基于虚拟领导者的多智能体蜂拥行为研究

蜂拥行为的产生来源于对飞鸟、鱼群、蚂蚁以及蜜蜂行为的研究,这些群体通过每个个体的局部信息交互而产生统一的觅食、迁徙、归巢等行为。多智能体的自组织行为促进了蜂拥行为在工程上的应用,包括大量在环境中移动的传感器、媒介的平行同步传输、军事任务中的侦查、监视和战斗协作。主要研究内容是具有虚拟领导者的多智能体蜂拥控制算法,分别对群体中只有一部分智能体具有引导信息和虚拟领导者具有变化速度的情况作了分析。通过个体之间的局部感知作用和相应的反应行为,使系统整体呈现一定的协调行为。     

基于社区划分的多智能体网络快速蜂拥控制

针对复杂网络社区特性对多智能体系统协同控制效率的影响,面向具有ER(Erdos-renyi)网络或BA (Barabasi-albert)网络性质的多智能体系统,提出一种基于社区划分的快速蜂拥控制算法.该算法充分考虑社区内个体的相对密集特性,通过在社区间引入虚拟领导者作用,避免系统在演化过程中因通信受限而导致的“分块”现象,可有效提高系统拓扑的代数连通度.仿真结果表明:具有相应性质的多智能体系统蜂拥行为的收敛速度与ER和BA网络的平均度以及BA网络度分布的幂指数正相关;优化社区个数有利于提高蜂拥收敛速度.     

具有时变通信延迟的多智能体系统改进蜂拥控制

针对不确定非线性二阶多智能体系统中存在的时变通信时延和未知干扰问题,提出了一种鲁棒自适应蜂拥控制规律。为了使二阶多智能体系统能够具有更好的抗干扰能力,设计了基于智能体位置状态信息和速度状态信息的鲁棒自适应算子,实现了系统在时变通信时延扰动下的分布控制。通过使用Lyapunov-Krasovskii方法构造能量函数,证明了多智能体系统的网络连通性,智能体的速度收敛于虚拟领导者的速度,并给出了具有时变通信时延的多智能体系统收敛条件。仿真实验结果表明,在不同干扰强度和不同通信时延下系统均能实现快速收敛,形成稳定的拓扑结构,证明所提方法正确有效。     

二阶多智能体系统量化蜂拥控制

针对在多智能体系统的通信网络中需要对交换信息进行量化的客观情况,研究基于量化信息的二阶多智能体系统蜂拥控制问题。首先,假设多智能体系统采用一致量化器对速度和位置信息进行量化,并且有一个虚拟领导者沿着固定方向匀速运动;然后,设计基于量化信息的多智能体蜂拥控制输入,并利用非平滑系统的Lyapunov稳定性判据和不变集原理证明系统的稳定性;最后,利用Matlab对多智能体系统在二维平面上的蜂拥运动进行仿真实验,仿真结果验证了理论分析的正确性。     

离散时变多智能体系统有限时间一致性迭代学习控制

针对一类离散时变多智能体系统,通过引入虚拟领导者产生期望轨迹的方法,将虚拟领导者和所有智能体组成固定的拓扑结构,在此基础上,提出一种离散时间迭代学习控制算法.该算法对多智能体系统中的每个智能体都设计一个控制器,各控制器都是利用上一次迭代时,该智能体与虚拟领导者之间的跟踪误差和该智能体与相邻智能体之间的跟踪误差,通过拓扑结构中通信权值的组合不断修正上一次的控制律,从而获得理想控制律.同时,基于范数理论严格证明所提出算法的收敛性,并给出算法在$\lambda$-范数意义下的收敛条件.该算法能够使离散时变多智能体的输出随着迭代次数的增加在有限时间区间内完全跟踪期望轨迹.理论分析和仿真结果都表明了所提出算法的有效性.     

融合局部自适应追踪的多目标牵制蜂拥算法

针对以往的多智能体蜂拥控制算法在考虑单个目标追踪情形时不具普适性,以及现有的多目标蜂拥控制都是基于全局目标信息来进行集中式协调控制,而非基于局部目标信息下的分布式协调控制的问题,提出一种融合局部自适应检测机制的分布式协同牵制蜂拥算法。首先,算法在分离、聚合、速度匹配和引导反馈的基础上,引入局部自适应追踪策略,实现智能体的局部动态跟随运动;其次,受牵制思想启发,根据节点影响力指数评估算法选取m个信息个体分别向m个目标进行多目标追踪,起到模拟外部信息的作用,不同的信息个体会由于局部自适应检测机制间接地引领周围局部个体向不同目标进行追踪;最后,设计一类新的聚集和排斥势能函数,实现相同目标智能体的聚集,以及不同目标智能体的避碰,具有可调参数少和效率高的优势。通过三维仿真实验验证了算法的多目标追踪可行性和有效性。     

