Finite-time consensus control for second-order multi-agent systems without velocity measurements

This paper investigates the finite-time consensus problem for second-order multi-agent systems with unknown velocities and disturbances. By introducing the second-order sliding mode observer, two novel distributed finite-time protocols with only relative position measurements are proposed for the both cases with known and unknown boundaries of disturbances. On the basis of Lyapunov stability theorem and homogeneous theory, it is proved that the consensus can be achieved in finite time. Simulation examples are provided to show the effectiveness of the theoretical results.     

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 heterogeneous multi-agent systems without velocity measurements

This article considers the consensus problem of heterogeneous multi-agent system composed of first-order and second-order agents, in which the second-order integrator agents cannot obtain the velocity (second state) measurements for feedback. Two different consensus protocols are proposed. First, we propose a consensus protocol and discuss the consensus problem of heterogeneous multi-agent system. By applying the graph theory and the Lyapunov direct method, some sufficient conditions for consensus are established when the communication topologies are undirected connected graphs and leader-following networks. Second, due to actuator saturation, we propose another consensus protocol with input constraint and obtain the consensus criterions for heterogeneous multi-agent system. Finally, some examples are presented to illustrate the effectiveness of the obtained criterions.     

Consensus control of discrete-time multi-agent systems with privacy preservation

Due to the dependence of consensus theory on multi-agent systems (MAS) and the need to openly exchange status information with neighbors on each agent, private status and information are inevitably exposed to the public. In this paper, we present a consensus privacy protection algorithm to solve the consensus privacy problem of second-order MAS. The proposed approach is based on the Paillier algorithm with semi-homomorphic characteristics while combining a distributed control perspective to solve the privacy issues of sharing system status information. Under the conditions of our design, as long as there is at least one trustworthy neighbor node, the privacy of the topology nodes can be protected, and thus, the interconnected nodes are unable to detect the state information of systems from one another. We provide a new method for the privacy of the state information of the discrete-time MAS and use restricted hardware devices to implement the consensus control. Finally, experiments verify the effectiveness of our method, while meeting the actual applicability     

Consensus of second-order discrete-time multi-agent systems with nonuniform time-delays and dynamically changing topologies

This paper studies the consensus problem of multi-agent systems with nonuniform time-delays and dynamically changing topologies. A linear consensus protocol is introduced to realize local control strategies for these second-order discrete-time agents. By model transformations and applying the properties of nonnegative matrices, sufficient conditions are derived for state consensus of the systems. It is shown that arbitrary bounded time-delays can safely be tolerated, even though the communication structures between agents dynamically change over time and the corresponding directed graphs may not have spanning trees. Finally, a numerical example is included to illustrate the obtained results.     

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.     

Consensus of second-order multi-agent systems via impulsive control using sampled hetero-information

In this paper, the consensus problem for second-order multi-agent systems using impulsive control with sampled hetero-information is investigated. Necessary and sufficient conditions for sampling interval to achieve consensus for the second-order multi-agent systems are obtained. Analysis for the upper bound of sampling interval, convergence performance, and communication cost of the proposed control protocols are also discussed. Some numerical examples are given to demonstrate the effectiveness of the proposed control protocols.     

随机多智能体系统稳定性综述

随机多智能体系统一致稳定性分析大致可区分为: 带随机噪声的多智能体系统的一致稳定性分析, 切换拓扑下随机多智能体系统一致稳定性分析, 随机时滞多智能体系统一致稳定性分析, 随机多智能体系统分布式优化控制一致稳定性分析. 对此, 从以上4 个方面对随机多智能体系统稳定性问题的研究进展及其存在的问题进行阐述, 并对随机多智能体系统一致稳定性的进一步研究方向进行了展望.

     

输出死区下的随机多智能体系统一致性饱和控制

针对一类存在输入饱和和输出死区现象的非严格反馈非线性随机多智能体系统,提出一种自适应神经网络一致性饱和控制算法.首先,为了解决非对称输入饱和问题,构造一类与所考虑智能体相同阶次的辅助系统;然后,以反步法和辅助系统作为框架,利用神经网络处理系统中的未知非线性函数,并结合Nussbaum函数解决输出死区问题;接着,利用动态面控制技术避免“计算爆炸”问题;然后,基于李雅普诺夫稳定性理论验证所提出的控制算法能够保证闭环系统全部信号依概率半全局一致最终有界;最后,通过数值仿真和实例仿真的结果验证所提出控制算法的有效性.     

