带通信时滞的多智能体系统的群集运动

由于环境的影响以及自身只能以有限的速度影响其他智能体,使得多智能体之间的影响不能立即作用,因此通常都有一定的时间延迟。在Cucker-Smale模型的基础之上研究了带有通信时滞的系统,主要利用二次函数理论证明了当智能体间的通信时滞在满足一定的条件下,依然可以达到群集运动。最后也给出了通信时滞下的Cucker-Smale模型的数值仿真结果,发现当其他系统参数不变时,耦合系数越小,系统能容忍的通信时滞越大。这也进一步证明了该理论的正确性。     

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。     

具通信时滞的二阶严格正则多智能体系统的一致性

研究通信时滞影响下的多智能体系统的一致性设计问题,其中智能体由单输入单输出的二阶严格正则传递函数表示。对具有向生成树的多智能体系统,提出了一类基于输出的二阶一致性协议。首先,在不考虑通信时滞的情形下,得到了维持一致性的参数条件。进而,在前述参数条件下,得到了闭环多智能体系统在的最大容许时滞的上界。最后,用数值仿真验证了所提理论结论的有效性。与已有研究文献相比,针对单输入单输出严格正则多智能体系统设计了一类基于输出反馈的一致性协议,二阶积分链多智能体系统可看作研究系统的特例。     

具有输入时滞多智能体系统的鲁棒H∞趋同控制

讨论了同时受外部扰动,输入时滞以及网络模型不确定的多智能体系统的趋同控制.通过定义一个适当的控制输出,我们将这个问题转化一个鲁棒H∞控制问题.基于此,我们给出了两个判断闭环多智能体系统趋同的准则,并且运用锥补线性化算法得到状态反馈控制器的参数.最后,给出一个仿真用以验证我们趋同算法的有效性.     

具有时滞的混合阶多智能体系统的组一致性

针对由离散时间一阶和二阶智能体组成的混合阶多智能体系统,研究其在固定和切换拓扑结构下受通信时滞影响时的组一致性问题。分别为两类智能体提出组一致性协议,引入模型变换,将闭环系统转化为等价系统。在一定假设条件下,以代数图论、矩阵理论为主要研究工具,分别在固定和切换拓扑结构下给出了混合阶多智能体系统实现渐近组一致性的条件。采用数值仿真对所得结果的有效性进行了验证。     

高阶时滞多智能体系统一致性控制

本文讨论了多输入网络化时滞多智能体系统的一致性问题.应用无向或有向图描述网络化系统的拓扑结构.多智能体的一致性收敛问题可以转化为线性时滞系统的稳定性问题.通过双线性矩阵不等式可以得到高阶多智能体系统时滞相依以及时滞独立的一致性准则.最后,举例一个无向拓扑结构的时滞多智能体来说明本文方法的有效性.     

通信受限的多智能体系统二分实用一致性

针对存在量化数据、通信时滞等通信约束以及带有竞争关系的多智能体系统, 研究其二分实用一致性问题, 提出了一种基于量化器的分布式控制协议. 该协议基于结构平衡拓扑假设, 通过规范变换将具有竞争关系系统转变为具有非负连接权重系统, 使二分实用一致性问题转变为一般实用一致性问题. 利用微分包含理论、菲利波夫解的框架、代数图论以及Lyapunov稳定性理论, 证明了在本文所提控制策略下, 具有竞争关系的多智能体系统能实现二分实用一致, 即智能体状态收敛至模相同但符号不同的可控区间, 并给出了误差收敛上界值. 仿真试验进一步验证了理论结果的有效性.     

多智能体机器人系统分散式通信决策研究

为了减少多智能体机器人系统协调所需通信的数量,提出了一种新的方法.利用有向无环图表示团队的可能联合信度,并基于此以分散式的方式制定通信决策,仅当智能体自身的观察信息显示共享信息将导致期望回报升高时才选择通信.通过维持以及推理团队的可能联合信度将集中式单智能体策略应用于分散式多智能体POM-DP问题.通过实验以及一个详细的实例表明,本文方法能够有效地减少通信资源的使用,同时提高分散执行的性能.     

多智能体机器人系统分布式通信决策研究

无偿通信可以将Multi-agent POMDP的计算复杂度简化为单Agent POMDP的，然而实际上通信不是无偿的，常常期望减少通信的数量。为此提出了一个新的方法，利用有向无环图维持以及推理团队的可能联合信度，基于此以分布式的方式制定通信决策，并将集中式单Agent策略应用于分布式Multi-agent POMDP问题。通过实验以及一个详细的实例表明本文方法能够有效地减少通信资源的使用，同时提高分布执行的性能。     

具有通信时延的离散时间二阶多个体网络的一致性问题

针对具有通信时延的离散时间二阶多个体系统的一致性问题,采用了具有静态领导者的一致性算法.根据广义Nyquist判据和Gerschgorin圆盘定理,得到了系统渐近收敛到领导者状态的充分条件.在个体与领导者构成的连接拓扑满足一定连通性的前提下,该充分条件是分散形式的,与控制参数、邻居个体之间的连接权值相关,而与通信时延大小无关.仿真结果证明了结论的正确性.     

Allowable delay bound for consensus of linear multi-agent systems with communication delay

This paper studies the consensus of a group of linear dynamic agents with a uniform communication delay and focuses on searching an allowable delay bound. As long as the delay is less than this bound, there exist linear feedback consensus protocols driving the multi-agent system to achieve consensus. Both fixed and switching topology cases are investigated. In both cases, the consensus problem is converted to the robust stability problem of corresponding uncertain state-delayed systems. By using Lyapunov–Krasovskii functional analysis, consensus conditions which contain the feedback gain conditions and delay conditions are proposed for systems over fixed and switching topologies, respectively. Furthermore, allowable delay bounds are obtained for both systems by solving the optimal robust stabilisation problems. Numerical examples are given to illustrate the results.     