非仿射非线性多智能体系统迭代学习一致跟踪

为了解决非仿射非线性多智能体系统在给定时间区间上一致性完全跟踪问题,基于迭代学习控制方法设计一种分布式一致性跟踪控制算法.首先,由引入的虚拟领导者与所有跟随者组成多智能体系统的通信拓扑,其中虚拟领导者的作用是提供期望轨迹.然后,在只有部分跟随者能够获得领导者信息的条件下,利用每个跟随者及其邻居的跟踪误差构造每个跟随者的迭代学习一致性跟踪控制器.同时采用中值定理将非仿射非线性多智能体系统转化仿射形式,并基于压缩映射方法证明所提算法的收敛性,给出算法的收敛条件.理论分析表明,在智能体的非线性函数未知情况下,利用所提算法可以使非仿射非线性多智能体系统在给定时间区间上随迭代次数增加逐次实现一致性完全跟踪.最后,通过仿真算例进一步验证所提算法的有效性.     

链式多种群多智能体进化算法

将多种群的进化方式和链式结构的动态邻域引入到多智能体进化算法中,提出了一种链式多种群多智能体进化算法.算法设置了多种群交互的演化结构.各种群中的智能体通过与其动态邻域智能体的竞争、合作及自学习操作来增加自身的能量;动态邻域的链式结构提高了算法的效率、降低了计算复杂度;多个种群之间的信息定期以一定的方式进行交互,增强了种群的多样性,减小了算法陷入局部最优的机率.理论分析和多个测试函数的仿真结果均表明:链式多种群多智能体进化算法在求解高维优化问题上具有很好的性能.     

带虚拟领导者的多智能体系统的非光滑一致性

研究了在限制交互范围条件下具有一个虚拟领导者的二阶多智能体系统的一致性问题。假设多智能体系统中所有智能体均可以接收到领导者的信息，而智能体之间只有距离在一定范围内才可以进行相互通信。在相对状态反馈的线性一致性协议下，通过李雅普诺夫法，证明了该多智能体系统二阶一致性的充分条件。接着通过仿真实例验证了理论结果，并对该算法作出了总结。     

多智能体布谷鸟算法的网络计划资源均衡优化

网络计划资源均衡属于组合优化问题,为了能快速有效地求解此类问题,提出了一种多智能体布谷鸟算法。针对标准布谷鸟算法缺乏信息共享的缺陷,将多智能体系统引入布谷鸟算法中。多智能体的邻域竞争合作算子实现智能体间信息的交流,加快算法收敛速度;变异算子扩大搜索范围增加种群多样性;自学习算子提高局部寻优的能力;布谷鸟算法的Levy飞行进化机制能有效地跳出局部最优实现全局收敛。实例仿真结果证实了,与其他算法相比多智能体布谷鸟算法能更有效地求解网络计划资源均衡优化问题。     

Flocking of Multi-Agents With a Virtual Leader

All agents being informed and the virtual leader traveling at a constant velocity are the two critical assumptions seen in the recent literature on flocking in multi-agent systems. Under these assumptions, Olfati-Saber in a recent IEEE Transactions on Automatic Control paper proposed a flocking algorithm which by incorporating a navigational feedback enables a group of agents to track a virtual leader. This paper revisits the problem of multi-agent flocking in the absence of the above two assumptions. We first show that, even when only a fraction of agents are informed, the Olfati-Saber flocking algorithm still enables all the informed agents to move with the desired constant velocity, and an uninformed agent to also move with the same desired velocity if it can be influenced by the informed agents from time to time during the evolution. Numerical simulation demonstrates that a very small group of the informed agents can cause most of the agents to move with the desired velocity and the larger the informed group is the bigger portion of agents will move with the desired velocity. In the situation where the virtual leader travels with a varying velocity, we propose modification to the Olfati-Saber algorithm and show that the resulting algorithm enables the asymptotic tracking of the virtual leader. That is, the position and velocity of the center of mass of all agents will converge exponentially to those of the virtual leader. The convergent rate is also given.      

