基于方位信息的无人机编队控制设计与验证

本文主要研究了无人机编队的抗扰跟踪控制设计. 针对各无人机只能获取邻机方位信息的情况, 文章设计了一种新的非线性控制器以完成多无人机系统的编队形成与跟踪任务. 考虑到无人机系统易受外界扰动影响的特性, 采用Leader-Follower式编队方法, 通过引入Leader位置信息来矫正基于方位信息的无人机编队系统的位置漂移.将反步法设计结合自适应设计与鲁棒控制设计, 来补偿未知参数与未知外界扰动对多无人机编队系统造成的影响,提高了多无人机方位编队系统的鲁棒性. 然后, 基于Lyapunov分析方法证明了系统的稳定性. 最后, 搭建了四旋翼无人机编队实验平台, 进行了基于方位信息的编队形成与跟踪飞行实验, 并与PD控制器进行了对比实验. 飞行实验结果验证了算法的有效性与实用性.     

基于分布式一致性的无人机编队控制方法

多无人机系统中,系统状态的一致性是实现多无人机协同控制的基础,针对多无人机中存在的三维空间编队控制问题,提出一种分布式一致性的无人机编队协同控制方法。在主机-从机组成的多无人机系统的基础上,引入分布式结构,设计无人机控制系统模型并建立无人机编队协同机制。根据协同机制设计基于一致性算法的协同编队控制器、基于匈牙利算法的任务分配策略以及避障策略。分别在简易模拟器和基于ROS-Gazebo的实景模拟器中仿真验证了协同控制方法的有效性。结果表明：无人机群能够有效地完成协同编队任务,并且可以通过调整层次结构进行有效编队重构。     

多无人机完全分布式有限时间编队控制

针对分布式通信网络,研究多无人机完全分布式编队生成和保持控制问题.基于滑模和自适应方法设计自适应耦合增益,进而结合与邻居无人机之间的相对状态设计一种新的有限时间编队控制器.该算法去掉了传统编队控制器依赖通信网络范围和拓扑及Leader无人机状态等全局信息的限制,基于Lyapunov理论证明无人机编队误差在有限时间可以收敛到边界可调的邻域内.对三维运动的多无人机编队进行仿真验证,结果显示,所设计的编队控制算法可以实现多无人机有限时间完全分布式编队生成和保持.     

有向切换通信拓扑下多无人机分布式编队控制

本文对多无人机分布式时变编队控制问题进行了研究. 无人机之间的通信拓扑假定是有向和切换的. 基于 自身状态与邻居状态的相对局部信息构建了分布式编队控制器. 通过引入一个恰当的编队误差向量, 将有向切换 通信拓扑下的多无人机编队问题转化为一个切换系统的镇定问题. 基于Lyapunov稳定性分析方法得到了达成编队 的充分性条件. 仿真实验结果验证了结论的有效性.     

有向切换通信拓扑下多无人机分布式编队控制（英文）

本文对多无人机分布式时变编队控制问题进行了研究.无人机之间的通信拓扑假定是有向和切换的.基于自身状态与邻居状态的相对局部信息构建了分布式编队控制器.通过引入一个恰当的编队误差向量,将有向切换通信拓扑下的多无人机编队问题转化为一个切换系统的镇定问题.基于Lyapunov稳定性分析方法得到了达成编队的充分性条件.仿真实验结果验证了结论的有效性.     

基于虚拟结构法的分布式多无人机鲁棒编队控制

针对多无人机编队控制(UAVs)问题, 本文提出了一种基于虚拟结构法的非线性鲁棒控制算法. 首先将编队 控制问题转化成两个子问题: 在惯性坐标系下虚拟刚体(VRB)光滑轨迹的生成设计, 以及在虚拟刚体坐标系下的无 人机编队队形控制设计. 针对部分无人机无法直接获取虚拟刚体状态的约束, 通过引入相邻无人机的跟踪状态, 实 现了分布式的编队控制. 同时, 考虑多无人机近距离编队飞行时相互间的气流扰动影响, 设计了基于supertwisting 的鲁棒控制算法, 提高了编队系统的控制精度和稳定性. 利用Lyapunov稳定性分析方法, 证明了位置跟踪误差在 有限时间内收敛到滑模面, 得到闭环系统全局渐近稳定的结果. 最后通过实际飞行实验, 验证了所提控制算法的有 效性和鲁棒性.     

异构集群系统分布式自适应输出时变编队跟踪控制

提出了一种能够解决高阶异构集群系统输出时变编队跟踪问题的控制方法. 集群系统中的智能体分为领导者和跟随者, 领导者和跟随者的动力学模型可以完全不同. 跟随者的输出在跟踪领导者输出的同时保持时变编队实现协同运动. 考虑了领导者存在已知或未知控制输入、领导者和跟随者均存在未知扰动、有向通信拓扑存在切换等多种因素并存的情况, 结合观测器理论、自适应控制理论和滑模控制理论设计了完全分布式的输出时变编队跟踪控制协议, 摆脱了对领导者控制输入上界值、与通信拓扑相关的拉普拉斯矩阵的特征值以及时变编队函数等全局信息的依赖. 利用Lyapunov理论证明了在有向拓扑切换条件下异构集群系统的闭环稳定性. 最后通过数值仿真对理论结果的有效性进行了验证.     

