一阶多智能体系统的一致性分析

研究一阶连续多智能体系统的一致性问题,其中每个智能体只能在一系列离散时刻上获得其相对邻居的状态信息,并且每个智能体的保持器的周期和采样器的周期是不同的.通过分析多智能体系统的稳定性,获得了一致性成立的充要条件,该条件揭示了交流拓扑、控制器增益、采样器的周期和保持器的周期的关系.最后,提供一个仿真例子以说明理论结果的有效性.     

具有非对称通信时滞和切换拓扑的高阶多智能体系统的一致性

研究具有切换有向拓扑和非对称时变时滞的高阶多智能体系统的一致性问题.通过引入正交线性变换和Lyapunov-Krasovskii泛函方法,依据线性矩阵不等式给出了系统解决一致性问题的充分条件以及可容许时变时滞的上界估计.其主要贡献是基于Lyapunov方程和代数不等式建立了协议参数的显性设计,该参数设计形式简单且易于计算,并保证了所给充分条件中线性矩阵不等式的可解性,使得高阶多智能体系统的一致性在切换有向拓扑下对非对称时变时滞是鲁棒的.     

不确定二阶多智能体系统的鲁棒最优一致

针对不确定二阶多智能体系统,研究了其鲁棒最优一致性问题.首先,基于每个智能体所获得的邻居信息,设计了一个使多智能体系统达到一致的控制协议.其次,研究了多智能体系统的最优一致性问题,给出了系统在满足一定性能指标下达到一致的条件.再次,基于该条件,利用Schur补引理和线性矩阵不等式技术,给出了不确定系统达到鲁棒最优一致的条件.最后,通过仿真验证了所得结果的可行性.     

基于干扰观测器的异构多智能体自适应滑模容错一致性控制

针对线性一阶和二阶异构多智能体系统,考虑到任意智能体可能发生的执行器故障以及受到外部干扰,研究了系统容错一致性控制设计问题.首先设计变增益扰动观测器,快速估计外部干扰;其次,利用一致性误差变量构造自适应积分滑模面,结合干扰观测器的估计值设计自适应滑模容错控制器.当异构多智能体系统存在执行器故障和外部扰动时,自适应滑模控制器可以保证智能体系统的位置和速度状态趋于一致.最后,利用Matlab仿真验证了所提方法的可行性与有效性.     

异质分数阶非线性多智能体系统的预设时间一致性北大核心CSCD

该文研究了一类异质分数阶非线性多智能体系统的预设时间一致性问题.设计了一类基于时变函数的预设时间分数阶积分控制器,将分数阶非线性多智能体系统转化为一阶非线性多智能体系统.然后综合利用整数阶Lyapunov函数法和预设时间控制技术,分别实现了具有连通无向图和具有含生成树有向图的多智能体系统的精确预设时间一致性控制.该预设时间可以通过时变函数预先设定,且不依赖于系统初始值和参数.最后,用实例验证了理论结果的有效性.     

带有未知参数的多智能体系统的自适应分布控制

讨论带有未知参数的多智能体系统的一致性问题.假设网络拓扑中领航者是全局可达的,设计带有未知时滞的自适应分布控制,基于Lyapunov-Krasovskii泛函,得到关于线性矩阵不等式的一致性的充分性条件.该条件保证所有跟随者跟踪领航者的状态,实现状态和参数的一致性.最后仿真算例验证方法的有效性.     

高阶离散时间多智能体系统的量化一致性

研究高阶线性多智能体系统在有向量化链路信息拓扑下的一致性问题,首先提出了包含智能体自身与其邻居量化信息的线性一致性协议,其次利用提出的线性变换,将一致性问题转化为稳定性问题,基于稳定性理论,得到基于矩阵Schur稳定性的充要条件,并得到依赖于信息拓扑、系统动态和整个系统初始状态的一致性函数,最后,通过求解代数Riccati不等式,提出增益矩阵的设计过程.     

具有领导者的非线性分数阶多智能体系统的一致性分析

研究了利用非线性分数阶模型描述的具有领导者的多智能体系统的一致性问题.基于智能体之间的通讯拓扑图,设计了系统的控制协议和相应的控制增益矩阵.利用广义Gronwall不等式和分数阶微分方程的稳定性理论,得到了多智能体系统达到一致的充分条件.最后,数值仿真结果显示了理论结果的有效性.     

基于事件触发策略的多智能体系统的最优主-从一致性分析

研究了具有领导者的线性多智能体系统的主 从一致性问题.借助各智能体间的通讯拓扑所构成的无向图,提出一种基于事件触发的自适应动态规划方法,并使用神经网络的逼近性质设计出了近似最优控制.利用Lyapunov稳定性定理,分析了多智能体误差系统的稳定性,并找到一个该误差系统最终有界的充分条件.数值仿真结果进一步验证了理论分析的有效性.     

