学习广泛适用和通用策略具有重要意义，可以实现包括图像和文本描述在内的各种目标。考虑到这类感知的目标，深度加强学习研究的前沿是学习一个没有手工制作奖励的目标条件政策。要了解这种政策，最近的作品通常会像奖励到明确的嵌入空间中的给定目标的非参数距离。从不同的观点来看，我们提出了一种新的无监督学习方法，名为目标条件政策，具有内在动机（GPIM），共同学习抽象级别政策和目标条件的政策。摘要级别策略在潜在变量上被调节，以优化鉴别器，并发现进一步的不同状态，进一步呈现为目标条件策略的感知特定目标。学习鉴别者作为目标条件策略的内在奖励功能，以模仿抽象级别政策引起的轨迹。各种机器人任务的实验证明了我们所提出的GPIM方法的有效性和效率，其基本上优于现有技术。

Go-Explore achieved breakthrough performance on challenging reinforcement learning (RL) tasks with sparse rewards. The key insight of Go-Explore was that successful exploration requires an agent to first return to an interesting state ('Go'), and only then explore into unknown terrain ('Explore'). We refer to such exploration after a goal is reached as 'post-exploration'. In this paper, we present a clear ablation study of post-exploration in a general intrinsically motivated goal exploration process (IMGEP) framework, that the Go-Explore paper did not show. We study the isolated potential of post-exploration, by turning it on and off within the same algorithm under both tabular and deep RL settings on both discrete navigation and continuous control tasks. Experiments on a range of MiniGrid and Mujoco environments show that post-exploration indeed helps IMGEP agents reach more diverse states and boosts their performance. In short, our work suggests that RL researchers should consider to use post-exploration in IMGEP when possible since it is effective, method-agnostic and easy to implement.

通过互动学习复杂的机器人行为需要结构化探索。规划应瞄准与优化长期绩效的潜力的相互作用，同时只减少有利于这一目标的不确定性。本文提出了潜在的乐观价值探索（爱），这一战略在面对不确定的长期奖励面前通过乐观探索能够深入探索。我们将潜在的世界模型与价值函数估计相结合以预测无限地平线返回并通过合并恢复相关的不确定性。然后，该政策培训了上束缚（UCB）目标，以确定和选择最有希望改善长期绩效的交互。我们在连续动作空间中应用了视觉机器人控制任务，并且与最先进的和其他探索目标相比，平均提高了样品效率的平均提高了20％以上。在稀疏和难以探索环境中，我们实现了超过30％的平均改善。

Meta-Renifiltive学习（Meta-RL）已被证明是利用事先任务的经验，以便快速学习新的相关任务的成功框架，但是，当前的Meta-RL接近在稀疏奖励环境中学习的斗争。尽管现有的Meta-RL算法可以学习适应新的稀疏奖励任务的策略，但是使用手形奖励功能来学习实际适应策略，或者需要简单的环境，其中随机探索足以遇到稀疏奖励。在本文中，我们提出了对Meta-RL的后视抢购的制定，该rl抢购了在Meta培训期间的经验，以便能够使用稀疏奖励完全学习。我们展示了我们的方法在套件挑战稀疏奖励目标达到的环境中，以前需要密集的奖励，以便在Meta训练中解决。我们的方法使用真正的稀疏奖励功能来解决这些环境，性能与具有代理密集奖励功能的培训相当。

Hierarchical Reinforcement Learning (HRL) algorithms have been demonstrated to perform well on high-dimensional decision making and robotic control tasks. However, because they solely optimize for rewards, the agent tends to search the same space redundantly. This problem reduces the speed of learning and achieved reward. In this work, we present an Off-Policy HRL algorithm that maximizes entropy for efficient exploration. The algorithm learns a temporally abstracted low-level policy and is able to explore broadly through the addition of entropy to the high-level. The novelty of this work is the theoretical motivation of adding entropy to the RL objective in the HRL setting. We empirically show that the entropy can be added to both levels if the Kullback-Leibler (KL) divergence between consecutive updates of the low-level policy is sufficiently small. We performed an ablative study to analyze the effects of entropy on hierarchy, in which adding entropy to high-level emerged as the most desirable configuration. Furthermore, a higher temperature in the low-level leads to Q-value overestimation and increases the stochasticity of the environment that the high-level operates on, making learning more challenging. Our method, SHIRO, surpasses state-of-the-art performance on a range of simulated robotic control benchmark tasks and requires minimal tuning.

Given a particular embodiment, we propose a novel method (C3PO) that learns policies able to achieve any arbitrary position and pose. Such a policy would allow for easier control, and would be re-useable as a key building block for downstream tasks. The method is two-fold: First, we introduce a novel exploration algorithm that optimizes for uniform coverage, is able to discover a set of achievable states, and investigates its abilities in attaining both high coverage, and hard-to-discover states; Second, we leverage this set of achievable states as training data for a universal goal-achievement policy, a goal-based SAC variant. We demonstrate the trained policy's performance in achieving a large number of novel states. Finally, we showcase the influence of massive unsupervised training of a goal-achievement policy with state-of-the-art pose-based control of the Hopper, Walker, Halfcheetah, Humanoid and Ant embodiments.

We propose a method for learning expressive energy-based policies for continuous states and actions, which has been feasible only in tabular domains before. We apply our method to learning maximum entropy policies, resulting into a new algorithm, called soft Q-learning, that expresses the optimal policy via a Boltzmann distribution. We use the recently proposed amortized Stein variational gradient descent to learn a stochastic sampling network that approximates samples from this distribution. The benefits of the proposed algorithm include improved exploration and compositionality that allows transferring skills between tasks, which we confirm in simulated experiments with swimming and walking robots. We also draw a connection to actorcritic methods, which can be viewed performing approximate inference on the corresponding energy-based model.

强化学习（RL）代理商可以通过与环境进行交互来学习解决复杂的顺序决策任务。但是，样品效率仍然是一个重大挑战。在多目标RL领域中，需要代理以达到多个目标来解决复杂任务，提高采样效率可能尤其具有挑战性。另一方面，人类或其他生物代理商以更具战略方式学习此类任务，遵循随着难度水平的增加，以便逐步高效的学习进步。在这项工作中，我们提出了一种以自我监督方式使用动态距离功能（DDF）的自动目标生成方法。 DDF是一种函数，它预测马尔可夫决策过程（MDP）内的任何两个状态之间的动态距离。有了这个，我们在适当的难度水平下生成一个目标课程，以便在整个培训过程中有效地学习。我们在几个目标条件的机器人操纵和导航任务中评估这种方法，并在基线方法上显示出样本效率的改进，该方法仅使用随机目标采样。