开发了一个领导者追随者系统,用于合作运输。据我们所知,这是一个不需要互联通信的第一工作,并且可以实时修改有效载荷的参考轨迹,以便它可以应用于动态变化的环境。为了在无通信条件下实时跟踪修改的参考轨迹,引导跟随系统被认为是非文展系统,其中开发了控制器以实现有效载荷的渐近跟踪。为了消除安装力传感器的需要,开发了UKFS(Unscented Kalman滤波器)以估计领导者和追随者所施加的力量。进行稳定性分析以证明闭环系统的跟踪误差。仿真结果表明跟踪控制器的良好性能。实验表明,领导者的控制器和追随者可以在现实世界中工作,但是跟踪误差受到限制空间中气流的干扰的影响。
translated by 谷歌翻译
在本文中,我们分析了具有基于视觉导航的无人机(UAV)的时间延迟动力学对控制器设计的影响。时间延迟是网络物理系统中不可避免的现象,并且对无人机的控制器设计和轨迹产生具有重要意义。时间延迟对无人机动态的影响随着基于视力较慢的导航堆栈的使用而增加。我们表明,文献中的现有模型不包括时间延迟,不适合控制器调整,因为一个微不足道的解决方案始终存在错误的解决方案。我们确定的微不足道的解决方案表明,使用无限控制器的利益来实现最佳性能,这与实际发现相矛盾。我们通过引入无人机的新型非线性时间延迟模型来避免这种缺点,然后获得与每个UAV控制回路相对应的一组线性解耦模型。分析了角度和高度动力学的线性时间延迟模型的成本函数,与无延迟模型相反,我们显示了有限的最佳控制器参数的存在。由于使用了时间延迟模型,我们在实验上表明,所提出的模型准确地表示系统稳定性限制。由于时间延迟的考虑,我们使用基于视觉探视的无人机(VO)导航,在跟踪峰值速度为2.09 m/s的lemsistate轨迹时,我们实现了RMSE 5.01 cm的跟踪结果,这与最新-艺术。
translated by 谷歌翻译
本文提出了一项新颖的控制法,以使用尾随机翼无人驾驶飞机(UAV)进行准确跟踪敏捷轨迹,该轨道在垂直起飞和降落(VTOL)和向前飞行之间过渡。全球控制配方可以在整个飞行信封中进行操作,包括与Sideslip的不协调的飞行。显示了具有简化空气动力学模型的非线性尾尾动力学的差异平坦度。使用扁平度变换,提出的控制器结合了位置参考的跟踪及其导数速度,加速度和混蛋以及偏航参考和偏航速率。通过角速度进纸术语包含混蛋和偏航率参考,可以改善随着快速变化的加速度跟踪轨迹。控制器不取决于广泛的空气动力学建模,而是使用增量非线性动态反演(INDI)仅基于局部输入输出关系来计算控制更新,从而导致对简化空气动力学方程中差异的稳健性。非线性输入输出关系的精确反转是通过派生的平坦变换实现的。在飞行测试中对所得的控制算法进行了广泛的评估,在该测试中,它展示了准确的轨迹跟踪和挑战性敏捷操作,例如侧向飞行和转弯时的侵略性过渡。
translated by 谷歌翻译
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.
