We study the use of model-based reinforcement learning methods, in particular, world models for continual reinforcement learning. In continual reinforcement learning, an agent is required to solve one task and then another sequentially while retaining performance and preventing forgetting on past tasks. World models offer a task-agnostic solution: they do not require knowledge of task changes. World models are a straight-forward baseline for continual reinforcement learning for three main reasons. Firstly, forgetting in the world model is prevented by persisting existing experience replay buffers across tasks, experience from previous tasks is replayed for learning the world model. Secondly, they are sample efficient. Thirdly and finally, they offer a task-agnostic exploration strategy through the uncertainty in the trajectories generated by the world model. We show that world models are a simple and effective continual reinforcement learning baseline. We study their effectiveness on Minigrid and Minihack continual reinforcement learning benchmarks and show that it outperforms state of the art task-agnostic continual reinforcement learning methods.

我们研究了任务不合时宜的持续强化学习方法（tACRL）。 TACRL是一种结合了部分观察RL（任务不可知论的结果）和持续学习的困难（CL）的困难，即在任务的非平稳序列上学习。我们将tACRL方法与以前文献规定的软上限进行比较：多任务学习（MTL）方法，这些方法不必处理非平稳数据分布以及任务感知方法，这些方法可以在完整的情况下进行操作可观察性。我们考虑了先前未开发的基线，用于基于重播的复发性RL（3RL），其中我们增强了具有复发机制的RL算法，以减轻部分可观察性和经验经验的重播机制，以使CL中的灾难性遗忘。通过研究一系列RL任务的经验性能，我们发现3RL匹配并克服MTL和任务感知的软上限的情况令人惊讶。我们提出假设，可以解释不断的和任务不足学习研究的这个拐点。通过对流行的多任务和持续学习基准元世界的大规模研究，我们的假设在连续控制任务中进行了经验检验。通过分析包括梯度冲突在内的不同培训统计数据，我们发现证据表明3RL的表现超出其能够快速推断新任务与以前的任务的关系，从而实现前进的转移。

Progress in continual reinforcement learning has been limited due to several barriers to entry: missing code, high compute requirements, and a lack of suitable benchmarks. In this work, we present CORA, a platform for Continual Reinforcement Learning Agents that provides benchmarks, baselines, and metrics in a single code package. The benchmarks we provide are designed to evaluate different aspects of the continual RL challenge, such as catastrophic forgetting, plasticity, ability to generalize, and sample-efficient learning. Three of the benchmarks utilize video game environments (Atari, Procgen, NetHack). The fourth benchmark, CHORES, consists of four different task sequences in a visually realistic home simulator, drawn from a diverse set of task and scene parameters. To compare continual RL methods on these benchmarks, we prepare three metrics in CORA: Continual Evaluation, Isolated Forgetting, and Zero-Shot Forward Transfer. Finally, CORA includes a set of performant, open-source baselines of existing algorithms for researchers to use and expand on. We release CORA and hope that the continual RL community can benefit from our contributions, to accelerate the development of new continual RL algorithms.

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。

The ability for an agent to continuously learn new skills without catastrophically forgetting existing knowledge is of critical importance for the development of generally intelligent agents. Most methods devised to address this problem depend heavily on well-defined task boundaries, and thus depend on human supervision. Our task-agnostic method, Self-Activating Neural Ensembles (SANE), uses a modular architecture designed to avoid catastrophic forgetting without making any such assumptions. At the beginning of each trajectory, a module in the SANE ensemble is activated to determine the agent's next policy. During training, new modules are created as needed and only activated modules are updated to ensure that unused modules remain unchanged. This system enables our method to retain and leverage old skills, while growing and learning new ones. We demonstrate our approach on visually rich procedurally generated environments.

In multi-agent reinforcement learning (MARL), many popular methods, such as VDN and QMIX, are susceptible to a critical multi-agent pathology known as relative overgeneralization (RO), which arises when the optimal joint action's utility falls below that of a sub-optimal joint action in cooperative tasks. RO can cause the agents to get stuck into local optima or fail to solve tasks that require significant coordination between agents within a given timestep. Recent value-based MARL algorithms such as QPLEX and WQMIX can overcome RO to some extent. However, our experimental results show that they can still fail to solve cooperative tasks that exhibit strong RO. In this work, we propose a novel approach called curriculum learning for relative overgeneralization (CURO) to better overcome RO. To solve a target task that exhibits strong RO, in CURO, we first fine-tune the reward function of the target task to generate source tasks that are tailored to the current ability of the learning agent and train the agent on these source tasks first. Then, to effectively transfer the knowledge acquired in one task to the next, we use a novel transfer learning method that combines value function transfer with buffer transfer, which enables more efficient exploration in the target task. We demonstrate that, when applied to QMIX, CURO overcomes severe RO problem and significantly improves performance, yielding state-of-the-art results in a variety of cooperative multi-agent tasks, including the challenging StarCraft II micromanagement benchmarks.