基于自适应分布式滤波观测器的多智能体系统编队控制

本文考虑了全局指令系统输出信息受到信道扰动情况下线性多智能体系统的编队控制问题.首先,基于协作式输出调节理论框架对线性多智能体系统的编队控制问题进行数学建模.其次,针对受到信道扰动的全局指令系统输出信息,提出了一类基于受扰输出的自适应分布式滤波观测器,在降低网络信息交换量的同时消除扰动的影响.最后,设计了输出反馈确定等价控制律,解决了线性多智能体系统的分布式编队控制问题.给出了数值仿真结果检验控制性能.     

存在时延的分布式无人机编队控制方法

多无人机协同是未来无人机应用的重要方式,多无人机编队作为多无人机协同的重要技术和研究热点也已引起越来越多关注,分布式无人机相较于集中式具有灵活性好、鲁棒性强,对通信及计算机性能要求低等优点;针对无人机的非线性动力学模型,在有向固定拓扑的条件下,运用高阶一致性理论解决无人机系统的分布式编队问题;基于Lyapunov稳定性原理,利用线性矩阵不等式(LMI),分别得出在具有时变时延导数信息及无导数信息情况下的稳定性充分条件;最后,仿真验证了这种编队控制方法的有效性;研究结果表明,利用文章所提出的方法控制无人机编队飞行,在满足稳定性的前提下,无人机系统能够形成稳定的编队,并达到预期速度。     

基于群集行为的分布式多无人机编队动态避障控制

针对无人机编队保持和动态障碍物规避控制问题,本文提出了一种新的基于群集行为的分布式多无人机编队控制和避障控制算法.首先考虑了由机间气流等因素带来的干扰,基于吸引/排斥势场和一致性方法,设计了分布式无人机编队的队形保持控制算法,对编队内无人机之间的距离进行控制.进一步考虑外部移动障碍对无人机编队的影响,引入了排斥势场产生...     

Fixed-time backstepping distributed cooperative control for multiple unmanned aerial vehicles

This paper proposes a fixed-time backstepping distributed cooperative control scheme based on fixed-time extended state observer (FxTESO) for multiple unmanned aerial vehicles (UAVs). A fixed-time ESO, which is convergent independently of initial conditions, is designed to estimate and compensate the external disturbances in tracking process. Moreover, to eliminate the “explosion of complexity” in the traditional backstepping architecture, a nonlinear first-order filter is adopted to construct the distributed fixed-time control scheme. Based on the local information of neighboring UAVs, a fixed-time backstepping cooperative controller is designed. The proposed formation algorithm can be shown practicable for the UAV control system by using of Lyapunov stability theory and graph theory. Simulation results are given to demonstrate the effectiveness of the proposed control scheme.     

时变不确定性系统的二自由度最优鲁棒稳态跟踪控制器设计

研究了被控系统存在范数有界的时变模型摄动和未知外部干扰时鲁棒稳态跟踪问题. 利用二自由度控制结构和Youla参数化方法.提出了一个最坏情况稳态绝对误差的精确计算公 式,利用该公式最优稳态跟踪控制器设计问题可化为一个有限维l1优化问题.因此控制器设计 只需解一个标准线性规划问题.此外,还证明了所提出的控制器可同时保证系统的鲁棒稳定性 和最优跟踪性能.仿真结果表明了该方法的有效性和可行性.     

具有输入饱和的近空间飞行器鲁棒控制

针对近空间飞行器这一类存在外部扰动,输入饱和和参数不确定的多输入多输出线性系统,提出了一种基于干扰观测器的抗饱和鲁棒控制方案.将干扰观测器与抗饱和控制技术相结合,从而消除系统存在的未知外部扰动、输入饱和和不确定性对系统控制的影响.首先,设计干扰观测器对线性外部系统产生的未知扰动进行估计.然后根据干扰观测器输出,通过超前抗饱和方法设计抗饱和补偿器,并将其加入到鲁棒控制器的设计中,保证闭环系统存在输入饱和、未知外部扰动和参数不确定情况下的稳定性.为便于设计,干扰观测器、抗饱和补偿器和控制器设计矩阵均通过求解线性矩阵不等式得到.最后,将提出的鲁棒抗饱和控制方法应用于近空间飞行器,仿真结果验证了该控制方案的有效性.     

