基于观测器的线性时变时滞多智能体系统一致性

针对系统状态不可测和具有通信时延的线性多智能体系统,提出一种基于观测器的一致性控制算法.设计观测器用于解决智能体状态不可测的问题,在观测器的基础上,提出一种控制协议来实现带时变时延的线性多智能体系统一致性.利用模型转换的方式将原系统转换为新的模型系统,在此基础上,构造Lyapunov-Krasovskii函数并分析系统稳定性,通过求解线性矩阵不等式获取控制器系数矩阵.最后通过Matlab数值仿真验证所提出方法的有效性.     

基于分布式PID控制的时变时延多智能体系统的一致性

研究普通阶多智能体系统存在时变时延条件下的一致性问题.首先,针对系统存在时变时延的情况,结合状态反馈与PID控制提出一种一致性协议;然后,将系统状态空间分解为一致子空间和一致补子空间,采用状态空间分解法将一致性问题转化为渐近稳定问题,给出系统实现一致的充分必要条件;并确定系统的一致性函数的显示表达式;最后,构造Lyapunov-Krasovskii泛函,基于线性矩阵不等式(LMI)给出控制参数的计算方法,采用可扩充性方法降低线性矩阵不等式的计算数量.仿真结果表明,系统的结构拓扑图存在全局可达节点时,系统在所提出的协议作用下通过计算合适的PID参数和控制参数可实现一致性,通过与纯比例控制的结果对比表明,所提出的协议能够消除系统稳态误差,使系统趋于一致.     

基于super-twisting算法的多航天器姿态有限时间分布式协同控制

针对受外界干扰和执行器故障影响的多航天器姿态协同控制问题,本文设计了一种基于干扰观测器的分布式协同supper-twisting滑模控制器.首先,将各航天器的外界干扰和执行器故障看作一个集总干扰,设计自适应滑模干扰观测器对其进行估计.其次,将supper-twisting算法和积分滑模面相结合,设计一种基于多航天器姿态一致性误差的分布式协同控制器,并由Lyapunov稳定性理论证明了所设计的多航天器姿态可以在有限时间内收敛到平衡点附近的邻域内.最后的仿真研究及比较结果表明,所设计的控制器可以加快系统的收敛速度,并提高系统的控制精度.     

基于事件触发的时变拓扑多智能体系统编队控制

针对资源受限的时变拓扑多智能体系统的编队控制问题,提出一种基于复合误差信息事件触发机制以减少不必要的信息传输,降低带宽占用,并设计了多智能体系统的编队控制协议和分布式事件触发机制.通过将多智能体系统的编队控制问题转化为闭环延时系统的稳定性问题,构造Lyapunov-Krasovskii函数并利用线性矩阵不等式技术,给出多智能体系统实现编队的充分条件.最后,通过仿真验证了所提出方法的有效性.     

一类多时变时延异质多智能体系统的组一致性

研究了一类由一阶和二阶智能体组成的异质多智能体系统的组一致性问题．首先,在多时变时延异质系统中设计了实现静态组一致的控制算法;其次,运用稳定性理论和线性矩阵不等式,分别给出了无时延、同时具有通信与输入时延的异质多智能体系统实现组一致性的充分条件;再次,通过求解一组可行的线性矩阵不等式,得到了输入时延的容许上界,并得出了通信时延与异质多智能体系统的组一致性无关的结论;最后,仿真结果验证了理论结果的有效性．     

含时延约束的多智能体系统二分一致性

针对多智能体系统中信息交互存在通信时延这一约束,在无向符号图拓扑结构下分别研究了含固定时延和时变时延的一阶多智能体系统二分一致性问题。通过设计相应的控制协议,使得该系统收敛到两个模值相同但符号不同的状态。在稳定性分析中,利用广义Nyquist准则的方法,得到含固定时延多智能体系统实现二分一致性的充分条件;对含时变时延系统构造包含三重积分项的Lyapunov函数,利用积分不等式和线性矩阵不等式理论,并结合自由矩阵的方法得到含时变时延多智能体系统实现二分一致性的充分条件。最后,数值仿真验证了所得结论的有效性和正确性。     

分布式多无人机的时变编队非线性控制设计

研究了基于分布式通信网络的多无人机时变编队控制问题,考虑到外界扰动对多无人机协同编队系统的影响,提出一种新的连续非线性鲁棒编队控制方法.首先基于一致性方法构造了分布式无人机编队误差系统,降低了编队控制器对全局编队信息的要求;然后采用一种基于误差符号函数积分的鲁棒控制算法补偿未知外界扰动的影响,提高了无人机编队系统的鲁棒性,并基于Lyapunov分析的方法,证明了多无人机编队误差的半全局渐进收敛性;最后在四旋翼无人机编队实验平台上进行了多无人机时变编队的实时实验验证,实验结果表明,所提出的分布式编队控制算法可以实现多无人机时变编队控制,且具有较好的协同性能和抗干扰能力.     

