考虑时变时滞的多移动智能体分布式编队控制

考虑到多移动智能体编队控制中的时变时滞问题,在所设计的编队框架下,基于一致性算法设计了具有不对称时变时滞的分布式编队控制律.该控制律仅使用全局速度导引信息和邻居状态反馈信息;在固定通信拓扑条件下,推导了具有时变时滞的闭环系统状态方程,应用改进的自由权矩阵方法获得了保守性更小的系统稳定条件,并在时变通信拓扑条件下,将拓扑变化处理为系统结构的不确定性,同样获得了时变通信拓扑下的系统稳定条件;进行了6个智能体在平面内编队运动的仿真,实例证明,理论结果是正确的.     

基于模糊人工势场法的多智能体编队控制及避障方法

针对动态环境中多智能体编队控制及避障问题,提出了一种基于模糊人工势场法的编队方法。首先,在领航跟随法的框架下控制编队队形,在动态队形变换策略的异构模式下,使用人工势场法为多智能体编队中每个智能体规划避障路径;其次,利用模糊控制器控制跟随智能体追踪领航智能体,同时保持跟随智能体之间与领航智能体的相对距离,遇到未知障碍物时,及时保持多智能体编队之间的队形并避免碰撞障碍物。针对人工势场法在引力增量系数和斥力增量系数设置的局限性,利用模糊控制器选择出适应环境的增量系数。Matlab仿真实验结果表明,该方法能够有效地解决复杂环境下多智能体编队控制及避障问题,使用效率函数对实验数据进行分析,验证了所优化方法的合理性和有效性。     

具有规定性能的多智能体动态事件触发编队控制

针对多智能体系统编队控制过程中面临的性能约束、输入饱和、通信资源受限等问题,研究一类具有规定性能的高阶非仿射多智能体系统编队控制问题,提出一种有限时间动态事件触发编队控制策略。首先利用反步法设计控制律,并引入微分跟踪技术解决“计算爆炸”问题,有效避免对复杂虚拟控制律的求导过程;其次采用模糊逻辑系统估计系统内部的不确定性,通过设计性能函数和饱和补偿系统使得多智能体满足规定瞬态性能并防止输入饱和所带来的影响;随后为了解决通信资源受限的问题,构造一个具有动态阈值的自适应事件触发协议,有效减少控制器与执行器之间的通信量;最后利用李雅普诺夫稳定性理论分析闭环系统的稳定性,保证编队误差将渐近收敛至0且系统中所有信号均有界。采用含有1个领导者和5个跟随者的多智能体模型进行仿真验证,结果表明,在该有限时间动态事件触发编队控制策略下,多智能体系统最终形成以领导者为圆心、跟随者都在圆上的编队队形,且编队误差在规定的范围内演化。     

通信时滞下事件驱动多智能体系统环形编队控制

针对一阶具有通信时滞的多智能体系统环形编队存在通信和计算资源消耗大的问题,引入事件驱动控制机制,综合设计适用于任意环形编队的控制律分别耦合状态相关和状态无关两类事件驱动条件。事件触发函数基于状态误差建立,使得个体之间的信息通信和控制信号更新仅在事件触发时刻进行。从理论上严格证明了系统在控制律作用下的收敛性,并通过数值仿真验证了控制算法的有效性。仿真结果也表明,在获得系统期望性能的前提下,降低了控制器输入的更新频率和减少了智能体的资源消耗。     

多智能体系统编队控制相关问题研究综述

首先梳理了编队控制研究的脉络, 介绍了3 种经典的编队控制方法, 即跟随领航者法、基于行为法和虚拟结构法的研究思想; 接着综述了近年来发展的, 包容了上述3 种方法且基于图论的编队控制理论的研究成果, 包括多智能体系统图论的建模, 基于代数图论和基于刚性图论的多智能体编队控制律设计、编队构型变换等方面的研究成果; 然后从图论结果出发, 回顾了与编队控制密切相关的一致性、聚集/同向、群集/蜂拥和包络控制的最新进展; 最后, 为了促进多智能体系统在实际中的应用, 指出了多智能体编队控制研究中有待解决的若干问题.

     

基于事件触发的时变拓扑多智能体系统编队控制

针对资源受限的时变拓扑多智能体系统的编队控制问题,提出一种基于复合误差信息事件触发机制以减少不必要的信息传输,降低带宽占用,并设计了多智能体系统的编队控制协议和分布式事件触发机制.通过将多智能体系统的编队控制问题转化为闭环延时系统的稳定性问题,构造Lyapunov-Krasovskii函数并利用线性矩阵不等式技术,给出多智能体系统实现编队的充分条件.最后,通过仿真验证了所提出方法的有效性.     