Consensus protocols for discrete-time multi-agent systems with time-varying delays

This paper addresses consensus problems for discrete-time multi-agent systems with time-varying delays and switching interaction topologies and provides a class of effective consensus protocols that are built on repeatedly using the same state information at two time-steps. We show that those protocols can solve consensus problems under milder conditions than the popular consensus algorithm proposed by Jadbabaie et al., specifically, the presented protocols allow for the case that agents can only use delayed information of themselves, whereas the popular one is invalid. It is proved that if the union of the interaction topologies across the time interval with some given length always has a spanning tree, then in the presence of bounded time-varying delays, those protocols solve consensus problems.     

Target-enclosing control for second-order multi-agent systems

This paper poses the enclosing control problem with identical geometry for a group of targets which are either stationary or moving and offers consensus-based distributed control protocols. An estimator is first introduced to estimate the central position of the targets. We then propose a target-enclosing control law with velocity information based on the centre estimating algorithm and consensus theory. A target-enclosing control law without the velocity information is further designed. The Lyapunov theory and Lasalle’s invariance principle are applied to show the convergence of the proposed control algorithms. Finally, numerical simulations are given to illustrate the effectiveness of our proposed strategy.     

离散时间系统的多智能体的一致性

动态多智能体系统的一致性是复杂动力学系统中很有现实意义的问题.假设智能体连接网络拓扑是无向、固定和连通的,而且个体之间信息传递存在通信时廷,分析了一个动态移动多智能体离散时间系统.应用广义Nyquist判据研究具有通信时延的多智能体离散时间系统,得到了保证系统达到一致的充分条件.最后应用计算机仿真验证了该结论的有效性.     

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.     

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。     

多智能体系统离散时间一致性问题中的参数设计

研究二阶多智能体系统在固定、有向通信拓扑条件下的离散时间一致性问题.针对每个智能体,采用基于速度、位置的分布式控制协议,分析速度、位置增益系数以及采样周期等参数对系统一致性的影响.结果表明,要实现二阶多智能体系统的一致性控制,在保持个体之间通信拓扑有生成树的同时,控制协议中的各个参数还必须满足一定的约束条件.系统拉普拉斯矩阵的特征值和采样周期对系统能否实现渐近一致起到了关键的作用.最后,给出一致性控制中参数设计的一种可行方法,并通过仿真对理论分析的正确性进行验证.     

离散异构多自主体系统时变编队-合围控制

针对高阶离散异构多自主体系统的时变编队-合围控制问题,考虑时变时延,提出分布式编队-合围控制协议.首先,在合理假设的基础上,通过模型转变和状态空间分解,将编队-合围控制问题转化为子系统的稳定性问题,再利用Lyapunov-Krasovskii函数,以LMIs的形式给出协议有效的充分条件,并指出LMIs的个数与系统中自主体的个数无关;然后,给出编队参考函数的具体形式,证明指出编队参考函数不受时变时延的影响;最后,通过固定和时变编队-合围仿真验证所设计的协议的有效性.     

速度不可测的异构多智能体系统一致性分析

近年来,随着异构系统在实际中的广泛应用,异构多智能体系统一致性分析成为研究热点。针对一阶部分智能体控制输入有界、二阶智能体速度不可测的异构多智能体系统,在无向网络拓扑图下给出了无领导者和有领导者两种控制输入设计方法,基于图论知识和LaSalle不变集原理给出了该异构系统实现一致性的充分条件。最后,通过数值仿真验证了该理论的正确性。     

Consensus of second-order multi-agent systems with nonlinear dynamics and time delays

In this paper, consensus problems of multi-agent systems with nonlinear dynamics and time delays are investigated. Two cases are considered that are the system without a leader and the one with a leader. New linear control protocols are introduced to make second-order multi-agent systems consensus. By applying the Lyapunov function method and the graph theory, some sufficient conditions for consensus of positions and velocities are derived. Finally, two simulation results are given to illustrate the effectiveness of our proposed methods.     

Consensus of second-order multi-agent systems with nonsymmetric interconnection and heterogeneous delays

In this paper, a consensus algorithm of multi-agent second-order dynamical systems with nonsymmetric interconnection and heterogeneous delays is studied. With the hypothesis of directed weighted topology graph with a globally reachable node, decentralized consensus condition is obtained by applying generalized Nyquist criterion. For the systems with both communication and input delays, it is shown that the consensus condition is dependent on input delays but independent of communication delays.