本文为自动驾驶车辆提供了基于激光雷达的同时定位和映射（SLAM）。研究了来自地标传感器的数据和自适应卡尔曼滤波器（KF）中的带状惯性测量单元（IMU）加上系统的可观察性。除了车辆的状态和具有里程碑意义的位置外，自我调整过滤器还估计IMU校准参数以及测量噪声的协方差。流程噪声，状态过渡矩阵和观察灵敏度矩阵的离散时间协方差矩阵以封闭形式得出，使其适合实时实现。检查3D SLAM系统的可观察性得出的结论是，该系统在地标对准的几何条件下仍然可以观察到。

姿势估计对于机器人感知，路径计划等很重要。机器人姿势可以在基质谎言组上建模，并且通常通过基于滤波器的方法进行估算。在本文中，我们在存在随机噪声的情况下建立了不变扩展Kalman滤波器（IEKF）的误差公式，并将其应用于视觉辅助惯性导航。我们通过OpenVINS平台上的数值模拟和实验评估我们的算法。在Euroc公共MAV数据集上执行的仿真和实验都表明，我们的算法优于某些基于最先进的滤波器方法，例如基于Quaternion的EKF，首先估计Jacobian EKF等。

近几十年来，Camera-IMU（惯性测量单元）传感器融合已经过度研究。已经提出了具有自校准的运动估计的许多可观察性分析和融合方案。然而，它一直不确定是否在一般运动下观察到相机和IMU内在参数。为了回答这个问题，我们首先证明，对于全球快门Camera-IMU系统，所有内在和外在参数都可以观察到未知的地标。鉴于此，滚动快门（RS）相机的时间偏移和读出时间也证明是可观察到的。接下来，为了验证该分析并解决静止期间结构无轨滤波器的漂移问题，我们开发了一种基于关键帧的滑动窗滤波器（KSWF），用于测量和自校准，它适用于单眼RS摄像机或立体声RS摄像机。虽然关键帧概念广泛用于基于视觉的传感器融合，但对于我们的知识，KSWF是支持自我校准的首先。我们的模拟和实际数据测试验证了，可以使用不同运动的机会主义地标的观察来完全校准相机-IMU系统。实际数据测试确认了先前的典故，即保持状态矢量的地标可以弥补静止漂移，并显示基于关键帧的方案是替代治疗方法。

Visual Inertial Odometry (VIO) is the problem of estimating a robot's trajectory by combining information from an inertial measurement unit (IMU) and a camera, and is of great interest to the robotics community. This paper develops a novel Lie group symmetry for the VIO problem and applies the recently proposed equivariant filter. The symmetry is shown to be compatible with the invariance of the VIO reference frame, lead to exact linearisation of bias-free IMU dynamics, and provide equivariance of the visual measurement function. As a result, the equivariant filter (EqF) based on this Lie group is a consistent estimator for VIO with lower linearisation error in the propagation of state dynamics and a higher order equivariant output approximation than standard formulations. Experimental results on the popular EuRoC and UZH FPV datasets demonstrate that the proposed system outperforms other state-of-the-art VIO algorithms in terms of both speed and accuracy.

We propose a multisensor fusion framework for onboard real-time navigation of a quadrotor in an indoor environment, by integrating sensor readings from an Inertial Measurement Unit (IMU), a camera-based object detection algorithm, and an Ultra-WideBand (UWB) localization system. The sensor readings from the camera-based object detection algorithm and the UWB localization system arrive intermittently, since the measurements are not readily available. We design a Kalman filter that manages intermittent observations in order to handle and fuse the readings and estimate the pose of the quadrotor for tracking a predefined trajectory. The system is implemented via a Hardware-in-the-loop (HIL) simulation technique, in which the dynamic model of the quadrotor is simulated in an open-source 3D robotics simulator tool, and the whole navigation system is implemented on Artificial Intelligence (AI) enabled edge GPU. The simulation results show that our proposed framework offers low positioning and trajectory errors, while handling intermittent sensor measurements.