translated by 谷歌翻译
二次运动的准确轨迹跟踪控制对于在混乱环境中的安全导航至关重要。但是,由于非线性动态,复杂的空气动力学效应和驱动约束,这在敏捷飞行中具有挑战性。在本文中,我们通过经验比较两个最先进的控制框架:非线性模型预测控制器(NMPC)和基于差异的控制器(DFBC),通过以速度跟踪各种敏捷轨迹,最多20 m/s(即72 km/h)。比较在模拟和现实世界环境中进行,以系统地评估这两种方法从跟踪准确性,鲁棒性和计算效率的方面。我们以更高的计算时间和数值收敛问题的风险来表明NMPC在跟踪动态不可行的轨迹方面的优势。对于这两种方法,我们还定量研究了使用增量非线性动态反演(INDI)方法添加内环控制器的效果,以及添加空气动力学阻力模型的效果。我们在世界上最大的运动捕获系统之一中进行的真实实验表明,NMPC和DFBC的跟踪误差降低了78%以上,这表明有必要使用内环控制器和用于敏捷轨迹轨迹跟踪的空气动力学阻力模型。
translated by 谷歌翻译
在本文中,提出了一个稳定稳定的轨迹跟踪控制器,用于多uav有效载荷运输。多uav有效负载系统在无人机和有效负载框架的垂直刚性链接之间具有2DOF磁球接头,因此无人机可以自由滚动或自由投球。这些垂直链接紧密地连接到有效载荷上,无法移动。为完整的有效载体 - uav系统得出了输入输出反馈线性化模型以及有效载荷轨迹跟踪的推力矢量控制。关于跟踪控制定律的理论分析表明,控制定律是指数稳定的,从而确保了沿期望轨迹的安全运输。为了验证拟议的控制定律的性能,提供了数值模拟以及高保真凉亭实时仿真的结果。接下来,针对两种实际情况分析了提议的控制器的鲁棒性:有效载荷和有效载荷质量不确定性的外部干扰。结果清楚地表明,所提出的控制器在实现指数稳定的轨迹跟踪的同时具有稳健性和计算效率。
translated by 谷歌翻译
该论文提出了两种控制方法,用于用微型四轮驱动器进行反弹式操纵。首先,对专门为反转设计设计的现有前馈控制策略进行了修订和改进。使用替代高斯工艺模型的贝叶斯优化通过在模拟环境中反复执行翻转操作来找到最佳运动原语序列。第二种方法基于闭环控制,它由两个主要步骤组成:首先,即使在模型不确定性的情况下,自适应控制器也旨在提供可靠的参考跟踪。控制器是通过通过测量数据调整的高斯过程来增强无人机的标称模型来构建的。其次,提出了一种有效的轨迹计划算法,该算法仅使用二次编程来设计可行的轨迹为反弹操作设计。在模拟和使用BitCraze Crazyflie 2.1四肢旋转器中对两种方法进行了分析。
translated by 谷歌翻译
This paper proposes a novel observer-based controller for Vertical Take-Off and Landing (VTOL) Unmanned Aerial Vehicle (UAV) designed to directly receive measurements from a Vision-Aided Inertial Navigation System (VA-INS) and produce the required thrust and rotational torque inputs. The VA-INS is composed of a vision unit (monocular or stereo camera) and a typical low-cost 6-axis Inertial Measurement Unit (IMU) equipped with an accelerometer and a gyroscope. A major benefit of this approach is its applicability for environments where the Global Positioning System (GPS) is inaccessible. The proposed VTOL-UAV observer utilizes IMU and feature measurements to accurately estimate attitude (orientation), gyroscope bias, position, and linear velocity. Ability to use VA-INS measurements directly makes the proposed observer design more computationally efficient as it obviates the need for attitude and position reconstruction. Once the motion components are estimated, the observer-based controller is used to control the VTOL-UAV attitude, angular velocity, position, and linear velocity guiding the vehicle along the desired trajectory in six degrees of freedom (6 DoF). The closed-loop estimation and the control errors of the observer-based controller are proven to be exponentially stable starting from almost any initial condition. To achieve global and unique VTOL-UAV representation in 6 DoF, the proposed approach is posed on the Lie Group and the design in unit-quaternion is presented. Although the proposed approach is described in a continuous form, the discrete version is provided and tested. Keywords: Vision-aided inertial navigation system, unmanned aerial vehicle, vertical take-off and landing, stochastic, noise, Robotics, control systems, air mobility, observer-based controller algorithm, landmark measurement, exponential stability.
