安全始终是航空的优先事项。但是,当前的最新被动断层控制太保守了,无法使用。当前的最新主动故障控制需要时间进行故障检测和诊断以及控制切换。但是以后可能会恢复受损的飞机。大多数设计取决于确定为先验的故障,无法处理故障,从而导致原始系统的状态无法控制。但是,经验丰富的人类飞行员可以尽可能地节省发球障碍的飞机。由此激励,本文制定了一个原则,试图解释背后的人类飞行员行为,创造了重力补偿优先原则。这进一步支持了对飞机的可靠飞行控制,例如四轮驱动器和尾灯无人驾驶汽车。
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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.
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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.
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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.
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This book provides a solution to the control and motion planning design for an octocopter system. It includes a particular choice of control and motion planning algorithms which is based on the authors' previous research work, so it can be used as a reference design guidance for students, researchers as well as autonomous vehicles hobbyists. The control is constructed based on a fault tolerant approach aiming to increase the chances of the system to detect and isolate a potential failure in order to produce feasible control signals to the remaining active motors. The used motion planning algorithm is risk-aware by means that it takes into account the constraints related to the fault-dependant and mission-related maneuverability analysis of the octocopter system during the planning stage. Such a planner generates only those reference trajectories along which the octocopter system would be safe and capable of good tracking in case of a single motor fault and of majority of double motor fault scenarios. The control and motion planning algorithms presented in the book aim to increase the overall reliability of the system for completing the mission.
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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。
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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.
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对于腿部机器人,航空动作是唯一可以通过标准运动步态绕过的障碍物的唯一选择。在这些情况下,机器人必须进行飞跃,以跳到障碍物或飞越障碍物上。但是,这些运动代表了一个挑战,因为在飞行阶段\ gls {com}无法控制,并且机器人方向的可控性有限。本文重点介绍了后一个问题,并提出了一个由两个旋转和驱动的质量(飞轮或反应轮)组成的\ gls {ocs},以获得机器人方向的控制权。由于角动量的保护,即使与地面没有接触,它们的旋转速度也可以调节以引导机器人方向。飞轮的旋转轴设计为入射,导致一个紧凑的方向控制系统,该系统能够控制滚动和俯仰角,考虑到这两个方向的不同惯性矩。我们通过机器人Solo12上的模拟测试了该概念。
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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。
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提出了一种能够改变形状中空飞行的新型Quadcopter,允许在四种配置中进行操作,其中包含持续的悬停在三个配置中。这是实现的,而不需要超出Quadcopter典型的四个电动机的执行器。通过自由旋转铰链来实现变形,使车臂通过减少或逆转推力向下折叠。放置在车辆的控制输入上的约束防止臂意外折叠或展开。这允许使用现有的四转器控制器和轨迹生成算法,只有最小的增加的复杂性。对于我们在悬停的实验载体中,我们发现这些约束导致车辆可以产生的最大偏航扭矩的36%减少,但不会导致最大推力或卷和螺距扭矩的减少。实验结果表明,对于典型的操纵,增加的限制对轨迹跟踪性能的影响忽略不计。最后,示出了改变配置的能力,使车辆能够在悬挂导线上移动小通道,并且执行有限的抓取任务。
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本文提出了一种用于特技飞行轨迹生成的新型算法,用于垂直起飞和降落(VTOL)TAILSITTER飞行飞机。该算法与固定翼轨迹生成的现有方法不同,因为它考虑了现实的六度自由度(6DOF)飞行动力学模型,包括空气动力学方程。使用全球动力学模型,能够生成特技轨迹,从而利用整个飞行信封,从而使敏捷的操纵通过摊位策略,侧向飞行,倒置飞行等。是在这项工作中得出的。通过在差异平坦的输出空间中执行快速最小化,可以获得适合在线运动计划的计算高效算法。该算法在包括六架特技飞行器的大型飞行实验中证明了这一算法,一个时间优势的无人机赛车轨迹以及三架尾灯飞机的飞机样有机赛序列。
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This paper introduces a structure-deformable land-air robot which possesses both excellent ground driving and flying ability, with smooth switching mechanism between two modes. The elaborate coupled dynamics model of the proposed robot is established, including rotors, chassis, especially the deformable structures. Furthermore, taking fusion locomotion and complex near-ground situations into consideration, a model based controller is designed for landing and mode switching under various harsh conditions, in which we realise the cooperation between fused two motion modes. The entire system is implemented in ADAMS/Simulink simulation and in practical. We conduct experiments under various complex scenarios. The results show our robot can accomplish land-air switching swiftly and smoothly, and the designed controller can effectively improve the landing flexibility and reliability.
