基于滑模的二阶多智能体快速抗扰一致性

针对带有外部未知扰动的二阶多智能体系统的领导—跟随有限时间一致性问题，本文设计出一种带有时变增益的有限时间干扰观测器，用以实现对每个跟随智能体中未知扰动的快速估计，在此基础上，本文结合超螺旋积分滑模控制方法并利用邻居智能体的位置和速度信息设计一种快速抗扰一致性协议，该协议能够保证存在非线性动态的多智能体系统有限时间一致性控制并能抑制抖振现象.同时，利用李亚普诺夫函数进行了稳定性的证明.最后，通过Matlab数值仿真进一步验证了所提出协议的可行性.     

带未知耦合权重的领导-跟随多智能体系统的实用一致性

一致性理论在许多领域有广泛应用.现有很多研究成果是关于恒同一致的.在实际中,由于任何系统都会不可避免地受到一定的外界扰动,要求误差函数的极限等于0是难以做到的,但当时间充分大时误差函数在可接受区间内是可行的.本文首先给出多智能体系统的实用一致性概念,然后研究含未知耦合权重的一阶非线性领导-跟随多智能体系统的实用一致性问题.通过设计合适的控制协议,运用图论、矩阵理论和强实用稳定性理论,得到该多智能体系统实现实用一致性的充分条件.数值模拟验证了理论结果的正确性.     

基于神经网络逼近的异构多智能体系统二分拟一致性

研究一类具有未知动力学的二阶异构非线性多智能体系统二分拟一致性问题.针对二阶多智能体系统中未知的非线性动态,基于神经网络逼近理论设计一类自适应控制协议,以保证所有智能体最终收敛到有界区域内.借助Lyapunov稳定性理论和不等式技巧得到异构多智能体系统实现领导-跟随二分拟一致性的充分性条件,并给出一致性误差的上界.最后通过数值仿真验证了理论结果的有效性.     

带有不连续动力学的非线性多智能体系统固定时间一致性EI北大核心CSCD

本文研究了一类带有不连续动力学和有界扰动的非线性多智能体系统领导跟随固定时间一致性问题.首先,在不对称的有向拓扑图下,本文设计了一种辅助信号,该辅助信号用于观测领导者状态,且该辅助信号不在通信信道中传输,可以有效地减少系统计算代价.随后,基于辅助信号,本文设计了一种不连续控制协议,以实现多智能体系统固定时间收敛.然后,利用非光滑分析、Lyapunov稳定性理论及代数图论等证明系统可在任意初始状态下达到固定时间一致.最后,仿真实例进一步验证了理论结果的有效性.     

基于事件触发的非线性多智能体系统的固定时间分群一致性

结合事件触发控制方法研究非线性多智能体系统的固定时间分群一致性问题.提出一种非线性分布式事件触发分群一致性控制协议,并给出状态信息触发控制器更新的条件.该控制协议不受入度平衡条件限制,且只需自身状态信息与邻居智能体进行通信即可在固定时间内快速实现分群一致性.系统收敛时间与智能体的初始状态无关,可有效降低系统控制器更新频率和系统的资源消耗.结合代数图论、矩阵分析及Lyapunov稳定性理论,证明在所提出协议作用下,多智能体系统在固定时间内能够实现分群一致性,且不存在Zeno行为.最后,通过仿真实例检验了理论结果的可行性.     

双层网络上多智能体系统的部分分量一致性

部分分量一致是指多智能体系统中所有状态变量的一些分量在时间趋于正无穷的情况下具有收敛性,是一种比恒同一致弱的动力学行为.本文将一阶领导–跟随多智能体系统推广到双层网络,在此基础上分别构造了两个合适的牵制控制器,并得到了相应的误差系统,然后运用矩阵理论和稳定性理论,将该系统的部分分量一致性问题转化为误差系统的部分变元稳定性问题,并导出该双层领导–跟随多智能体系统实现部分分量一致性的充分条件.最后,数值模拟验证了理论结果的正确性.     

ODE–热方程级联系统的事件触发控制

本文针对常微分方程(ODE)耦合偏微分方程(PDE)建模的分布式参数多智能体系统进行研究, 针对一致性同步问题, 提出了事件触发的网络化ODE–热方程级联系统多智能体一致性边界交互协议. 本文考虑的热方程左边界为Neumann边界条件, 并且与ODE系统耦合, 右边界为绝热边界条件. 假设网络化多智能体系统的连接方式为全联通有向拓扑图, 给出ODE–热方程级联系统的多智能体的一致性控制协议. 另外针对现有数字式控制器, 设计了事件触发的一致性控制协议, 并利用李雅普诺夫函数验证了在事件触发条件下ODE–热方程级联系统的稳定性. 最后给出了由5个ODE–热方程级联的多智能体系统的仿真结果, 验证了事件触发控制器的有效性.     