时延异构多自主体系统的群一致性分析

针对由一阶自主体和二阶自主体构成的异构多自主体系统的静态群一致性问题,分别提出了在固定连接拓扑和切换连接拓扑结构下的静态群一致性算法。通过构造Lyapunov-Krasovskii函数,得到了系统在具有相同时变通信时延的群一致性算法作用下渐近收敛群一致的充分条件,并以线性矩阵不等式表示。最后,仿真结果表明,所提算法在满足一定条件下能使时延异构多自主体系统渐近收敛群一致。     

异构变时延多智能体系统编队控制分析

实际工程应用中,异构多智能体的编队控制问题研究具有十分重要的意义。考虑现实环境影响,编队系统个体之间的通信变时延难以忽略。系统收敛速率是评价系统性能的重要依据,然而现有编队控制问题研究很少能给出相应的量化指标。针对上述情形,对包含一、二阶智能体的异构变时延系统的编队控制问题进行分析研究。首先,考虑固定有向通信拓扑情况,对领航跟随者模式下异构变时延多智能体系统提出线性一致性控制协议。然后,构建误差系统模型,利用图论与矩阵论分析方法,并结合Routh-Hurwitz定理与牛顿-莱布尼兹公式,获得系统实现编队控制的充要条件,同时得到估算系统收敛速率的不等式关系。最后,仿真算例中随机给定一种系统节点0全局可达的通信拓扑,并对不同时延情况的编队控制效果进行分析,验证一致性控制协议的正确性和有效性。     

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.     

有向切换拓扑下多智能体系统编队控制

针对多智能体系统编队形成过程中受lur'e型非线性项影响,并考虑降低系统通信要求,基于一致性理论,设计了分布式控制器,使得多智能体系统形成时变编队.利用Laplacian矩阵的特殊性质,对其进行分解,将多智能体系统的编队控制问题转化为低阶系统的稳定性问题.给出了切换拓扑的平均驻留时间概念,据此提供了一种设计分布式控制器...     

Consensus of nonlinear multiagent systems with mode-dependent delay via stochastic sampled data under Markovian switching topologies

In this article, we investigate the mean-square consensus problem of multiagent systems with one leader and multiple followers. In consideration of the uncertain disturbance from external environment or internal change of system, the interaction topology and time-varying delay switch randomly which are regulated by a time-homogeneous Markovian chain. The distributed control protocol is designed based on the stochastic sampling information from its neighbors and the leader. Using stochastic Lyapunov theory and linear matrix inequality (LMI) approach, the sufficient condition is concluded to guarantee the mean-square consensus. For the undirected topology case, a low-dimensional LMI-based consensus criterion is further derived based on the matrix diagonalization method. Finally, a numerical simulation is provided to demonstrate the reasonability of the theoretical results.     

有向切换拓扑条件下多航天器分组姿态协同控制

针对有向切换拓扑条件下多航天器分组姿态协同控制问题,提出一种基于变量代换和矩阵分解的控制方法.首先,给出分组情况下系统Laplacian矩阵特征值的性质,并对航天器姿态模型进行变量代换,将非线性系统的分组姿态协同问题转化为线性系统的分组一致问题;然后,通过分解Laplacian矩阵,将分组一致问题转化为线性切换系统的稳定性问题,从而通过Lyapunov稳定性理论进行分析,给出系统拓扑的最小驻留时间;最后,对包含两个分组的系统进行仿真,结果表明了所提出控制方法的有效性.     

基于SO(3)的多四旋翼无人机编队协同控制

针对多四旋翼无人机系统的编队飞行问题,提出了基于特殊正交群SO(3)的协同控制设计方法.在给出编队空间队形和通信拓扑描述后,建立了多四旋翼无人机系统SO(3)控制模型.由于SO(3)与传统俯仰/偏航/滚转三通道模型具有不同的结构,文中进一步研究了SO(3)中无人机之间相对误差的表示方法,设计了适用于多飞行器的SO(3)控制器实现对编队和姿态的协同控制.推力控制器用于调节无人机的位置与速度,并在此基础上构造旋转矩阵形式的姿态协同指令.文中相应设计了SO(3)姿态控制器用于实现指令跟踪,最后从理论上对协同稳定性进行了分析.提出的控制方法能够使得多四旋翼无人机形成期望的队形,并且保持姿态一致进行稳定飞行.仿真结果验证了本文方法的有效性.     

