Search

This paper focuses on studying the group consensus tracking issue of continuous-time second-order multi-agent systems (MASs) under directed fixed topology. A new protocol is introduced under the assumption that all the subgroups satisfy the in-degree balanced condition. For MASs with two subgroups, we first establish the relationship between the positive stability of matrix H and the connectedness of the topology graph. Then, we prove that MASs can achieve group consensus tracking if the system parameters satisfy some inequalities and matrix H is positive stable. Moreover, our paper extends the results for MASs with two subgroups to multiple χ -group consensus tracking. Especially, for a special graph with acyclic partition, a necessary and sufficient condition of χ -group consensus tracking is established. Finally, simulation examples are given to illustrate the effectiveness of our results. [ABSTRACT FROM AUTHOR]

This paper discusses the continuous-time consensus problems for directed multi-agent networks under certain coupling or control. Since agents are driven not only by their neighbors' states but also by their derivatives in many realistic situations, dynamical networks described by singular systems are appropriate to study. Consensus problems for such multi-agent networks are considered when the agents communicate in the presence or absence of time delays. The maximum tolerated time-delay is obtained when the multi-agent network asymptotically reaches consensus. The results of this paper indicate that such multi-agent networks can achieve consensus with a demanding convergent speed through agents' interactions. Numerical examples are given to demonstrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

This paper focuses on the consensus control and fault estimation problems for a class of time-delayed multi-agent systems with Markov switching topologies. Two different event-triggered mechanisms are adopted with hope to reduce burden of shared network and improve energy efficiency. Under Markov process, by establishing the consensus control protocol and designing a novel adaptive fault estimation observer, the consensus control and fault estimation problems are transformed into two stochastic stability problems in different forms. Then, according to the switching Lyapunov function method and free-weighting matrix technique, two delay-dependent stability criteria on the consensus control and fault estimation are derived, respectively. However, the two criteria containing nonlinear coupling terms are not standard linear matrix inequalities (LMIs) and cannot be solved directly with the LMI toolbox. In order to eliminate the coupling terms, two improved path-following algorithms are presented. These algorithms depend on the initial conditions, so it is very crucial to choose the appropriate preset parameters. The computational complexity is increasing with the number of iterations, system size and matrix dimension, which is a fully new challenge for the study of consensus control and fault estimation of multi-agent systems. Based on the algorithms, the switching consensus controller gains and model gain matrices of fault estimation can be efficiently solved out. Finally, a simulation example of tailless fighter airplanes is given to illustrate the practicality and validity of the theoretical results. [ABSTRACT FROM AUTHOR]

Differential privacy, a strict privacy notion, prevents the presence or absence of a single data from being identified. This paper proposes a novel average consensus algorithm to achieve differentially private average consensus on multi-agent systems (MASs) with general directed graphs. For MASs under the proposed algorithm, necessary and sufficient conditions are established on achieving average consensus and preserving differential privacy of the states of the agents at any time instant. Finally, numerical examples are provided to illustrate these results. [ABSTRACT FROM AUTHOR]

This paper focuses on the consensus control and fault estimation problems for a class of time-delayed multi-agent systems with Markov switching topologies. Two different event-triggered mechanisms are adopted with hope to reduce burden of shared network and improve energy efficiency. Under Markov process, by establishing the consensus control protocol and designing a novel adaptive fault estimation observer, the consensus control and fault estimation problems are transformed into two stochastic stability problems in different forms. Then, according to the switching Lyapunov function method and free-weighting matrix technique, two delay-dependent stability criteria on the consensus control and fault estimation are derived, respectively. However, the two criteria containing nonlinear coupling terms are not standard linear matrix inequalities (LMIs) and cannot be solved directly with the LMI toolbox. In order to eliminate the coupling terms, two improved path-following algorithms are presented. These algorithms depend on the initial conditions, so it is very crucial to choose the appropriate preset parameters. The computational complexity is increasing with the number of iterations, system size and matrix dimension, which is a fully new challenge for the study of consensus control and fault estimation of multi-agent systems. Based on the algorithms, the switching consensus controller gains and model gain matrices of fault estimation can be efficiently solved out. Finally, a simulation example of tailless fighter airplanes is given to illustrate the practicality and validity of the theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, the distributed event-triggered control (ETC) problems for nonlinear stochastic multi-agent systems (MASs) with external disturbance and time-delay are discussed. The leader-following input-to-state actual exponential mean-square consensus (EMSC) criteria are established in networks containing a directed spanning tree. By devising appropriate Lyapunov–Krasovskii function, sufficient conditions for the model to achieve leader-following input-to-state actual EMSC are obtained. The control gain matrix is designed to realize the controller. The lower bounds of interexecution times are given to show that the Zeno-behavior will not appear. Besides, the validity of theoretical analyses is verified by simulation. [ABSTRACT FROM AUTHOR]