四阶偏微分多智能体系统的迭代学习控制

该文研究多智能体系统基于一致性收敛的迭代学习控制问题,该系统中所有的智能体是由四阶梁方程构建而成.基于网络拓扑结构,并利用相邻智能体的信息,构建得到基于一致性的迭代学习控制协议.当该迭代学习律作用于系统时,一致性误差在给定的有限时间段上有界;进一步,在无初始偏差情形下,当迭代次数趋于无穷时,该一致性误差于L~2空间中能够收敛于零.仿真算例验证了算法的有效性.     

非平衡拓扑和随机干扰情形下多自主体系统的趋同条件

研究了具有一般有向通信拓扑和高斯通信噪声的多自主体系统的趋同条件.这里所研究的有向拓扑不仅包含有向平衡图,而且包含非平衡图,后者是本文的重点.我们利用马氏链的结果得到了一个网络节点的互通类;通过对噪声影响的细化,给出了不同噪声情形下系统趋同条件:(1)对互通类的自主体获取信息受到噪声干扰情形,给出了系统均方趋同的充要条件,并证明该条件也保证以概率1 趋同;(2)对互通类的自主体获取信息未受到噪声干扰但其余自主体获取信息受到干扰情形,给出了系统均方趋同的充分条件,并证明该条件在一定意义下也是必要的;(3)对整个系统无噪声情形,给出了系统趋同的充要条件.     

Consensus problems in discrete-time multiagent systems with fixed topology

In this paper, we study the consensus problems in discrete-time multiagent systems with fixed topology. A necessary and sufficient condition for a system that solves a consensus problem is established, and the structure of consensus functions is characterized. Based on them, we introduce the standard topologies (graphs) of information flow, with which the systems can be viewed as single-leader-multi-follower systems. Moreover, the convex combination of these topologies can create a system that solves any predeterminate consensus problem. Additionally, we characterize the structural decomposition—the leaders-followers decomposition of a multiagent system, and establish a necessary and sufficient condition for an agent to be a leader.     

Necessary and sufficient conditions for consensus of third-order discrete-time multi-agent systems in directed networks

This paper studies consensus of third-order discrete-time multi-agent systems in directed networks. When each agent can only receive its neighbor’s position information, necessary and sufficient conditions for consensus of the system are established. Compared with the preceding work, we not only answer what consensus value the system eventually achieves, but also clearly show the equivalent relationship between consensus, scaling parameters and nonzero eigenvalues of the involved Laplacian matrix. Illustrative examples are also given to demonstrate the effectiveness of the obtained theoretical results.     

The problem of coordination and consensus achievement in groups of autonomous mobile robots with limited communication

The paper considers a consensus seeking problem for a multirobot system with limited communication. Multirobot systems with limited communication are modelled as hybrid dynamical systems. The proposed model is a modification of some mathematical models introduced in physics and biology. We derive a necessary and sufficient condition for the system to converge to a single value of the coordination variable with probability 1.     

序列位差空间的拓扑性质

利用拓扑学的一般理论,研究了序列位差空间的连通性,给出了序列位差空间为可分空间、紧致空间的充分必要条件.     

多复变全纯映射正规族关于连续移动超平面的一个充要条件

证明了从C~n的一个区域到P~N(C)中的多复变全纯映射族为正规族的一个充要条件.这个充要条件与P~N(C)中的逐点处于一般位置的连续移动超平面族有关.证明的主要方法来自于微分方程.     

Sampling Consensus of 2nd-Order Multi-Agent Systems Based on Time-Varying Topology北大核心CSCD

基于速度一致位移差保持不变的一致性概念,研究了二阶多智能体系统在时变拓扑下的采样一致性问题。首先,引入虚拟领导者,将具有时变拓扑结构的多智能体系统的采样一致性问题转换为误差系统的采样控制稳定性问题。其次,通过预估采样误差,研究采样误差对系统达到一致性的影响。最后,应用Lyapunov稳定性理论,分析所构造的误差系统的稳定性,并给出该误差系统最终稳定的充分条件。数值仿真结果验证了理论分析的有效性和正确性。     

A sufficient condition and a necessary condition for the diffusion approximations of multiclass queueing networks under priority service disciplines

We establish a sufficient condition for the existence of the (conventional) diffusion approximation for multiclass queueing networks under priority service disciplines. The sufficient condition relates to a sufficient condition for the weak stability of the fluid networks that correspond to the queueing networks under consideration. In addition, we establish a necessary condition for the network to have a continuous diffusion limit; the necessary condition is to require a reflection matrix (of dimension equal to the number of stations) to be completely-S. When applied to some examples, including generalized Jackson networks, single station multiclass queues, first-buffer-first-served re-entrant lines, a two-station Dai–Wang network and a three-station Dumas network, the sufficient condition coincides with the necessary condition.     

The Logical vs. the Ontological Understanding of Conditions

According to the truth-functional analysis of conditions, to be ‘necessary for’ and ‘sufficient for’ are converse relations. From this, it follows that to be ‘necessary and sufficient for’ is a symmetric relation, that is, that if P is a necessary and sufficient condition for Q, then Q is a necessary and sufficient condition for P. This view is contrary to common sense. In this paper, I point out that it is also contrary to a widely accepted ontological view of conditions, according to which if P is a necessary and sufficient condition for Q, then Q is in no sense a condition for P; it is a mere consequence of P.