Stochastic bounded consensus tracking of second-order multi-agent systems with measurement noises based on sampled-data with small sampling delay

This paper is devoted to the stochastic bounded consensus tracking problems of second-order multi-agent systems, where the control input of each agent can only use the information measured at the sampling instants from its neighbors or the virtual leader with a time-varying reference state, the measurements are corrupted by random noises, and the signal sampling process induces the small sampling delay. The augmented matrix method, the probability limit theory and some other techniques are employed to derive the necessary and sufficient conditions guaranteeing the mean square bounded consensus tracking. We show that the convergence of the proposed protocol simultaneously depends on the constant feedback gains, the network topology, the sampled period and the sampling delay, and that the static consensus tracking error depends on not only the above mentioned factors, but also the noise intensity and the upper bound of the velocity and the acceleration of the virtual leader. The obtained results cover no sampling delay as its one special case. Simulations are provided to demonstrate the effectiveness of the theoretical results.     

Controller design for stochastic Markovian switching systems with time-varying delay and actuator saturation

The paper deals with controller design for stochastic Markovian switching systems with time-varying delay and actuator saturation by implying a new criterion for the domain of attraction firstly. By constructing more appropriate Lyapunov–Krasovskii functional, some new conditions for verifying stochastic stability of the plant are established. Then, the state feedback controller is designed to expand the domain of attraction of the corresponding closed-loop system. The procedure of deriving controller gain matrices is converted into an optimisation problem with constraints of a set of linear matrix inequalities. The mathematical model of RLC series circuit illustrates the validity of the obtained results.     

短时延多包传输网络控制系统的容错控制

研究了存在数据丢失的短时延多包传输网络控制系统在静态调度和动态调度下的控制器设计问题。把未能成功传输数据的传感器节点视为暂时失效,将网络控制系统建模为一类具有时变传感器“故障”的系统。在静态调度策略下,将系统建模为一类具有一定切换规则的周期系统,利用容错控制理论和周期系统理论得到系统稳定性判据;在动态调度策略下,将系统建模为一类具有有限子系统的自主切换系统,利用容错控制理论和切换系统理论给出了系统的稳定性条件。并利用控制器和观测器的协同设计方法给出了系统在静态调度和动态调度下的容错控制律和状态观测器设计方法。数值仿真算例证明了结论的可行性和有效性。     

Robustly Exponential Stability Analysis for Discrete-Time Stochastic Neural Networks with Interval Time-Varying Delays

This paper deals with the problems of the global exponential stability and stabilization for a class of uncertain discrete-time stochastic neural networks with interval time-varying delay. By using the linear matrix inequality method and the free-weighting matrix technique, we construct a new Lyapunov–Krasovskii functional and establish new sufficient conditions to guarantee that the uncertain discrete-time stochastic neural networks with interval time-varying delay are globally exponential stable in the mean square. Furthermore, we extend our consideration to the stabilization problem for a class of discrete-time stochastic neural networks. Based on the state feedback control law, some novel delay-dependent criteria of the robust exponential stabilization for a class of discrete-time stochastic neural networks with interval time-varying delay are established. The controller gains are designed to ensure the global robust exponential stability of the closed-loop systems. Finally, numerical examples illustrate the effectiveness of the theoretical results we have obtained.     

Consensus Control of Leader-Following Multi-Agent Systems in Directed Topology With Heterogeneous Disturbances

This paper investigates the consensus problem for linear multi-agent systems with the heterogeneous disturbances generated by the Brown motion. Its main contribution is that a control scheme is designed to achieve the dynamic consensus for the multi-agent systems in directed topology interfered by stochastic noise. In traditional ways, the coupling weights depending on the communication structure are static. A new distributed controller is designed based on Riccati inequalities, while updating the coupling weights associated with the gain matrix by state errors between adjacent agents. By introducing time-varying coupling weights into this novel control law, the state errors between leader and followers asymptotically converge to the minimum value utilizing the local interaction. Through the Lyapunov directed method and It? formula, the stability of the closed-loop system with the proposed control law is analyzed. Two simulation results conducted by the new and traditional schemes are presented to demonstrate the effectiveness and advantage of the developed control method.