Impulsive observer-based consensus control for multi-agent systems with time delay

The paper deals with the distributed consensus problem of a class of general linear multi-agent systems with time delay. Assuming that the state of the multi-agent system cannot be measured and the output of the multi-agent system is measured discontinuously, a novel impulsive observer is constructed. Based on the impulsive observer, a distributed consensus protocol is proposed for the multi-agent system with a directed communication topology. In view of the hybrid characteristic of the multi-agent system with the impulsive observer, a novel type of piecewise Lyapunov functional which can overcome the jump phenomena at impulsive times is introduced. Based on this, some sufficient conditions in terms of linear matrix inequalities are presented such that the consensus of the multi-agent system can be achieved with an exponential convergence rate. A numerical example under two cases is given to show the effectiveness of the theoretical results.     

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.     

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.     

非平衡拓扑结构的多智能体网络系统一致性协议

针对多智能体网络系统,本文分别研究了非平衡拓扑结构的多智能体连续状态和离散状态下的一致性协议.首先提出了能使用有向图表示的多智能体网络系统的拓扑结构,并根据该拓扑结构建立了网络系统的1阶数学模型和提出了多智能体网络系统一致收敛准则.对于多智能体网络连续系统,该系统的一致平衡点最终收敛于初始状态的凸组合,本文最终确定了非平衡拓扑结构的一致平衡点.如果多智能体网络系统的拓扑结构没有改变,在离散状态下系统的一致平衡点仍收敛于初始状态的凸组合,并且离散状态下系统的一致平衡点与连续状态下系统的一致平衡点相等.最后采用8个智能体组成的网络拓扑进行计算机仿真,验证理论的正确性.     

Joining consensus of networked multi-agent systems with nonlinear couplings and weighting constraints

This paper studies the joining consensus of networked multi-agent systems subject to nonlinear couplings and weighted directed graphs via pinning control. A weighted-average consensus protocol is proposed to achieve the collective decision by interacting with the local information of some pinned agents. By proposing a novel joining consensus protocol, average consensus and general consensus strategies are joined to achieve an agreement for the weighting networked system. Furthermore, by calculating a proper consensus gain and using finite control Lyapunov controllers, an efficient joining consensus protocol is presented to improve the consensus speed. Sufficient conditions for achieving the consensuses asymptotically are proved. Finally, theoretical results are validated via simulations.     

基于部分稳定性方法的离散时间多智能体系统的一致性

研究有向信息拓扑下离散时间线性多智能体系统的一致性分析与设计问题.利用提出的线性变换,将一致性问题转换为相应线性系统的部分变元渐近稳定性问题.基于部分变元稳定性理论,得到有向信息拓扑下离散时间线性多智能体系统达到渐近一致的基于矩阵Schur稳定性的充要条件和状态一致函数的解析表达式.同时设计了反馈增益矩阵.最后数值实例验证了所得理论的有效性.     

自适应事件触发控制的多智能体系统一致性

研究了拓扑结构为有向强连通图的多智能体系统的一致性问题。提出一种新的自适应事件触发控制方案,根据采样数据动态调整触发时间间隔,提高了系统的控制性能。基于Lyapunov稳定性理论和线性矩阵不等式方法,得到多智能系统渐进趋于一致的充分条件。同时,得到一致性条件与触发参数和通信拓扑有关的结论,数值仿真结果进一步验证了理论分析的有效性。     

基于噪声的非线性多智能体系统的均方一致性

本文主要研究拓扑结构为有向强连接的非线性多智能体系统的均方一致性问题.考虑到非线性系统中的个体在传递信息时受到噪声环境的干扰,提出一种新的延迟控制方案,提高了系统的控制性能.基于Lyapunov稳定性和Ito^积分方程理论,得到多智能体系统渐近趋于均方一致的充分条件.同时,得到相同的耦合强度下容许的最大延迟间隔,数值仿真结果进一步验证了理论分析的有效性.     

Discrete-time multi-agent consensus with quantization and communication delays

In this paper, discrete-time multi-agent consensus problem with quantization and communication delays is investigated. A new discrete-time multi-agent consensus model is considered in which each agent can only receive the delayed quantized information from its neighbors. In the presence of quantization and communication delays, it is shown that the multi-agent network can achieve consensus under the connectivity network topology. Simulation examples are also provided to demonstrate the correctness of the theoretical results.     

Integral-based event-triggered control for multi-agent systems with general linear dynamics

ABSTRACT

This paper proposes an integral-based event-triggered control strategy to solve the consensus problem of multi-agent systems with general linear dynamics. We first consider the leader-following consensus problem where the communication topology has a directed spanning tree with the leader as the root. It is proved that under the proposed strategy leader-following consensus is guaranteed and the inter-event intervals are lower bounded by positive constants. Then, the leaderless consensus problem of multi-agent systems is investigated under directed topology. We show that consensus is achieved and no Zeno behaviour occurs. Simulation results verify the effectiveness of the obtained results.     

Leader-following consensus of nonlinear multi-agent systems with randomly occurring uncertainties and stochastic disturbances under impulsive control input

This paper focuses on the leader-following consensus problem of nonlinear multi-agent systems with randomly occurring uncertainties and stochastic disturbances under impulsive control input. Based on the average impulsive interval, a unified consensus criterion is derived for multi-agent systems. On the other hand, our consensus criterion is applicable to impulsive control sequences in which the lower bound of impulsive interval is allowed to be arbitrarily small and the upper bound of impulsive interval is allowed to be big enough. The proposed consensus criterion is theoretically and numerically proved to be less conservative than existing results. Two numerical simulations illustrate the effectiveness of theoretical results.     