倾转式三旋翼无人机的有限时间收敛控制设计

倾转式三旋翼无人机是一种多旋翼无人机的特殊构型,其兼具单旋翼无人机与普通多旋翼无人机的特点.目前对于此类无人机的鲁棒控制设计研究成果较少,多数已有的控制方法未考虑模型参数的不确定性与外界扰动对此类无人机控制的影响.为此本文针对倾转式三旋翼无人机动力学模型存在的转动惯量未知,以及飞行中受到未知外界扰动影响的情况,基于super-twisting算法,设计了一种新型非线性鲁棒控制方法.通过基于Lyapunov的稳定性分析方法,证明了闭环系统的稳定性,并得到在有限时间内三旋翼无人机的姿态跟踪误差收敛的结果.本文中所提出的控制算法,在倾转式三旋翼无人机实验平台上进行了实时飞行控制实验,取得了较好的控制效果.     

Distributed attitude synchronization control for multiple flexible spacecraft without modal variable measurement

This paper solves the attitude synchronization and tracking problem for a group of flexible spacecraft without flexible‐mode variable measurement. The spacecraft formation is studied in a leader‐following synchronization scheme with a dynamic virtual leader. With the application of adaptive sliding‐mode control technique, a distributed modified Rodriguez parameters‐based dynamic controller is proposed for flexible spacecraft without requiring modal variable measurement. It is proved that the attitude synchronization and tracking can be achieved asymptotically under the control strategy through the Lyapunov's stability analysis. Furthermore, a distributed robust continuous control algorithm is designed to guarantee the ultimate boundedness of both the attitude tracking error and the modal variable observation error when bounded external disturbances exist. Some numerical simulation examples for multiple flexible spacecraft formation are given to demonstrate the effectiveness of the proposed method.     

Distributed adaptive robust tracking and model matching control with actuator faults and interconnection failures

In this paper, direct adaptive-state feedback control schemes are developed to solve the robust tracking and model matching control problem for a class of distributed large scale systems with actuator faults, faulty and perturbed interconnection links, and external disturbances. The adaptation laws are proposed to update the controller parameters on-line when all the eventual faults, the upper bounds of perturbations and disturbances are assumed to be unknown. Then a class of distributed state feedback controllers is constructed to automatically compensate the fault, perturbation and disturbance effects based on the information from adaptive schemes. The proposed distributed adaptive tracking controller can ensure that the resulting adaptive closed-loop large-scale system is stable and the tracking error decreases asymptotically to zero in the presence of uncertain faults of actuators and interconnections, perturbations in interconnection channels, and disturbances. The proposed adaptive design technique is finally evaluated in the light of a simulation example.     

Operator-based robust control design for a human arm-like manipulator with time-varying delay measurements

In this paper, an operator-based robust nonlinear control for a human multi-joint arm-like manipulator with time-varying delay measurements is proposed by using robust right coprime factorization approach, a delay compensation operator and a forward predictive operator. That is, first, considering the uncertainties of dynamic model consisting of measurement error and disturbances, an operator-based nonlinear feedback control scheme is designed to eliminate effect of uncertainties. Second, an operator controller based on real measured data from human multi-joint arm viscoelasticity is presented to obtain desired motion mechanism of human multi-joint arm viscoelastic properties, the unknown time-varying delay measurements are described by a delay operator, the delay compensation operator is designed to remove the effect of unknown time-varying delay measurements, and the forward predictive operator is designed to compensate the term related to effect of central nervous system (CNS) during human multi-joint arm movements. The BIBO stability can be guaranteed and the tracking performance can be realized by the designed operator controller, the delay compensation operator and the forward predictive operator. Finally, the effectiveness of the proposed design scheme is confirmed by the simulation results based on experimental data.     

Enhanced adaptive nonlinear extended state observer for pure feedback systems withmatched andmismatched disturbances

In this paper, an enhanced adaptive nonlinear extended state observer (EANESO) for single-input single-output pure feedback systems in the presence of external time-varying disturbances is proposed. In this paper, a nonlinear system with matched and mismatched disturbances is considered. The conventional extended state observer (ESO) can only be applied to systems that are in the form of integral chains. Moreover, this method has limitations in the face of mismatched disturbances. In the presence of time-varying disturbances, the traditional ESOs cannot estimate the disturbances accurately. To overcome this limitation, an EANESO is proposed in this paper. The main idea is to design the nonlinear ESO (NESO) to estimate the states of the system and multiple disturbances simultaneously. The observer gains are considered time-varying and adjusted with adaptation laws to improve the estimation accuracy and overcome the peaking phenomenon. Next, the proposed controller is designed based on output feedback to eliminate the effects of multiple disturbances and stabilize the closed-loop system. Subsequently, the stability analysis of the closed-loop system and convergence of the observer error are discussed. Finally, the proposed method is applied to the inverted pendulum system. The simulated results show good performance of the proposed method as compared with a recently published scheme in the related literature.