Adaptive Event-Triggered Time-Varying Output Group Formation Containment Control of Heterogeneous Multiagent Systems

In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed topology.The MAS is composed of a number of tracking leaders,formation leaders and followers,where two different types of leaders are used to provide reference trajectories for movement and to achieve certain formations,respectively.Firstly,compen-sators are designed whose states are estimations of tracking lead-ers,based on which,a controller is developed for each formation leader to accomplish the expected formation.Secondly,two event-triggered compensators are proposed for each follower to evalu-ate the state and formation information of the formation leaders in the same group,respectively.Subsequently,a control protocol is designed for each follower,utilizing the output information,to guide the output towards the convex hull generated by the forma-tion leaders within the group.Next,the triggering sequence in this paper is decomposed into two sequences,and the inter-event intervals of these two triggering conditions are provided to rule out the Zeno behavior.Finally,a numerical simulation is intro-duced to confirm the validity of the proposed results.

Fixed-Time Antidisturbance Consensus Tracking for Nonlinear Multiagent Systems With Matching and Mismatching Disturbances

In this paper,fixed-time consensus tracking for mul-tiagent systems(MASs)with dynamics in the form of strict feed-back affine nonlinearity is addressed.A fixed-time antidistur-bance consensus tracking protocol is proposed,which consists of a distributed fixed-time observer,a fixed-time disturbance observer,a nonsmooth antidisturbance backstepping controller,and the fixed-time stability analysis is conducted by using the Lyapunov theory correspondingly.This paper includes three main improvements.First,a distributed fixed-time observer is developed for each follower to obtain an estimate of the leader’s output by utilizing the topology of the communication network.Second,a fixed-time disturbance observer is given to estimate the lumped disturbances for feedforward compensation.Finally,a nonsmooth antidisturbance backstepping tracking controller with feedforward compensation for lumped disturbances is designed.In order to mitigate the“explosion of complexity”in the tradi-tional backstepping approach,we have implemented a modified nonsmooth command filter to enhance the performance of the closed-loop system.The simulation results show that the pro-posed method is effective.

Distributed model predictive control for multiagent systems with improved consistency

This paper addresses an improved distributed model predictive control （DMPC） scheme for multiagent systems with an attempt to improving its consistency. The deviation between what an agent is actually doing and what its neighbors believe that agent is doing is penalized in the cost function of each agent. At each sampling instant the compatibility constraint of each agent is set tighter than the previous sampling instant. Like the traditional approach, the performance cost is utilized as the Lyapunov function to prove closed-looped stability. The closed-loop stability is guaranteed if the weight matrix for deviation in the cost function are sufficiently large. The proposed distributed control scheme is formulated as quadratic programming with quadratic constraints. A numerical example is given to illustrate the effectiveness of the proposed scheme.

Consensus of multiagent systems based on disturbance observer

The objectives of this work are the development and design of disturbance observers (DO’s) for a team of agents that accomplish consensus on agents’ states in the presence of exogenous disturbances. A pinning control strategy is designed for a part of agents of the multiagent systems without disturbances, and this pinning control can bring multiple agents’ states to reaching an expected consensus value. Under the effect of the disturbances, nonlinear disturbance observers are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multiagent systems with disturbances under the composite controller can be achieved. Finally, by applying an example of multiagent systems with switching topologies and exogenous disturbances, the design of the parameters of DO’s are illuminated.

On consensus protocols for high-order multiagent systems

In this paper,the static consensus problem and the dynamic consensus problem are considered for a class of high-order multiagent systems.With the proposed consensus protocols,necessary and sufficient conditions for the consensus problems are obtained.For the static consensus protocol,the desired consensus speed can be achieved by adjusting feedback gains.Simulations show the effectiveness of the proposed consensus protocols.

