Search and Rescue (SAR) missions in remote environments often employ autonomous multi-robot systems that learn, plan, and execute a combination of local single-robot control actions, group primitives, and global mission-oriented coordination and collaboration. Often, SAR coordination strategies are manually designed by human experts who can remotely control the multi-robot system and enable semi-autonomous operations. However, in remote environments where connectivity is limited and human intervention is often not possible, decentralized collaboration strategies are needed for fully-autonomous operations. Nevertheless, decentralized coordination may be ineffective in adversarial environments due to sensor noise, actuation faults, or manipulation of inter-agent communication data. In this paper, we propose an algorithmic approach based on adversarial multi-agent reinforcement learning (MARL) that allows robots to efficiently coordinate their strategies in the presence of adversarial inter-agent communications. In our setup, the objective of the multi-robot team is to discover targets strategically in an obstacle-strewn geographical area by minimizing the average time needed to find the targets. It is assumed that the robots have no prior knowledge of the target locations, and they can interact with only a subset of neighboring robots at any time. Based on the centralized training with decentralized execution (CTDE) paradigm in MARL, we utilize a hierarchical meta-learning framework to learn dynamic team-coordination modalities and discover emergent team behavior under complex cooperative-competitive scenarios. The effectiveness of our approach is demonstrated on a collection of prototype grid-world environments with different specifications of benign and adversarial agents, target locations, and agent rewards.

Modern multi-agent reinforcement learning frameworks rely on centralized training and reward shaping to perform well. However, centralized training and dense rewards are not readily available in the real world. Current multi-agent algorithms struggle to learn in the alternative setup of decentralized training or sparse rewards. To address these issues, we propose a self-supervised intrinsic reward ELIGN - expectation alignment - inspired by the self-organization principle in Zoology. Similar to how animals collaborate in a decentralized manner with those in their vicinity, agents trained with expectation alignment learn behaviors that match their neighbors' expectations. This allows the agents to learn collaborative behaviors without any external reward or centralized training. We demonstrate the efficacy of our approach across 6 tasks in the multi-agent particle and the complex Google Research football environments, comparing ELIGN to sparse and curiosity-based intrinsic rewards. When the number of agents increases, ELIGN scales well in all multi-agent tasks except for one where agents have different capabilities. We show that agent coordination improves through expectation alignment because agents learn to divide tasks amongst themselves, break coordination symmetries, and confuse adversaries. These results identify tasks where expectation alignment is a more useful strategy than curiosity-driven exploration for multi-agent coordination, enabling agents to do zero-shot coordination.

政策梯度方法在多智能体增强学习中变得流行，但由于存在环境随机性和探索代理（即非公平性​​），它们遭受了高度的差异，这可能因信用分配难度而受到困扰。结果，需要一种方法，该方法不仅能够有效地解决上述两个问题，而且需要足够强大地解决各种任务。为此，我们提出了一种新的多代理政策梯度方法，称为强大的本地优势（ROLA）演员 - 评论家。 Rola允许每个代理人将个人动作值函数作为当地评论家，以及通过基于集中评论家的新型集中培训方法来改善环境不良。通过使用此本地批评，每个代理都计算基准，以减少对其策略梯度估计的差异，这导致含有其他代理的预期优势动作值，这些选项可以隐式提高信用分配。我们在各种基准测试中评估ROLA，并在许多最先进的多代理政策梯度算法上显示其鲁棒性和有效性。

最先进的多机构增强学习（MARL）方法为各种复杂问题提供了有希望的解决方案。然而，这些方法都假定代理执行同步的原始操作执行，因此它们不能真正可扩展到长期胜利的真实世界多代理/机器人任务，这些任务固有地要求代理/机器人以异步的理由，涉及有关高级动作选择的理由。不同的时间。宏观行动分散的部分可观察到的马尔可夫决策过程（MACDEC-POMDP）是在完全合作的多代理任务中不确定的异步决策的一般形式化。在本论文中，我们首先提出了MacDec-Pomdps的一组基于价值的RL方法，其中允许代理在三个范式中使用宏观成果功能执行异步学习和决策：分散学习和控制，集中学习，集中学习和控制，以及分散执行的集中培训（CTDE）。在上述工作的基础上，我们在三个训练范式下制定了一组基于宏观行动的策略梯度算法，在该训练范式下，允许代理以异步方式直接优化其参数化策略。我们在模拟和真实的机器人中评估了我们的方法。经验结果证明了我们在大型多代理问题中的方法的优势，并验证了我们算法在学习具有宏观actions的高质量和异步溶液方面的有效性。