The electric vehicle (EV) is gradually being introduced in cities. The impact of this introduction is less due, among other reasons, to the lack of charging infrastructure necessary to satisfy the demand. In today's cities there is no adequate infrastructure and it is necessary to have action plans that allow an easy deployment of a network of EV charging points in current cities. These action plans should try to place the EV charging stations in the most appropriate places for optimizing their use. According to this, this paper presents an agent-oriented approach that analyses the different configurations of possible locations of charging stations for the electric vehicles in a specific city. The proposed multi-agent system takes into account data from a variety of sources such as social networks activity and mobility information in order to estimate the best configurations. The proposed approach employs a genetic algorithm (GA) that tries to optimize the possible configurations of the charging infrastructure. Additionally, a new crossover method for the GA is proposed considering this context. [ABSTRACT FROM AUTHOR]

This paper investigates the distributed event-triggered control problems of second-order nonlinear multi-agent systems (MASs) with directed graph. Firstly, an event-triggered consensus algorithm is developed for second-order nonlinear MASs. It is proved that MASs reach practical consensus and Zeno-behavior doesn't occur. Secondly, for leader–follower MASs, an event-triggered tracking algorithm is presented, which ensures that follower agents track leader agent even when leader agent has a nonzero input. Finally, a numerical simulation is given to show effectiveness of the proposed consensus algorithm. [ABSTRACT FROM AUTHOR]

In this paper, we study the distributed output tracking problem for nonlinear multi-agent systems (MASs) perturbed by second-order moment processes. This is in contrast with most of the existing results where only white noise model is considered. For the case where the graph topology is directed and the leader is the neighbor of only a small portion of followers, new distributed tracking control laws are designed via the distributed backstepping method. By using the stochastic analysis tools, it is shown that the output tracking errors between the followers and the leader can be tuned arbitrarily small while all the states of the closed-loop system remain bounded in probability. Finally, the effectiveness of the tracking controller is demonstrated by a simulation example. [ABSTRACT FROM AUTHOR]

This paper addresses the virtual leader-follower synchronization control problem for a class of distributed parameter multi-agent systems, and all agents are governed by the heat equations with structured time-varying perturbations and time-varying disturbances, communicating through an undirected and connected static topology. A stable heat equation is designed as the virtual leader, and all agents as followers need to track the leader, such that the multi-agent systems can achieve a consensus. The design of the controller is split into two parts: one is design infinite dimension observers to estimate the total disturbances online by using the estimation/cancellation strategy in active disturbance rejection control (ADRC), the other is that the adaptive proportional differential (PD) synchronous controller determined by the Lyapunov functional is proposed to ensure all agent's states and the leader's state reach a consensus. The linear local interaction protocol realizes the synchronization of multi-agent system, and the adaptive PD control accelerates the subsystem to follow the virtual leader. The well-posedness of the closed-loop system is analyzed and proved. Simulation results illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Nonconvex distributed constrained optimization over multi-agent systems plays an increasingly important role in control community. However, the duality gap for a nonconvex distributed constrained optimization problem is not always zero. This brings some difficulties for the algorithm design and convergence analysis about such problems. In this paper, to eliminate the duality gap, the original distributed optimization problem is converted to an equivalent distributed one by using a partial power reformulation. Next, for solving this equivalence problem, a continuous-time algorithm is proposed over the multi-agent system where each agent exchanges local information with other agents under an undirected communication graph. It is proved that the proposed continuous-time algorithm locally converges to a strict local optimal solution of the considered original nonconvex distributed optimization problem. Numerical examples show the validness of the presented algorithm. Finally, the algorithm is applied for optimal placement. [ABSTRACT FROM AUTHOR]

• The SPFTS scheme is applied to deal with the consensus issue for nonstrict nonlinear MASs. With the help of the proposed strategy, an adaptive NN fixed-time controller is devised to ensure the consensus of MASs. Compared with the finite-time control, the convergence time of the fixed-time consensus control doesn't depend on the initial values. • Full state constrains and input delay are first considered in nonstrict uncertain MASs. By using the backstepping technique, the barrier Lyapunov functions are created to overcome the difficulties caused by full state constraints and the method of Pade approximation is adopted to eliminate the influence of input delay. Then, the output trajectories of followers can track with the signal of the leader in fixed time. • A novel stability analysis method is developed to solve fixed-time consensus problem for for nonlinear nonstrict uncertain MASs in this note. This paper concentrates on a fixed-time consensus issue for nonstrict nonlinear uncertain multi-agent systems (MASs) with state constraints and input delay. In comparison with previous works, the topic of full state constraints and input delay is first embodied in nonstrict MASs in a fixed time. A semi-global practical fixed-time stability (SPFTS) is employed to handle the consensus problem in this note. The radial basis function neural networks (RBFNNs) are developed to counteract unknown items in each agent. Pade approximation approach is introduced to cope with input delay. By using the backstepping technique, adaptive virtual controllers, adaption laws and the actual consensus controller are devised. And the rest followers can converge to a specified trajectory built by the leader in fixed time. Finally, a practical example is employed to test the correctness for the proposed control protocol. [ABSTRACT FROM AUTHOR]

