视觉惯性进程（VIO）被广泛用于多次计算机的状态估计，但在很少的视觉特征或过度攻击性飞行中的环境中起作用可能很差。在这项工作中，我们建议使用任何基于功能的VIO算法使用的多杆避免感知碰撞轨迹轨迹计划器。我们的方法能够以快速的速度飞行车辆到达目标位置，从而避免在未知的固定环境中遇到障碍，同时达到良好的VIO状态估计精度。拟议的规划师样本了一组最小的混蛋轨迹，并发现其中无冲突的轨迹，然后根据其目标和感知质量对其进行评估。特征及其位置的运动模糊都是为了感知质量。我们对功能运动模糊的新颖考虑使轨迹在具有不同光级别的环境下的侵略性自动适应。评估中的最佳轨迹是由车辆跟踪的，当从相机中收到新图像时，将以退缩的方式更新。仅对VIO做出了通用假设，因此计划器可以与各种现有系统一起使用。提出的方法可以在船上的小型嵌入式计算机上实时运行。我们通过在室内和室外环境中进行实验验证了我们提出的方法的有效性。与感知不可或缺的策划者相比，提议的计划者在摄像机的视野中保留了更多功能，并使飞行变得不那么侵略性，从而使VIO更加准确。它还减少了VIO失败，这是对感知态度计划者的发生，但并非针对拟议的计划者。还验证了拟议的规划师飞越密集障碍的能力。可以在https://youtu.be/qo3lzirpwtq上找到实验视频。

Autonomous Micro Aerial Vehicles are deployed for a variety tasks including surveillance and monitoring. Perching and staring allow the vehicle to monitor targets without flying, saving battery power and increasing the overall mission time without the need to frequently replace batteries. This paper addresses the Active Visual Perching (AVP) control problem to autonomously perch on inclined surfaces up to $90^\circ$. Our approach generates dynamically feasible trajectories to navigate and perch on a desired target location, while taking into account actuator and Field of View (FoV) constraints. By replanning in mid-flight, we take advantage of more accurate target localization increasing the perching maneuver's robustness to target localization or control errors. We leverage the Karush-Kuhn-Tucker (KKT) conditions to identify the compatibility between planning objectives and the visual sensing constraint during the planned maneuver. Furthermore, we experimentally identify the corresponding boundary conditions that maximizes the spatio-temporal target visibility during the perching maneuver. The proposed approach works on-board in real-time with significant computational constraints relying exclusively on cameras and an Inertial Measurement Unit (IMU). Experimental results validate the proposed approach and shows the higher success rate as well as increased target interception precision and accuracy with respect to a one-shot planning approach, while still retaining aggressive capabilities with flight envelopes that include large excursions from the hover position on inclined surfaces up to 90$^\circ$, angular speeds up to 750~deg/s, and accelerations up to 10~m/s$^2$.

By utilizing only depth information, the paper introduces a novel but efficient local planning approach that enhances not only computational efficiency but also planning performances for memoryless local planners. The sampling is first proposed to be based on the depth data which can identify and eliminate a specific type of in-collision trajectories in the sampled motion primitive library. More specifically, all the obscured primitives' endpoints are found through querying the depth values and excluded from the sampled set, which can significantly reduce the computational workload required in collision checking. On the other hand, we furthermore propose a steering mechanism also based on the depth information to effectively prevent an autonomous vehicle from getting stuck when facing a large convex obstacle, providing a higher level of autonomy for a planning system. Our steering technique is theoretically proved to be complete in scenarios of convex obstacles. To evaluate effectiveness of the proposed DEpth based both Sampling and Steering (DESS) methods, we implemented them in the synthetic environments where a quadrotor was simulated flying through a cluttered region with multiple size-different obstacles. The obtained results demonstrate that the proposed approach can considerably decrease computing time in local planners, where more trajectories can be evaluated while the best path with much lower cost can be found. More importantly, the success rates calculated by the fact that the robot successfully navigated to the destinations in different testing scenarios are always higher than 99.6% on average.

