Consensus of Nonlinear Multiagent Systems with Transmission Delays and Deception Attacks via Sampled-Data Control

This article examines the nonfragile bipartite tracking consensus issue in the context of sampled-data nonlinear multiagent systems (MASs) undergoing denial-of-service (DoS) attacks and control gain fluctuations, where both cooperative and competitive interactions between the agents over the network are taken into account. During the DoS attacks, with communication services being denied, a halt in data transmission among the agents is experienced, which might result in performance degradation, undesirable oscillatory behavior, or even hinders the agents from performing their intended tasks. Consequently, there emerges a pressing requirement for the analysis and design of a secure bipartite tracking consensus protocol for MASs under the threat of DoS attacks. In pursuit of this goal, a modified Halanay-like inequality is initially established, which provides a basis for us to derive certain sufficient conditions ensuring the MASs to achieve the bipartite tracking consensus, despite the disruptive presence of malicious DoS attacks. Additionally, the control gain matrix can be readily computed by resolving a collection of linear matrix inequalities. For specific scenarios that demand reduced computational complexity, the matrix decoupling method is introduced, enabling a reduction in the dimensionality of the matrix inequalities and, consequently, facilitating its straightforward application to large-scale MASs. This article culminates in a numerical simulation, which is performed to validate the developed results.

This article investigates the leader-following consensus problem of discrete-time nonlinear multiagent systems (MASs) over fading channels. With the consideration of the transmission among followers maybe affected by the fading networks, the nonidentical fading channels model is constructed. To reduce the transmission network burden, the dynamical event-triggered mechanism (DETM) is developed. Different from most of existing event-triggered strategies, the threshold parameter in the developed dynamical event-triggering condition is dynamically adjusted according to a dynamic rule. Based on the DETM, a distributed consensus control protocol is designed under fading channels. Then, sufficient criteria are provided to ensure that MASs can achieve the leaser-following consensus, and satisfy the H∞ performance index in the presence of fading channels. The desired controller parameters can be derived in terms of solutions of matrix inequalities that are lightly solvable. In the end, simulation results show that the designed dynamical event transmission policy is capable of diminishing communication burden more promptly and effectively than some existing ones.

The consensus problem of nonlinear multi-agent systems is studied in this paper, considering the semi-Markov switching topologies under DoS (denial-of-service) attacks. In this regard, an event-triggered mechanism is introduced for multi-agent systems under DoS attacks. Moreover, combining the semi-Markov topology with the event-triggered mechanism, a new consensus controller under DoS attacks is proposed. Furthermore, by choosing the Lyapunov–Krasovskii function and applying the matrix inequality technique, a sufficient and necessary condition is derived for the system stability as well as the state consensus. Subsequently, H∞ norm is proposed to enhance the performance of the multi-agent systems. Finally, a numerical example is provided to show the effectiveness and applicability of the proposed approach.

Sampled-data leader-following consensus for nonlinear multi-agent systems with Markovian switching topologies and communication delay

consensus problem of multi agent systems catch great attention in recent years. It is mainly due to its vast applications. Designing an appropriate control protocol that guarantees the desired agreement between the agents is the main purpose of the consensus problem. A linear matrix inequality (LMI)-based approach for the H_∞ consensus of leader-follower nonlinear multi-agent system (MAS) is proposed in this paper. In the proposed framework, fuzzy Lyuponov function (FLF) is chosen. Some slack matrices are introduced to decouple the Lyapunov matrices from the systems' one which provide more degrees of freedom to the consensus problem and leads to decrease the conservativeness. As a result, sufficient conditions for consensus problem are presented in terms of LMIs. Finally, In order to evaluate the validity and effectiveness of the proposed approach, a numerical example for consensus of nonlinear MAS with thirteen followers is solved and simulation results are provided. Obtained results demonstrate the solid validity and great effectiveness of the proposed approach.