This paper considers the Internet congestion control and consensus problems of a multi-agent system composed of a congested node, some aggregation nodes and their following nodes. First, a novel multi-agent Internet congestion control system with both discrete and distributed delays is proposed. Second, the stability and Hopf bifurcation of the congested node are discussed. Subsequently, a simple error controller designed for aggregation nodes, some necessary and sufficient conditions have been established to solve the bifurcation consensus problem between aggregating nodes and the congested node. Bifurcation consensus of aggregation nodes and their following nodes are also obtained through consensus protocols which based on a novel predictive controller. So far, the bifurcation asymptotically consensus of multi-agent Internet congestion control system is achieved. It is worth noting that conditions for global stability of system can be obtained by selecting appropriate control parameters, and conclusions of global asymptotic stability consensus is given to draw conditions for avoiding network congestion in the whole system. Finally, numerical examples illustrated the correctness and validity of the main results. [ABSTRACT FROM AUTHOR]

Distinguished from the stationary group consensus problem, in this paper, the dynamic group consensus for a class of heterogeneous multi-agent systems under the influence of input time delays is investigated. A novel dynamic group consensus protocol is designed, where the coexisted cooperation and competition interaction relationships among the agents are considered. Two cases including identical and diverse input time delays are discussed, respectively. Based on matrix theory, system stability theory and pinning control strategy, some sufficient conditions for the heterogeneous systems are established to achieve dynamic group consensus asymptotically. The obtained results reveal that the achievement of systems' dynamic group consensus is related to systems control parameters, the in-degree and input time delays of the agents. Finally, the effectiveness of our theoretical results is verified by some numerical simulations. [ABSTRACT FROM AUTHOR]

This paper discusses the consensus tracking problem for a class of nonlinear multi-agent systems (MASs) with output constraints, unmodeled dynamics, nonsymmetric input dead-zones and actuator failures under directed graphs, and proposes an adaptive cooperative neural dynamic surface control (DSC) strategy. Using the properties of invertible nonlinear mapping and Gaussian function, output constraints and non-strict feedback terms are separately dealt with. A measurable dynamic signal produced by an auxiliary first-order system is used to eliminate the influence of unmodeled dynamics on the system. Two input models of input dead-zone and actuator failure are linearized, each follower control signal is constructed via DSC. All the signals of the closed-loop system are proved to be cooperative semi-globally uniformly ultimately bounded, and all the followers can accomplish a desired consensus results. Finally, the simulation results are provided to illustrate the availability of the presented adaptive control approach. [ABSTRACT FROM AUTHOR]

This paper investigates the adaptive event-triggered consensus control problem for a class of linear multi-agent systems subject to cyber attacks and communication delays. To effectively alleviate unnecessary signals transmission among the agents and achieve the reasonable allocation of resources, an adaptive event-triggering scheme, whose threshold parameters are adaptively adjusted based on system performance needs, is proposed. The event-triggering scheme can achieve the discontinuous communication and significantly reduce the number of signals transmission while ensuring the desired control performance. By considering the communication scheme and consensus control protocol in a unified framework, the linear multi-agent system is reformulated as a time-delay error system. Sufficient conditions are developed to guarantee the asymptotical stability and security of time-delay error system. Moreover, a co-design for the gain of the controller and the parameters of the adaptive event-triggering scheme is provided. Finally, an example on the tunnel diode circuit system is given to show the effectiveness and advantages of the proposed method. [ABSTRACT FROM AUTHOR]

The containment control problems of fractional order multi-agent systems (FOMASs) over directed networks are discussed in this paper. Firstly, two distributed intermittent sampled data control (ISDC) protocols which can reduce controllers' update rates and work hours, are introduced. Subsequently, some necessary and sufficient containment conditions are derived by virtue of Laplace transform and stability theory. The containment conditions reveal the relations among the fractional orders, sampling periods, communication constraints, coupling strengths and network topologies. Finally, two numerical experiments are presented to validate the theoretical results. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of time-varying output formation tracking of heterogeneous linear multi-agent systems on a directed communication topology that the leaders do not communicate with each other. Specifically, with injecting impulses to the states of the controllers, a dynamical control protocol is proposed, which not only reduces communication consumption, but also avoids the damage of the impulsive energy to the devices at impulsive instants. Besides, the protocol is designed using the measured output of the agents, which is more practical than those designed using the states of the agents. Then, some sufficient conditions with regard to the gain matrices and the coupling parameter are derived to guarantee that the states of the followers achieve time-varying output formation and track the convex combination of the states of the leaders as well. Finally, a numerical example is shown to validate the effectiveness of the theoretical result. [ABSTRACT FROM AUTHOR]