Pseudo-Predictor Feedback Control for Multiagent Systems with Both State and Input Delays

This paper is concerned with the consensus problem for high-order continuous-time multiagent systems with both state and input delays.A novel approach referred to as pseudopredictor feedback protocol is proposed.Unlike the predictorbased feedback protocol which utilizes the open-loop dynamics to predict the future states,the pseudo-predictor feedback protocol uses the closed-loop dynamics of the multiagent systems to predict the future agent states.Full-order/reduced-order observer-based pseudo-predictor feedback protocols are proposed,and it is shown that the consensus is achieved and the input delay is compensated by the proposed protocols.Necessary and sufficient conditions guaranteeing the stability of the integral delay systems are provided in terms of the stability of the series of retarded-type time-delay systems.Furthermore,compared with the existing predictor-based protocols,the proposed pseudo-predictor feedback protocol is independent of the input signals of the neighboring agents and is easier to implement.Finally,a numerical example is given to demonstrate the effectiveness of the proposed approaches.

Distributed optimization for discrete-time multiagent systems with nonconvex control input constraints and switching topologies

This paper addresses the distributed optimization problem of discrete-time multiagent systems with nonconvex control input constraints and switching topologies.We introduce a novel distributed optimization algorithm with a switching mechanism to guarantee that all agents eventually converge to an optimal solution point,while their control inputs are constrained in their own nonconvex region.It is worth noting that the mechanism is performed to tackle the coexistence of the nonconvex constraint operator and the optimization gradient term.Based on the dynamic transformation technique,the original nonlinear dynamic system is transformed into an equivalent one with a nonlinear error term.By utilizing the nonnegative matrix theory,it is shown that the optimization problem can be solved when the union of switching communication graphs is jointly strongly connected.Finally,a numerical simulation example is used to demonstrate the acquired theoretical results.

The Formation Control of Multi-agent Systems on a Circle

This paper investigates the formation control of a class of multi-agent systems moving on a circle, whose topology is a cyclic graph, and presents several new results for the following two cases: Case I, the agents with single-integrator kinematics,and Case II, the agents with double-integrator kinematics. Firstly,for Case I, two control protocols are proposed under which the multiagent systems keep a uniformly-spaced formation. Secondly,we study Case II, and a control protocol is designed for this case, then the stability of the formation is proved. Finally, three simulations are studied by using our presented results. The study of illustrative examples with simulations shows that our results as well as designed control protocols work very well in studying the formation control of this class of multi-agent systems.

Multiagent flocking with formation in a constrained environment

We consider the problem of controlling a group of mobile agents to form a designated formation while flocking within a constrained environment. We first propose a potential field based method to drive the agents to move in connection with their neighbors, and regulate their relative positions to achieve the specific formation. The communication topology is preserved during the motion. We then extend the method to flocking with environmental constraints. Stability properties are analyzed to guarantee that all agents eventually form the desired formation while flocking, and flock safely without collision with the environment boundary. We verify our algorithm through simulations on a group of agents performing maximum coverage flocking and traveling through an unknown constrained environment.

Maximizing Convergence Speed for Second Order Consensus in Leaderless Multi-Agent Systems

The paper deals with the consensus problem in a leaderless network of agents that have to reach a common velocity while forming a uniformly spaced string.Moreover,the final common velocity(reference velocity)is determined by the agents in a distributed and leaderless way.Then,the consensus protocol parameters are optimized for networks characterized by a communication topology described by a class of directed graphs having a directed spanning tree,in order to maximize the convergence rate and avoid oscillations.The advantages of the optimized consensus protocol are enlightened by some simulation results and comparison with a protocol proposed in the related literature.The presented protocol can be applied to coordinate agents such as mobile robots,automated guided vehicles(AGVs)and autonomous vehicles that have to move with the same velocity and a common inter-space gap.