translated by 谷歌翻译
我们提出了通过现实的模拟和现实世界实验来支持可复制研究的多运动无人机控制(UAV)和估计系统。我们提出了一个独特的多帧本地化范式,用于同时使用多个传感器同时估算各种参考框架中的无人机状态。该系统可以在GNSS和GNSS贬低的环境中进行复杂的任务,包括室外室内过渡和执行冗余估计器,以备份不可靠的本地化源。提出了两种反馈控制设计:一个用于精确和激进的操作,另一个用于稳定和平稳的飞行,并进行嘈杂的状态估计。拟议的控制和估计管道是在3D中使用Euler/Tait-Bryan角度表示的,而无需使用Euler/Tait-Bryan角度表示。取而代之的是,我们依靠旋转矩阵和一个新颖的基于标题的惯例来代表标准多电流直升机3D中的一个自由旋转自由度。我们提供了积极维护且有据可查的开源实现,包括对无人机,传感器和本地化系统的现实模拟。拟议的系统是多年应用系统,空中群,空中操纵,运动计划和遥感的多年研究产物。我们所有的结果都得到了现实世界中的部署的支持,该系统部署将系统塑造成此处介绍的表单。此外,该系统是在我们团队从布拉格的CTU参与期间使用的,该系统在享有声望的MBZIRC 2017和2020 Robotics竞赛中,还参加了DARPA SubT挑战赛。每次,我们的团队都能在世界各地最好的竞争对手中获得最高位置。在每种情况下,挑战都促使团队改善系统,并在紧迫的期限内获得大量高质量的体验。
translated by 谷歌翻译
Hybrid unmanned aerial vehicles (UAVs) integrate the efficient forward flight of fixed-wing and vertical takeoff and landing (VTOL) capabilities of multicopter UAVs. This paper presents the modeling, control and simulation of a new type of hybrid micro-small UAVs, coined as lifting-wing quadcopters. The airframe orientation of the lifting wing needs to tilt a specific angle often within $ 45$ degrees, neither nearly $ 90$ nor approximately $ 0$ degrees. Compared with some convertiplane and tail-sitter UAVs, the lifting-wing quadcopter has a highly reliable structure, robust wind resistance, low cruise speed and reliable transition flight, making it potential to work fully-autonomous outdoor or some confined airspace indoor. In the modeling part, forces and moments generated by both lifting wing and rotors are considered. Based on the established model, a unified controller for the full flight phase is designed. The controller has the capability of uniformly treating the hovering and forward flight, and enables a continuous transition between two modes, depending on the velocity command. What is more, by taking rotor thrust and aerodynamic force under consideration simultaneously, a control allocation based on optimization is utilized to realize cooperative control for energy saving. Finally, comprehensive Hardware-In-the-Loop (HIL) simulations are performed to verify the advantages of the designed aircraft and the proposed controller.
translated by 谷歌翻译
In this paper, we propose an effective unified control law for accurately tracking agile trajectories for lifting-wing quadcopters with different installation angles, which have the capability of vertical takeoff and landing (VTOL) as well as high-speed cruise flight. First, we derive a differential flatness transform for the lifting-wing dynamics with a nonlinear model under coordinated turn condition. To increase the tracking performance on agile trajectories, the proposed controller incorporates the state and input variables calculated from differential flatness as feedforward. In particular, the jerk, the 3-order derivative of the trajectory, is converted into angular velocity as a feedforward item, which significantly improves the system bandwidth. At the same time, feedback and feedforward outputs are combined to deal with external disturbances and model mismatch. The control algorithm has been thoroughly evaluated in the outdoor flight tests, which show that it can achieve accurate trajectory tracking.