In this paper, pinning control and delta operator skills are applied to study couple-group consensus for heterogeneous MASs (multi-agent systems) with switched topology in cooperative-competitive networks. A new couple-group consensus agreement has been designed for this heterogeneous MASs with time delay. On the basis of delta operator and stability theory, couple-group consensus of the continuous or discrete systems can be transformed to analyze stability of a system with time lag. By using stability theory and LMI (Linear matrix inequality) technique, some meaningful results are put forward to obtain couple-group consensus of the heterogeneous MASs. In addition, these conclusions are also suitable for MASs whose switched topologies networks can't meet the equilibrium of in-degree or can't meet the requirements of any sub-topology with a spanning tree. In the end, some digital experiments are listed to prove the validity of the obtained achievements. [ABSTRACT FROM AUTHOR]

In this paper, a formation control strategy with collision, obstacle avoidance and connectivity maintenance is developed for a class of second-order nonlinear multi-agent systems under external disturbances. Firstly, in order to handle the nonlinear dynamics of the multi-agent systems and the unknown disturbances in the environment, neural network (NN) techniques are employed in the proposed control strategy. Then, the distributed formation controller with collision, obstacle avoidance is designed by combining artificial potential field (APF) methods and leader–follower formation methods. Secondly, due to the collision or obstacle avoidance terms within the formation controller may result in large separation distance among agents and each agent's communication distance is limited by its hardware, the collision or obstacle avoidance terms increase the chance of losing connectivity between agents. In order to guarantee the connectivity of the formation, the connectivity maintenance controller is designed with taking the communication topology into account. Based on Lyapunov stability theory, it is proved that the stability of the closed-loop multi-agent systems can be guaranteed. Finally, the simulation results verify the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper addresses the event-triggered global consensus issue of second-order multi-agent systems (MASs) with asymmetric input saturation, where the zero saturation bounds are allowed. First, for the leaderless situation, we propose an event-triggered mechanism and give the criterion for realizing global consensus. Different from the traditional event-triggered strategy in an effort to exclude the Zeno behavior, a preset minimum triggering interval is introduced. That is, the control input will not be updated within this interval after the latest trigger time, and the event-triggered condition is activated after this interval. Moreover, the above results are extended to the leader–follower case. Finally, some numerical examples illustrate the effectiveness of the developed schemes. [ABSTRACT FROM AUTHOR]

Consensus control in multi-agent systems (MASs) has wide-ranging applications in various domains. As the scope of applications continues to expand, ensuring the secure control of these systems to counter a diverse range of network attacks becomes highly necessary. Among these threats, Denial of Service (DoS) attacks have emerged as a major network security threat, capable of rendering targeted agents or networks unable to provide normal services. This paper presents an effective control protocol aiming to achieve leader-following consensus in a second-order MAS with event-triggered control mechanism and nonlinear dynamics under DoS attacks. The protocol utilizes absolute velocity and relative position measurements. The maximum attack frequency and duration of the DoS attacks have been obtained. Furthermore, the possibility of Zeno behavior is eliminated. Theoretical analysis demonstrates that, even under DoS attacks, consensus can be maintained among the leaders and followers within the MASs. In conclusion, the effectiveness of the proposed distributed security control protocol is validated through a case study involving a multi-vehicle cooperative system with unmanned cars. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the leader-following guaranteed performance consensus problem for multi-agent systems(MASs) controlled by event-triggered under external disturbances. First, a disturbance observer is designed for each follower, which can be used to efficiently estimate external disturbances. Second, to reduce the waste of communication resources, a new distributed event-triggered strategy based on the state estimation of neighboring agents is presented, which does not need continuous communication among agents. And the growing estimation error is reset by communication updates. The analysis illustrates that Zeno behavior can be effectively averted by formulating a lower bound on the number of normals for the minimum inter-event interval. Also, based on the above proposed state feedback consensus protocol with guaranteed performance, sufficient conditions are derived to guarantee that a MASs can achieve leader-following consensus. In addition, the consensus criterion with guaranteed performance is put forward in the form of a linear matrix inequality. The cost of guaranteed performance with leader-following structural properties is also established. At last, an example of numerical simulation is presented to confirm the derived analytical solution. [ABSTRACT FROM AUTHOR]