本文提出了一种容忍故障的3D视觉系统，用于自动机器人操作。特别是，使用集成的Kalman滤波器（KF）中的3D视觉数据和闭环配置中的迭代最接近点（ICP）算法来实现空间对象的姿势估计。内部ICP迭代的最初猜测是由卡尔曼申报人的国家估计传播提供的。卡尔曼过滤器不仅能够估计目标状态，还可以估算其惯性参数。这允许目标一旦滤波，目标就可以预测。因此，由于ICP初始化的精度提高，ICP可以在更广泛的速度上保持姿势跟踪。此外，即使传感器暂时失去其信号，估计器即使由于阻塞造成的损失，估计器将目标的动力学模型纳入估计器中。姿势估计方法的功能通过自动化合作和对接的地面测试床证明。在该实验中，Neptec的激光摄像头系统（LCS）用于对连接到操纵器臂的卫星模型进行实时扫描，该卫星模型是根据轨道和态度动力学驱动的。结果表明，只有在Kalman滤波器和ICP处于闭环配置时，才能实现自由浮动翻滚卫星的可靠跟踪。

虽然已经提出了用于国家估计的利用现有LIE组结构的许多作品，但特别是不变的扩展卡尔曼滤波器（IEKF），少数论文解决了允许给定系统进入IEKF框架的组结构的构造，即制造动态群体染色和观察不变。在本文中，我们介绍了大量系统，包括涉及在实践中遇到的导航车辆的大多数问题。对于那些系统，我们介绍一种新的方法，系统地为状态空间提供组结构，包括诸如偏差的车身框架的载体。我们使用它来派生与线性观察者或过滤器那些类似的观察者。建议的统一和多功能框架包括IHKF已经成功的所有系统，改善了用于传感器偏差的惯性导航的最新的“不完美”IEKF，并且允许寻址新颖的示例，如GNSS天线杆臂估计。

我们为腿部机器人提供了一个开源视觉惯性训练率（VILO）状态估计解决方案Cerberus，该机器人使用一组标准传感器（包括立体声摄像机，IMU，联合编码器，，imu，联合编码器）实时实时估算各个地形的位置和接触传感器。除了估计机器人状态外，我们还执行在线运动学参数校准并接触离群值拒绝以大大减少位置漂移。在各种室内和室外环境中进行的硬件实验验证了Cerberus中的运动学参数可以将估计的漂移降低到长距离高速运动中的1％以下。我们的漂移结果比文献中报道的相同的一组传感器组比任何其他状态估计方法都要好。此外，即使机器人经历了巨大的影响和摄像头遮挡，我们的状态估计器也表现良好。状态估计器的实现以及用于计算我们结果的数据集，可在https://github.com/shuoyangrobotics/cerberus上获得。

近年来，视觉惯性进程（VIO）取得了许多重大进展。但是，VIO方法遭受了长期轨迹的定位漂移。在本文中，我们建议通过将超宽带（UWB）的范围测量纳入VIO框架\ TextIt {Conseply}，提议首次估计Jacobian Visual惯性范围射程（FEJ-VIRO）来减少VIO的定位漂移。考虑到UWB锚的初始位置通常不可用，我们提出了一个长短的窗口结构，以初始化UWB锚位置以及状态增强的协方差。初始化后，FEJ-VIRO与机器人姿势同时估算了UWB锚定位置。我们进一步分析了视觉惯性范围估计器的可观察性，并证明了理想情况下存在\ textit {fortiT {fortiT {fortiT {四}，而其中一个在实际情况下由于浪费信息而消失。基于这些分析，我们利用FEJ技术来执行不可观察的方向，从而减少估计器的不一致。最后，我们通过模拟和现实世界实验验证分析并评估所提出的FEJ-VIRO。

