This paper presents the ARCAD simulator for the rapid development of Unmanned Aerial Systems (UAS), including underactuated and fully-actuated multirotors, fixed-wing aircraft, and Vertical Take-Off and Landing (VTOL) hybrid vehicles. The simulator is designed to accelerate these aircraft's modeling and control design. It provides various analyses of the design and operation, such as wrench-set computation, controller response, and flight optimization. In addition to simulating free flight, it can simulate the physical interaction of the aircraft with its environment. The simulator is written in MATLAB to allow rapid prototyping and is capable of generating graphical visualization of the aircraft and the environment in addition to generating the desired plots. It has been used to develop several real-world multirotor and VTOL applications. The source code is available at https://github.com/keipour/aircraft-simulator-matlab.

Visual localization plays an important role for intelligent robots and autonomous driving, especially when the accuracy of GNSS is unreliable. Recently, camera localization in LiDAR maps has attracted more and more attention for its low cost and potential robustness to illumination and weather changes. However, the commonly used pinhole camera has a narrow Field-of-View, thus leading to limited information compared with the omni-directional LiDAR data. To overcome this limitation, we focus on correlating the information of 360 equirectangular images to point clouds, proposing an end-to-end learnable network to conduct cross-modal visual localization by establishing similarity in high-dimensional feature space. Inspired by the attention mechanism, we optimize the network to capture the salient feature for comparing images and point clouds. We construct several sequences containing 360 equirectangular images and corresponding point clouds based on the KITTI-360 dataset and conduct extensive experiments. The results demonstrate the effectiveness of our approach.

检测和避免（DAA）功能对于无人飞机系统（UAS）的安全操作至关重要。本文介绍了Airtrack，这是一个仅实时视觉检测和跟踪框架，尊重SUAS系统的大小，重量和功率（交换）约束。鉴于遥远飞机的低信噪比（SNR），我们建议在深度学习框架中使用完整的分辨率图像，以对齐连续的图像以消除自我动态。然后，对齐的图像在级联的初级和次级分类器中下游使用，以改善多个指标的检测和跟踪性能。我们表明，Airtrack在亚马逊机载对象跟踪（AOT）数据集上胜过最先进的基线。多次现实世界的飞行测试与CESSNA 172与通用航空交通相互作用，并在受控的设置中朝着UAS飞向UAS的其他近碰撞飞行测试，该拟议方法满足了新引入的ASTM F3442/F3442M标准DAA标准。经验评估表明，我们的系统的概率超过900m，范围超过95％。视频可在https://youtu.be/h3ll_wjxjpw上找到。

基于学习的视觉探针计（VO）算法在常见的静态场景上实现了显着的性能，受益于高容量模型和大量注释的数据，但在动态，填充的环境中往往会失败。语义细分在估计摄像机动作之前主要用于丢弃动态关联，但以丢弃静态功能为代价，并且很难扩展到看不见的类别。在本文中，我们利用相机自我运动和运动分割之间的相互依赖性，并表明两者都可以在单个基于学习的框架中共同完善。特别是，我们提出了Dytanvo，这是第一个涉及动态环境的基于学习的VO方法。它需要实时两个连续的单眼帧，并以迭代方式预测相机的自我运动。我们的方法在现实世界动态环境中的最先进的VOUTESS的平均提高27.7％，甚至在动态视觉SLAM系统中进行竞争性，从而优化了后端的轨迹。在很多看不见的环境上进行的实验也证明了我们的方法的普遍性。

本文通过讨论参加了为期三年的SubT竞赛的六支球队的不同大满贯策略和成果，报道了地下大满贯的现状。特别是，本文有四个主要目标。首先，我们审查团队采用的算法，架构和系统；特别重点是以激光雷达以激光雷达为中心的SLAM解决方案（几乎所有竞争中所有团队的首选方法），异质的多机器人操作（包括空中机器人和地面机器人）和现实世界的地下操作（从存在需要处理严格的计算约束的晦涩之处）。我们不会回避讨论不同SubT SLAM系统背后的肮脏细节，这些系统通常会从技术论文中省略。其次，我们通过强调当前的SLAM系统的可能性以及我们认为与一些良好的系统工程有关的范围来讨论该领域的成熟度。第三，我们概述了我们认为是基本的开放问题，这些问题可能需要进一步的研究才能突破。最后，我们提供了在SubT挑战和相关工作期间生产的开源SLAM实现和数据集的列表，并构成了研究人员和从业人员的有用资源。