本文提出了一种新颖的方法，用于在具有复杂拓扑结构的地下领域的搜索和救援行动中自动合作。作为CTU-Cras-Norlab团队的一部分，拟议的系统在DARPA SubT决赛的虚拟轨道中排名第二。与专门为虚拟轨道开发的获奖解决方案相反，该建议的解决方案也被证明是在现实世界竞争极为严峻和狭窄的环境中飞行的机上实体无人机的强大系统。提出的方法可以使无缝模拟转移的无人机团队完全自主和分散的部署，并证明了其优于不同环境可飞行空间的移动UGV团队的优势。该论文的主要贡献存在于映射和导航管道中。映射方法采用新颖的地图表示形式 - 用于有效的风险意识长距离计划，面向覆盖范围和压缩的拓扑范围的LTVMAP领域，以允许在低频道通信下进行多机器人合作。这些表示形式与新的方法一起在导航中使用，以在一般的3D环境中可见性受限的知情搜索，而对环境结构没有任何假设，同时将深度探索与传感器覆盖的剥削保持平衡。所提出的解决方案还包括一条视觉感知管道，用于在没有专用GPU的情况下在5 Hz处进行四个RGB流中感兴趣的对象的板上检测和定位。除了参与DARPA SubT外，在定性和定量评估的各种环境中，在不同的环境中进行了广泛的实验验证，UAV系统的性能得到了支持。

Micro aerial vehicles (MAVs) hold the potential for performing autonomous and contactless land surveys for the detection of landmines and explosive remnants of war (ERW). Metal detectors are the standard tool, but have to be operated close to and parallel to the terrain. As this requires advanced flight capabilities, they have not been successfully combined with MAVs before. To this end, we present a full system to autonomously survey challenging undulated terrain using a metal detector mounted on a 5 degrees of freedom (DOF) MAV. Based on an online estimate of the terrain, our receding-horizon planner efficiently covers the area, aligning the detector to the surface while considering the kinematic and visibility constraints of the platform. For resilient localization, we propose a factor-graph approach for online fusion of GNSS, IMU and LiDAR measurements. A simulated ablation study shows that the proposed planner reduces coverage duration and improves trajectory smoothness. Real-world flight experiments showcase autonomous mapping of buried metallic objects in undulated and obstructed terrain. The proposed localization approach is resilient to individual sensor degeneracy.

神经辐射场（NERF）最近被成为自然，复杂3D场景的代表的强大范例。 NERFS表示神经网络中的连续体积密度和RGB值，并通过射线跟踪从看不见的相机观点生成照片逼真图像。我们提出了一种算法，用于通过仅使用用于本地化的板载RGB相机表示为NERF的3D环境导航机器人。我们假设现场的NERF已经预先训练了离线，机器人的目标是通过NERF中的未占用空间导航到目标姿势。我们介绍了一种轨迹优化算法，其避免了基于NERF中的高密度区域的碰撞，其基于差分平整度的离散时间版本，其可用于约束机器人的完整姿势和控制输入。我们还介绍了基于优化的过滤方法，以估计单位的RGB相机中的NERF中机器人的6dof姿势和速度。我们将轨迹策划器与在线重新循环中的姿势过滤器相结合，以提供基于视觉的机器人导航管道。我们使用丛林健身房环境，教堂内部和巨石阵线导航的四轮车机器人，使用RGB相机展示仿真结果。我们还展示了通过教会导航的全向地面机器人，要求它重新定位以缩小差距。这项工作的视频可以在https://mikh3x4.github.io/nerf-navigation/找到。

We address the theoretical and practical problems related to the trajectory generation and tracking control of tail-sitter UAVs. Theoretically, we focus on the differential flatness property with full exploitation of actual UAV aerodynamic models, which lays a foundation for generating dynamically feasible trajectory and achieving high-performance tracking control. We have found that a tail-sitter is differentially flat with accurate aerodynamic models within the entire flight envelope, by specifying coordinate flight condition and choosing the vehicle position as the flat output. This fundamental property allows us to fully exploit the high-fidelity aerodynamic models in the trajectory planning and tracking control to achieve accurate tail-sitter flights. Particularly, an optimization-based trajectory planner for tail-sitters is proposed to design high-quality, smooth trajectories with consideration of kinodynamic constraints, singularity-free constraints and actuator saturation. The planned trajectory of flat output is transformed to state trajectory in real-time with consideration of wind in environments. To track the state trajectory, a global, singularity-free, and minimally-parameterized on-manifold MPC is developed, which fully leverages the accurate aerodynamic model to achieve high-accuracy trajectory tracking within the whole flight envelope. The effectiveness of the proposed framework is demonstrated through extensive real-world experiments in both indoor and outdoor field tests, including agile SE(3) flight through consecutive narrow windows requiring specific attitude and with speed up to 10m/s, typical tail-sitter maneuvers (transition, level flight and loiter) with speed up to 20m/s, and extremely aggressive aerobatic maneuvers (Wingover, Loop, Vertical Eight and Cuban Eight) with acceleration up to 2.5g.