用于在线状态估计的随机过滤器是自治系统的核心技术。此类过滤器的性能是系统能力的关键限制因素之一。此类过滤器的渐近行为（例如，用于常规操作）和瞬态响应（例如，对于快速初始化和重置）对于保证自主系统的稳健操作至关重要。本文使用n个方向测量值（包括车身框架和参考框架方向类型测量值）引入了陀螺仪辅助姿态估计器的新通用公式。该方法基于一种集成状态公式，该公式结合了导航，所有方向传感器的外部校准以及在单个模棱两可的几何结构中的陀螺式偏置状态。这种新提出的对称性允许模块化的不同方向测量及其外部校准，同时保持在同一对称性中包括偏置态的能力。随后使用此对称性的基于滤波器的估计量明显改善了瞬态响应，与最新方法相比，渐近偏置和外部校准估计。估计器在统计代表性的模拟中得到了验证，并在现实世界实验中进行了测试。

滑动检测对于在外星人表面驾驶的流浪者的安全性和效率至关重要。当前的行星流动站滑移检测系统依赖于视觉感知，假设可以在环境中获得足够的视觉特征。然而，基于视觉的方法容易受到感知降解的行星环境，具有主要低地形特征，例如岩石岩，冰川地形，盐散发物以及较差的照明条件，例如黑暗的洞穴和永久阴影区域。仅依靠视觉传感器进行滑动检测也需要额外的计算功率，并降低了流动站的遍历速率。本文回答了如何检测行星漫游者的车轮滑移而不取决于视觉感知的问题。在这方面，我们提出了一个滑动检测系统，该系统从本体感受的本地化框架中获取信息，该框架能够提供数百米的可靠，连续和计算有效的状态估计。这是通过使用零速度更新，零角度更新和非独立限制作为惯性导航系统框架的伪测量更新来完成的。对所提出的方法进行了对实际硬件的评估，并在行星 - 分析环境中进行了现场测试。该方法仅使用IMU和车轮编码器就可以达到150 m左右的92％滑动检测精度。

The performance of inertial navigation systems is largely dependent on the stable flow of external measurements and information to guarantee continuous filter updates and bind the inertial solution drift. Platforms in different operational environments may be prevented at some point from receiving external measurements, thus exposing their navigation solution to drift. Over the years, a wide variety of works have been proposed to overcome this shortcoming, by exploiting knowledge of the system current conditions and turning it into an applicable source of information to update the navigation filter. This paper aims to provide an extensive survey of information aided navigation, broadly classified into direct, indirect, and model aiding. Each approach is described by the notable works that implemented its concept, use cases, relevant state updates, and their corresponding measurement models. By matching the appropriate constraint to a given scenario, one will be able to improve the navigation solution accuracy, compensate for the lost information, and uncover certain internal states, that would otherwise remain unobservable.

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 .

在本文中，我们提出了一种新颖的观察者来解决视觉同时定位和映射（SLAM）的问题，仅使用来自单眼摄像机和惯性测量单元（IMU）的信息。系统状态在歧管$ se（3）\ times \ mathbb {r} ^ {3n} $上演变，我们在其中仔细设计动态扩展，以便产生不变的叶片，使得问题重新加入在线\ EMPH{常量参数}识别。然后，遵循最近引入的基于参数估计的观察者（PEBO）和动态回归扩展和混合（DREM）过程，我们提供了一个新的简单解决方案。值得注意的优点是，拟议的观察者保证了几乎全局渐近稳定性，既不需要激发的持久性也不是完全可观察性，然而，在大多数现有的工作中广泛采用了保证稳定性。

理想情况下，机器人应该以最大化关于其内部系统和外部操作环境的状态所获得的知识的方式移动。轨迹设计是一个具有挑战性的问题，从各种角度来看，从信息理论分析到基于倾斜的方法。最近，已经提出了基于可观察性的指标来找到能够快速准确的状态和参数估计的轨迹。这些方法的活力和功效尚未在文献中众所周知。在本文中，我们比较了两个最先进的方法，以便可观察性感知轨迹优化，并寻求增加重要的理论澄清和对其整体效力的宝贵讨论。为了评估，我们使用逼真的物理模拟器检查传感器到传感器外部自校准的代表性任务。我们还研究了这些算法的灵敏度，以改变易欣欣传感器测量的信息内容。