MAS Based Distributed Automatic Generation Control for Cyber-Physical Microgrid System

The microgrid is a typical cyber-physical microgrid system (CPMS). The physical unconventional distributed generators (DGs) are intermittent and inverter-interfaced which makes them very different to control. The cyber components, such as the embedded computer and communication network, are equipped with DGs, to process and transmit the necessary information for the controllers. In order to ensure system-wide observability, controllability and stabilization for the microgrid, the cyber and physical component need to be integrated. For the physical component of CPMS, the droop-control method is popular as it can be applied in both modes of operation to improve the grid transient performance. Traditional droop control methods have the drawback of the inherent trade-off between power sharing and voltage and frequency regulation. In this paper, the global information (such as the average voltage and the output active power of the microgrid and so on) are acquired distributedly based on multi-agent system (MAS). Based on the global information from cyber components of CPMS, automatic generation control (AGC) and automatic voltage control (AVC) are proposed to deal with the drawback of traditional droop control. Simulation studies in PSCAD demonstrate the effectiveness of the proposed control methods. © 2014 Chinese Association of Automation.

A Personalized Search Model Using Online Social Network Data Based on a Holonic Multiagent System

Personalized search utilizes user preferences to optimize search results,and most existing studies obtain user preferences by analyzing user behaviors in search engines that provide click-through data.However,the behavioral data are noisy because users often clicked some irrelevant documents to find their required information,and the new user cold start issue represents a serious problem,greatly reducing the performance of personalized search.This paper attempts to utilize online social network data to obtain user preferences that can be used to personalize search results,mine the knowledge of user interests,user influence and user relationships from online social networks,and use this knowledge to optimize the results returned by search engines.The proposed model is based on a holonic multiagent system that improves the adaptability and scalability of the model.The experimental results show that utilizing online social network data to implement personalized search is feasible and that online social network data are significant for personalized search.

Semantic-based dynamic positioning mechanism for problem solving in multi-agent systems

In multi-agent systems(MAS),finding agents which are able to service properly in an open and dynamic environment are the key issue in problem solving.However,it is difficult to find agent resources quickly and position agents accurately and complete the system integration by the keyword matching method,due to the lack of clear semantic information of the classical agent model.An semantic-based agent dynamic positioning mechanism was proposed to assist in the system dynamic integration.According to the semantic agent model and the description method,a two-stage process including the domain positioning stage and the service semantic matching positioning stage,was discussed.With this mechanism,proper agents that provide appropriate service to assign sub-tasks for task completion can be found quickly and accurately.Finally,the effectiveness of the positioning mechanism was validated through the in-depth performance analysis in the application of simulation experiments to the system dynamic integration.

A Multiagent-based Organizational Decision Support System

In this paper, a multiagent based organizational decision support system(ODSS) is presented. Firstly, the ODSS architecture is introduced. Then a multiagent based organizational decision support system is studied and the implementation of the multiagent based ODSS is presented. Finally, an example, to which the ODSS is applied, is provided.

ACE2-Ang(1-7)-MasR轴对心血管系统保护作用的研究进展

肾素-血管紧张素系统(RAS)是人体重要的体液调节系统之一,在维持机体血压稳定和水电解质平衡中发挥了重要作用。近年来,发现了RAS系统的新支路,ACE2和Ang(1-7)等是心血管系统的关键保护因子,ACE2-Ang(1-7)-MasR轴成为了心血管疾病领域的研究热点。非经典的RAS系统ACE2-Ang(1-7)-MasR轴能够拮抗经典的ACE-AngⅡ-AT1R轴,二者共同维系机体的平衡,该轴在高血压、冠心病、心律失常和心力衰竭等心血管疾病治疗中可能成为新的治疗靶点。