This paper investigates the flocking control issue of multi-agent systems, where each agent utilizes the broadcasting communication manner and takes the Cucker–Smale style dynamic model. In the setting of broadcasting scenario, each agent broadcasts the state information only at certain moments determined by its own clock, and recalculates the control input only when its clock ticks or it receives information from the neighbors. In the Cucker–Smale model, a nonlinear weight function about the communication distance is set to portray the mutual influence degree between agents. With the help of the properties of sub-stochastic matrix, a comprehensive analysis of the asymptotic convergence of the model is performed and the algebraic conditions for achieving flocking control are established. In addition, the obtained theoretical results are further extended to the bipartite flocking control issue for multi-agent systems with both cooperative and competitive interactions. At last, numerical simulations are provided to verify the theoretical results. [ABSTRACT FROM AUTHOR]

This paper investigates the enclosing control of hybrid multi-agent systems under directed networks. Firstly, we establish some criteria for continuous-time and discrete-time multi-agent systems to achieve enclosing control. Secondly, according to the communication modes among agents, four distributed enclosing control protocols are proposed for hybrid multi-agent systems. Then, under the proposed protocols, we give the corresponding sufficient conditions to guarantee enclosing control. Finally, the correctness of our results is verified by simulations. [ABSTRACT FROM AUTHOR]

In this paper, a distributed economic dispatch algorithm based on event-triggered and fixed-time consensus is proposed for optimal dispatching among generators in smart grid. Aiming to quickly achieve economic dispatch in distributed smart grid and significantly reduce the frequency of communication between generators, the algorithm can address the supply–demand balance between the generation side and the consumption side, as well as the capacity constraints of the generators. Different from the relevant work, the proposed incremental cost can converge in fixed-time and the settling time is independent of the initial state of the generators. It will provide more flexibility for the system. Meanwhile, a fully distributed event-triggered strategy is adopted, which can reduce the interactive information between generators and avoid the waste of communication resources. Furthermore, the proposed algorithm is robust to the time-varying communication network topology. Finally, several examples are presented that validate the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

A well-known drawback in distributed average consensus of multi-agent systems is that the exchanged information is usually delayed due to the time elapsed during the data transmission process. Using classical dynamic average consensus, delays may lead to poor performance or even instability. In this paper, we propose a novel dynamic consensus method that counteracts the negative effects of delays by means of delay compensation techniques. The interest of our dynamic consensus method with delay compensation is that it converges under mild conditions on graph connectivity and bounded reference signals, no matter how large the delays are, as long as delays are fixed and known. We also provide a formal characterization of the convergence speed of our method. Additionally, our results apply to fixed directed strongly connected, and undirected topologies. • We propose a dynamic consensus method for discrete-time systems. • We include a predictor feedback strategy for delay compensation. • Our results apply to fixed directed graphs that are strongly connected. • These results rely on a thorough eigenvalue-based analysis. • We propose parameter tuning rules aimed at improving the speed of convergence. [ABSTRACT FROM AUTHOR]

This paper investigates the fully distributed consensus control problem for general linear multi-agent systems via dynamic event-triggered scheme. To address the need to reduce network communication burdens and avoid involving any global features of multi-agent networks, a novel fully distributed controller based on the open-loop state estimator of agents is presented. To improve anti-interference ability and practicability of the proposed approach, an event-triggered strategy which can guarantee a precise lower bound of triggering intervals for each follower is designed with a virtual internal variable. Then, the stability of the multi-agent systems is analyzed without any global network information. Several simulation experiments are conducted to illustrate theoretical results. [ABSTRACT FROM AUTHOR]

This paper explores the problem of distributed cooperative tracking control for networked nonlinear multi-agent systems (MASs) with communication delays. The difficulty of distributed control of subsystems across several geographic areas is addressed by utilizing MASs in this study. To overcome modeling difficulties, a model-free control algorithm is employed. To handle networked delay, a network predictive control approach is utilized. To address these issues in a unified manner, a novel distributed model-free integral sliding mode predictive control strategy is proposed. This approach requires simple data to make predictions to achieve distributed tracking performance while also actively compensating for delays. The effectiveness of the proposed method is demonstrated through simulations and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, the impulsive consensus of multi-agent nonlinear systems with control gain error is further studied. The paper indicates that the condition in Theorem 1 of the original paper (Ma et al., 2015) [1] is not correct. To correct the mistake, the new version is given, which deletes one unnecessary coefficient in the inequality condition in the paper Ma et al. (2015) [1] . Moreover, two modified results ( Theorems 2 and 3 ) are given to increase the practicality. Due to the modification of consensus condition, the new simulations are also given correspondingly to verify the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