Flocking for multi-agent systems with optimally rigid topology based on information weighted Kalman consensus filter

This paper investigates the leader-follower flocking problem of multi-agent systems. The leader with input noise is estimated by a proposed continuous-time information weighted Kalman consensus filter (IWKCF) for agents. A novel distributed flocking algorithm based on the IWKCF is further presented to make agents achieve flocking to the leader. It is shown that the proposed flocking algorithm based on the continuous-time IWKCF is asymptotically stable. Applying the topology optimization scheme, the communication complexity of system topologies of multi-agent systems is effectively reduced. Finally, simulations are provided to demonstrate the effectiveness of the proposed results.     

A local flocking algorithm of multi-agent dynamic systems

In this paper, the local flocking of multi-agent systems is investigated, which means all agents form some groups of surrounding multiple targets with the partial information exchange. For the purpose of realising local multi-flocking, a control algorithm of local flocking is proposed, which is a biologically inspired approach that assimilates key characteristics of flocking and anti-flocking. In the process of surrounding mobile targets through the control algorithm, all agents can adaptively choose between two work modes to depend on the variation of visual field and the number of pursuing agents with the mobile target. One is a flocking pursuing mode which is that some agents pursue each mobile target, the other is an anti-flocking searching mode that means with the exception of the pursing agents of mobile targets, other agents respectively hunt for optimal the mobile target with a closest principle between the agent and the target. In two work modes, the agents are controlled severally via the different control protocol. By the Lyapunov theorem, the stability of the second-order multi-agent system is proven in detail. Finally, simulation results verify the effectiveness of the proposed algorithm.     

Second-order tracking control for leader-follower multi-agent flocking in directed graphs with switching topology

This paper investigates the flocking problem for leader-follower multi-agent systems in directed graphs with switching topology. A decentralized state control rule, namely, a second-order protocol, is designed for each agent to track the leader. And it is proved that the proposed control scheme can effectively estimate the tracking error of each agent when the leader is active. Particularly, to ensure the tracking error can be estimated, the following two questions are solved: (1) How many agents are needed to connect to the leader? (2) How should these connections be distributed? Finally, a simple example is also given to verify the effectiveness of the proposed theorems.     

基于k-shell分解的多智能体牵制控制算法

针对多智能体网络在牵制控制过程中存在的网络分裂现象,考虑到牵制节点选择对多智能体收敛速度的影响,提出一种基于k-shell分解的牵制控制算法.首先根据节点连通度划分子网;然后提出基于k-shell分解的牵制节点选择方法;最后完成多智能体的牵制控制.理论推导证明,采用该算法后整个智能体网络最终将形成一个子网.分析对比3种牵制控制算法,通过实验仿真结果验证所提出算法能够实现多智能体的一致性,有利于提高多智能体的收敛速度.     

Flocking of multi‐agent dynamical systems with intermittent nonlinear velocity measurements

In this paper, the problem of flocking control in networks of multiple dynamical agents with intermittent nonlinear velocity measurements is studied. A new flocking algorithm is proposed to guarantee the states of the velocity variables of all the dynamical agents to converge to consensus while ensuring collision avoidance of the whole group, where each agent is assumed to obtain some nonlinear measurements of the relative velocity between itself and its neighbors only on a sequence of non‐overlapping time intervals. The results are then extended to the scenario of flocking with a nonlinearly dynamical virtual leader, where only a small fraction of agents are informed and each informed agent can obtain intermittent nonlinear measurements of the relative velocity between itself and the virtual leader. Theoretical analysis shows that the achieved flocking in systems with or without a virtual leader is robust against the time spans of the agent speed‐sensors. Finally, some numerical simulations are provided to illustrate the effectiveness of the new design. Copyright © 2011 John Wiley & Sons, Ltd.     

基于局部估计的功率驱动多智能体网络牵制蜂拥控制算法

针对复杂功率驱动系统控制中现有牵制控制策略在保持拓扑结构连通性和降低功率消耗方面存在的不足,提出一种基于局部估计的功率驱动多智能体网络的牵制蜂拥控制算法。该算法首先利用幂迭代一致估计算法动态估计多智能体网络的代数连通度;然后根据代数连通度的局部估计值及最大功率约束自适应调整个体发射半径,以保持多智能体网络在演化过程中拓扑结构的连通性,并有效降低功率消耗;最后通过仿真实验验证了所提出控制算法的有效性。     

Flocking shape analysis of multi-agent systems

In this paper,we consider the shape control in flocking behavior of a multi-agent system with a virtual leader.Besides the traditional flocking control terms,which include a gradient-based term,a velocity consensus term and a navigational feed-back in general,a new piecewise smooth neighbor-based local controller is added to regulate the configuration to the desired flocking shape.All agent velocities approach the desired velocity asymptotically,while collisions among agents can be avoided.Furthermore,based...