本文在移动平台上介绍了四摩托车的自动起飞和着陆系统。设计的系统解决了三个具有挑战性的问题：快速姿势估计，受限的外部定位和有效避免障碍物。具体而言，首先，我们基于Aruco标记设计了着陆识别和定位系统，以帮助四极管快速计算相对姿势。其次，我们利用基于梯度的本地运动计划者快速生成无冲突的参考轨迹；第三，我们构建了一台自主状态机器，使四极管能够完全自治完成其起飞，跟踪和着陆任务；最后，我们在模拟，现实世界和室外环境中进行实验，以验证系统的有效性并证明其潜力。

The field of autonomous mobile robots has undergone dramatic advancements over the past decades. Despite achieving important milestones, several challenges are yet to be addressed. Aggregating the achievements of the robotic community as survey papers is vital to keep the track of current state-of-the-art and the challenges that must be tackled in the future. This paper tries to provide a comprehensive review of autonomous mobile robots covering topics such as sensor types, mobile robot platforms, simulation tools, path planning and following, sensor fusion methods, obstacle avoidance, and SLAM. The urge to present a survey paper is twofold. First, autonomous navigation field evolves fast so writing survey papers regularly is crucial to keep the research community well-aware of the current status of this field. Second, deep learning methods have revolutionized many fields including autonomous navigation. Therefore, it is necessary to give an appropriate treatment of the role of deep learning in autonomous navigation as well which is covered in this paper. Future works and research gaps will also be discussed.

本文着重于影响弹性的移动机器人的碰撞运动计划和控制的新兴范式转移，并开发了一个统一的层次结构框架，用于在未知和部分观察的杂物空间中导航。在较低级别上，我们开发了一种变形恢复控制和轨迹重新启动策略，该策略处理可能在本地运行时发生的碰撞。低级系统会积极检测碰撞（通过内部内置的移动机器人上的嵌入式霍尔效应传感器），使机器人能够从其内部恢复，并在本地调整后影响后的轨迹。然后，在高层，我们提出了一种基于搜索的计划算法，以确定如何最好地利用潜在的碰撞来改善某些指标，例如控制能量和计算时间。我们的方法建立在A*带有跳跃点的基础上。我们生成了一种新颖的启发式功能，并进行了碰撞检查和调整技术，从而使A*算法通过利用和利用可能的碰撞来更快地收敛到达目标。通过将全局A*算法和局部变形恢复和重新融合策略以及该框架的各个组件相结合而生成的整体分层框架在模拟和实验中都经过了广泛的测试。一项消融研究借鉴了与基于搜索的最先进的避免碰撞计划者（用于整体框架）的链接，以及基于搜索的避免碰撞和基于采样的碰撞 - 碰撞 - 全球规划师（对于更高的较高的碰撞 - 等级）。结果证明了我们的方法在未知环境中具有碰撞的运动计划和控制的功效，在2D中运行的一类撞击弹性机器人具有孤立的障碍物。

陆地 - 空中双模车辆在学术界和工业中绽放，因为它们融入了空中车辆的高流动性和地面车辆的长期耐力。在这项工作中，我们提出了一种自主和自适应的导航框架，为这类车辆带来完全自主权。该框架主要包括1）分层运动规划器，在未知环境中产生安全和低功率的地面 - 鸟轨迹，2）统一运动控制器，其动态地调整陆地运动中的能量消耗。广泛的现实实验和基准比较是在定制的机器人平台上进行的，以验证所提出的框架的稳健性和性能。在测试期间，机器人安全地穿越了陆地集成流动性的复杂环境，并在地面运动中实现了7美元的节能。最后，我们将为社区的引用发出我们的代码和硬件配置。