Model-driven development allows IT professionals to specify the system functionality, organization and behavior in a logical or platform-independent manner. Modeling using services allows domain analysts to focus on the added-value and core business the enterprise offers to its stakeholders. Those services are coarse-grained elements able to encapsulate a composition of business process models. The framework presented in this paper provides models together at strategic, tactical and operational levels to develop an agent-oriented software system. The strategic level is concerned with long-term decisions; this top-level uses a service model to understand the business’ high-level (added) values as well as the Quality Expectations and the threats they face. The tactical level is concerned with a broader description of the business processes automated by the system; the i ⁎ strategic dependency and rationale models are used here to further document the service behavior. Actors’ accountability and responsibility can be determined in the visual representation of these strategic and tactical levels. Finally, i ⁎ models are mapped into a set of operational models to document the (multi-agent) system behavior when achieving modeled functionalities. These operational models instantiate the Belief/Desire/Intentions (BDI) paradigm proposing entities – the agents – mapping as closely as possible the real life organization. The paper thus builds a business-driven transformation process leading to a run-time agent-architecture in a single and common framework. It both uses existing models and introduces or refines existing ones to dispose of a method ensuring better alignment and traceability between the business and the IT system. [ABSTRACT FROM AUTHOR]

This paper addresses region aggregation issues of multi-agent networks (MANs) that consist of finite number of isolated sub-multi-agent systems (sub-MASs) with multiple equilibria (ME) in multi-dimensional coordinate systems (MDCSs). To investigate aggregation of this kind of MANs via switching strategies, switched systems with ME are used to describe such networks under the case that each agent has a unique equilibrium point and all the equilibria are different from each other. Based on the novel stability concepts of region stability ( RS ) and exponential region stability ( ERS ) introduced, this paper proposes several RS and ERS results for sub-MASs with ME via the maximum energy function method, and then presents several region aggregation results for such MANs under three suitable assumptions. Also, a numerical example illustrates the effectiveness and practicality of our new results. [ABSTRACT FROM AUTHOR]

This paper studies second-order consensus problem on the matrix-weighted undirected network, which is a generalization of second-order scalar-weighted network. The matrix coupling can describe the interdependencies of multi-dimensional states among agents. To highlight the influence of matrix coupling, we analyze the double integral model in matrix-weighted multiagent system network. A sufficient and necessary algebraic condition based on coupling strength, matrix theory and Lyapunov stability theory is established to achieve second-order consensus. With aid of the established property, a fairly straightforward algebraic graph condition is obtained, which ensures that the matrix-weighted multiagent system achieves second-order consensus. Moreover, owing to the existence of positive semi-definite connections, the clustering phenomena naturally exists, which shows that matrix coupling plays an important role in the convergence of the matrix-weighted multiagent system network. And an algebraic graph condition for finding all clusters is offered, which can guarantee the desired number of clusters via designing matrix-weights in practical applications. Finally, four simulation examples are given to illustrate the effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of bipartite consensus tracking for a class of linear singular multi-agent systems under a signed graph topology, where the control input of each agent is subject to saturation. By exploiting a parametric algebraic Riccati equation (ARE)-based low-gain feedback approach, a static state feedback control protocol and a dynamic observer-based output feedback control protocol are developed utilizing local information. It is shown that under the presented protocols, semi-global bipartite consensus tracking can be achieved if the underlying signed communication graph is structurally balanced and contains a spanning tree rooted at the leader. A numerical example is finally given to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

The prescribed-time containment control problem for second-order multi-agent systems with multiple leaders is studied in this paper. The control objective is that all the followers are able to enter the convex hull formed by leaders at any preassigned time. Suppose that only a few followers can obtain the information of leaders, we design the distributed observer to estimate the information of the convex hull spanned by leaders firstly. Furthermore, the prescribed-time containment controller is designed with the estimation of the distributed observer. Based on a nonlinear scaling function, the tracking process is divided into four stages. The results imply that the tracking error between the followers and the convex hull could converge to zero within prescribed time. Finally, two numerical examples illustrate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

This paper investigates the leader–follower cooperative tracking control for nonlinear multi-agent systems with unknown nonlinearities, quantized input and unknown control gain. Moreover, the system order of each follower agent can be different from each other. The obstacle of unknown nonlinearities is removed by utilizing the universal approximation property of neural network, and then we introduce a command filter to the backstepping design to generate the virtual control signal and its derivative, which averts the "explosion of complexity" phenomenon. Meanwhile, by developing a novel decomposition of quantizer, Nussbaum-based scheme can be implemented to overcome the difficulties of input quantization and unknown control input coefficient. The controllers are designed only using local information, and the control scheme is fully distributed. Furthermore, there is only one online estimator needs to be calculated for each follower agent. By implementing the proposed controller into the MASs, the consensus tracking errors converge to zero with adjustable accuracy. The examples demonstrate the performance of the presented approach. [ABSTRACT FROM AUTHOR]

In this paper, the consensus problem for a class of nonlinear multi-agent systems is investigated, where each agent is described by a first- or second-order differential equation. Due to the presence of unknown control gain, unknown parameter vector in the dynamical systems of agents, and the unknown interaction topology information, an adaptive consensus protocol is proposed. It is proven that the asymptotic consensus of the nonlinear multi-agent systems can be achieved without using any global information via the given protocol. Finally, a demonstrative example is presented in the simulation studies to illustrative the effectiveness of the given protocol. [ABSTRACT FROM AUTHOR]

