二阶有向多智能体网络的可控包含控制

研究随机给定拓扑结构的二阶有向多智能体网络的可控包含控制问题.针对当前包含控制研究成果大多没有考虑多智能体网络领导者和跟随者的可控配置问题,结合复杂网络可控性理论和二分图最大匹配算法给出满足网络可控的领导者和跟随者集合,并为跟随者智能体设计相应的控制协议,驱使跟随者能够渐近收敛到由多个领导者构成的静态凸包中,从而实现网络的可控包含控制.仿真结果验证了理论分析的正确性.     

带强连通分支的多智能体系统可控包含控制

研究有强连通子图拓扑结构的有向多智能体系统领导者选择及可控包含控制问题.根据网络拓扑结构,智能体被分为两类:单元智能体和一般智能体.首先设计强连通子图中个体组成的单元智能体的一致性协议实现各个单元的一致;后由单元智能体和一般智能体构成新的拓扑结构,结合复杂网络可控性理论与二分图最大匹配算法确定满足网络可控的最少领导者集合,并为所有智能个体设计相应的控制协议,驱使跟随者渐近收敛到多个领导者组成的动态凸包中,从而实现网络的可控包含控制.仿真结果验证了理论分析的正确性.     

基于高阶自包含协同过滤的有向网络链路预测

针对大部分现存有向网络链路预测方法仅关注有向局部结构及互惠链接信息而忽略有向全局结构的问题,提出高阶自包含协同过滤(HSCF)链路预测框架。首先,利用随机游走方法计算高阶相似度矩阵去保持有向网络的高阶路径信息;其次,将高阶相似度矩阵与协同过滤方法相融合构建HSCF框架;最后,把所提框架分别与有向共同邻居(DCN)、有向Adamic-Adar(DAA)、有向资源分配(DRA)和势能理论Bifan 4个典型有向结构相似度相融合,并由此提出HSCF-DCN、HSCF-DAA、HSCF-DRA和HSCF-Bifan 4个有向网络预测指标。在10个真实有向网络上的实验结果表明,与基准指标相比,HSCF-DCN、HSCF-DAA、HSCF-DRA和HSCF-Bifan的受试者工作特征（ROC）曲线下方面积（AUC）值分别平均提高了8.16%、8.85%、9.64%和10.33%,且F分数值分别平均提高了66.62%、68.32%、68.95%和76.18%。     

基于有向通信拓扑的高阶分布式一致性算法

为了提高有向通信拓扑下分布式一致性算法的收敛速度,提出了一种基于有向通信拓扑的高阶分布式一致性算法。该算法通过有向单跳通信,利用有向二跳邻接节点的前多步信息提高分布式一致性算法的收敛速度。对有向通信拓扑下该算法的收敛性能和收敛速度进行了分析和仿真比较。结果显示,该算法在满足一定条件下能收敛到初始状态的平均值,与其他同样利用二跳邻接节点信息的一致性算法相比,具有通信量小、收敛速度更快的特点,但是能容忍的最大通信延时变小。     

分布式事件触发控制下的有向多智能体网络一致性分析

现有关于多智能体一致性事件触发控制策略的研究工作都是假设智能体的通信拓扑图为无向的,而在实际应用中,智能体网络中的通信更多的具有方向性。针对上述问题,提出一种事件触发控制下的有向网络一致性分析方法,使智能体能避免连续通信,同时建立网络的代数连通度和一致性收敛性能之间的联系,证明每个智能体的时间间隔都是正实数,从而可以避免Zeno行为。仿真结果表明了该分析方法的有效性。     

含约束和通信时滞的多智能体系统包含控制

随着人工智能的发展,包含控制成为近年来研究的热点问题.为了解决有向切换通信拓扑下含非凸输入约束和通信时滞的采样多智能体系统包含控制问题,设计了一种基于投影的分布式非线性包含控制算法.该算法只需要利用智能体自身和相邻智能体的交互信息就能实现输入受限跟随者的包含.首先将跟随者与领导者构成的凸区域的最大距离选定为李雅普诺夫函...     

