Adaptive Event-triggered Consensus Research Articles

Distributed adaptive event-triggered consensus control for high-order multi-agent systems

In this paper, a distributed adaptive event-triggered control approach is proposed for the consensus problem of high-order multi-agent systems (MASs) with unknown dynamics and external disturbances. First, to save communication resources, the event-triggered control is proposed to ensure the consensus of MASs, where the trigger condition is established based on the neighbors’ information. The approximation properties of neural networks are used to address the unknown dynamics and external disturbances. Second, rigorous theoretical analysis proves that the MASs can achieve the leader-following consensus, as long as the communication graph of MASs contains a spanning tree with the leader as the root node. The filtered tracking errors and adaptive parameters estimated errors are proved to be uniformly ultimately bounded without Zeno behavior. Finally, the simulations and experiments illustrate the feasibility and effectiveness of the theoretical results.

Strong Non-Zeno Mixed Adaptive Dynamic Event-Triggered Control for Distributed Consensus.

This article studies the distributed adaptive event-triggered consensus control problem of linear multiagent systems. A strong non-Zeno mixed adaptive dynamic event-triggering scheme is proposed, which guarantees a strictly positive minimum interevent time (MIET) between any two consecutive events. A model-based event-triggered fully distributed adaptive control law is presented without using prior global information about the communication topology. Moreover, a hybrid system model is constructed to facilitate the stability analysis of the closed-loop system. It is shown that the proposed control strategy can achieve asymptotic consensus of all agents via intermittent communication in a fully distributed way, while guaranteeing the strictly positive MIET property. Finally, the effectiveness of the designed control method is illustrated by a simulation example.

Hybrid Adaptive Event-Triggered Consensus Control with Intermittent Communication and Control Updating

Hybrid Adaptive Event-Triggered Consensus Control with Intermittent Communication and Control Updating

Adaptive Event-Triggered Consensus of Multi-Agent Systems in Sense of Asymptotic Convergence.

In this paper, the asymptotic consensus control of multi-agent systems with general linear agent dynamics is investigated. A neighbor-based adaptive event-triggering strategy with a dynamic triggering threshold is proposed, which leads to a fully distributed control of the multi-agent system, depending only on the states of the neighboring agents at triggering moments. By using the Lyapunov method, we prove that the states of the agents converge asymptotically. In addition, the proposed event-triggering strategy is proven to exclude Zeno behavior. The numerical simulation results illustrate that the agent states achieve consensus in sense of asymptotic convergence. Furthermore, the proposed strategy is shown to be scalable in case of variable agent numbers.

A Novel Adaptive Event-Triggered Consensus Control Approach to Multi-Agent Systems With Guaranteed Positive MIET

A Novel Adaptive Event-Triggered Consensus Control Approach to Multi-Agent Systems With Guaranteed Positive MIET

Adaptive event-triggered consensus of multi-agent systems with spherical polar coordinate quantization mechanism

Adaptive event-triggered consensus of multi-agent systems with spherical polar coordinate quantization mechanism

Switching adaptive event-triggered consensus control for MASs subject to sequential scaling attacks and transmission delays

The secure consensus issue has been examined for multi-agent systems that are vulnerable to sequential scaling attacks with network communication delays in this paper. It is suggested to use the innovative sampled data based switching event-triggered techniques to prevent neighbors from constantly exchanging information. This research differs from previous works in that it introduces sequential scaling attacks, which combine deception and DoS attacks when communication delays are present. Then, the time-delay closed loop system is established by the technique of interval decomposition and the modeling method of augmented system. Moreover, based on the switching Lyapunov functional, a sufficient condition of the secure consensus is proposed by the utilization of linear matrix inequality technique with free weighting matrices. Finally, there are two illustrative examples employed to confirm the availability of the conceptual results.

An Adaptive Event-Triggered Consensus Approach for MASs With Network-Induced Delays

This study investigates the consensus control problem of linear multi-agent systems (MASs) with network-induced delays (NIDs). A state feedback controller based on an event-triggered transmission scheme is proposed, where the novel adaptive event-triggering mechanism (ETM) is used to lower the frequency of data transmission. In contrast to previous works, sufficient conditions related to the consensus for the resulting closed-loop control systems are derived using a discontinuous looped Lyapunov functional (DLLF) and the corresponding reciprocally convex protocol. It is demonstrated that the consensus errors of resulting closed-loop control systems are asymptotically stable and the Zeno behavior is excluded. Finally, a numerical example of an unmanned aerial vehicle (UAV) model is presented to demonstrate the effectiveness of our proposed theoretical results.

