离散时间混合多智能体的拟平均一致性控制

为了研究混合一阶和二阶异质无向多智能体网络离散时间一致性问题,提出了固定和可变拓扑结构的多智能体网络的拟平均一致性协议.根据Lyapunov函数和代数图论,分析了多智能体网络的稳定性,表明在固定和可变拓扑结构的情况下,混合阶多智能体系统可以达到拟平均一致.对6个节点组成的4种不同的无向网络拓扑结构进行了仿真,结果显示了变拓扑离散时间异质多智能体网络的位置和速度均能达到拟平均一致.仿真结果表明,该算法对混合阶多智能体网络的拟平均一致性控制有效.     

时变时滞与切换有向通信拓扑协议下线性多智能体系统一致性的平均驻留时间条件

研究时变时滞与切换有向通信拓扑协议下高阶连续时间线性多智能体系统的一致性问题. 利用一个线性变换将该问题等价转化为一个切换时滞系统的稳定性问题. 假定出现的每一个通信拓扑都是可一致的, 借助时滞切换系统稳定性的平均驻留时间方法, 以线性矩阵不等式(LMIs) 形式给出多智能体系统达到全局一致的充分条件. 数值实例验证了结果的正确性.

     

具有时滞的二阶多智能体系统的一致性分析

多智能体系统是由多个自主的智能体组成的集合,实现协调合作的首要条件就是各个多智能体达到一致.本文应用频域分析法研究了具有时滞的二阶定拓扑多智能体系统的一致性问题,得到了保证所有智能体状态达到一致的充分必要条件,并且给出了系统最大容许时滞与定拓扑图的Laplacian矩阵特征值之间的关系.最后,通过数值仿真验证了所得结论的有效性.     

线性多智能体系统在固定和切换拓扑下的领航跟随控制

研究线性多智能体系统的领航跟随一致性问题. 假设每个多智能体系统只能得到其邻域的输出测量信息, 在此条件下, 讨论多智能体在有向固定网络拓扑和无向切换网络拓扑两种情况下的一致性问题. 针对这两种情况, 提出含有一种分布式观测器的一致性控制算法. 应用Lyapunov 稳定性理论证明了若单个多智能体系统是可镇定和可检测的, 且网络连接拓扑只需满足简单的结构, 则系统能够达到领航跟随一致性. 仿真结果验证了理论分析的正确性.     

多智能体一致性预测控制算法及其仿真研究

离散多智能体系统的一致性问题是复杂动态大系统中重要问题,对收敛速度更是研究的重点.设计了一种适用于任意无向连通结构的多智能体一致性预测控制算法μ-MPC,提高智能体的一致性收敛速度并扩展了离散系统采样步长的取值范围,增强了系统的稳定性.在一定理论分析的基础上,通过大量的仿真实例和与经典模型的比较,研究了算法在固定拓扑和切换拓扑系统中的快速性和鲁棒性.特别对于全连通结构系统有一定的参考价值.     

切换信息拓扑和时变时滞下离散时间线性多智能体系统一致性的平均驻留时间条件

研究了有向切换信息拓扑和时变时滞下离散时间线性多智能体系统的一致性问题.首先,通过适当的线性变换把一致性问题转化为相应的时变时滞线性切换系统的渐近稳定问题; 然后,利用构建的李亚普诺夫函数和平均驻留时间模式,建立了一致性问题可解的基于线性矩阵不等式的时滞依赖充分条件,研究了如下两种情形: 1)所有信息拓扑都是可一致的,2) 部分信息拓扑是可一致的; 最后,数值实例验证了结果的正确性.     

二阶多智能体系统包含控制的时滞范围优化

研究具有未知时滞的二阶多智能体系统的鲁棒包含控制问题,考虑智能体之间同时具有通信延时和自延时,分别在无向拓扑和有向拓扑通信下,获得多智能体系统保持鲁棒包含控制所能允许的最大时滞范围.借助函数的凸分析和非线性规划方法解析地获得了无向图下包含控制所允许的最大时滞范围.对于有向图,通过遗传算法求解非光滑的优化问题获得最大时滞范围的数值解,同时结果可退化为领导-跟随控制所能获得的最大时滞范围.最后,通过仿真例子验证所提出理论和算法的有效性.     