基于四阶模体的有向网络链路预测方法

网络模体是出现频次较高的子图模式,代表了复杂系统中的重要功能单元或者某种特定的组织结构,揭示了复杂网络的内在机理.一些学者已经基于三阶模体进行了链接预测的相关研究,但是多数学者通常忽略四阶模体在相似性计算中的作用.为此,提出一种基于四阶模体的有向网络链路预测方法.面对众多的四阶子图,提出限定条件简化情况,使用Z-sco...     

具有通信时延和有向网络的多智能体分布式优化

本文对非平衡有向拓扑下一阶多智能体系统的分布式优化问题进行研究.研究的智能体在与邻居的通信过程中都有一个变化的时延.本文的目标是找到使得目标函数f(x)=(NΣi=1)fi(xi)最小的智能体的状态.提出了一种基于有向图的拉普拉斯矩阵的零特征值对应的左特征向量和智能体的局部信息的控制器.在这项研究中,去掉了fi(xi)...     

有向相依网络的可控性研究

针对相依方式对有向相依网络可控性的影响,研究了不同相依方式下有向相依网络的可控性。通过构建基本的有向相依网络模型,结合严格可控性理论,给出了可控性评判指标。同时基于经典的有向随机网络和有向无标度网络,提出3种有向相依网络模型,并研究了随机相依条件下有向相依网络的可控性。随后定义了3种相依方式,并对比分析了在不同相依方式下有向相依网络的可控性。结果表明,在同等相依比例下,基于最低入度与最低出度节点相依的有向相依网络可控性最强,而基于最高入度与最高出度节点相依的有向相依网络可控性最弱,研究成果能够为实际有向相依网络的构建提供有益的参考和指导。     

Edge event-triggered control for multi-agent systems under directed communication topologies

The edge event-triggered consensus control for multi-agent systems with single- or double-integrator dynamics under directed communication topologies is investigated in this paper. With the edge event-triggered sampling strategies, a class of novel consensus protocols is proposed to reduce control update frequency. The main features of the proposed edge event-triggered control include three aspects: (i) measurement errors are defined based on directed information flow and thus they allow that the communication topology is directed, (ii) each individual controller updates its output only when the associated edge event occurs and the control actions are independent of other agents, and (iii) the proposed edge event-triggered control does not exhibit Zeno behaviour and it is shown that the inter-event intervals are lower bounded by a positive constant. In the consensus analysis, matrix transformation techniques are used to convert the high-dimensional system into a low-dimensional system, and some sufficient consensus conditions are derived for the multi-agent systems with single- or double-integrator dynamics. Finally, the effectiveness of the edge event-triggered sampling strategies is illustrated by simulations.     

Robust finite-time containment control for high-order multi-agent systems with matched uncertainties under directed communication graphs

In this paper, we study the robust finite-time containment control problem for a class of high-order uncertain nonlinear multi-agent systems modelled as high-order integrator systems with bounded matched uncertainties. When relative state information between neighbouring agents is available, an observer-based distributed controller is proposed for each follower using the sliding mode control technique which solves the finite-time containment control problem under general directed communication graphs. When only relative output information is available, robust exact differentiators and high-order sliding-mode controllers are employed together with the distributed finite-time observers. It is shown that robust finite-time containment control can still be achieved in this situation. An application in the coordination of multiple non-holonomic mobile robots is used as an example to illustrate the effectiveness of the proposed control strategies.     

Leader-following scaled consensus of second-order multi-agent systems under directed topologies

ABSTRACT

This paper investigates the leader-following scaled consensus problem of second-order multi-agent systems under directed topologies. Three novel leader-following scaled consensus protocols are designed. First, a novel scaled consensus protocol is proposed. It can guarantee the velocity of each agent in one sub-group exactly follow that of a leader, and the follower agents achieve scaled consensus. Second, another proposed protocol enables the agents' positions and velocities of one sub-group accurately track those of a leader, and the follower agents achieve scaled consensus. Third, consider the case where the leader's states available to one or multiple followers and the leader travels with a varying velocity, a novel scaled consensus tracking protocol is proposed. Sufficient and necessary conditions are obtained to guarantee scaled consensus tracking for the three cases,respectively. Finally, simulation examples are made to verify the effectiveness of the theoretical results.     