Prescribed performance adaptive event-triggered consensus control for multiagent systems with input saturation.

In this paper, a prescribed performance adaptive event-triggered consensus control method is developed for a class of multiagent systems with the consideration of input dead zone and saturation. In practical engineering applications, systems are inevitably suffered from input saturation. In addition, input dead zone is widely existing. As the larger signal is limited and the smaller signal is difficult to effectively operate, system efficacious input encounters unknown magnitude limitations, which seriously impact system control performance and even lead to system instability. Furthermore, when constrained multiagent systems are required to converge quickly, the followers would achieve it with drastic and quick variation of states, which may violate the constraints and even cause security problems. To address those problems, an adaptive event-triggered consensus control is proposed. By constructing the transform function and the barrier Lyapunov function, while state constrained is guaranteed, multiagent systems quickly converge with prescribed performance. Finally, some examples are adopted to confirm the effectiveness of the proposed control method.

Adaptive Event-Triggered Consensus Tracking Control Schemes for Uncertain Constrained Nonlinear Multi-Agent Systems

Adaptive Event-Triggered Consensus Tracking Control Schemes for Uncertain Constrained Nonlinear Multi-Agent Systems

Fuzzy Adaptive Finite-Time Consensus Control for High-Order Nonlinear Multiagent Systems Based on Event-Triggered

This article studies the fuzzy adaptive finite-time consensus control problem for high-order nonlinear multiagent systems with unknown nonlinear dynamics. In control design,fuzzy logic systems (FLSs) are adopted to approximate the unknown nonlinear dynamics, and under the frameworks of adaptive backstepping recursive design and finite-time stability theory, an adaptive fuzzy finite-time consensus control method is developed. To save communication resources and reduce the numbers of controller execution times, a dynamic event-triggered mechanism with a relative threshold is established. Subsequently, an event-triggered-based finite-time fuzzy adaptive control scheme is formulated. Furthermore, by constructing novel integral-type Lyapunov functions and adding a power integrator technique, the finite-time stability of the closed-loop system and the convergence of consensus tracking errors are proved. Finally, a numerical simulation example is provided to verify the effectiveness of the proposed adaptive event-triggered consensus control method.

Adaptive Event-Triggered Consensus of Linear Multiagent Systems With Resilience to Communication Link Faults for Digraphs

This brief investigates the leader-follower consensus problem for multiagent systems (MASs) with resilience to unknown communication link faults. To deal with the unknown faults and avoid using global information, the adaptive event-triggered observers are designed to estimate the leader state, namely, resilience for communication link faults is transformed into the design observers by adaptive control technology. Then, based on the designed observers, controllers are designed to stabilize the given MASs. Finally, an example is introduced to demonstrate the effectiveness of the obtained results.

Event-Based Fuzzy Adaptive Consensus FTC for Microgrids With Nonlinear Item via Prescribed Fixed-Time Performance

The device faults commonly exist in microgrids (MGs) and often undermine the system stability. However, the existing distributed methods generally design control protocols based on the absence of faults or only considering actuator faults, which limits the applicability of controllers in MG systems. Therefore, this paper investigates an adaptive prescribed fixed-time performance (PFTP) consensus fault-tolerant control (FTC) problem for the voltage regulation of a nonlinear islanded MG inverter-based distributed generators (DGs) with output contactor and actuator fault via the state event-triggered mechanism. The PFTP method for the voltage restoration synchronization error is proposed by constructing a novel performance function to increase the speed of voltage recovery. Based on the estimation properties of fuzzy logic system, an unknown nonlinear function and the residual term of output contactor are estimated. Then, an adaptive state event-triggering mechanism is designed to reduce the communication burden, and its main advantage is that the control protocol is updated in the aperiodic way at the triggering instants. Further, according to backstepping technology, a novel adaptive event-triggered consensus FTC protocol is constructed to achieve the voltage regulation of islanded MG, and a parameter adaptive law is designed to compensate the adverse effects of the output contactor fault. Based on the Lyapunov stability theory, it is proved that the voltage recovery synchronization error satisfies the PFTP, and all signals in the closed-loop systems are cooperatively uniformly ultimately bounded. Finally, the proposed control strategy is also validated by using the MATLAB.

Adaptive event-triggered consensus of multi-agent systems with general linear dynamics

This paper is concerned with adaptive event-triggered consensus of general linear multi-agent systems (MASs). Leaderless consensus and leader-following consensus are both considered. In order to avoid dependence on global information about system topology and reduce communication frequency, distributed adaptive event-triggered consensus protocols are designed. Through model transformation, the consensus problems of MASs are transformed into the stability problems of the corresponding error systems. By using algebraic graph theory and Lyapunov stability theory, some sufficient criteria for MASs to achieve consensus are obtained. Meanwhile, it is proved that the proposed event-trigger conditions can exclude Zeno behaviour effectively. One simulation example is provided to validate the effectiveness of obtained theoretical results.

