The proliferation of unmanned aircraft systems (UAS) has caused airspace regulation authorities to examine the interoperability of these aircraft with collision avoidance systems initially designed for large transport category aircraft. Limitations in the currently mandated TCAS led the Federal Aviation Administration to commission the development of a new solution, the Airborne Collision Avoidance System X (ACAS X), designed to enable a collision avoidance capability for multiple aircraft platforms, including UAS. While prior research explored using deep reinforcement learning algorithms (DRL) for collision avoidance, DRL did not perform as well as existing solutions. This work explores the benefits of using a DRL collision avoidance system whose parameters are tuned using a surrogate optimizer. We show the use of a surrogate optimizer leads to DRL approach that can increase safety and operational viability and support future capability development for UAS collision avoidance.

Compared with model-based control and optimization methods, reinforcement learning (RL) provides a data-driven, learning-based framework to formulate and solve sequential decision-making problems. The RL framework has become promising due to largely improved data availability and computing power in the aviation industry. Many aviation-based applications can be formulated or treated as sequential decision-making problems. Some of them are offline planning problems, while others need to be solved online and are safety-critical. In this survey paper, we first describe standard RL formulations and solutions. Then we survey the landscape of existing RL-based applications in aviation. Finally, we summarize the paper, identify the technical gaps, and suggest future directions of RL research in aviation.

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.

小型无人驾驶飞机的障碍避免对于未来城市空袭（UAM）和无人机系统（UAS）交通管理（UTM）的安全性至关重要。有许多技术用于实时强大的无人机指导，但其中许多在离散的空域和控制中解决，这将需要额外的路径平滑步骤来为UA提供灵活的命令。为提供无人驾驶飞机的操作安全有效的计算指导，我们探讨了基于近端政策优化（PPO）的深增强学习算法的使用，以指导自主UA到其目的地，同时通过连续控制避免障碍物。所提出的场景状态表示和奖励功能可以将连续状态空间映射到连续控制，以便进行标题角度和速度。为了验证所提出的学习框架的性能，我们用静态和移动障碍进行了数值实验。详细研究了与环境和安全操作界限的不确定性。结果表明，该拟议的模型可以提供准确且强大的指导，并解决了99％以上的成功率的冲突。

The high emission and low energy efficiency caused by internal combustion engines (ICE) have become unacceptable under environmental regulations and the energy crisis. As a promising alternative solution, multi-power source electric vehicles (MPS-EVs) introduce different clean energy systems to improve powertrain efficiency. The energy management strategy (EMS) is a critical technology for MPS-EVs to maximize efficiency, fuel economy, and range. Reinforcement learning (RL) has become an effective methodology for the development of EMS. RL has received continuous attention and research, but there is still a lack of systematic analysis of the design elements of RL-based EMS. To this end, this paper presents an in-depth analysis of the current research on RL-based EMS (RL-EMS) and summarizes the design elements of RL-based EMS. This paper first summarizes the previous applications of RL in EMS from five aspects: algorithm, perception scheme, decision scheme, reward function, and innovative training method. The contribution of advanced algorithms to the training effect is shown, the perception and control schemes in the literature are analyzed in detail, different reward function settings are classified, and innovative training methods with their roles are elaborated. Finally, by comparing the development routes of RL and RL-EMS, this paper identifies the gap between advanced RL solutions and existing RL-EMS. Finally, this paper suggests potential development directions for implementing advanced artificial intelligence (AI) solutions in EMS.

安全是空中交通时的主要问题。通过成对分离最小值确保无人驾驶飞机（无人机）之间的飞行安全性，利用冲突检测和分辨方法。现有方法主要处理成对冲突，但由于交通密度的预期增加，可能会发生两个以上的无人机的遇到。在本文中，我们将多UAV冲突解决模型作为多功能加强学习问题。我们实现了一种基于图形神经网络的算法，配合代理可以与共同生成分辨率的操作进行通信。该模型在具有3和4个当前代理的情况下进行评估。结果表明，代理商能够通过合作策略成功解决多UV冲突。