Cooperative multi-agent reinforcement learning (MARL) has achieved significant results, most notably by leveraging the representation-learning abilities of deep neural networks. However, large centralized approaches quickly become infeasible as the number of agents scale, and fully decentralized approaches can miss important opportunities for information sharing and coordination. Furthermore, not all agents are equal -- in some cases, individual agents may not even have the ability to send communication to other agents or explicitly model other agents. This paper considers the case where there is a single, powerful, \emph{central agent} that can observe the entire observation space, and there are multiple, low-powered \emph{local agents} that can only receive local observations and are not able to communicate with each other. The central agent's job is to learn what message needs to be sent to different local agents based on the global observations, not by centrally solving the entire problem and sending action commands, but by determining what additional information an individual agent should receive so that it can make a better decision. In this work we present our MARL algorithm \algo, describe where it would be most applicable, and implement it in the cooperative navigation and multi-agent walker domains. Empirical results show that 1) learned communication does indeed improve system performance, 2) results generalize to heterogeneous local agents, and 3) results generalize to different reward structures.

Reinforcement learning in multi-agent scenarios is important for real-world applications but presents challenges beyond those seen in singleagent settings. We present an actor-critic algorithm that trains decentralized policies in multiagent settings, using centrally computed critics that share an attention mechanism which selects relevant information for each agent at every timestep. This attention mechanism enables more effective and scalable learning in complex multiagent environments, when compared to recent approaches. Our approach is applicable not only to cooperative settings with shared rewards, but also individualized reward settings, including adversarial settings, as well as settings that do not provide global states, and it makes no assumptions about the action spaces of the agents. As such, it is flexible enough to be applied to most multi-agent learning problems.

多代理深入的强化学习已应用于解决各种离散或连续动作空间的各种复杂问题，并取得了巨大的成功。但是，大多数实际环境不能仅通过离散的动作空间或连续的动作空间来描述。而且很少有作品曾经利用深入的加固学习（DRL）来解决混合动作空间的多代理问题。因此，我们提出了一种新颖的算法：深层混合软性角色 - 批评（MAHSAC）来填补这一空白。该算法遵循集中式训练但分散执行（CTDE）范式，并扩展软actor-Critic算法（SAC），以根据最大熵在多机构环境中处理混合动作空间问题。我们的经验在一个简单的多代理粒子世界上运行，具有连续的观察和离散的动作空间以及一些基本的模拟物理。实验结果表明，MAHSAC在训练速度，稳定性和抗干扰能力方面具有良好的性能。同时，它在合作场景和竞争性场景中胜过现有的独立深层学习方法。

许多现实世界的应用程序都可以作为多机构合作问题进行配置，例如网络数据包路由和自动驾驶汽车的协调。深入增强学习（DRL）的出现为通过代理和环境的相互作用提供了一种有前途的多代理合作方法。但是，在政策搜索过程中，传统的DRL解决方案遭受了多个代理具有连续动作空间的高维度。此外，代理商政策的动态性使训练非平稳。为了解决这些问题，我们建议采用高级决策和低水平的个人控制，以进行有效的政策搜索，提出一种分层增强学习方法。特别是，可以在高级离散的动作空间中有效地学习多个代理的合作。同时，低水平的个人控制可以减少为单格强化学习。除了分层增强学习外，我们还建议对手建模网络在学习过程中对其他代理的政策进行建模。与端到端的DRL方法相反，我们的方法通过以层次结构将整体任务分解为子任务来降低学习的复杂性。为了评估我们的方法的效率，我们在合作车道变更方案中进行了现实世界中的案例研究。模拟和现实世界实验都表明我们的方法在碰撞速度和收敛速度中的优越性。

We explore deep reinforcement learning methods for multi-agent domains. We begin by analyzing the difficulty of traditional algorithms in the multi-agent case: Q-learning is challenged by an inherent non-stationarity of the environment, while policy gradient suffers from a variance that increases as the number of agents grows. We then present an adaptation of actor-critic methods that considers action policies of other agents and is able to successfully learn policies that require complex multiagent coordination. Additionally, we introduce a training regimen utilizing an ensemble of policies for each agent that leads to more robust multi-agent policies. We show the strength of our approach compared to existing methods in cooperative as well as competitive scenarios, where agent populations are able to discover various physical and informational coordination strategies.