在终生学习中，代理人在整个生命中都在不重复的一生中学习，就像人类一样，在不断变化的环境中。因此，终身学习带来了许多研究问题，例如连续领域的转移，这导致了非平稳的奖励和环境动态。由于其连续的性质，这些非平稳性很难检测和应对。因此，需要探索策略和学习方法，这些方法能够跟踪稳定的领域变化并适应它们。我们提出反应性探索，以跟踪和反应终生增强学习中持续的域转移，并相应地更新策略。为此，我们进行实验以研究不同的勘探策略。我们从经验上表明，政策阶级家族的代表更适合终身学习，因为它们比Q学习更快地适应了分销的变化。因此，政策梯度方法从反应性探索中获利最大，并在终身学习中显示出良好的结果，并进行了持续的领域变化。我们的代码可在以下网址提供：https：//github.com/ml-jku/reactive-ecploration。

文本冒险游戏由于其组合大的动作空间和稀疏奖励而导致加强学习方法具有独特的挑战。这两个因素的相互作用尤为苛刻，因为大型动作空间需要广泛的探索，而稀疏奖励提供有限的反馈。这项工作提出使用多级方法来解决探索 - 与利用困境，该方法明确地解除了每一集中的这两种策略。我们的算法称为Exploit-Dear-Descore（XTX），使用剥削策略开始每个剧集，该策略是从过去的一组有希望的轨迹开始，然后切换到旨在发现导致未经看不见状态空间的新动作的探索政策。该政策分解允许我们将全球决策结合在该空间中返回基于好奇的本地探索的全球决策，这是由人类可能接近这些游戏的情况。我们的方法在杰里科基准（Hausknecht等人，2020）中，在杰里科基准（Hausknecht等人，2020）中，在确定性和随机设置的比赛中显着优于27％和11％的平均正常化分数。在Zork1的游戏中，特别是，XTX获得103的得分，超过先前方法的2倍改善，并且在游戏中推过已经困扰先前的方法的游戏中的几个已知的瓶颈。

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。

深度神经网络的强大学习能力使强化学习者能够直接从连续环境中学习有效的控制政策。从理论上讲，为了实现稳定的性能，神经网络假设I.I.D.不幸的是，在训练数据在时间上相关且非平稳的一般强化学习范式中，输入不存在。这个问题可能导致“灾难性干扰”和性能崩溃的现象。在本文中，我们提出智商，即干涉意识深度Q学习，以减轻单任务深度加固学习中的灾难性干扰。具体来说，我们求助于在线聚类，以实现在线上下文部门，以及一个多头网络和一个知识蒸馏正规化术语，用于保留学习上下文的政策。与现有方法相比，智商基于深Q网络，始终如一地提高稳定性和性能，并通过对经典控制和ATARI任务进行了广泛的实验。该代码可在以下网址公开获取：https：//github.com/sweety-dm/interference-aware-ware-deep-q-learning。

Lifelong learning aims to create AI systems that continuously and incrementally learn during a lifetime, similar to biological learning. Attempts so far have met problems, including catastrophic forgetting, interference among tasks, and the inability to exploit previous knowledge. While considerable research has focused on learning multiple input distributions, typically in classification, lifelong reinforcement learning (LRL) must also deal with variations in the state and transition distributions, and in the reward functions. Modulating masks, recently developed for classification, are particularly suitable to deal with such a large spectrum of task variations. In this paper, we adapted modulating masks to work with deep LRL, specifically PPO and IMPALA agents. The comparison with LRL baselines in both discrete and continuous RL tasks shows competitive performance. We further investigated the use of a linear combination of previously learned masks to exploit previous knowledge when learning new tasks: not only is learning faster, the algorithm solves tasks that we could not otherwise solve from scratch due to extremely sparse rewards. The results suggest that RL with modulating masks is a promising approach to lifelong learning, to the composition of knowledge to learn increasingly complex tasks, and to knowledge reuse for efficient and faster learning.