本文提出了一种新型数据驱动导航系统，用于在GPS拒绝，特征缺陷的环境中导航无人驾驶车辆（UV），例如隧道或矿山。该方法利用车辆可以部署和测量范围从其使本地化作为车辆穿过隧道预定路径来实现的地标。在此类方案中出现的一个关键问题是估计和减少在使命开始之前需要部署的地标数量，以便在使命开始之前，给定有关环境的一些信息。主要焦点是保持所需值的最大位置不确定性。在本文中，我们通过组合来自估计，机器学习和混合整数凸优化的技术，在GPS拒绝的功能缺陷环境中开发一种新的车辆导航系统。本文开发了一种新颖，系统的方法，用于通过环境执行本地化并通过环境导航UV，同时保持所需的本地化精度。我们还对不同情景进行了广泛的模拟实验，这些实验证实了所提出的导航系统的有效性。

A reliable self-contained navigation system is essential for autonomous vehicles. Based on our previous study on Wheel-INS \cite{niu2019}, a wheel-mounted inertial measurement unit (Wheel-IMU)-based dead reckoning (DR) system, in this paper, we propose a multiple IMUs-based DR solution for the wheeled robots. The IMUs are mounted at different places of the wheeled vehicles to acquire various dynamic information. In particular, at least one IMU has to be mounted at the wheel to measure the wheel velocity and take advantages of the rotation modulation. The system is implemented through a distributed extended Kalman filter structure where each subsystem (corresponding to each IMU) retains and updates its own states separately. The relative position constraints between the multiple IMUs are exploited to further limit the error drift and improve the system robustness. Particularly, we present the DR systems using dual Wheel-IMUs, one Wheel-IMU plus one vehicle body-mounted IMU (Body-IMU), and dual Wheel-IMUs plus one Body-IMU as examples for analysis and comparison. Field tests illustrate that the proposed multi-IMU DR system outperforms the single Wheel-INS in terms of both positioning and heading accuracy. By comparing with the centralized filter, the proposed distributed filter shows unimportant accuracy degradation while holds significant computation efficiency. Moreover, among the three multi-IMU configurations, the one Body-IMU plus one Wheel-IMU design obtains the minimum drift rate. The position drift rates of the three configurations are 0.82\% (dual Wheel-IMUs), 0.69\% (one Body-IMU plus one Wheel-IMU), and 0.73\% (dual Wheel-IMUs plus one Body-IMU), respectively.

Estimation algorithms, such as the sliding window filter, produce an estimate and uncertainty of desired states. This task becomes challenging when the problem involves unobservable states. In these situations, it is critical for the algorithm to ``know what it doesn't know'', meaning that it must maintain the unobservable states as unobservable during algorithm deployment. This letter presents general requirements for maintaining consistency in sliding window filters involving unobservable states. The value of these requirements when designing a navigation solution is experimentally shown within the context of visual-inertial SLAM making use of IMU preintegration.

We propose AstroSLAM, a standalone vision-based solution for autonomous online navigation around an unknown target small celestial body. AstroSLAM is predicated on the formulation of the SLAM problem as an incrementally growing factor graph, facilitated by the use of the GTSAM library and the iSAM2 engine. By combining sensor fusion with orbital motion priors, we achieve improved performance over a baseline SLAM solution. We incorporate orbital motion constraints into the factor graph by devising a novel relative dynamics factor, which links the relative pose of the spacecraft to the problem of predicting trajectories stemming from the motion of the spacecraft in the vicinity of the small body. We demonstrate the excellent performance of AstroSLAM using both real legacy mission imagery and trajectory data courtesy of NASA's Planetary Data System, as well as real in-lab imagery data generated on a 3 degree-of-freedom spacecraft simulator test-bed.

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.