基于事件触发非线性多智能体系统的固定时间一致性

本文研究了在有向拓扑下,带有非线性动力学多智能体系统的固定时间一致性问题.提出了一种新的基于事件触发机制的非线性控制策略,对于每个智能体给出了基于状态信息的事件触发条件,当状态误差满足所给条件时才触发事件,能有效的减小系统的能量耗散和控制器的更新频次.利用Lyapunov稳定性理论和代数图论,证明在该控制策略下,多智能体系统在固定时间能实现领导跟随一致性,且不存在Zeno行为.相较于有限时间一致性策略,采用固定时间一致性策略系统的收敛时间不再依赖于系统的初始状态.最后,仿真实例验证了理论结果的有效性.     

脉冲控制下基于合作机制的多智能体系统分组一致性研究

针对在脉冲控制下非线性多智能体系统的分组一致性协同控制问题,本文基于复杂系统中智能体间的合作机制,提出了一种新颖的具有领导-跟随网络的分组一致性控制协议.该协议控制智能体仅在脉冲时刻接收来自邻居节点的信息并更新自己的状态,减少智能体因持续接收邻居信息更新自己状态而造成的网络开销.针对不同组之间智能体的信息交互,该协议具有防止组间干扰的机制,降低了不同组之间的通信干扰,提高系统鲁棒性.此外,本文还介绍了一种适用于非线性系统的方案,增强协议的适应性.基于实现分组一致性条件,构建了多智能体系统的动力学模型,并进行了协议的详细设计和理论推导.最后,通过仿真验证了协议的正确性和有效性.     

事件触发机制下的多智能体领导跟随一致性

研究了一类具有动态领导者的一阶多智能体系统的一致性问题。基于事件触发机制给出两种一致性协议,即集中式触发控制协议和分散式触发控制协议。利用李雅普诺夫稳定性理论和模型转化方法分别给出多智能体系统在两种协议作用下达到领导跟随一致的充分条件。同时,理论计算表明,系统在两种控制协议下均不存在Zeno行为。实例仿真结果验证了理论方案的有效性。     

Adaptive fuzzy leader-follower consensus control using sliding mode mechanism for a class of high-order unknown nonlinear dynamic multi-agent systems

In this article, a distributed leader-follower consensus approach is developed for a class of high-order unknown nonlinear dynamic multi-agent systems (MASs). Because every agent of the MAS contains multiple state variables, the existing consensus methods are not completely applicable for it. In order to find the qualified consensus protocol for this high-order MAS, sliding mode mechanism can be naturally considered for designing the consensus control because it can manage multiple state variables with the help of a constructed hyperplane. To this consensus control design, the sliding mode term is composed of all tracking error variables. Since the method does not require the switching control term around sliding surface, it can avoid the chattering phenomenon, which exits in most of the published sliding mode controls (SMCs). Furthermore, to handle the unknown nonlinear dynamic problem, the adaptive approximation strategy is implemented by employing fuzzy logic system (FLS). In the light of Lyapunov stability analysis, it is demonstrated that the proposed control approach can accomplish the consensus tasks. Finally, a numerical example is implemented to further show the desired results.     

Event-triggered Sliding Mode Fault-tolerant Consensus for a Class of Leader-follower Multi-agent Systems

This paper concerns with the robust sliding mode fault-tolerant consensus problem for a class of undertain second-order leader-follower multi-agent systems based on event-triggering strategies. First, a sliding mode fault-tolerant controller which uses the bound information of actuator failure rate and the event-triggering threshold is designed to ensure the robust consensus of the multi-agent systems, and the range of the sliding mode band is also shown. Second, by constructing an equivalent relationship, the upper bound of robust consensus error is also given. Third, the minimum event-triggered execution time for the second-order leader-follower multi-agent systems is calculated. Finally, the simulation results verify the effectiveness of the proposed event-triggered sliding mode fault-tolerant consensus algorithm.