应对深层终身强化学习（LRL）挑战的一种方法是仔细管理代理商的学习经验，以学习（不忘记）并建立内部元模型（任务，环境，代理商和世界）。生成重播（GR）是一种以生物学启发的重播机制，可以通过从内部生成模型中绘制的自标记示例来增强学习经验，该模型随着时间的推移而更新。在本文中，我们提出了一个满足两个Desiderata的GR版本：（a）使用深RL学习的策略的潜在策略的内省密度建模，以及（b）无模型的端到端学习。在这项工作中，我们研究了三个无模型GR的深度学习体系结构。我们在三种不同的情况下评估了我们提出的算法，其中包括来自Starcraft2和Minigrid域的任务。我们报告了几个关键发现，显示了设计选择对定量指标的影响，包括转移学习，对看不见的任务的概括，任务更改后的快速适应，与任务专家相当的绩效以及最小化灾难性遗忘。我们观察到我们的GR可以防止从深层批评剂的潜在矢量空间中的特征映射中漂移。我们还显示了既定的终身学习指标的改进。我们发现，当与重播缓冲液和生成的重播缓冲液结合使用时，需要引入一个小的随机重放缓冲液，以显着提高训练的稳定性。总体而言，我们发现“隐藏的重播”（一种众所周知的班级入学分类体系结构）是最有前途的方法，它推动了LRL的GR中最新的方法。

Interacting with a complex world involves continual learning, in which tasks and data distributions change over time. A continual learning system should demonstrate both plasticity (acquisition of new knowledge) and stability (preservation of old knowledge). Catastrophic forgetting is the failure of stability, in which new experience overwrites previous experience. In the brain, replay of past experience is widely believed to reduce forgetting, yet it has been largely overlooked as a solution to forgetting in deep reinforcement learning. Here, we introduce CLEAR, a replay-based method that greatly reduces catastrophic forgetting in multi-task reinforcement learning. CLEAR leverages off-policy learning and behavioral cloning from replay to enhance stability, as well as on-policy learning to preserve plasticity. We show that CLEAR performs better than state-of-the-art deep learning techniques for mitigating forgetting, despite being significantly less complicated and not requiring any knowledge of the individual tasks being learned.

稀疏奖励学习通常在加强学习（RL）方面效率低下。 Hindsight Experience重播（她）已显示出一种有效的解决方案，可以处理低样本效率，这是由于目标重新标记而导致的稀疏奖励效率。但是，她仍然有一个隐含的虚拟阳性稀疏奖励问题，这是由于实现目标而引起的，尤其是对于机器人操纵任务而言。为了解决这个问题，我们提出了一种新型的无模型连续RL算法，称为Relay-HER（RHER）。提出的方法首先分解并重新布置原始的长马任务，以增量复杂性为新的子任务。随后，多任务网络旨在以复杂性的上升顺序学习子任务。为了解决虚拟阳性的稀疏奖励问题，我们提出了一种随机混合的探索策略（RME），在该策略中，在复杂性较低的人的指导下，较高复杂性的子任务的实现目标很快就会改变。实验结果表明，在五个典型的机器人操纵任务中，与香草盖相比，RHER样品效率的显着提高，包括Push，Pickandplace，抽屉，插入物和InstaclePush。提出的RHER方法还应用于从头开始的物理机器人上的接触式推送任务，成功率仅使用250集达到10/10。

As Artificial and Robotic Systems are increasingly deployed and relied upon for real-world applications, it is important that they exhibit the ability to continually learn and adapt in dynamically-changing environments, becoming Lifelong Learning Machines. Continual/lifelong learning (LL) involves minimizing catastrophic forgetting of old tasks while maximizing a model's capability to learn new tasks. This paper addresses the challenging lifelong reinforcement learning (L2RL) setting. Pushing the state-of-the-art forward in L2RL and making L2RL useful for practical applications requires more than developing individual L2RL algorithms; it requires making progress at the systems-level, especially research into the non-trivial problem of how to integrate multiple L2RL algorithms into a common framework. In this paper, we introduce the Lifelong Reinforcement Learning Components Framework (L2RLCF), which standardizes L2RL systems and assimilates different continual learning components (each addressing different aspects of the lifelong learning problem) into a unified system. As an instantiation of L2RLCF, we develop a standard API allowing easy integration of novel lifelong learning components. We describe a case study that demonstrates how multiple independently-developed LL components can be integrated into a single realized system. We also introduce an evaluation environment in order to measure the effect of combining various system components. Our evaluation environment employs different LL scenarios (sequences of tasks) consisting of Starcraft-2 minigames and allows for the fair, comprehensive, and quantitative comparison of different combinations of components within a challenging common evaluation environment.