我们提出Automerge，这是一种LIDAR数据处理框架，用于将大量地图段组装到完整的地图中。传统的大规模地图合并方法对于错误的数据关联是脆弱的，并且主要仅限于离线工作。 Automerge利用多观点的融合和自适应环路闭合检测来进行准确的数据关联，并且它使用增量合并来从随机顺序给出的单个轨迹段组装大图，没有初始估计。此外，在组装段后，自动制度可以执行良好的匹配和姿势图片优化，以在全球范围内平滑合并的地图。我们展示了城市规模合并（120公里）和校园规模重复合并（4.5公里x 8）的汽车。该实验表明，自动化（i）在段检索中超过了第二和第三最佳方法的14％和24％的召回，（ii）在120 km大尺度地图组件（III）中实现了可比较的3D映射精度，IT对于暂时的重新审视是强大的。据我们所知，Automerge是第一种映射方法，它可以在无GPS的帮助下合并数百公里的单个细分市场。

基于激光雷达的本地化方法是用于大规模导航任务的基本模块，例如最后一英里交付和自动驾驶，并且本地化鲁棒性高度依赖于观点和3D功能提取。我们以前的工作提供了一个观点不变的描述符来处理观点差异；但是，全局描述符在无监督聚类中的信号噪声比率低，从而降低了可区分的特征提取能力。我们开发了SphereVlad ++，这是这项工作中一种引起注意的观点不变的位置识别方法。 SphereVlad ++在每个唯一区域的球形视角上投射点云，并通过全局3D几何分布捕获本地特征及其依赖关系之间的上下文连接。作为回报，全局描述符中的群集元素以本地和全球几何形式为条件，并支持SphereVlad的原始视点不变属性。在实验中，我们评估了SphereVlad ++在匹兹堡市的公共Kitti360数据集和自我生成的数据集上的本地化性能。实验结果表明，SphereVlad ++在小甚至完全逆转的视点差异下优于所有相对最新的3D位置识别方法，并显示0.69％和15.81％的成功检索率，比第二好的检索率更好。低计算要求和高时间效率也有助于其用于低成本机器人的应用。

Enabling vertical take-off and landing while providing the ability to fly long ranges opens the door to a wide range of new real-world aircraft applications while improving many existing tasks. Tiltrotor vertical take-off and landing (VTOL) unmanned aerial vehicles (UAVs) are a better choice than fixed-wing and multirotor aircraft for such applications. Prior works on these aircraft have addressed aerodynamic performance, design, modeling, and control. However, a less explored area is the study of their potential fault tolerance due to their inherent redundancy, which allows them to tolerate some degree of actuation failure. This paper introduces tolerance to several types of actuator failures in a tiltrotor VTOL aircraft. We discuss the design and modeling of a custom tiltrotor VTOL UAV, which is a combination of a fixed-wing aircraft and a quadrotor with tilting rotors, where the four propellers can be rotated individually. Then, we analyze the feasible wrench space the vehicle can generate and design the dynamic control allocation so that the system can adapt to actuator failures, benefiting from the configuration redundancy. The proposed approach is lightweight and is implemented as an extension to an already-existing flight control stack. Extensive experiments validate that the system can maintain the controlled flight under different actuator failures. To the best of our knowledge, this work is the first study of the tiltrotor VTOL's fault-tolerance that exploits the configuration redundancy. The source code and simulation can be accessed at https://theairlab.org/vtol.

多模式传感器的融合在自动驾驶和智能机器人中变得越来越流行，因为它可以比任何单个传感器提供更丰富的信息，从而在复杂的环境中增强可靠性。多传感器外部校准是传感器融合的关键因素之一。但是，由于传感器方式的种类以及对校准目标和人工的需求，这种校准很困难。在本文中，我们通过关注立体相机，热摄像机和激光传感器之间的外部转换，展示了一个新的无目标跨模式校准框架。具体而言，立体声和激光器之间的校准是通过最小化登记误差在3D空间中进行的，而通过优化边缘特征的对齐方式来估计其他两个传感器的热外部传感器。我们的方法不需要专门的目标，并且可以在没有人类相互作用的情况下进行一次镜头进行多传感器校准。实验结果表明，校准框架是准确且适用于一般场景的。

Fingerprints are key tools in climate change detection and attribution (D&A) that are used to determine whether changes in observations are different from internal climate variability (detection), and whether observed changes can be assigned to specific external drivers (attribution). We propose a direct D&A approach based on supervised learning to extract fingerprints that lead to robust predictions under relevant interventions on exogenous variables, i.e., climate drivers other than the target. We employ anchor regression, a distributionally-robust statistical learning method inspired by causal inference that extrapolates well to perturbed data under the interventions considered. The residuals from the prediction achieve either uncorrelatedness or mean independence with the exogenous variables, thus guaranteeing robustness. We define D&A as a unified hypothesis testing framework that relies on the same statistical model but uses different targets and test statistics. In the experiments, we first show that the CO2 forcing can be robustly predicted from temperature spatial patterns under strong interventions on the solar forcing. Second, we illustrate attribution to the greenhouse gases and aerosols while protecting against interventions on the aerosols and CO2 forcing, respectively. Our study shows that incorporating robustness constraints against relevant interventions may significantly benefit detection and attribution of climate change.