This paper investigates the fixed-time formation tracking control problem for multi-agent systems with model uncertainties and in absence of leader's velocity measurements. For each follower, a novel fixed-time cascaded leader state observer (FTCLSO) without velocity measurements is first designed to reconstruct the states of the leader. Then, radial basis function neural networks (RBFNNs) are adopted to approximate the model uncertainties online. Based on the proposed FTCLSO and RBFNNs, a novel fixed-time formation control scheme is constructed to address the time-varying formation tracking problem by utilizing fixed-time nonsmooth backstepping technique. The fixed-time convergence of the formation tracking error is guaranteed through Lyapunov stability analysis. Finally, simulation results demonstrate the effectiveness of the proposed formation tracking control scheme. [ABSTRACT FROM AUTHOR]

A data-based output tracking formation control strategy for nonlinear MIMO multiagent systems (MASs) is provided in this paper, where the dynamic of each agent is disparate. The novel linearization method is used to construct the agent models dynamically, and only one linearization parameter needs to be estimated via I/O data. Then, the data-driven formation control protocol is presented for heterogeneous MIMO MASs under switching topologies. The convergence analysis using contraction mapping principle shows that the output tracking errors of the group of agents are uniformly ultimately bounded. We also prove that the presented formation control protocol can be extended to the MASs with time-variable geometry formation. The combination of data-driven method, heterogeneous MASs, MIMO agent, switching topologies and time-varying formation control makes the presented control strategy more general and practical. In the end, two simulation experiments are given to elucidate the effectiveness of this formation control protocol of MASs. [ABSTRACT FROM AUTHOR]

In this paper, we devise a distributed protocol to study the consensus of multi-agent systems (MASs) with input saturation over directed networks. Firstly, a low-gain feedback control method is applied to overcome the saturation constraints, and an observation system without saturation constraints is designed. The semiglobal consensus condition over directed strongly connected networks is developed by using Ricatti equation. Secondly, a novel of tree-type error scheme is proposed to solve the consensus of MASs with general directed spanning tree networks. Combination with inequality techniques and Lyapunov stability theory, some criteria for achieving semiglobal consensus are obtained. In addition, the semiglobal consensus of MASs with directed switching networks is further considered, in which the network topologies only need to contain a directed spanning tree in some time intervals. Some related conditions are derived to ensure the consensus. Finally, some numerical simulations are given to demonstrate the validity of the theoretical results. [ABSTRACT FROM AUTHOR]

This paper addresses the adaptive finite-time consensus tracking problem for high-order nonlinear multi-agent systems (MASs) with powers of positive odd rational numbers under prescribed performance. Since the virtual and actual control parts of the dynamics of each follower agent are power functions containing positive odd rational numbers, the method of adding a power integrator is used to overcome the controller design difficulties caused by the power functions. With the aid of a finite-time performance function (FTPF) and neural networks (NNs), a distributed adaptive finite-time consensus tracking controller with prescribed tracking performance is properly designed by the backstepping process. It is shown that the proposed control strategy can guarantee that the consensus tracking error converges to an arbitrarily small neighborhood around zero at any settling time, while all signals of the closed-loop system are semi-globally practical finite-time stable (SGPF-stable). Finally, a simulation example is presented to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the distributed control problem for multi-agent systems (MASs) subject to multiplicative and additive noises over switching networks, where both cooperative and antagonistic interactions coexist. The communication topology is governed by a continuous-time Markovian chain. A stochastic approximation technique is utilized to handle stochastic bipartite consensus with communication noises. The major challenge, due to the fact that the intensity of the multiplicative noise is nonlinearly coupled with the distance between agents, is that the coexistence of antagonistic information and multiplicative noise makes the multiplicative noise term impossible to be converted into an error form. This leads to the inapplicability of the Lyapunov-based method. To cope with this, we first show the boundedness of agents' states where the second moment approach is employed. Based on it, the mean square and almost surely bipartite consensus are achieved under some mild requirements. The efficiency of the proposed method is supported by an example. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new neural network-based iterative learning leader-less consensus control algorithm for the second-order uncertain time-varying nonlinear multi-agent systems, where the position of each agent is constrained in an open interval which can be pre-selected and the control direction can be non-identical and partially unknown. With the help of a novel barrier composite energy function and multiple piece-wise Nussbaum functions, the designed completely distributed learning protocols can make the positions and velocities of the agents achieve the exact consensus on a finite time interval as the iteration number increases to infinity. Meanwhile, the position trajectories of the agents at each iteration do not exceed the constraints bounds. Besides, to testify the feasibility and utility of the presented algorithm, two simulation examples are given in the end. [ABSTRACT FROM AUTHOR]