Deep reinforcement learning algorithms require large amounts of experience to learn an individual task. While in principle meta-reinforcement learning (meta-RL) algorithms enable agents to learn new skills from small amounts of experience, several major challenges preclude their practicality. Current methods rely heavily on on-policy experience, limiting their sample efficiency. The also lack mechanisms to reason about task uncertainty when adapting to new tasks, limiting their effectiveness in sparse reward problems. In this paper, we address these challenges by developing an offpolicy meta-RL algorithm that disentangles task inference and control. In our approach, we perform online probabilistic filtering of latent task variables to infer how to solve a new task from small amounts of experience. This probabilistic interpretation enables posterior sampling for structured and efficient exploration. We demonstrate how to integrate these task variables with off-policy RL algorithms to achieve both metatraining and adaptation efficiency. Our method outperforms prior algorithms in sample efficiency by 20-100X as well as in asymptotic performance on several meta-RL benchmarks.

机器人将在整个生命周期中都会经历非平稳环境动态：机器人动态可能会因磨损而改变，或者周围的环境可能会随着时间而改变。最终，机器人在遇到的所有环境变化中都应表现良好。同时，它仍然应该能够在新环境中快速学习。我们在这样的终身学习环境中确定了强化学习（RL）的两个挑战：首先，现有的现有非政策算法在保持旧环境中保持良好绩效和有效学习之间的权衡方面挣扎尽管将所有数据保留在重播缓冲区中，但新环境。我们提出了离线蒸馏管道，以通过将培训程序分离为在线互动阶段和离线蒸馏阶段来打破这一权衡。第二，我们发现，通过从一生中多个环境中的不平衡的非政策数据进行培训会产生重要性能下降。我们确定这种性能下降是由数据集中质量不平衡和大小的组合引起的，这些质量和大小加剧了Q功能的外推误差。在蒸馏阶段，我们通过使策略更接近生成数据的行为策略来应用一个简单的解决方案。在实验中，我们在各种环境变化中通过模拟的两足机器人步行任务证明了这两个挑战和拟议的解决方案。我们表明，离线蒸馏管线在所有遇到的环境中都能取得更好的性能，而不会影响数据收集。我们还提供了一项全面的实证研究，以支持我们对数据不平衡问题的假设。

任务 - 无人探索的常见方法学习塔杜拉 - RASA - 代理商假设隔离环境，没有先验的知识或经验。然而，在现实世界中，代理商在许多环境中学习，并且随着他们探索新的环境，始终伴随着事先经验。探索是一场终身的过程。在本文中，我们提出了对任务无关探索的制定和评估的范式变迁。在此设置中，代理首先学会在许多环境中探索，没有任何外在目标的任务不可行的方式。后来，代理商有效地传输了学习探索政策，以便在解决任务时更好地探索新环境。在这方面，我们评估了几种基线勘探战略，并提出了一种简单但有效的学习任务无关探索政策方法。我们的主要思想是，有两种勘探组成部分：（1）基于代理人的信仰，促进探索探索环境的经验主义部分; （2）以环境为中心的组件，鼓励探索固有的有趣物体。我们表明我们的配方是有效的，并提供多种训练测试环境对的最一致的探索。我们还介绍了评估任务无关勘探策略的基准和指标。源代码在https://github.com/sparisi/cbet/处获得。

持续学习系统将知识从先前看到的任务转移以最大程度地提高新任务的能力是该领域的重大挑战，从而限制了持续学习解决方案对现实情况的适用性。因此，本研究旨在扩大我们在不断加强学习的特定情况下对转移及其驱动力的理解。我们采用SAC作为基础RL算法和持续的世界作为连续控制任务的套件。我们系统地研究SAC（演员和评论家，勘探和数据）的不同组成部分如何影响转移功效，并提供有关各种建模选项的建议。在最近的连续世界基准中评估了最佳的选择，即称为clonex-sac。 Clonex-SAC获得了87％的最终成功率，而Packnet的80％是基准中的最佳方法。此外，根据连续世界提供的指标，转移从0.18增至0.54。

从视觉感觉数据中控制人造代理是一项艰巨的任务。强化学习（RL）算法可以在这方面取得成功，但需要代理与环境之间进行大量相互作用。为了减轻该问题，无监督的RL建议采用自我监督的互动和学习，以更快地适应未来的任务。但是，目前的无监督策略是否可以改善概括能力，尤其是在视觉控制设置中。在这项工作中，我们为数据有效的视觉控制设计了有效的无监督RL策略。首先，我们表明，使用无监督的RL收集的数据预先训练的世界模型可以促进适应未来的任务。然后，我们与我们的混合计划者分析了一些设计选择，以有效地适应了代理的预训练组件，并在想象中学习和计划，并与我们的混合计划者一起使用，我们将其dub dyna-mpc进行了。通过结合一项大规模实证研究的发现，我们建立了一种方法，该方法强烈改善了无监督的RL基准测试的性能，需要20美元$ \ times $ $ $ $ $ \少于数据以符合监督方法的性能。该方法还表明了在现实词的RL基准测试上的稳健性能，暗示该方法概括为嘈杂的环境。