translated by 谷歌翻译
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$^2$.
translated by 谷歌翻译
在过去的几年中,无人驾驶汽车(UAV)的领域已经达到了高水平的成熟度。因此,将此类平台从封闭的实验室带到与人类的日常互动对于无人机的商业化很重要。本文的一种特殊人类企业感兴趣的方案是有效载荷切换计划,无人机应要求人将有效载荷移交给人类的有效载荷。在此范围内,本文提出了一种新型的实时人类UAV相互作用检测方法,其中开发了基于短期记忆(LSTM)的神经网络,以检测由人类相互作用动态导致的状态概况。提出了一种新的数据预处理技术;该技术利用培训和测试无人机的估计过程参数来构建动态不变测试数据。提出的检测算法是轻量级的,因此可以使用Off Shelf UAV平台实时部署;此外,它仅取决于任何经典无人机平台上存在的惯性和位置测量。提出的方法是在多电动无人机和人类之间的有效载荷切换任务上证明的。使用实时实验收集培训和测试数据。检测方法的准确性为96 \%,即使存在外部风干扰,也没有误报,并且在两种不同的无人机上进行部署和测试时。
translated by 谷歌翻译
空中操纵的生长场通常依赖于完全致动的或全向微型航空车(OMAV),它们可以在与环境接触时施加任意力和扭矩。控制方法通常基于无模型方法,将高级扳手控制器与执行器分配分开。如有必要,在线骚扰观察员拒绝干扰。但是,虽然是一般,但这种方法通常会产生次优控制命令,并且不能纳入平台设计给出的约束。我们提出了两种基于模型的方法来控制OMAV,以实现轨迹跟踪的任务,同时拒绝干扰。第一个通过从实验数据中学到的模型来优化扳手命令并补偿模型错误。第二个功能优化了低级执行器命令,允许利用分配无空格并考虑执行器硬件给出的约束。在现实世界实验中显示和评估两种方法的疗效和实时可行性。
translated by 谷歌翻译
在腿的运动中重新规划对于追踪所需的用户速度,在适应地形并拒绝外部干扰的同时至关重要。在这项工作中,我们提出并测试了实验中的实时非线性模型预测控制(NMPC),用于腿部机器人,以实现各种地形上的动态运动。我们引入了一种基于移动性的标准来定义NMPC成本,增强了二次机器人的运动,同时最大化腿部移动性并提高对地形特征的适应。我们的NMPC基于实时迭代方案,使我们能够以25美元的价格重新计划在线,\ Mathrm {Hz} $ 2 $ 2 $ 2美元的预测地平线。我们使用在质量框架中心中定义的单个刚体动态模型,以提高计算效率。在仿真中,测试NMPC以横穿一组不同尺寸的托盘,走进V形烟囱,并在崎岖的地形上招揽。在真实实验中,我们展示了我们的NMPC与移动功能的有效性,使IIT为87美元\,\ Mathrm {kg} $四分之一的机器人HIQ,以实现平坦地形上的全方位步行,横穿静态托盘,并适应在散步期间重新定位托盘。
translated by 谷歌翻译
以前已经评估过使用轮毂,无人驾驶飞机,立方体,小萨特人等进行空中和地面操纵,感知和侦察的可行性。在所有这些解决方案中,基于气球的系统具有使其极具吸引力的优点,例如,简单的操作机构和持久的操作时间。但是,在基于气球的应用中,有许多障碍要克服,以实现强大的游荡性能。我们试图确定设计和控制挑战,并提出一个新型的机器人平台,该平台允许在火星陨石坑的侦察和感知中应用气球。这项工作简要涵盖了我们建议的驱动和模型预测控制设计框架,用于转向此类气球系统。我们提出了多个无人接地车辆(UGV)的协调伺服,以调节电缆驱动的气球中的张力,并将其连接到未成熟的悬挂有效载荷上。
translated by 谷歌翻译
稳定性和安全性是成功部署自动控制系统的关键特性。作为一个激励示例,请考虑在复杂的环境中自动移动机器人导航。概括到不同操作条件的控制设计需要系统动力学模型,鲁棒性建模错误以及对安全\ newzl {约束}的满意度,例如避免碰撞。本文开发了一个神经普通微分方程网络,以从轨迹数据中学习哈密顿系统的动态。学识渊博的哈密顿模型用于合成基于能量的被动性控制器,并分析其\ emph {鲁棒性},以在学习模型及其\ emph {Safety}中对环境施加的约束。考虑到系统的所需参考路径,我们使用虚拟参考调查员扩展了设计,以实现跟踪控制。州长国家是一个调节点,沿参考路径移动,平衡系统能级,模型不确定性界限以及违反安全性的距离,以确保稳健性和安全性。我们的哈密顿动力学学习和跟踪控制技术在\修订后的{模拟的己谐和四型机器人}在混乱的3D环境中导航。
translated by 谷歌翻译
微空中车辆(MAVS)在户外操作的限制靠近障碍物,通过他们承受风阵风的能力。目前广泛的位置控制方法,例如比例整体衍生物控制在阵风的影响下不会均匀。增量非线性动态反转(INDI)是一种基于传感器的控制技术,可以控制受扰动的非线性系统。它是为载人飞机或MAVS的态度控制而开发的。在本文中,我们将这种方法概括为严重燃烧负载下MAV的外环控制。在一个实验中对传统的比例积分衍生物(PID)控制器的显着改进进行了说明,其中四轮电机在10米/秒的吹风机排气进出中。控制方法不依赖于频繁的位置更新,如使用标准GPS模块的外部实验中所示。最后,我们研究了使用线性化来计算推力向量增量的效果,与非线性计算相比。该方法需要很少的建模并且是计算效率。
translated by 谷歌翻译
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.
translated by 谷歌翻译
跟踪位置和方向独立提供了更敏捷的动作,以实现过度射击的多旋翼无人机(UAV),同时引入了不希望的倒入效果;推力发电机产生的倾斜流可能会因接近性而抵消其他流动,从而极大地威胁了平台的稳定性。建模空气动力气流的复杂性挑战了适当补偿这种副作用的算法。利用无人机分配的输入冗余,我们通过新的控制分配框架来解决此问题,该框架考虑了倾斜效果,并探索了整个分配空间以获得最佳解决方案。该最佳解决方案避免了倾斜效果,同时在硬件约束中提供了高推力效率。据我们所知,我们的是第一个调查对过度驱动无人机的倾斜影响的正式推导。我们在模拟和实验中验证了不同硬件配置的框架。
translated by 谷歌翻译