机器学习算法中多个超参数的最佳设置是发出大多数可用数据的关键。为此目的，已经提出了几种方法，例如进化策略，随机搜索，贝叶斯优化和启发式拇指规则。在钢筋学习（RL）中，学习代理在与其环境交互时收集的数据的信息内容严重依赖于许多超参数的设置。因此，RL算法的用户必须依赖于基于搜索的优化方法，例如网格搜索或Nelder-Mead单简单算法，这对于大多数R1任务来说是非常效率的，显着减慢学习曲线和离开用户的速度有目的地偏见数据收集的负担。在这项工作中，为了使RL算法更加用户独立，提出了一种使用贝叶斯优化的自主超参数设置的新方法。来自过去剧集和不同的超参数值的数据通过执行行为克隆在元学习水平上使用，这有助于提高最大化获取功能的加强学习变体的有效性。此外，通过紧密地整合在加强学习代理设计中的贝叶斯优化，还减少了收敛到给定任务的最佳策略所需的状态转换的数量。与其他手动调整和基于优化的方法相比，计算实验显示了有希望的结果，这突出了改变算法超级参数来增加所生成数据的信息内容的好处。

Hybrid FSO/RF system requires an efficient FSO and RF link switching mechanism to improve the system capacity by realizing the complementary benefits of both the links. The dynamics of network conditions, such as fog, dust, and sand storms compound the link switching problem and control complexity. To address this problem, we initiate the study of deep reinforcement learning (DRL) for link switching of hybrid FSO/RF systems. Specifically, in this work, we focus on actor-critic called Actor/Critic-FSO/RF and Deep-Q network (DQN) called DQN-FSO/RF for FSO/RF link switching under atmospheric turbulences. To formulate the problem, we define the state, action, and reward function of a hybrid FSO/RF system. DQN-FSO/RF frequently updates the deployed policy that interacts with the environment in a hybrid FSO/RF system, resulting in high switching costs. To overcome this, we lift this problem to ensemble consensus-based representation learning for deep reinforcement called DQNEnsemble-FSO/RF. The proposed novel DQNEnsemble-FSO/RF DRL approach uses consensus learned features representations based on an ensemble of asynchronous threads to update the deployed policy. Experimental results corroborate that the proposed DQNEnsemble-FSO/RF's consensus-learned features switching achieves better performance than Actor/Critic-FSO/RF, DQN-FSO/RF, and MyOpic for FSO/RF link switching while keeping the switching cost significantly low.

This article proposes a model-based deep reinforcement learning (DRL) method to design emergency control strategies for short-term voltage stability problems in power systems. Recent advances show promising results in model-free DRL-based methods for power systems, but model-free methods suffer from poor sample efficiency and training time, both critical for making state-of-the-art DRL algorithms practically applicable. DRL-agent learns an optimal policy via a trial-and-error method while interacting with the real-world environment. And it is desirable to minimize the direct interaction of the DRL agent with the real-world power grid due to its safety-critical nature. Additionally, state-of-the-art DRL-based policies are mostly trained using a physics-based grid simulator where dynamic simulation is computationally intensive, lowering the training efficiency. We propose a novel model-based-DRL framework where a deep neural network (DNN)-based dynamic surrogate model, instead of a real-world power-grid or physics-based simulation, is utilized with the policy learning framework, making the process faster and sample efficient. However, stabilizing model-based DRL is challenging because of the complex system dynamics of large-scale power systems. We solved these issues by incorporating imitation learning to have a warm start in policy learning, reward-shaping, and multi-step surrogate loss. Finally, we achieved 97.5% sample efficiency and 87.7% training efficiency for an application to the IEEE 300-bus test system.

