Synchronization Control Of Multi-agent Systems Research Articles

Leader-Following Synchronization Control of Multiagent Systems Under Hybrid Cyber Attacks via Impulsive Control Based on Topology Switching.

This article investigates the leader-following synchronization problem of multiagent systems (MASs) under hybrid cyber attacks, which refers to deception attacks and multichannel independent denial-of-service (DoS) attacks in communication channels. In order to achieve the secure control of MASs under hybrid cyber attacks, a novel impulsive control method based on topology switching is proposed, and a new algorithm for determining impulsive instants is designed. In addition, the cooperative-competitive relationship between agents is also considered, which is more in line with reality. Sufficient conditions for ensuring secure control of MASs and a parametric upper bound on the error vector norm between the agents and the leader are obtained. Finally, the numerical simulation verified the effectiveness of the proposed algorithm.

Observer-Based Asynchronous Communication and Adaptive Control Protocols With Intermittent Updating and Interaction

This paper focuses on the distributed observer-based synchronization control of multi-agent systems (MASs) over wireless networks. Unlike existing works mostly focusing on the communication reduction of control sides, a perception-based data reduction and transmission approach is proposed to design an asynchronous communication and control mechanism, which can avoid continuous inter-agents communications for both the communication as well as control sides. Then, an observer-based asynchronously distributed controller with intermittent updating and interaction based on the proposed perception-based data-reduction communication scheme. The criteria of new data transmission of communication triggering strategy and control triggering strategy are developed, respectively. Moreover, it is further extended to develop an observer-based asynchronous projection-type adaptive control strategy for online self-tuning of parameters. Theoretical analysis shows that the proposed two asynchronous communication and control strategies not only ensure that all agents stabilize to their initial average state without requiring any global information, but also ensure the reduction of both communications and controller update frequencies. An example is demonstrated to verify the theoretical analysis.

Observer‐based hybrid synchronization control of multiagent systems under dynamic need‐based communication policies

AbstractThis article focuses on the problem of observer‐based synchronization control of multi‐agent systems (MASs) subject to chattering phenomenon. Considering that full states of agents are not available and the limited network bandwidth of MAS networks exists, a novel observer‐based hybrid event‐triggered communication (or called need‐based communication) policy is exploited for synchronization of MASs, which is implemented in a fully distributed fashion without requiring any prior knowledge of global network parameters over an undirected graph. Then, to release the limitation of applications for the synchronous algorithm in undirected graphs, an observer‐based hybrid event‐triggered leader‐follower protocol and corresponding to its static triggering policy are developed to study the tracking control problem in a directed graph. Besides, the dynamic triggering policy is proposed by introducing an extra key variable for the directed graph case to reduce considerable triggering instants compared with the static one, which also subsume several existing synchronization schemes as special cases. It is shown that the proposed observer‐based event‐triggered policies can guarantee that leaderless and leader‐following synchronization with intermitted communications among agents. Moreover, Zeno behavior can be excluded. Finally, the practical merits of the proposed methods are corroborated using two numerical examples.

Cooperative adaptive fault-tolerant control for multi-agent systems with deception attacks

The fault tolerant control problem for multi-agent systems with deception attacks and actuator faults is studied in this paper. Under deception attacks, the false data will be injected to communication channels, and change the transmittal signals. It is extremely difficult to ensure synchronization control of multi-agent systems with deception attacks and actuator bias faults by using the existing fault-tolerant control methods. A novel distributed adaptive fault tolerant controller is constructed in physical layer, and a distributed impulsive controller is proposed to deal with deception attacks in communication layer. It is proved that the proposed fault-tolerant controller guarantees the synchronization of multi-agent systems with deception attacks and actuator bias. Simulation results verify the effectiveness of the proposed method.

Secure impulsive synchronization control of multi-agent systems under deception attacks

This paper is concerned with secure synchronization of multi-agent systems under deception attacks in the impulsive control framework. False data is injected into sensor-to-controller channels, which causes the transmittal signals being changed. Some stochastic variables obeying the Bernoulli distribution associated with communication channels between neighbouring agents are proposed to describe the case whether channels are suffered from the attack. A distributed impulsive controller is proposed and bounded synchronization, caused by false data injection is studied. Several mean-square bounded synchronization conditions are derived and the error bound is also given. Finally, two examples are provided to verify the theoretical results.

A Multiple Lyapunov Function Approach to Distributed Synchronization Control of Multi-Agent Systems With Switching Directed Communication Topologies and Unknown Nonlinearities

This paper investigates the distributed adaptive control problem for synchronization of multi-agent systems where the dynamics of the agents are nonlinear, nonidentical, unknown and subject to external disturbances. In our recent work, we solved this problem for general higher order systems under two types of communication topologies, represented, respectively, by a fixed strongly connected directed graph and by a switching connected undirected graph. A common Lyapunov function technique is employed to establish the results. In this paper, we solve the problem for a more general communication topology which is represented by a switching strongly-connected directed graph. We construct a sequence of different Lyapunov functions and use them to establish our results. Simulation study verifies the effectiveness of our theoretical results.

Distributed Synchronization Control of Multiagent Systems With Unknown Nonlinearities.

This paper revisits the distributed adaptive control problem for synchronization of multiagent systems where the dynamics of the agents are nonlinear, nonidentical, unknown, and subject to external disturbances. Two communication topologies, represented, respectively, by a fixed strongly-connected directed graph and by a switching connected undirected graph, are considered. Under both of these communication topologies, we use distributed neural networks to approximate the uncertain dynamics. Decentralized adaptive control protocols are then constructed to solve the cooperative tracker problem, the problem of synchronization of all follower agents to a leader agent. In particular, we show that, under the proposed decentralized control protocols, the synchronization errors are ultimately bounded, and their ultimate bounds can be reduced arbitrarily by choosing the control parameter appropriately. Simulation study verifies the effectiveness of our proposed protocols.

Distributed attitude synchronization control of multi-agent systems with switching topologies

This paper addresses the attitude synchronization problem in multi-agent systems with directed and switching interconnection topologies. Two cases for the synchronization problem are discussed under different assumptions about the measurable information. In the first case the agents can measure their rotations relative to a global reference coordinate frame, whilst in the second case they can only measure the relative rotations between each other. Two intuitive distributed control laws based on the axis–angle representations of the rotations are proposed for the two cases, respectively. The invariance of convex balls in SO(3) is guaranteed. Moreover, attitude synchronization is ensured under the well-known mild switching assumptions, the joint strong connection for the first case and joint quasi-strong connection for the second case. To show the effectiveness of the proposed control schemes, illustrative examples are provided.