Adaptive Event-Triggered Consensus of Fractional-Order Nonlinear Multi-Agent Systems

The leader-following consensus of fractional-order nonlinear multi-agent systems is studied in this paper. An adaptive event-triggered control protocol is proposed to achieve the leader-following consensus scheme. By applying Lyapunov stability theory of fractional-order systems and some effective inequality techniques, some sufficient conditions for ensuring the consensus are derived intensively, and the proposed control method can reduce the communication between the agents greatly. Moreover, the Zeno behavior of event-triggered algorithm for multi-agent systems is excluded. Finally, a simulation example is presented to validate the effectiveness of the proposed consensus protocol.

A New Event-Triggered Consensus Control for Microgrids

In this paper, an adaptive event-triggered consensus problem considering the time delay of the communication network is studied for heterogeneous multi-agent systems. An event-triggered interval is here considered as a specific delay and unified round trip time (RTT) delay. Furthermore, an efficient optimal predictive-based coordination control strategy is introduced for balancing the non-ideal behaviors of communication channels. In order to evaluate the efficiency of the proposed method for controlling network-based multi-agent systems with coupled subsystems, two stages are studied. In the first stage, the very method is implemented on two coupled continuous stirred tank reactors while in the second one, it is used for controlling the voltage and current of a DC microgrid consisting of several distributed generation units. To prevent the unessential utilization of communication resources, the transfer of information will actually occur in this mechanism if a specific event is triggered. The simulation results show the fact that in spite of being non-ideal and time-delayed communication channels, the proposed technique is capable for improving the performance of power grids.

Neural networks-based adaptive event-triggered consensus control for a class of multi-agent systems with communication faults

This paper studies the adaptive distributed event-triggered fault-tolerant consensus problem for a class of multi-agent systems with time delays and external disturbance. The communication faults between the agent and its neighbours are considered, and a fault-tolerant control mechanism is designed to overcome the communication faults. Moreover, a distributed event-triggered mechanism is constructed based on the distributed errors, and hence the communication burden can be reduced. Combining the Lyapunov stability theorem with the Lyapunov-Krasovskii function, it verifies that the consensus tracking errors are bounded with the guaranteed security performance, and the time delays phenomenon can also be compensated. Finally, the effectiveness and utility of the proposed control method are fully validated by two simulation examples.

Design of distributed adaptive event-triggered consensus control strategies with positive minimum inter-event times

This paper studies the design of distributed adaptive event-triggered control strategies with positive minimum inter-event times for linear multi-agent systems. To present our design idea, this paper focuses on the consensus problem of linear multi-agent systems defined on a fixed communication graph. In order to solve the consensus problem, a distributed adaptive event-triggered control strategy is proposed that consists of a distributed event-triggered adaptive control law and a distributed asynchronous event-triggering mechanism. It is shown that under the proposed event-triggered control strategy, the states of all agents asymptotically reach consensus via intermittent communication without using any global information of the communication graph. Moreover, using the proposed event-triggering mechanism, not only the exclusion of the Zeno behavior but also the existence of a uniform strictly positive minimum inter-event time is guaranteed for each agent. A simulation example demonstrates the effectiveness of the proposed event-triggered control strategy.

Adaptive event-triggered consensus control of linear multi-agent systems with cyber attacks

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.

Adaptive Event-Triggered Consensus Control of a Class of Second-Order Nonlinear Multiagent Systems.

This paper addresses an adaptive event-triggered consensus control problem for a class of second-order nonlinear multiagent systems (MASs) in an undirected communication topology. A novel adaptive distributed event-triggered consensus control scheme is presented for the MAS with unknown functions based on the definition of an auxiliary state, and the coefficient of the triggered function can be regulated adaptively with dependence on the auxiliary state error to ensure not only the control performance but also the efficiency of the network interactions. Furthermore, two self-triggered algorithms are developed for two cases, known functions and unknown ones, by the current state and information at the previous event time instant instead of the requirement for continuous monitoring auxiliary state errors. In theory, the stability of the resulting closed-loop system is rigorously investigated, and it is proven that all signals in the closed-loop system are bounded and the Zeno behavior is ruled out. Finally, two simulation examples, both real-time and numerical ones, are provided to verify the theoretical claims.