强化学习和最近的深度增强学习是解决如Markov决策过程建模的顺序决策问题的流行方法。问题和选择算法和超参数的RL建模需要仔细考虑，因为不同的配置可能需要完全不同的性能。这些考虑因素主要是RL专家的任务;然而，RL在研究人员和系统设计师不是RL专家的其他领域中逐渐变得流行。此外，许多建模决策，例如定义状态和动作空间，批次的大小和批量更新的频率以及时间戳的数量通常是手动进行的。由于这些原因，RL框架的自动化不同组成部分具有重要意义，近年来它引起了很多关注。自动RL提供了一个框架，其中RL的不同组件包括MDP建模，算法选择和超参数优化是自动建模和定义的。在本文中，我们探讨了可以在自动化RL中使用的文献和目前的工作。此外，我们讨论了Autorl中的挑战，打开问题和研究方向。

自主驾驶有可能彻底改变流动性，因此是一个积极的研究领域。实际上，自动驾驶汽车的行为必须是可以接受的，即高效，安全和可解释的。尽管香草钢筋学习（RL）找到了表现的行为策略，但它们通常是不安全且无法解释的。安全性是通过安全的RL方法引入的，但是它们仍然无法解释，因为学习的行为在没有分别进行建模的情况下共同优化了安全性和性能。可解释的机器学习很少应用于RL。本文提出了SAFEDQN，它允许在仍然有效的同时使自动驾驶汽车的行为安全可解释。 SAFEDQN在算法上透明的同时，在预期风险和效用的效用之间提供了可以理解的语义权衡。我们表明，SAFEDQN为各种场景找到了可解释且安全的驾驶政策，并展示了最先进的显着性技术如何帮助评估风险和实用性。

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.

具有成本效益的资产管理是多个行业的兴趣领域。具体而言，本文开发了深入的加固学习（DRL）解决方案，以自动确定不断恶化的水管的最佳康复政策。我们在在线和离线DRL设置中处理康复计划的问题。在在线DRL中，代理与具有不同长度，材料和故障率特征的多个管道的模拟环境进行交互。我们使用深Q学习（DQN）训练代理商，以最低限度的平均成本和减少故障概率学习最佳政策。在离线学习中，代理使用静态数据，例如DQN重播数据，通过保守的Q学习算法学习最佳策略，而无需与环境进行进一步的交互。我们证明，基于DRL的政策改善了标准预防，纠正和贪婪的计划替代方案。此外，从固定的DQN重播数据集中学习超过在线DQN设置。结果保证，由大型国家和行动轨迹组成的水管的现有恶化概况为在离线环境中学习康复政策提供了宝贵的途径，而无需模拟器。

In this paper, we build on advances introduced by the Deep Q-Networks (DQN) approach to extend the multi-objective tabular Reinforcement Learning (RL) algorithm W-learning to large state spaces. W-learning algorithm can naturally solve the competition between multiple single policies in multi-objective environments. However, the tabular version does not scale well to environments with large state spaces. To address this issue, we replace underlying Q-tables with DQN, and propose an addition of W-Networks, as a replacement for tabular weights (W) representations. We evaluate the resulting Deep W-Networks (DWN) approach in two widely-accepted multi-objective RL benchmarks: deep sea treasure and multi-objective mountain car. We show that DWN solves the competition between multiple policies while outperforming the baseline in the form of a DQN solution. Additionally, we demonstrate that the proposed algorithm can find the Pareto front in both tested environments.

由于交通的固有复杂性和不确定性，自主驾驶决策是一项具有挑战性的任务。例如，相邻的车辆可能随时改变其车道或超越，以通过慢速车辆或帮助交通流量。预期周围车辆的意图，估算其未来状态并将其整合到自动化车辆的决策过程中，可以提高复杂驾驶场景中自动驾驶的可靠性。本文提出了一种基于预测的深入强化学习（PDRL）决策模型，该模型在公路驾驶决策过程中考虑了周围车辆的操纵意图。该模型是使用真实流量数据训练的，并通过模拟平台在各种交通条件下进行了测试。结果表明，与深入的增强学习（DRL）模型相比，提出的PDRL模型通过减少碰撞数量来改善决策绩效，从而导致更安全的驾驶。

