组合连通拓扑下基于事件触发的多智能体快速一致性算法

针对组合连通拓扑下多智能体系统控制过程中存在通信和计算资源损耗大以及系统收敛速度慢等问题,提出一种新的具有状态预测器的事件触发一致性控制协议,通过设计状态预测器使每个智能体都能对其邻居智能体的未来状态作出预测;同时,对于智能个体给出了基于状态信息的事件触发条件,当状态误差满足该条件才触发事件.在该控制策略下多智能体系统可在节约通信和计算资源的同时具有更快的收敛速度.利用Lyapunov稳定性理论和代数图论,证明了所提事件触发控制策略能够有效实现组合连通拓扑结构下的平均一致性,且不存在Zeno行为.仿真实例进一步验证了理论结果的有效性.     

Decentralized Event-Triggered Average Consensus for Multi-Agent Systems in CPSs with Communication Constraints

The paper investigates decentralized event-triggered average consensus problem for multi-agent systems in cyberphysical systems (CPSs) with communication constraints. To reduce communication burden and improve the communication efficiency of multi-agent systems in CPSs, event-trigger is distributed at subsystem/agent level. A multi-agent system is then modeled as a reduced dimension hybrid system by taking into account decentralized event-triggered mechanism, communication delays and data dropouts within one framework. Some sufficient conditions for average consensus of each agent and an upper bound of communication delay and maximal allowable number of successive data dropouts (MANSD) are obtained, which can conveniently provide the relationship between the triggering parameters, communication constraints and the system stability. Specially, the quantitative relationship between the triggering parameters, MANSD and the system stability is derived. Finally, simulation results are given to illustrate the effectiveness of the proposed method.      

自适应事件触发的马尔科夫跳变多智能体系统一致性

针对非线性马尔科夫跳变多智能体系统在有向固定拓扑下的领导跟随一致性问题,为减少智能体间不必要的通信传输,节约网络资源,保证系统性能,提出一种自适应事件触发控制策略.首先,将每一个智能体均视为马尔科夫跳变系统,且马尔科夫链的转移概率部分未知;通过简单的模型转换建立误差系统,将多智能体系统一致性问题转化为误差系统的稳定性问题;在此基础上,构造合适的Lyapunov-Krasovskii泛函并利用Jensen不等式和线性矩阵不等式等技术给出使多智能体系统达到领导跟随一致性的充分条件及控制器设计方法;通过求解线性矩阵不等式可以得到多智能体系统一致性控制器增益矩阵和事件触发参数矩阵;最后,通过数值仿真验证所提出方法的有效性.     

基于事件触发的二阶多智能体系统平均一致性

针对二阶多智能体系统在固定无向拓扑下的平均一致性问题,为减少不必要的资源浪费,给出一种基于事件触发控制的一致性算法．首先,针对每个智能体设计基于状态误差形式的触发函数,只有当状态误差达到特定值时智能体才触发事件,在两个相邻事件触发时刻之间保持控制输入不变．然后,利用模型转换思想将系统的一致性问题转化为稳定性问题,并利用矩阵理论和李亚普诺夫理论给出系统达到平均一致的充分条件．最后,通过仿真实验验证该理论方案的有效性.     

基于事件触发的三阶离散多智能体系统一致性分析

研究了基于事件触发控制的三阶离散多智能体系统的一致性问题.首先,基于位置、速度和加速度三者的测量误差,设计了一个新颖的事件触发控制机制.然后,利用不等式技巧,得到了使离散多智能体系统达到一致的充分条件.所得到的条件揭示了系统的通信拓扑的Laplacian矩阵特征值和耦合强度对于系统一致性的影响.此外,还给出了事件触发控制器排除类Zeno行为的确定条件,这意味着事件触发控制器不会每个迭代时刻都更新.最后,通过仿真实验验证了所获得理论结果的正确性和可用性     

脉冲式事件触发控制的时变多个体系统一致性

针对时变拓扑连接环境下的时变多个体系统的一致性问题,提出基于事件触发的脉冲控制协议。在该协议里对于每个个体,只有当相关状态误差超过阈值时才会更新控制器,同时控制输入将仅在事件触发时刻执行,且个体间不需要持续通信。该协议将大幅节约系统实现一致性的通信和控制成本。使用代数图论、李雅普诺夫稳定性和脉冲微分方程等数学理论分析和推导具有时变特性的多个体系统在事件触发脉冲控制下达到一致性的充分条件,同时理论证明事件触发的时间序列不存在芝诺行为。最后,数值仿真验证了所得到的理论结论的有效性。     

Generalised exponential consensus of the fractional-order nonlinear multi-agent systems via event-triggered control

In this paper, the leader-following consensus problem of the fractional-order nonlinear multi-agent systems via event-triggered control is considered. An effective event-triggered controller is designed and then generalised exponential consensus of the controlled multi-agent systems is studied in the sense of Mittag-Leffler stability of fractional-order systems. The event-triggering function design is dependent on the parameter of the system structure and the minimum inter-event interval can be flexibly adjusted with different fractional-order α. With the event-triggered control scheme, the consensus condition is obtained and the convergence rate of the system is estimated. Numerical simulation indicates the effectiveness of the theoretical results.     