Containment control of switched multi-agent systems

In this paper, we consider the containment control problem for the switched multi-agent system which is composed of continuous-time and discrete-time subsystems. Continuous-time protocol based on the relative state measurements of agents are designed for the switched multi-agent system with multiple stationary and dynamic leaders, respectively. By using graph theory and matrix theory, some necessary and sufficient conditions are obtained for solving the containment control problem under arbitrary switching. When the leaders are dynamic, impulsive protocol are also proposed for the switched multi-agent system. The simulation results are given to verify the effectiveness of the theoretical results.     

Distributed adaptive containment control for high-order nonlinear multi-agent systems

This paper considers the adaptive containment control of high-order nonlinear multi-agent systems with nonlinear parameterisation. Without imposing any conditions on the unknown nonlinearities and unknown parameters, the distributed controllers are constructed recursively with only neighbours’ information by using the backstepping design method. Under the assumption that the leaders set is globally reachable, it is shown that all the signals of the closed-loop systems are global uniformly ultimately bounded (UUB), and all the followers will exponentially converge to the convex hull spanned by the dynamic leaders with adjustable tracking errors. Finally, two simulation examples demonstrate the effectiveness of the control scheme.     

Leader-following consensus for single-integrator multi-agent systems with multiplicative noises in directed topologies

This paper proposes a leader-following consensus control for continuous-time single-integrator multi-agent systems with multiplicative measurement noises under directed fixed and switching topologies. The consensus controller is developed by combining the graph theory and stochastic tools. The control input for each agent relies on its own state and its neighbours’ states corrupted by noises, the noises are considered proportional to the relative distance between agents, both of the noisy case and the noise-free case are studied, and conditions to achieve mean square convergence under noisy measurement and asymptotic convergence in absence of noises are derived. Finally, in order to prove the validity of the consensus control, some simulations were carried out.     

切换拓扑下多自主体系统的事件触发一致性控制

本文针对一阶非线性多自主体系统,考察了切换拓扑下的事件触发一致性控制问题.当切换拓扑子图的并图包含有向生成树时,基于一阶保持器提出了一种分布式事件触发一致性算法,用以降低网络的通信负载.运用迭代法和不等式法,得到了多自主体系统达到有界一致性的充分条件.此外,证明了所提事件触发机制不存在Zeno现象,并得到了触发间隔的正下界.最后,给出仿真实例,验证了所提事件触发一致性算法和理论分析结果的有效性.     

Adaptive containment control of heterogeneous high-order fully actuated multi-agent systems

In this article, the distributed containment control schemes are presented for a class of nonlinear heterogeneous high-order fully actuated multi-agent systems. First, for each follower, the reference trajectory generator is constructed by using the output information of the neighbor agents. Then, the distributed containment controllers are designed for the system with known nonlinear system function matrices and control gain matrices. Further, since the existence of modeling errors and other uncertain factors, the obtained system model is often not accurate enough, that is, the system function matrix and control gain matrix are actually unknown nonlinear matrices. To tackle these obstacles, we employ the radial basis function neural network method to approximate the unknown nonlinear system function matrices and skillfully construct the controllers combined with the adaptive technology to eliminate the effects of the unknown control gain matrices. The developed control strategies can guarantee that the containment control can be realized and the containment errors can be adjusted to arbitrary precision. In the end, the simulation results on the electromechanical system and robotic system demonstrate the availability and effectiveness of the provided schemes.     

Cluster consensus of high-order multi-agent systems with switching topologies

This paper investigates the cluster consensus problems of generic linear multi-agent systems with switching topologies. Sufficient criteria for cluster consensus, which generalise the results in existing literatures, are derived for both state feedback and observer-based control schemes. By using an averaging method, it is shown that cluster consensus can be achieved when the union of the acyclic topologies contains a directed spanning tree within each cluster frequently enough. We also provide a principle to construct digraphs with inter-cluster cyclic couplings that promote cluster consensus regardless of the magnitude of inter-agent coupling weights. Finally, numerical examples are given to demonstrate the effectiveness of the proposed approaches.