Leader-following Consensus of Nonlinear Delayed Multi-agent Systems with Randomly Occurring Uncertainties and Stochastic Disturbances under Impulsive Control Input

This paper investigates the leader-following consensus problem for a class of nonlinear delayed multiagent systems with randomly occurring uncertainties and stochastic disturbances under impulsive control inputs. For this class of multi-agent system, we present a novel impulsive control protocol which can effectively reduce the control cost and is easy to implement. Two consensus criteria are derived for ensuring global exponential consensus of nonlinear delayed multi-agent systems under non-uniformly distributed impulsive control signals based on comparison principle and average impulsive interval. Compared with the consensus criteria which are derived by the upper bound or lower bound of the impulse intervals in existing results, the obtained criteria are proved to be easier to be satisfied. Simulation results illustrate the effectiveness of the theoretical results.     

Stochastic consensus of double-integrator leader-following multi-agent systems with measurement noises and time delays

This paper studies a leader-following consensus problem of continuous-time double-integrator multi-agent systems with measurement noises and time-varying communication delays under directed topology. By utilising the neighbour position and velocity information, which are delayed and disturbed by measurement noises whose intensities are considered a function related to the neighbour position and velocity of agents, a distributed consensus protocol is presented, sufficient conditions of the tracking consensus in the sense of mean square are derived. Finally, the effectiveness of the proposed consensus protocol is proved by some simulations.     

具有引导者的多智能体网络系统的脉冲一致性

多智能体网络系统的协调与控制在工程领域中有着重要的作用. 本文给出了具有引导者的一阶多智能体网络系统的动力学模型. 模型中, 假设网络系统中仅有一个智能体在一系列离散时刻基于自身及引导者的信息, 以脉冲跳跃方式改变自身的状态.应用矩阵理论、数值分析理论、脉冲微分方程等理论给出了网络系统达到一致的一个充分条件. 计算机仿真实验验证了算法的正确性和有效性,展示了系统的一致收敛速度与脉冲间隔、脉冲强度之间的关系.     

Consensus of multi-agent linear dynamic systems via impulsive control protocols

In this article, we introduce impulsive control protocols for multi-agent linear dynamic systems. First, an impulsive control protocol is designed for network with fixed topology based on the local information of agents. Then sufficient conditions are given to guarantee the consensus of the multi-agent linear dynamic systems by the theory of impulsive systems. Furthermore, how to select the discrete instants and impulsive matrices is discussed. The case that the topologies of networks are switching is also considered. Numerical simulations show the effectiveness of our theoretical results.     

Necessary and sufficient condition for average consensus of networked multi-agent systems with heterogeneous time delays

This paper deals with an average-consensus problem of networked multi-agent systems with heterogeneous time delays. First, a necessary and sufficient condition is derived for multi-agent systems to achieve average consensus. This condition is represented in the form of an algebraic condition by using the delay-transition and the delay-weighted Laplacians. Second, a performance criterion is introduced to evaluate multi-agent systems that do not achieve average consensus. The criterion is represented in terms of the norms with respect to the above Laplacians. These results imply that the introduced Laplacians play important roles in analysing multi-agent systems with heterogeneous time delays. The validity of the analysis results is demonstrated by simulations with six-agent systems.     

Quantised consensus of multi-agent systems with nonlinear dynamics

This paper studies the consensus problem of first-order and second-order multi-agent systems with nonlinear dynamics and quantised interactions. Continuous-time and impulsive control inputs are designed for the multi-agent systems on the logarithmic quantised relative state measurements of agents, respectively. By using nonsmooth analysis tools, we get some sufficient conditions for the consensus of multi-agent systems under the continuous-time inputs. Compared with continuous-time control inputs, impulsive distributed control inputs just use the state variables of the systems at discrete-time instances. Based on impulsive control theory, we prove that the multi-agent systems can reach consensus by choosing proper control gains and impulsive intervals. The simulation results are given to verify the effectiveness of the theoretical results.     

An output formation consensus control for leader–follower networked multi-agent systems under communication constraints and switching topologies

In this paper, the formation consensus problem for a class of leader–follower networked multi-agent systems under communication constraints and switching topologies is investigated. A networked predictive control scheme is proposed to achieve stability and output formation consensus with the switching topology, capable of compensating for data loss and time delays in the network. By equating the whole closed-loop networked multi-agent system with the proposed control scheme to the corresponding switched system, the sufficient and necessary condition of output formation consensus and stability for agents is given. Finally, using three-degree-of-freedom air-bearing spacecraft simulators as the control objects, the proposed scheme is demonstrated to be able to actively compensate for the communication constraints through numerical simulations, and it is also verified to have a good control performance by further realizing the formation task of the simulators through practical experiments.     

Guaranteed performance consensus in second-order multi-agent systems with hybrid impulsive control

This paper studies the problem of guaranteed performance consensus in second-order multi-agent systems. Taking advantage of impulsive control, a hybrid cooperative control is presented, and an index function is introduced to assess the performance of agents. It is shown that by synthesizing the coupling weights and the average impulsive intermittence, multi-agent systems can achieve guaranteed performance consensus. A numerical example is given to illustrate the theoretical results.     

离散时间多智能体系统一致性的平均驻留时间条件

研究高阶离散时间线性多智能体系统在有向切换信息拓扑下的状态一致性问题。首先通过提出的线性变换将该一致性问题转换为相应离散时间线性切换系统的渐近稳定性问题。然后借助于切换系统稳定性的平均驻留时间方法,分别得到如下两种情形下该一致性问题可解的充分条件：1)信息拓扑集合中的一部分拓扑是可一致的;2)信息拓扑集合中所有信息拓扑是可一致的。最后通过数值仿真验证了所得理论结果的正确性。