Consensus problem of networked multi-agent systems with constant communication delay: stochastic switching topology case

This article proposes an observer-based control strategy for networked multi-agent systems with constant communication delay and stochastic switching topology. First, using the system transformation method, the mean-square consensus problem of multi-agent systems can be converted into the mean-square stability problem of an equivalent system, and some equivalent conditions concerning the mean-square consensus are presented. Then, an example is given to illustrate that the connection weights should be regarded as the parameters to be designed, since they have a great effect on the mean-square consensus of multi-agent systems. By choosing appropriate connection weights, the mean-square consensus problem can be converted into the mean-square stabilisation problem of N-1 delay systems with stochastic switching signal, whose related observer-based stabilisability criteria can be established in the form of linear matrix inequalities (LMIs). Furthermore, if the LMIs are feasible, the multi-agent systems achieve mean-square consensus if and only if the union of graphs in the switching topology set has a directed spanning tree. Finally, numerical simulations are given to illustrate our results.     

通信时延下多智能体系统的安全一致性控制

研究了离散时间多智能体系统存在通信时延条件下的安全一致性问题.本文的目标是设计一种一致性控制算法能够使得网络中各正常智能体抵御敌对智能体的攻击并实现最终状态一致.该算法仅利用个体的自身状态和相邻个体的时延信息作为控制输入,并根据控制器参数、拓扑属性和通信时延,获得了所提算法实现收敛的充要条件.最后,通过仿真实例对理论结果进行了验证.     

无速度输入多智能体系统的一致性

本文研究了有无引导者的多智能体系统在非线性协议下的一致性问题.当智能体速度信息无法获知时,分别针对有无引导者的多智能体系统设计了包含辅助系统和智能体相对位移信息的非线性分布式协议.借助图论、Lyapunov稳定性理论、Barbalat引理等方法,推导出有无引导者的多智能体系统在连通无向通讯网络中实现一致的充分条件,其次,设计了一种新的能使引导–追随者多智能体系统在有向通讯网络中实现期望一致的协议.最后,数值仿真验证了结果的正确性.     

Consensus of feedforward nonlinear systems with a time-varying communication delay

The consensus problem of feedforward nonlinear systems under an undirected network with a time-varying communication delay is studied. In order to solve this problem, new consensus controller with an additional design parameter that can eliminate the effect of a feedforward nonlinearity and a time-varying communication delay on the consensus problem is proposed. Also, it is proved that if an upper bound of time-varying delay is known, the proposed consensus controller can always solve the consensus problem of multi-agent systems even in the presence of feedforward nonlinearity and an arbitrarily large communication delay. A numerical example is given to illustrate the validness of the proposed approach.     

Consensus tracking control for sampled-data second-order multi-agent systems with arbitrary weights under fixed communication topology

This paper focuses on the consensus tracking control problem of multi-agent systems (MASs) with arbitrary adjacency weights instead of traditional nonnegative weights in a sampling setting. First, unlike Lemma 4 in Hu and Hong [2007. Leader-following coordination of MASs with coupling time delays. Physica A: Statistical Mechanics and its Applications, 374(2), 853–863], for MASs with arbitrary weights, the global reachability of the leader node is just a necessary but not a necessary and sufficient condition to guarantee the positive stability of matrix H. Hence, it's urgent for us to establish some positive stability criteria of matrix H first, which is a necessary condition for MASs to achieve consensus tracking. Simultaneously, we also solve the following problems successfully: which nodes should have direct connection with the leader? What's the range size of the leader adjacency coefficients? Then, some sufficient consensus tracking control conditions are obtained for MASs without time-delays and with time-delays by using matrix analysis method and perturbation theory, respectively. Finally, numerical examples are given to illustrate the effectiveness of our results.     

不确定通信拓扑下多智能体系统鲁棒一致性

本文研究一类具有通信不确定的多智能体系统鲁棒一致性问题.本文提出基于标称通信拓扑有向生成树的线性变换方法,将线性多智能体系统的状态一致性问题转化为相应线性系统的鲁棒部分变元渐近稳定性问题.首先采用基于有向生成树关联矩阵的线性变换,将多智能体系统网络的全局状态方程转化为一个降阶子系统;其次,将拉普拉斯矩阵的摄动部分进行分解,利用降阶系统设计鲁棒二次镇定控制器,推导出所有智能体状态达到渐近一致的充分条件.在此基础上将控制协议的参数设计转化为求解线性矩阵不等式的可行解.最后,通过数值仿真验证了所提出的一致性协议分析与设计方法的可行性和有效性.     

Controllability of discrete-time multi-agent systems with directed topology and input delay

This paper investigates the controllability of first-order and second-order discrete-time multi-agent systems with directed topology and input delay. The problem is studied in the leader–follower framework where a number of agents are selected to be leaders and serve as control inputs to all other agents. Sufficient and necessary conditions are derived for the controllability of first-order discrete-time multi-agent systems. With sampling period and feedback gain satisfying certain conditions, it is proved under three different protocols that the controllability of second-order discrete-time multi-agent systems is equivalent to that of a pair of submatrices of Laplacian matrix. In addition, the controllability of both first-order and second-order discrete-time multi-agent systems with input delay is shown, through some transformations, to be equivalent to that of the transformed non-delayed systems. Finally, some simulation examples are given to illustrate the theoretical results.