有向网络下非线性多智能体系统的协调跟踪

基于一致性理论,在有向拓扑结构下研究非线性多智能体系统的协调跟踪控制问题．考虑智能体动力学模型为一般且仅满足Lipschitz条件的非线性系统,在仅有部分跟随智能体能获取领航智能体信息的情形下,当领航智能体与跟随智能体之间的拓扑结构具有有向生成树,即存在领航智能体到所有跟随智能体的有向路径时,所设计的分布式控制律可实现所有跟随智能体对领航智能体的跟踪,并指出该拓扑结构是系统实现跟踪的一个必要条件．最后,仿真实验验证了所设计控制算法的有效性．     

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.     

复杂无向网络连通性的一种高效判定算法

通信网络的拓扑结构连通性是多智能体系统一致性控制或编队控制等的理论前提.以往, 各种多智能体系统一致性控制或编队控制方面的文献仅侧重于控制协议、智能体动力学模型和控制律设计, 而缺乏对多智能体通信网络拓扑结构的连通性研究.网络连通性高效判定算法不仅是大规模多智能体系统一致性控制或编队控制的保证, 而且在图论、现代移动通信、计算机与交通等各种网络中有着重要和广泛的应用.针对复杂无向网络的连通性问题, 本文给出了一种新的高效判定算法、以及该算法的时间复杂度和空间复杂度的上界.该算法具有非常低的时间复杂度和空间复杂度, 且便于计算机实现, 因而具有重要的理论意义和广泛的实用价值.     

脉冲控制下多智能体系统的保性能双向编队控制

研究混杂脉冲控制下二阶非线性多智能体系统的双向编队控制问题,以及保性能双向编队控制问题.根据领导智能体、目标编队以及邻居智能体的状态对每个智能体设计双向编队控制的状态反馈控制器及脉冲控制器.基于双向编队的目标,定义适当的误差系统,将双向编队问题转化为误差系统的稳定性问题.利用平均脉冲强度以及平均脉冲区间的定义,给出在混...     

Leader-following consensus for a class of second-order nonlinear multi-agent systems

This paper deals with the leader-following consensus problem for a class of multi-agent systems with nonlinear dynamics and directed communication topology. The control input of the leader agent is assumed to be unknown to all follower agents. A distributed adaptive nonlinear control law is constructed using the relative state information between neighboring agents, which achieves leader-following consensus for any directed communication graph that contains a spanning tree with the root node being the leader agent. Compared with previous results, the nonlinear functions are not required to satisfy the globally Lipschitz or Lipschitz-like condition and the adaptive consensus protocol is in a distributed fashion. A numerical example is given to verify our proposed protocol.     

基于有向网络的智能群体群集运动控制

对具有二次积分动态的智能群体(flock/swarm),在有向网络取得群集运动(flocking/swarming)进行了研究．提出了一个分散控制方法对智能群体进行分散控制．用有向图模型表示智能体之间的相互作用及通信关系．对固定的网络拓扑,控制互连拓扑是固定的,时不变的,运用传统的LaSalle不变集原理,代数图论的有关技巧进行了稳定性分析,并得到以下主要结论:i)智能群体速度方向渐进收敛,并保持方向一致;ii)智能群体速度大小渐进收敛,并保持大小相等;iii)有邻接关系的智能体(Agent)之间没有碰撞发生;iv)智能群体的势场函数被最小化．理论分析显示,有向图的弱连通性及一种称为平衡图的有向图在系统的稳定性分析中扮演着关键角色．最后,给出了一个仿真例子对理论结果进行了验证．     

Global behavior of dynamical agents in directed network

This paper investigates the global behavior of controlled dynamical agents in directed networks. The agents are Lyapunov stable, are distributed in a line, and communicate through a directed network. The communication topology of the network is characterized by a directed graph and the control protocol is designed in simple linear decentralized feedback law. We study the different conditions under which agents will achieve aggregation, and critical and divergent trajectories, respectively. Our investigation on the dynamical agent system under network is extended to the time-delay network case. Furthermore, we study the case with two pre-specified virtual leaders in the system. Numerical simulations are given and demonstrate that our theoretical results are effective.     

Coordinated orbit-tracking control of second-order non-linear agents with directed communication topologies

This paper deals with two-dimensional and three-dimensional cooperative control of multiple agents formation tracking a set of given closed orbits, where each agent has intrinsic second-order non-linear dynamics and the communication topology among agents is directed. By using our previous curve extension method, the cooperative control system can be regarded as a cascade system composed of the orbit-tracking subsystem and the formation subsystem with the orbit-tracking error as input. A novel solution is established by separatively designing the orbit-tracking control law and the formation control protocol ignoring the perturbation at first and then applying input-to-state stability theory to analyse the asymptotic stability of the cascade system. It is shown that the closed-loop system is asymptotic stability if the directed communication topology contains a directed spanning tree. The effectiveness of the analytical results is verified by numerical simulations.     