     

Leaderless consensus for the fractional-order nonlinear multi-agent systems under directed interaction topology

Leaderless consensus for the fractional-order nonlinear multi-agent systems is investigated in this paper. At the first part, a control protocol is proposed to achieve leaderless consensus for the nonlinear single-integrator multi-agent systems. At the second part, based on sliding mode estimator, a control protocol is given to solve leaderless consensus for the the nonlinear single-integrator multi-agent systems. It shows that the control protocol can improve the systems’ convergence speed. At the third part, a control protocol is designed to accomplish leaderless consensus for the nonlinear double-integrator multi-agent systems. To judge the systems’ stability in this paper, two classic continuous Lyapunov candidate functions are chosen. Finally, several worked out examples under directed interaction topology are given to prove above results.     

Finite-time consensus tracking for multi-agent systems with inherent uncertainties and disturbances

In this paper, finite-time consensus tracking is investigated via time-varying feedback for uncertain nonlinear multi-agent systems (NMASs). The presence of inherent uncertainties and disturbances in the NMASs highlights the main novelty : (1) The inherent uncertainties imply that more serious unknowns and time-variations are allowed in the nonlineartities and the control coefficients of the NMASs. (2) The inherent disturbances mean that the upper bound of the disturbances is unknown. To compensate the inherent uncertainties and disturbances, time-varying protocols are proposed by integrating time-varying technique and sliding mode method. Based on the proposed protocols, the finite-time leader-following consensus and finite-time containment are achieved under directed graph. Finally, the validation of the proposed protocols is verified by two examples.     

Distributed adaptive consensus control of Lipschitz nonlinear multi-agent systems using output feedback

This paper addresses output-feedback-based distributed adaptive consensus control of multi-agent systems having Lipschitz nonlinear dynamics. Distributed dynamic protocols are designed based on the relative outputs of neighbouring agents and the adaptive coupling weights, under which consensus is reached between the nonlinear systems for all undirected connected communication topologies. Extension to the case of Lipschitz nonlinear multi-agent systems subjected to external disturbances is further studied, and a robust adaptive fully distributed consensus protocol is suggested. By application of a decoupling technique, necessary and sufficient conditions for the existence of these consensus protocols are provided in terms of linear matrix inequalities. Finally, numerical simulation results are demonstrated to validate the effectiveness of the theoretical results.     

Finite-time consensus for multi-agent systems via nonlinear control protocols

This paper investigates the fnite-time consensus problem of multi-agent systems with single and double integrator dynamics,respectively.Some novel nonlinear protocols are constructed for frst-order and second-order leader-follower multi-agent systems,respectively.Based on the fnite-time control technique,the graph theory and Lyapunov direct method,some theoretical results are proposed to ensure that the states of all the follower agents can converge to its leader agent s state in fnite time.Finally,some simulation results are presented to illustrate the efectiveness of our theoretical results.     

Leader-follower Consensus of Upper-triangular Nonlinear Multi-agent Systems

This paper is concerned with the leader-follower consensus problem by using both state and output feedback for a class of nonlinear multi-agent systems. The agents considered here are all identical upper-triangular nonlinear systems which satisfy the Lipschitz growth condition. First, it is shown that the leader-follower consensus problem is equivalent to the control design problem of a high-dimensional multi-variable system. Second, by introducing an appropriate state transformation, the control design problem can be converted into the problem of finding a constant parameter, which can be obtained by solving the Lyapunov equation and estimating the nonlinear terms of the given system. At last, an example is given to verify effectiveness of the proposed consensus algorithms.      

Leader-follower consensus for a class of nonlinear multi-agent systems

This paper deals with the leader-follower consensus problem for a class of nonlinear multiagent systems. All agents have identical nonlinear dynamics in the strict feedback form with Lipschitz growth condition. Both full state consensus protocol and dynamic output consensus protocol are provided. It is shown that under a connected undirected information communication topology, the proposed protocols can solve the leader-follower consensus problem. Two consensus protocol design procedures are presented and a numerical example is given to illustrate the proposed protocols.     

Distributed robust finite-time nonlinear consensus protocols for multi-agent systems

This paper investigates the robust finite-time consensus problem of multi-agent systems in networks with undirected topology. Global nonlinear consensus protocols augmented with a variable structure are constructed with the aid of Lyapunov functions for each single-integrator agent dynamics in the presence of external disturbances. In particular, it is shown that the finite settling time of the proposed general framework for robust consensus design is upper bounded for any initial condition. This makes it possible for network consensus problems to design and estimate the convergence time offline for a multi-agent team with a given undirected information flow. Finally, simulation results are presented to demonstrate the performance and effectiveness of our finite-time protocols.