Leader-following consensus of nonlinear fractional-order multi-agent systems via event-triggered control

This paper investigates the consensus problem of leader-following multi-agent systems with fractional-order nonlinear dynamics. A typical event is defined as some error signals exceeding a given threshold. By applying Lyapunov functional approach and skills of computing function limit, consensus of the controlled multi-agent systems can be reached asymptotically. Meanwhile, the event-triggered algorithm can exclude Zeno behaviours. Finally, a numerical simulation is exploited to verify the effectiveness of the theoretical result.     

Asynchronous sampled-data consensus of singular multi-agent systems based on event-triggered strategy

This paper is concerned with sampled-data consensus for multi-agent systems with singular dynamics. It is assumed that the sampling period of each agent is independent of the other's. Based on event-triggered sampled-data transmission strategy, a distributed consensus protocol is presented. The consensus of singular multi-agent system is transformed into the stability of singular systems with multiple time-varying delays. By employing the Lyapunov-Krasovskii functional method, a sufficient condition on the consensus of multi-agent singular system is derived. Based on the obtained condition, an algorithm to design consensus controller gains is presented in terms of linear matrix inequalities. Two numerical examples are given to show the effectiveness of the proposed method.     

Some necessary and sufficient conditions for second-order consensus in multi-agent dynamical systems

This paper studies some necessary and sufficient conditions for second-order consensus in multi-agent dynamical systems. First, basic theoretical analysis is carried out for the case where for each agent the second-order dynamics are governed by the position and velocity terms and the asymptotic velocity is constant. A necessary and sufficient condition is given to ensure second-order consensus and it is found that both the real and imaginary parts of the eigenvalues of the Laplacian matrix of the corresponding network play key roles in reaching consensus. Based on this result, a second-order consensus algorithm is derived for the multi-agent system facing communication delays. A necessary and sufficient condition is provided, which shows that consensus can be achieved in a multi-agent system whose network topology contains a directed spanning tree if and only if the time delay is less than a critical value. Finally, simulation examples are given to verify the theoretical analysis.     

Event-triggered consensus control for uncertain multi-agent systems with external disturbance

This paper investigates the event-triggered consensus control for a general linear multi-agent system with model uncertainties and external disturbances. A consensus protocol is proposed using the local state information at asynchronous event-triggering time instants, where each agent determines when to perform sampling and control updating using the designed event-triggered condition. Then the robust consensus condition and the feedback matrix design method are derived to make the uncertain multi-agent system reach consensus with a desired disturbance attenuation ability. Furthermore, it is demonstrated that the Zeno behaviour will never occur by giving the lower bound of inter-event time intervals. Finally, a simulation example is given to verify the obtained theoretical results, with the comparison simulation conducted by using the periodic triggering strategy.     

基于事件触发控制的二阶多智能体的一致性

研究二阶多智能体系统在固定有向拓扑下的一致性问题。为减少不必要的网络带宽资源的浪费,给出一种基于事件触发控制的一致性算法。该算法基于状态误差对系统中的所有个体建立事件触发函数,使得个体之间的信息通讯和控制信号更新仅在事件触发时刻进行。采用矩阵理论和模型变换思想对系统进行了分析和转化,并利用Lyapunov理论给出了系统达到渐近一致的充分条件。仿真结果验证了理论方案的有效性。     

Decentralised consensus for multiple Lagrangian systems based on event-triggered strategy

This paper considers the decentralised event-triggered consensus problem for multi-agent systems with Lagrangian dynamics under undirected graphs. First, a distributed, leaderless, and event-triggered consensus control algorithm is presented based on the definition of generalised positions and velocities for all agents. There is only one triggering function for both the generalised positions and velocities and no Zeno behaviour exhibited under the proposed consensus strategy. Second, an adaptive event-triggered consensus control algorithm is proposed for such multi-agent systems with unknown constant parameters. Third, based on sliding-mode method, an event-triggered consensus control algorithm is considered for the case with external disturbance. Finally, simulation results are given to illustrate the theoretical results.     