Distributed impulsive consensus of nonlinear multi-agent systems with input saturation

This article studies the distributed adaptive failures compensation output-feedback consensus for a class of nonlinear multiagent systems (MASs) with multiactuator failures allowing unmatched redundancy under directed switching graphs. With estimated information of neighbors, a novel distributed reference generator is designed. To compensate the unmeasured state variables of each agent, a reduced-order dynamic gain filter is constructed. Based on the generator and filter, and using the recursive design method, a distributed adaptive protocol is designed, where the adaptive technique is used to compensate the actuator failures. The proposed scheme can significantly relax conditions on the communication graph, which allows the graph to be disconnected at any time instant. The number of introduced variables in the filter and its dimension is greatly reduced and, thus, reduces the numerical challenge. The output-feedback consensus for nonlinear MASs with actuator failures and possible unmatched actuator redundancy is addressed for the first time. The consensus error can converge to an arbitrarily small set not affected by actuator failures, and the resulting closed-loop system is semiglobally stable. Finally, simulation results are given to illustrate the effectiveness of the proposed method.

Distributed leader-following consensus of nonlinear multi-agent systems with nonlinear input dynamics

This paper focuses on the consensus of multi-agent systems with unknown nonlinear dynamics under heterogenous topologies. The stability analysis is based on Lyapunov method and graph theory. Sufficient conditions in terms of linear matrix inequality (LMI) are given to guarantee the consensus of the multi-agent systems. The algorithms of none-zero velocity consensus and the zero velocity consensus are provided in this paper. We give two simulations at the end of this paper, showing the states of positions and velocities of all agents can reach consensus, under the proposed control laws.

Distributed dynamic average consensus for nonlinear multi-agent systems in the presence of external disturbances over a directed graph

In this paper, the nonlinear multi-agent system which contains uncertainty and is controlled by state-constraint impulsive protocol is taken into consideration. For the uncertainty of the multi-agent system, it is replaced by fuzzy logic system approximately and a judgement strategy which only contains the relative information with neighbors is proposed in this paper. In order to do research in state-constraint impulsive protocol, three kinds of impulsive control protocols which conclude partial input saturation, double actuator saturation and single actuator saturation are discussed. Then, some sufficient conditions of the system are obtained to reach consensus. Finally, some numerical simulation examples are provided to prove the effectiveness of the theoretical analysis.

Fixed-time leader-following/containment consensus of nonlinear multi-agent systems based on event-triggered mechanism

This paper investigates the event-triggered prescribed-time bipartite consensus of nonlinear multi-agent systems. In order to significantly reduce the communication burden and energy consumption, a novel event-triggered mechanism and triggering condition are proposed. Then, a distributed prescribed-time control protocol is proposed for the discussed nonlinear multi-agent systems to achieve bipartite consensus within the prescribed time based on the event-triggered mechanism. Using the Lyapunov stability theory, the stability of the nonlinear multi-agent systems is proved and the corresponding sufficient conditions are obtained. Moreover, it is shown that the Zeno behavior can be excluded. Simulation results are presented to show the effectiveness of the theoretical results.

In this brief, the authors study the fixed-time consensus problem for a class of first-order nonlinear multi-agent systems where the communication topologies are general directed. Both fixed-time tracking consensus and fixed-time leaderless consensus problems are investigated. For the leader-follower situation, the communication topology is only required to contain a directed spanning tree. As for the leaderless situation, the topology is required strongly connected. Simulations are finally provided to verify the effectiveness of the proposed algorithms.

In this paper, the leader–follower consensus problem is investigated for a class of lower-triangular nonlinear multi-agent systems with unknown measurement sensitivities. By developing a dual-domination gain method, a distributed compensator is proposed for each follower by utilising the output information of the follower and its neighbour agents. Based on the compensator, an output feedback control law is designed to achieve consensus. These two gains are used to deal with the unknown measurement noises and nonlinear terms, respectively. Then the consensus problem is transformed into a stability problem by introducing an appropriate state transformation. Based on the Lyapunov stability theory, it is proved that the states of the leader and followers can achieve consensus asymptotically. In the end, numerical simulations are provided to verify the correctness of the proposed consensus algorithm.