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。

在自主驾驶场中，人类知识融合到深增强学习（DRL）通常基于在模拟环境中记录的人类示范。这限制了在现实世界交通中的概率和可行性。我们提出了一种两级DRL方法，从真实的人类驾驶中学习，实现优于纯DRL代理的性能。培训DRL代理商是在Carla的框架内完成了机器人操作系统（ROS）。对于评估，我们设计了不同的真实驾驶场景，可以将提出的两级DRL代理与纯DRL代理进行比较。在从人驾驶员中提取“良好”行为之后，例如在信号交叉口中的预期，该代理变得更有效，并且驱动更安全，这使得这种自主代理更适应人体机器人交互（HRI）流量。

A long-standing challenge in artificial intelligence is lifelong learning. In lifelong learning, many tasks are presented in sequence and learners must efficiently transfer knowledge between tasks while avoiding catastrophic forgetting over long lifetimes. On these problems, policy reuse and other multi-policy reinforcement learning techniques can learn many tasks. However, they can generate many temporary or permanent policies, resulting in memory issues. Consequently, there is a need for lifetime-scalable methods that continually refine a policy library of a pre-defined size. This paper presents a first approach to lifetime-scalable policy reuse. To pre-select the number of policies, a notion of task capacity, the maximal number of tasks that a policy can accurately solve, is proposed. To evaluate lifetime policy reuse using this method, two state-of-the-art single-actor base-learners are compared: 1) a value-based reinforcement learner, Deep Q-Network (DQN) or Deep Recurrent Q-Network (DRQN); and 2) an actor-critic reinforcement learner, Proximal Policy Optimisation (PPO) with or without Long Short-Term Memory layer. By selecting the number of policies based on task capacity, D(R)QN achieves near-optimal performance with 6 policies in a 27-task MDP domain and 9 policies in an 18-task POMDP domain; with fewer policies, catastrophic forgetting and negative transfer are observed. Due to slow, monotonic improvement, PPO requires fewer policies, 1 policy for the 27-task domain and 4 policies for the 18-task domain, but it learns the tasks with lower accuracy than D(R)QN. These findings validate lifetime-scalable policy reuse and suggest using D(R)QN for larger and PPO for smaller library sizes.

从意外的外部扰动中恢复的能力是双模型运动的基本机动技能。有效的答复包括不仅可以恢复平衡并保持稳定性的能力，而且在平衡恢复物质不可行时，也可以保证安全的方式。对于与双式运动有关的机器人，例如人形机器人和辅助机器人设备，可帮助人类行走，设计能够提供这种稳定性和安全性的控制器可以防止机器人损坏或防止伤害相关的医疗费用。这是一个具有挑战性的任务，因为它涉及用触点产生高维，非线性和致动系统的高动态运动。尽管使用基于模型和优化方法的前进方面，但诸如广泛领域知识的要求，诸如较大的计算时间和有限的动态变化的鲁棒性仍然会使这个打开问题。在本文中，为了解决这些问题，我们开发基于学习的算法，能够为两种不同的机器人合成推送恢复控制政策：人形机器人和有助于双模型运动的辅助机器人设备。我们的工作可以分为两个密切相关的指示：1）学习人形机器人的安全下降和预防策略，2）使用机器人辅助装置学习人类的预防策略。为实现这一目标，我们介绍了一套深度加强学习（DRL）算法，以学习使用这些机器人时提高安全性的控制策略。

新一代网络威胁的兴起要求更复杂和智能的网络防御解决方案，配备了能够学习在没有人力专家知识的情况下做出决策的自治代理。近年来提出了用于自动网络入侵任务的几种强化学习方法（例如，马尔可夫）。在本文中，我们介绍了一种新一代的网络入侵检测方法，将基于Q学习的增强学习与用于网络入侵检测的深馈前神经网络方法相结合。我们提出的深度Q-Learning（DQL）模型为网络环境提供了正在进行的自动学习能力，该网络环境可以使用自动试验误差方法检测不同类型的网络入侵，并连续增强其检测能力。我们提供涉及DQL模型的微调不同的超参数的细节，以获得更有效的自学。根据我们基于NSL-KDD数据集的广泛实验结果，我们确认折扣因子在250次训练中设定为0.001，产生了最佳的性能结果。我们的实验结果还表明，我们所提出的DQL在检测不同的入侵课程和优于其他类似的机器学习方法方面的高度有效。