事件触发机制下的二阶多智能体系统的一致性

研究二阶多智能体系统的一致性问题.为了减少智能体之间的信息通信量,给出一种改进的事件触发控制方法, 在该方法下,每个智能体仅在自身事件触发时刻执行控制任务.利用模型转化、线性矩阵不等式方法和Lyapunov稳定性理论给出系统达到一致性的充分条件,同时,理论计算结果表明,系统在所提出的方法下不存在Zeno现象.仿真实例验证了理论分析的有效性.     

多智能体系统的事件驱动控制

近年来事件驱动控制发展迅速,并引起了多智能体系统领域研究者的极大关注.本文对基于事件驱动控制的多智能体系统的研究现状进行综述.从智能体动力学角度,分别对这个领域的一些代表性成果和研究方法进行了归纳总结.进一步,论述了边事件驱动控制策略下的多智能体系统的研究成果.随后,利用一类新型事件驱动控制来探讨多智能体系统的一致性问题.最后,给出了尚未解决的问题和未来值得关注的研究方向.     

Consensus of multi-agent systems via intermittent event-triggered control

This paper addresses the consensus issue for multi-agent systems with fixed directed interaction topology, and each agent is supposed to have nonlinear dynamics. By introducing the event-triggered mechanism into intermittent control, suitable consensus protocols are provided, which can save communication resources and reduce the number of control updates. Based on the Lyapunov functional method and stability analysis for switching systems, both centralised and decentralised event-triggered strategies for consensus are proposed. Furthermore, the proof of Zeno behaviour being excluded is given. Finally, some numerical examples are shown to demonstrate the effectiveness of the theoretical results.     

Asynchronous decentralised event-triggered control of multi-agent systems

In this paper, the consensus problem of first-order multi-agent systems under linear asynchronous decentralised event-triggered control is investigated. Both undirected and directed topologies are considered. In the analysis, the closed-loop multi-agent systems with the event-triggered control are modelled as switched systems. After proposing the decentralised event-triggered consensus protocols, decentralised state-dependent event conditions are derived, which act as switching signals. The consensus analyses are performed based on graph theory and stability results of switched systems. Under the event-triggered control schemes presented, consensus is reached with enlarged sampling periods and no Zeno behaviour. Simulation examples are given to illustrate the effectiveness of the proposed theoretical results.     

Dynamic event-triggered bipartite consensus for uncertain high-order nonlinear multi-agent systems

In this paper, the bipartite consensus problem is studied for a class of uncertain high-order nonlinear multi-agent systems. A signed digraph is presented to describe the collaborative and competitive interactions among agents. For each agent with lower triangular structure, a time-varying gain compensator is first designed by relative output information of neighboring agents. Subsequently, a distributed controller with dynamic event-triggered mechanism is proposed to drive the bipartite consensus error to zero. It is worth noting that an internal dynamic variable is introduced in triggering function, which plays an essential role in excluding the Zeno behavior and reducing energy consumption. Furthermore, the dynamic event-triggered control protocol is developed for upper triangular multi-agent systems to realize the bipartite consensus without Zeno behavior. Finally, simulation examples are provided to illustrate the effectiveness of the presented results.     

Distributed event-triggered consensus for multi-agent systems with quantisation

This paper studies the consensus problem for multi-agent systems with quantised information communication via event-triggered control. First, the asynchronous event-triggered control for multi-agent systems is considered based on distributed uniform-quantised protocols. It is shown that practical consensus among agents is guaranteed and occurrence of Zeno behaviour is prevented under the designed event-triggering mechanisms. Second, under the proposed protocols using logarithmic quantised information, both synchronous and asynchronous event-triggered control algorithms are given to solve the practical consensus problem. Meanwhile, Zeno behaviour of the closed-loop systems can be excluded under the proposed event-triggered algorithms. Finally, numerical simulations are given to illustrate the effectiveness of the derived results.     

基于事件触发的二阶多智能体领导跟随一致性

研究二阶多智能体系统在固定有向拓扑下的领导跟随一致性问题.为了节省网络和计算资源,给出一种基于事件触发控制的一致性算法.针对每个跟随者智能体,设计基于状态误差形式的触发函数,只有当状态误差满足一定条件,即触发函数取值为零时智能体才触发事件,同时更新并传递自身的采样信息,在两个相邻事件触发时刻之间,控制输入只受领导者控制信号的影响.利用模型变换、矩阵理论和Lyapunov稳定性理论给出多智能体系统达到领导跟随一致性的充分条件.仿真结果验证了理论方案的可行性和有效性.