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。     

混合阶多智能体无向网络的拟平均一致性

为解决混合阶动态多智能体网络的拟平均一致性,将混合阶动态多智能体网络的拟平均一致性转化为增广的一阶多智能体网络的平均一致性,并给出相应一致性问题协议的定义,根据网络的拓扑结构连通性特点,运用代数图论、矩阵理论中的圆盘定理和李雅普诺夫理论证明了定拓扑和变拓扑无向网络下一致性协议的稳定性定理,并以由4个一阶智能体和2个二阶智能体所组成的混合阶智能体网络为例进行具体说明.理论研究和仿真结果都表明所提协议的正确性.     

具有定常输入的二阶多智能体系统的平均一致性滤波

本文考察了具有定常输入的二阶多智能体系统平均一致性滤波问题,提出了一种比例-积分一致性滤波算法。在定常输入和固定对称连通拓扑的前提下,根据Routh判据和Nyquist判据分别得到二阶多智能体系统在无时延和相同通信时延约束下渐近收敛一致的收敛条件,且多智能体系统最终一致性状态为定常输入的平均值。最后,通过由5个智能体组成的多智能体系统在连通拓扑结构下的数值仿真,验证了理论结果的正确性。     

网路化双线性系统的预测控制优化算法研究

本文对一类离散时间双线性系统进行网络化预测控制研究.针对控制系统网络信道传输引起的前向通道和反馈通道时延问题,基于双线性系统结构特性提出2种逐步优化算法对非凸优化问题进行求解,进而得到未来时刻的预测控制序列.仿真实例说明所求预测控制序列可以主动补偿网络引起的时延问题,从而说明所提出预测控制算法的有效性.     

存在通信约束和时延的多输入多输出网络控制系统镇定研究

讨论了一类存在通信约束和时延的多输入多输出网络控制系统（NCS）的建模和控制问题.该NCS具有多个传感器和执行器，由于网络通信受限,在同一时刻只能允许部分传感器和执行器访问网络.传感器和执行器访问网络的过程可以用两个马尔可夫链来描述,并且在假设传感器—控制器时延和控制器—执行器时延均为短时延的情况下,将整个闭环NCS建模成一个具有两个模式的马尔可夫切换系统.基于LMI技术和李亚普诺夫方法,给出了闭环NCS随机稳定的充分条件,并给出了状态反馈控制器的设计方法.最后的数值算例验证了所提方法的有效性.     

网络控制系统的稳定性分析和研究

该文针对目前网络控制系统的研究现状,阐述了在网络控制系统的分析和设计中需要明确的几个基本问题。综述了具有时变传输周期、网络调度、数据丢包以及网络时滞时的网络控制系统的建模与各种控制策略问题。尤其是网络控制系统在这些情况下的稳定性研究问题,然后列举了一些具有代表性的网络控制系统稳定性分析的最新结果。在此基础上分析了网络控制系统稳定性分析研究中尚待解决的问题,以及新的研究方向。     

Consensus of networked multi-agent systems with communication delays based on the networked predictive control scheme

The consensus problem of discrete-time networked multi-agent systems (NMASs) with a communication delay is investigated in this article, where the dynamics of agents described by discrete-time linear time-invariant systems can be either uniform or non-uniform. For the NMASs with a directed topology and constant delay, a novel protocol based on the networked predictive control scheme is proposed to compensate for communication delay actively. Using algebraic graph theories and matrix theories, necessary and/or sufficient conditions of achieving consensus are obtained, which indicates that, under the proposed protocol, the consensus is independent of the network delay and only dominated by agents' dynamics and communication topology. Meanwhile, the protocol design and consensus analysis are also presented in the case of no network delay. Simulation results are further presented to demonstrate the effectiveness of theoretical results.     