Fuzzy sliding-mode formation control for multirobot systems: design and implementation

This paper mainly addresses the decentralized formation problems for multiple robots, where a fuzzy sliding-mode formation controller (FSMFC) is proposed. The directed networks of dynamic agents with external disturbances and system uncertainties are discussed in consensus problems. To perform a formation control and to guarantee system robustness, a novel formation algorithm combining the concepts of graph theory and fuzzy sliding-model control is presented. According to the communication topology, formation stability conditions can be determined so that an FSMFC can be derived. By Lyapunov stability theorem, not only the system stability can be guaranteed, but the desired formation pattern of a multirobot system can be also achieved. Simulation results are provided to demonstrate the effectiveness of the provided control scheme. Finally, an experimental setup for the e-puck multirobot system is built. Compared to first-order formation algorithm and fuzzy neural network formation algorithm, it shows that real-time experimental results empirically support the promising performance of desire.     

基于中间观测器的多智能体系统分布式故障估计

针对发生执行器故障的多智能体系统,论文提出一种新型分布式中间观测器的设计方法,可以同时估计系统的状态和故障.本文设计的观测器可以应用于严格正实条件和观测器匹配条件不满足的系统.针对多智能体系统的通讯拓扑是有向图和无向图的情况,分别获得估计误差系统稳定的条件.观测器的参数矩阵可以通过求解线性矩阵不等式(Linear matrix inequality,LMI)计算.针对具有有向拓扑的多智能体系统,本文方法所需求解的LMI的维数,等于对单个智能体系统设计观测器所需求解的LMI的维数.这表明应用本文方法进行故障估计时,计算量不会随着系统中智能体数目的增加而增加.针对多智能体系统通讯拓扑是无向图的情况,利用Laplacian矩阵的对称性,可以得到保守性更小的结论.最后,仿真算例验证了本文方法的有效性.     

Leader-following control of multiple nonholonomic systems over directed communication graphs

This paper considers the leader-following control problem of multiple nonlinear systems with directed communication topology and a leader. If the state of each system is measurable, distributed state feedback controllers are proposed using neighbours’ state information with the aid of Lyapunov techniques and properties of Laplacian matrix for time-invariant communication graph and time-varying communication graph. It is shown that the state of each system exponentially converges to the state of a leader. If the state of each system is not measurable, distributed observer-based output feedback control laws are proposed. As an application of the proposed results, formation control of wheeled mobile robots is studied. The simulation results show the effectiveness of the proposed results.     

基于事件触发的离散多智能体二分一致性

针对一阶离散多智能体系统,研究了事件触发控制下的二分一致性问题.首先考虑智能体间通信拓扑结构为无向连通结构平衡图的情形,针对各智能体设计事件触发控制,包括仅依赖于自身及邻居智能体采样状态的控制输入,以及仅依赖自身状态的事件触发条件,实现了对通信资源的节约利用.基于图论、离散系统稳定性理论,证明系统能够实现二分一致性.同时,合理设置控制输入及事件触发条件中参数,保证系统不存在Zeno现象.之后,进一步分析设计了包含有向生成树的结构平衡图下,多智能体系统的事件触发控制.最后利用仿真实例验证了理论结果的有效性.     

A distributed control and parameter estimation protocol with prescribed performance for homogeneous lagrangian multi-agent systems

In this paper, we consider the formation control problem for uncertain homogeneous Lagrangian nonlinear multi-agent systems in a leader-follower scheme under a directed communication protocol. A distributed adaptive control protocol of minimal complexity is proposed that achieves prescribed, arbitrarily fast and accurate formation establishment as well as synchronization of the parameter estimates of all followers. The estimation and control laws are distributed in the sense that the control signal and the update laws are calculated based solely on local relative state information. Moreover, provided that the communication graph is strongly connected and contrary to the related works on multi-agent systems, the controller-imposed transient and steady state performance bounds are fully decoupled from: (i) the underlying graph topology, (ii) the control gains selection and (iii) the agents’ model uncertainties. Finally, extensive simulation studies on the attitude control of flying spacecrafts clarify and verify the approach.     

Bipartite tracking of homogeneous and heterogeneous linear multi-agent systems

In this paper, we consider bipartite tracking of linear multi-agent systems with a leader. Both homogeneous and heterogeneous systems are investigated. The communication between agents is modelled by a directed signed graph, where the negative (positive) edges represent the antagonistic (cooperative) interactions among agents. Linear Quadratic Regulator (LQR)-based approach is used to derive the distributed protocol for the follower agent to achieve bipartite tracking of the leader. It is shown that solving the bipartite tracking problem over the structurally balanced signed graph is equivalent to solving the cooperative tracking problem over a corresponding graph with nonnegative edge weights. This bridges the gap between the newly raised bipartite tracking problem and the well-studied cooperative tracking problem. Three novel control protocols are proposed for both cooperative and bipartite output tracking of heterogeneous linear multi-agent systems. Numerical examples are given to show the effectiveness of our control protocols.