Compared with the traditional cooperative networks, the signed networks containing both cooperative and competitive interactions have prevailed. In light of such consideration, the problem of bipartite containment control for second-order multiagent systems (MASs) including multiple leaders over signed networks is investigated in this paper, in which time-varying delays and switching topologies are considered. Firstly, an augmented system method is explored such that the bipartite containment problem is formulated as the convergence problem of the product of an infinite number of sub-stochastic matrices. Then, by constructing a new leader–follower topology for each switching topology, the corresponding relationships between two topologies are used to simplify our model. Moreover, based on the properties of non-negative matrix and the technique of edge composition, a mild topological condition is developed for guaranteeing the bipartite containment collective behavior. Finally, numerical examples are presented for verifying the correctness of our conclusion. [ABSTRACT FROM AUTHOR]

Denial-of-Service (DoS) attack is one of the major threats in network. The goal of DoS attacks is to make the target agent or network cannot provide normal service. However, the cooperative control of nonlinear multi-agent systems (MASs) subject to DoS attack is not well understood. This paper investigates the leader-follower secure consensus for second-order MAS with nonlinear dynamics and event-triggered control strategy under DoS attacks. A novel secure controller is proposed by using event-triggered control scheme. Based on the proposed controller, the upper bounds of the length rate, frequency of DoS attack and parameters conditions of controller are obtained to ensure that the tracking errors between the follower and leader converge to zero under DoS attack. Besides, the Zeno behavior can be excluded due to the trigger interval is designed to be greater than zero. Finally, a numerical example is presented to demonstrate the correctness of the theoretical analysis. [ABSTRACT FROM AUTHOR]

This paper studies the finite-time time-varying formation-containment tracking problems for second-order multi-agent systems with directed topology, where the multi-agent system consists of one virtual leader with fully unknown input, several real leaders and followers. In contrast with traditional formation and containment cases studied in most of the existing literature, apart from accomplishing the expected time-varying formation, the real leaders are required to track the trajectory generated by the virtual leader, and the followers need to get into the convex envelope spanned by the real leaders in finite time. The method for solving the finite-time formation-containment tracking problems is divided into the following steps. First, distributed finite-time observers are designed for each real leader and follower, in order to obtain the estimated states of their neighbor agents. Then, formation-containment tracking protocols are presented by using the neighboring information for both real leaders and followers. Furthermore, based on Lyapunov theory, it is proved that the given formation-containment tracking can be realized in finite time by the multi-agent system under the designed protocols. Finally, a case study on multi-robot transport operation is given to verify the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

This paper focuses on a class of nonlinear switching multi-agent systems about event-triggered adaptive tracking control. Compared with existing results, the event-triggered mechanism is first employed in nonlinear switched multi-agent systems with unknown parameters, and it can reduce the amount of computation and the frequency of the controller updates. By utilizing the backstepping technology, adaptive laws are designed to analyze the unknown parameters. In the sequel, all signals of multi-agent systems are bounded, the tracking errors converge to a small neighborhood of the origin. Finally, simulation results verify the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

In this paper, the distributed cooperative control problem of heterogeneous nonlinear multi-agent systems (HNMASs) which are of pure-feedback forms coupled with nonaffine dynamics is considered with momentous emphasis on finite-time convergence. Multiple kinds of input constraints are also considered and can be completely unknown. To achieve the dynamic tracking for the heterogeneous followers with unknown input constrains, there are two consensus theorems are proposed, one of which can be utilized to achieve finite-time convergence. Meanwhile, it is the blend of fraction power feedback method and neural network (NN) technique that let the controlled systems have the finite-time characteristic. In the proposed tracking control protocols, only the local position information from neighbors or leader is required. In the end, the effectiveness of two proposed consensus algorithms is confirmed and compared by numerical simulation. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of event-triggered consensus control for high-order multi-agent systems with arbitrary switching topologies. To achieve this goal, a novel model partitioning approach is proposed, where the high-order error systems are partitioned into stable subsystems and unstable subsystems through coordinate transformations. By analyzing the unstable subsystems under arbitrary switching, an appropriate controller can be designed to guarantee the subsystems stable. Then the controller gain of the multi-agent systems can be derived through inverse transformations. The designed controller can guarantee the error state convergence under each topology within any time interval, which further ensures the consensus of high-order multi-agent systems under arbitrary switching topologies. Finally, a numerical example is provided to illustrate the feasibility of the theoretical results. [ABSTRACT FROM AUTHOR]

This paper investigates group consensus for the first-order multi-agent systems with nonlinear input constraints. And group consensus protocols for discrete-time and continuous-time multi-agent systems are proposed. By using the tools of the Lyapunov function, LaSalle׳s invariance principle and graph theory, group consensus/finite-time group consensus conditions are obtained. Finally, two simulation examples are provided to illustrate the effectiveness of our proposed methods in the paper. [ABSTRACT FROM AUTHOR]