无线网络控制系统的研究

介绍了无线网络控制系统出现的背景,综述了无线网络控制系统的研究内容及现状。无线网络控制系统是基于无线网络的分布式控制系统。它融合了控制技术、计算机技术、网络技术与通信技术,已成为控制界的热点研究之一。针对无线网络控制系统中存在的随机时延和数据丢包,讨论了系统的建模问题,分析了目前的研究现状,并总结了国内外在无线网络控制系统研究过程中所提出的方法和取得的成果,提出了有待进一步解决的问题及以后的研究方向。     

Input–output method to fault detection for discrete-time fuzzy networked systems with time-varying delay and multiple packet losses

The fault detection (FD) problem for discrete-time fuzzy networked systems with time-varying delay and multiple packet losses is investigated in this paper. The communication links between the plant and the FD filter (FDF) are assumed to be imperfect, and the missing probability is governed by an individual random variable satisfying a certain probabilistic distribution over the interval [0 1]. The discrete-time delayed fuzzy networked system is first transformed into the form of interconnect ion of two subsystems by applying an input–output method and a two-term approximation approach, which are employed to approximate the time-varying delay. Our attention is focused on the design of fuzzy FDF (FFDF) such that, for all data missing conditions, the overall FD dynamics are input–output stable in mean square and preserves a guaranteed performance. Sufficient conditions are first established via H_∞ performance analysis for the existence of the desired FFDF; meanwhile, the corresponding solvability conditions for the desired FFDF gains are characterised in terms of the feasibility of a convex optimisation problem. Moreover, we show that the obtained criteria based on the input–output approach can also be established by applying the direct Lyapunov method to the original time-delay systems. Finally, simulation examples are provided to demonstrate the effectiveness of the proposed approaches.     

具有时变通信受限非线性信息物理系统的网络化预测控制

针对具有时变通信受限的一类非线性信息物理系统,本文采用网络化预测控制策略,对于时变通信时延和数据丢失,不是使用常规的被动方式抑制,而是进行主动补偿.为了使补偿时变通信受限的方式简单、主动和通用,提出了一种新颖的网络化非线性预测控制方法.所设计的网络化非线性预测控制器能达到具有与无网络的本地闭环控制系统完全相同的期望控制...     

Networked model predictive control based on neighbourhood optimization for serially connected large-scale processes

In this paper, two novel networked model predictive control schemes based on neighbourhood optimization are presented for on-line optimization and control of a class of serially connected processes (known as the cascade processes in some references), in which the on-line optimization of the whole system is decomposed into that of several small-scale subsystems in distributed structures. Under network environment, the connectivity of the communication network is assumed to be sufficient for each subsystem to exchange information with its neighbour subsystems. An iterative algorithm for networked MPC and a networked MPC algorithm with one-step delay communication are developed according to different network capacities. The optimality of the iteration based networked MPC algorithm is analyzed and the nominal stability is derived for unconstrained distributed control systems. The nominal stability with one-step delay communication is employed for distributed control systems without the inequality constraints. Finally, an illustrative example and the simulation study of the fuel feed flow control for the walking beam reheating furnace are provided to test the effectiveness and practicality of the proposed networked MPC algorithms.     

Stabilization of Uncertain Systems With Markovian Modes of Time Delay and Quantization Density

This work studies the stabilization of a class of control systems that use communication networks as signal transmission medium. The lateral motion of independently actuated four-wheel vehicle is modeled as an uncertain-linear system. Time delay and quantization density are modeled as Markov chains. The networked control systems (NCSs) with plants being lateral motion are first transformed to switched linear systems with uncertain parameters. Sufficient and necessary conditions for the stochastic stability of closed-loop networked control systems are then established. By solving the matrix inequalities, this work presents an output-feedback controller that depends on the modes of time delay and quantization density. The controller performance is illustrated via a vehicular lateral motion system.      

网络控制中基于FSMC观测器的时延补偿

针对网络控制系统中因存在通讯时延、网络诱导噪声及数据丢失等而可能引起系统性能降低或不稳定的问题,利用模糊滑模控制理论,在时延存在的情况下,基于观测器建立不确定网络控制系统模型;并利用预估方法对网络控制系统的时延进行补偿,从而保证系统的稳定。设计模糊滑模控制器（FSMC）来抑制网络控制系统中的诱导噪声及滑模面上的“抖动”,以及采用预估补偿策略处理网络中的时滞和数据包丢失等,可有效保证系统的稳定。仿真实例表明了该算法的合理性、有效性。