我们开发了一个多功能辅助救援学习（MARL）方法，以了解目标跟踪的可扩展控制策略。我们的方法可以处理任意数量的追求者和目标;我们显示出现的任务，该任务包括高达1000追踪跟踪1000个目标。我们使用分散的部分可观察的马尔可夫决策过程框架来模拟追求者作为接受偏见观察（范围和轴承）的代理，了解使用固定的未知政策的目标。注意机制用于参数化代理的价值函数;这种机制允许我们处理任意数量的目标。熵 - 正规的脱助政策RL方法用于培训随机政策，我们讨论如何在追求者之间实现对冲行为，尽管有完全分散的控制执行，但仍然导致合作较弱的合作形式。我们进一步开发了一个掩蔽启发式，允许训练较少的问题，少量追求目标和在更大的问题上执行。进行彻底的仿真实验，消融研究和对现有技术算法的比较，以研究对不同数量的代理和目标性能的方法和鲁棒性的可扩展性。

在现实设置中跨多个代理的决策同步是有问题的，因为它要求代理等待其他代理人终止和交流有关终止的终止。理想情况下，代理应该学习和执行异步。这样的异步方法还允许暂时扩展的动作，这些操作可能会根据执行的情况和操作花费不同的时间。不幸的是，当前的策略梯度方法不适用于异步设置，因为他们认为代理在每个时间步骤中都同步推理了动作选择。为了允许异步学习和决策，我们制定了一组异步的多代理参与者 - 批判性方法，这些方法使代理可以在三个标准培训范式中直接优化异步策略：分散的学习，集中学习，集中学习和集中培训以进行分解执行。各种现实域中的经验结果（在模拟和硬件中）证明了我们在大型多代理问题中的优势，并验证了我们算法在学习高质量和异步解决方案方面的有效性。

This work considers the problem of learning cooperative policies in complex, partially observable domains without explicit communication. We extend three classes of single-agent deep reinforcement learning algorithms based on policy gradient, temporal-difference error, and actor-critic methods to cooperative multi-agent systems. We introduce a set of cooperative control tasks that includes tasks with discrete and continuous actions, as well as tasks that involve hundreds of agents. The three approaches are evaluated against each other using different neural architectures, training procedures, and reward structures. Using deep reinforcement learning with a curriculum learning scheme, our approach can solve problems that were previously considered intractable by most multi-agent reinforcement learning algorithms. We show that policy gradient methods tend to outperform both temporal-difference and actor-critic methods when using feed-forward neural architectures. We also show that recurrent policies, while more difficult to train, outperform feed-forward policies on our evaluation tasks.

流动性和流量的许多方案都涉及多种不同的代理，需要合作以找到共同解决方案。行为计划的最新进展使用强化学习以寻找有效和绩效行为策略。但是，随着自动驾驶汽车和车辆对X通信变得越来越成熟，只有使用单身独立代理的解决方案在道路上留下了潜在的性能增长。多代理增强学习（MARL）是一个研究领域，旨在为彼此相互作用的多种代理找到最佳解决方案。这项工作旨在将该领域的概述介绍给研究人员的自主行动能力。我们首先解释Marl并介绍重要的概念。然后，我们讨论基于Marl算法的主要范式，并概述每个范式中最先进的方法和思想。在这种背景下，我们调查了MAL在自动移动性场景中的应用程序，并概述了现有的场景和实现。

将深度强化学习（DRL）扩展到多代理领域的研究已经解决了许多复杂的问题，并取得了重大成就。但是，几乎所有这些研究都只关注离散或连续的动作空间，而且很少有作品曾经使用过多代理的深度强化学习来实现现实世界中的环境问题，这些问题主要具有混合动作空间。因此，在本文中，我们提出了两种算法：深层混合软性角色批评（MAHSAC）和多代理混合杂种深层确定性政策梯度（MAHDDPG）来填补这一空白。这两种算法遵循集中式培训和分散执行（CTDE）范式，并可以解决混合动作空间问题。我们的经验在多代理粒子环境上运行，这是一个简单的多代理粒子世界，以及一些基本的模拟物理。实验结果表明，这些算法具有良好的性能。