最近的研究通过使用直接非线性模型预测控制（NMPC），使固定翼无人驾驶飞行器（无人机）能够在受约束空间中操纵。然而，这种方法仅限于先验的已知地图和地面真理状态测量。在本文中，我们介绍了一种直接的NMPC方法，它利用Nanomap，一种光重点云映射框架，用于使用车载立体视觉产生自由的轨迹。我们首先探讨了我们在模拟中的方法，并证明我们的算法足以使城市环境中的视觉导航。然后，我们使用42英寸的固定翼UAV在硬件中展示我们的方法，并显示我们的运动规划算法能够使用一组简约的目标点围绕建筑物导航。我们还显示存储点云历史，对于导航这些类型的约束环境非常重要。

微型航空车（MAV）具有很高的信息收集任务的潜力，以支持搜索和救援方案中的情况意识。在这种情况下，手动控制MAV需要经验丰富的飞行员，并且容易出错，尤其是在真正紧急情况的压力下。灾难情景的条件对于自动MAV系统也充满挑战。通常不知道环境，GNSS可能并不总是可用。我们介绍了一个不依赖全球定位系统的未知环境中自动MAV航班的系统。该方法在多个搜索和救援方案中进行评估，即使在室内和室外区域之间过渡时，也可以进行安全的自动飞行。

室内运动计划的重点是解决通过混乱环境导航代理的问题。迄今为止，在该领域已经完成了很多工作，但是这些方法通常无法找到计算廉价的在线路径计划和路径最佳之间的最佳平衡。除此之外，这些作品通常证明是单一启动单目标世界的最佳性。为了应对这些挑战，我们为在未知室内环境中进行导航的多个路径路径计划者和控制器堆栈，在该环境中，路点将目标与机器人必须在达到目标之前必须穿越的中介点一起。我们的方法利用全球规划师（在任何瞬间找到下一个最佳航路点），本地规划师（计划通往特定航路点的路径）以及自适应模型预测性控制策略（用于强大的系统控制和更快的操作） 。我们在一组随机生成的障碍图，中间航路点和起始目标对上评估了算法，结果表明计算成本显着降低，具有高度准确性和可靠的控制。

去中心化的国家估计是GPS贬低的地区自动空中群体系统中最基本的组成部分之一，但它仍然是一个极具挑战性的研究主题。本文提出了Omni-swarm，一种分散的全向视觉惯性-UWB状态估计系统，用于解决这一研究利基市场。为了解决可观察性，复杂的初始化，准确性不足和缺乏全球一致性的问题，我们在Omni-warm中引入了全向感知前端。它由立体宽型摄像机和超宽带传感器，视觉惯性探测器，基于多无人机地图的本地化以及视觉无人机跟踪算法组成。前端的测量值与后端的基于图的优化融合在一起。所提出的方法可实现厘米级的相对状态估计精度，同时确保空中群中的全球一致性，这是实验结果证明的。此外，在没有任何外部设备的情况下，可以在全面的无人机间碰撞方面支持，表明全旋转的潜力是自动空中群的基础。

A monocular visual-inertial system (VINS), consisting of a camera and a low-cost inertial measurement unit (IMU), forms the minimum sensor suite for metric six degreesof-freedom (DOF) state estimation. However, the lack of direct distance measurement poses significant challenges in terms of IMU processing, estimator initialization, extrinsic calibration, and nonlinear optimization. In this work, we present VINS-Mono: a robust and versatile monocular visual-inertial state estimator. Our approach starts with a robust procedure for estimator initialization and failure recovery. A tightly-coupled, nonlinear optimization-based method is used to obtain high accuracy visual-inertial odometry by fusing pre-integrated IMU measurements and feature observations. A loop detection module, in combination with our tightly-coupled formulation, enables relocalization with minimum computation overhead. We additionally perform four degrees-of-freedom pose graph optimization to enforce global consistency. We validate the performance of our system on public datasets and real-world experiments and compare against other state-of-the-art algorithms. We also perform onboard closed-loop autonomous flight on the MAV platform and port the algorithm to an iOS-based demonstration. We highlight that the proposed work is a reliable, complete, and versatile system that is applicable for different applications that require high accuracy localization. We open source our implementations for both PCs 1 and iOS mobile devices 2 .