Integrated Standardization and Systems Engineering Management

Integrated standardization is one of the fundamenta l forms of modern standardization. It is the combination of system science and the content of standardization. The development of system science has provided theo retic foundation and precondition for integrated standardization. The relevant r esearch on integrated standardization and system engineering illustrate that int egrated standardization is a advanced method which presented with the developmen t of modern science and technology . Integrated standardization treat the re levant factors of standardization as a system, and wholly standarlize the factor s in order to reach the best level of technology and quality. Integrated standardization is a large system engineering. In modern industr y the contact among different departments is being constantly enlarged and t he complexity of product is being constantly increased. This situation demands s trict correspond and united request in all the following aspects: raw mate rial, organs, fittings, technical measures of production, preparation for produc tion, ways of organizing the production. The traditional measure which establish the respective standard separately must be replaced by multi-spetialty standa rdization in large spectrum. The current situation and the development of syste m science has provided theoretic foundation and precondition for this kind of st andardization. Product or project can be managed with system engineering of proj ect, while the correspond standardization can be managed with system engineering of standardization. Integrated standardization virtually is system engineering of standardization, w hich use the theory to deal with the problem about standardization . This thesis included 3 chapters: 1. the brief summary of integrated standardization and sys tem engineering management in the development of type in foreign countries; 2. t he current situation and existing problems in the development of products; 3. ho w to organize and actualize integrated standardization and system engineering ma nagement in the development of products.

从现实世界到MAS世界——基于MAS理论的复杂系统建模思想探讨

首先对Agent及MAS的本质特性进行分析,指出Agent在本质上是具有一定理性的意识系统,MAS则是一种基于涌现的分布式问题求解模式。其次,重点讨论了MAS与复杂系统的关系,指出MAS与其在本质上的相关性。最后,通过揭示MAS建模思想所反映出的世界观,将MAS建模的意义扩展到自然系统、社会系统、生态系统等广泛的现实世界,从而得出,在对各类复杂系统进行分析的过程中,从现实世界映射到MAS世界是直观、合理、可行的。

Multiagent仿真与资源稀缺下的适应行为

以信息经济学和多ａｇｅｎｔ系统理论为分析框架，借助美国Ｓａｎｔａ Ｆｅ Ｉｎｓｔｉｔｕｔｅ 开发的仿真工具Ｓｗ ａｒｍ ，研究了短缺经济下个体的选择、竞争与适应行为，以及制度的进化过程．研究表明，简单的个体适应行为可以产生复杂的整体效果；个体基于历史以及相互间的信息交流导致了学习；满足一定的条件，新的制度安排将突现；个体之间信息的不对称可能使系统进化出类似道德风险和逆向选择的复杂行为．本研究有助于理解现实社会中普遍存在的占座现象；有助于解释财产权利以及制度的变迁．

New Algorithm for FMS Scheduling Based on Multiagent System Architecture

Redefined benefit-driven function is used to study the dynamic scheduling of FMS based on multiagent architecture. Each agent is dedicated to a work center, i.e. a set of the manufacturing system. In one hand, each agent selects locally and dynamically the dispatching rule(DR) that seems to be most suited to the operating conditions, production objectives and current shop status. On the other hand, each task should bring certain amount of benefit for the manufacturer. So, it is reasonable to have the dynamic scheduling of FMS relying upon multiagent architecture using the benefit-driven function as a strategy. Well, today's manufacturing corporation, especially the high & new technology one and deep machining one, the cost of their products is mainly determined by how much the knowledge is input From this viewpoint, we redefined the benefit-driven function, hi the end, this approach is compared with other existing DRs on a job-shop problem, already used in other research works.

基于MAS和RL的舰船设备协同控制方法

在构建舰船设备协同控制多智能体系统(MAS)过程中,各Agent之间存在某种内在的冲突、联系和规律,为了有效地发现和消解这些问题,引入智能控制解决方案和强化学习方法,能为MAS系统的构建提供有效的技术保障。本文提出了基于强化学习(RL)算法即改进的遗传算法并辅之以贝叶斯学习算法,来解决舰船MAS中各Agent中的任务分配问题、实现设备协同控制的优化和学习,并以舰船运动目标下的设备协同控制来具体验证上述算法,从而体现舰船运动控制MAS的可行性。