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从生物力学的角度来看,秋千臂在通过更大的角动量控制空间通过更大的角动量控制空间来促进两体机器人的高度动态运动方面具有不可替代的作用。由于缺乏适当的运动控制策略,很少有双足机器人使用摇摆臂及其多个自由度的冗余特征来完美整合建模和控制。本文通过将两足机器人建模为飞轮弹簧载倒摆(F-SLIP)来提取挥杆臂的特征并使用全身控制器(WBC)来实现这些特征,并提出了建议,并提出了建议,也建议您提出,则本文提出了一种控制策略。一个评估系统,包括美国定义的敏捷性的三个方面,双皮亚机器人高度动态运动的稳定性和能耗。我们设计了几组仿真实验,并根据评估系统的紫色运动(东方紫能量上升)V1.0分析了摇臂的效果,这是一种旨在测试高爆炸性运动的两足机器人。结果表明,紫色的敏捷性增加了10%以上,稳定时间减少了两倍,并且引入挥杆臂后,能源消耗降低了20%以上。
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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。
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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。
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随着垂直起飞和着陆和长航时的特点,倾转旋翼吸引了相当多的关注近几十年来其在民用和科研应用潜力。然而,强耦合,非线性特性和不匹配的干扰的问题,不可避免地存在于倾转旋翼机,它带来的过渡模式控制器的设计极大的挑战。在本文中,我们结合一个超扭曲扩张状态观测器(STESO)具有自适应递归滑模控制(ARSMC)一起使用STESO-ARSMC(SAC)来设计以过渡模式倾转旋翼飞行器姿态系统控制器。首先,六个自由度的倾转旋翼的(DOF)的非线性数学模型被建立。其次,美国和干扰是由STES观察者估计。第三,ARSM控制器旨在实现有限时间内收敛。 Lyapunov函数用来作证的倾转旋翼无人机系统的融合。新的方面是,状态的评估被并入控制规则来调整中断。相较于先前技术,控制系统,这项工作可以大大提高抗干扰性能提出。最后,模拟试验,是要证明建议的技术的有效性。
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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。
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全向多旋转器具有脱钩的转换和旋转运动的有利的可操作性,可以极大地取代传统的多电气运动能力。这样的可操作性需要全向多旋转器,才能经常改变推力振幅甚至方向,这是转子从转子自身动态引起的沉降时间的容易产生的。此外,在存在转子动力学的情况下,全向多动物在跟踪控制的稳定性尚未得到解决。为了解决此问题,我们提出了一个几何跟踪控制器,该控制器考虑了转子动力学。我们表明,所提出的控制器几乎呈指数稳定的误差动力学的零平衡。在模拟中验证了控制器的跟踪性能和稳定性。此外,已经执行了具有全向多动物的单轴力实验,以确认所提出的控制器在减轻现实世界中转子的沉降时间方面的性能。
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用无人驾驶飞行器(无人机)的操纵和抓住目前需要准确定位,并且通常以减小的速度执行,以确保成功的掌握。这是由于典型的无人机只能容纳具有少量自由度的刚性机械手,这限制了它们可以补偿由车辆定位误差引起的扰动的能力。此外,无人机必须最小化外部接触力以保持稳定性。另一方面,生物系统利用柔软度来克服类似的限制,并利用遵守来实现积极的抓握。本文调查了软空气机械手的控制和轨迹优化,由四射线和肌腱驱动的软夹持器组成,其中可以充分利用柔软度的优点。据我们所知,这是软操作和UAV控制之间交叉路口的第一个工作。我们介绍了四轮电机和软夹具的解耦方法,组合(i)几何控制器和四峰值(刚性)基础的最小拍摄轨迹优化,(ii)准静态有限元模型和控制空间软夹具的插值。我们证明了尽管添加了软载荷,但几何控制器渐近稳定了四轮流速度和姿态。最后,我们在逼真的软动力学模拟器中评估所提出的系统,并表明:(i)几何控制器对软有效载荷相对不敏感,(ii)尽管定位和初始条件不准确和初始条件,平台可以可靠地掌握未知对象,以及(iii)解耦控制器可用于实时执行。
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为了追踪和运动捕获(MOCAP)在其自然栖息地中的动物,非常适合安全和无声的空中平台,例如带有车载摄像机的飞艇。但是,与多旋转器不同,飞艇受到严格的运动限制和受环境风的影响。它们的方向和飞行方向也紧密耦合。因此,用于感知任务的基于最新的MPC的形成控制方法不适用于飞艇团队。在本文中,我们首先利用飞艇的空速与其与主题的距离之间的定期关系来解决这个问题。我们使用它来得出满足MOCAP感知约束的分析和数字解决方案。基于此,我们开发了一个基于MPC的编队控制器。我们对解决方案进行了详细的分析,包括改变物理参数(例如攻击角度和俯仰角)的影响。提出了广泛的仿真实验,比较了不同的形成大小,不同的风条件和各种受试者速度的结果。还包括我们关于真实飞艇的方法的演示。我们已经在https://github.com/robot-pocepepon-group/airship-mpc上发布了所有源代码。可以在https://youtu.be/ihs0_vrd_kk上观看描述我们方法和结果的视频。
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