本文有助于设计一种利用基于学习的碰撞预测网络的新型导航计划程序的方法。神经网络是任务，以预测机器人的速度转向角度空间中的预定运动原语库中的每个动作序列的碰撞成本，仅给出电流深度图像和机器人的估计线性和角速度。此外，我们通过使用Monte Carlo辍学来处理机器人的部分状态的不确定性。然后将不确定性感应的碰撞成本与由全球计划者给出的目标方向组合，以便以倒退的地平线方式确定最佳动作序列。为了展示该方法，我们开发了集成轻量级传感和计算资源的弹性小型飞行机器人。进行了一组模拟和实验研究，包括杂乱和感知挑战性环境的现场部署，以评估预测网络的质量和所提出的规划师的性能。

This paper presents an image-based visual servo control (IBVS) method for a first-person-view (FPV) quadrotor to conduct aggressive aerial tracking. There are three major challenges to maneuvering an underactuated vehicle using IBVS: (i) finding a visual feature representation that is robust to large rotations and is suited to be an optimization variable; (ii) keeping the target visible without sacrificing the robot's agility; and (iii) compensating for the rotational effects in the detected features. We propose a complete design framework to address these problems. First, we employ a rotation on $SO(3)$ to represent a spherical image feature on $S^{2}$ to gain singularity-free and second-order differentiable properties. To ensure target visibility, we formulate the IBVS as a nonlinear model predictive control (NMPC) problem with three constraints taken into account: the robot's physical limits, target visibility, and time-to-collision (TTC). Furthermore, we propose a novel attitude-compensation scheme to enable formulating the visibility constraint in the actual image plane instead of a virtual fix-orientation image plane. It guarantees that the visibility constraint is valid under large rotations. Extensive experimental results show that our method can track a fast-moving target stably and aggressively without the aid of a localization system.

近年来，空中机器人背景下的高速导航和环境互动已成为几个学术和工业研究研究的兴趣领域。特别是，由于其若干环境中的潜在可用性，因此搜索和拦截（SAI）应用程序造成引人注目的研究区域。尽管如此，SAI任务涉及有关感官权重，板载计算资源，致动设计和感知和控制算法的具有挑战性的发展。在这项工作中，已经提出了一种用于高速对象抓握的全自动空中机器人。作为一个额外的子任务，我们的系统能够自主地刺穿位于靠近表面的杆中的气球。我们的第一款贡献是在致动和感觉水平的致动和感觉水平的空中机器人的设计，包括具有额外传感器的新型夹具设计，使机器人能够高速抓住物体。第二种贡献是一种完整的软件框架，包括感知，状态估计，运动计划，运动控制和任务控制，以便快速且强大地执行自主掌握任务。我们的方法已在一个具有挑战性的国际竞争中验证，并显示出突出的结果，能够在室外环境中以6米/分来自动搜索，遵循和掌握移动物体

四型是敏捷平台。对于人类专家，他们可以在混乱的环境中进行极高的高速航班。但是，高速自主飞行仍然是一个重大挑战。在这项工作中，我们提出了一种基于走廊约束的最小控制工作轨迹优化（MINCO）框架的运动计划算法。具体而言，我们使用一系列重叠球来表示环境的自由空间，并提出了两种新型设计，使算法能够实时计划高速四轨轨迹。一种是一种基于采样的走廊生成方法，该方法在两个相邻球之间生成具有大型重叠区域（因此总走廊大小）的球体。第二个是一个后退的地平线走廊（RHC）策略，其中部分生成的走廊在每个补给中都重复使用。这两种设计一起，根据四极管的当前状态扩大走廊的空间，因此使四极管可以高速操纵。我们根据其他最先进的计划方法基准了我们的算法，以显示其在模拟中的优势。还进行了全面的消融研究，以显示这两种设计的必要性。最终在木材环境中对自动激光雷达四型二次无人机进行了评估，该方法的飞行速度超过13.7 m/s，而没有任何先前的环境或外部定位设施图。