缩放多智能体增强学习的卓越障碍之一是为大量代理商分配给个别代理的行动。在本文中，我们通过呼叫\ yrest {部分奖励去耦}（prd）的方法来解决这一信用分配问题，该方法试图将大型合作多代理RL问题分解成涉及代理子集的解耦子问题，从而简化了信用分配。我们经验证明使用PRD在演员 - 批评算法中分解RL问题导致较低的差异策略梯度估计，这提高了各种其他跨越多个代理RL任务的数据效率，学习稳定性和渐近性能。演员 - 评论家方法。此外，我们还将我们的反事实多代理政策梯度（COMA），最先进的MARL算法以及经验证明我们的方法通过更好地利用代理商奖励流的信息来实现昏迷状态，以及启用最近的优势估计的进步。

多项式增强学习（MARL）最近的许多突破都需要使用深层神经网络，这对于人类专家来说是挑战性的解释和理解。另一方面，现有的关于可解释的强化学习（RL）的工作在从神经网络中提取更可解释的决策树政策方面显示了有望，但仅在单一机构设置中。为了填补这一空白，我们提出了第一组算法，这些算法从接受MARL训练的神经网络中提取可解释的决策策略。第一种算法IVIPER将Viper扩展到了单代代理可解释的RL的最新方法到多代理设置。我们证明，艾维尔（Iviper）学习每个代理商的高质量决策树政策。为了更好地捕捉代理之间的协调，我们提出了一种新型的集中决策树培训算法，Maviper。 Maviper通过使用其预期的树来预测其他代理的行为，并使用重新采样来集中精力，以重点放在对其与其他代理相互作用至关重要的状态上，从而共同生长了每个代理的树木。我们表明，这两种算法通常都优于基础线，而在三种不同的多代理粒子世界环境上，受过iviper训练的药物比iviper训练的药物获得了更好的协调性能。

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.

信息共享是建立团队认知并实现协调与合作的关键。高性能的人类团队也从战略性地采用迭代沟通和合理性的层次结构级别中受益，这意味着人类代理可以推理队友在决策中的行动。然而，多代理强化学习（MARL）的大多数先前工作不支持迭代的理性性，而只能鼓励跨性别的沟通，从而实现了次优的平衡合作策略。在这项工作中，我们表明，在优化政策梯度（PG）时，将代理商的政策重新制定为有条件依靠其邻近队友的政策，从而固有地提高了相互信息（MI）的最大程度。在有限的理性和认知层次结构理论下的决策观念的基础上，我们表明我们的修改后的PG方法不仅可以最大化本地代理人的奖励，而且还隐含着关于代理之间MI的理由，而无需任何明确的临时正则化术语。我们的方法Infopg在学习新兴的协作行为方面优于基准，并在分散的合作MARL任务中设定了最先进的工作。我们的实验通过在几个复杂的合作多代理域中实现较高的样品效率和更大的累积奖励来验证InfoPG的实用性。

多代理深度增强学习（Marl）缺乏缺乏共同使用的评估任务和标准，使方法之间的比较困难。在这项工作中，我们提供了一个系统评估，并比较了三种不同类别的Marl算法（独立学习，集中式多代理政策梯度，价值分解）在各种协作多智能经纪人学习任务中。我们的实验是在不同学习任务中作为算法的预期性能的参考，我们为不同学习方法的有效性提供了见解。我们开源EPYMARL，它将Pymarl CodeBase扩展到包括其他算法，并允许灵活地配置算法实现细节，例如参数共享。最后，我们开源两种环境，用于多智能经纪研究，重点关注稀疏奖励下的协调。

在从同质机器人群到异构人类自治团队的多机构团队的运营中，可能会发生意外的事件。虽然对多代理任务分配问题的操作效率是主要目标，但决策框架必须足够聪明，可以用有限的资源来管理意外的任务负载。否则，操作效率将大幅下降，而超载的代理人面临不可预见的风险。在这项工作中，我们为多机构团队提供了一个决策框架，以通过分散的强化学习来考虑负载管理，以学习负载管理，并避免了不必要的资源使用。我们说明了负载管理对团队绩效的影响，并在示例场景中探索了代理行为。此外，在处理潜在的超负荷情况时，开发了一种衡量协作中的代理重要性的衡量标准。