In this paper, we investigate the distributed resilient observer-based fault-tolerant control problem for heterogeneous linear multi-agent systems in the presence of actuator faults and denial-of-service (DoS) attacks. In order to estimate the system matrix and the state of the exosystem, novel resilient adaptive distributed observers are proposed. By using the dwell time technique and the Lyapunov stability theory, the observer error system is shown to be exponentially stable even under the influence of DoS attacks. Then, an algorithm is proposed to determine observer parameters with the aim of maximizing the ability to resist attacks. Besides, a novel fault-tolerant controller without causing chattering behaviors is designed to compensate for actuator faults. Moreover, it is proved that the developed controller solves the cooperative fault-tolerant output regulation problem by using a newly derived lemma. Finally, an illustrative example is provided to verify the effectiveness of the proposed method.

This article addresses the distributed model-free adaptive control (DMFAC) problem for learning nonlinear multiagent systems (MASs) subjected to denial-of-service (DoS) attacks. An improved dynamic linearization method is proposed to obtain an equivalent linear data model for learning systems. To alleviate the influence of DoS attacks, an attack compensation mechanism is developed. Based on the equivalent linear data model and the attack compensation mechanism, a novel learning-based DMFAC algorithm is developed to resist DoS attacks, which provides a unified framework to solve the leaderless consensus control, the leader-following consensus control, and the containment control problems. Finally, simulation examples are shown to illustrate the effectiveness of the developed DMFAC algorithm.

The distributed tracking problem for uncertain nonlinear multiagent systems (MASs) under event-triggered communication is an important issue. However, existing results provide solutions that can only ensure stability with bounded tracking errors, as asymptotic tracking is difficult to be achieved mainly due to the errors caused by event-triggering mechanisms and system uncertainties. In this article, with the aim of overcoming such difficulty, we propose a new methodology. The subsystems in MASs are divided into two groups, in which the first group consists of the subsystems that can access partial output of the reference system and the second one contains all the remaining subsystems. To estimate the state of the reference system, a new distributed event-triggered observer is first designed for the first group based on a combined output observable condition. Then, a distributed event-triggered observer is proposed for the second group by employing the observer state of the first group. Based on the designed observers, adaptive controllers are derived for all subsystems. It is established that global stability of the closed loop system is ensured and asymptotic convergence of all the tracking errors is achieved. Moreover, a simulation example is provided to show the effectiveness of the proposed method.

In this paper, we investigate the consensus problem for high-order nonlinear multi-agent systems (MASs) with an uncertain leader under event-triggered communication. Compared with the existing consensus results for nonlinear MASs under event-triggered communication, the class of systems considered is more general, while achieving better performance in term of asymptotic tracking. To estimate the unknown parameters of the uncertain leader, distributed intermediate parameter estimators based on dynamic event-triggered communication mechanism are first introduced. To guarantee that high-order derivatives exist when applying the backstepping method, such estimators are further modified to obtain final estimators having a polynomial form by using the Hermite interpolation method. Moreover, novel high-order filters are proposed to generate local reference signals and to ensure the existence of high-order derivatives of the filter states. Based on the developed filters, a backstepping based decentralized adaptive controller is developed. It is proved that consensus errors are asymptotically convergent with the developed method. Finally, simulation examples are provided to sho

The resilient cooperative output regulation problem for a class of uncertain nonlinear multi-agent systems (MASs) under denial-of-service (DoS) attacks is addressed in this paper. This is the first attempt to investigate the cooperative output regulation problem for nonlinear MASs under DoS attacks, and a novel distributed control scheme consisting of a resilient distributed observer and a distributed adaptive controller is proposed. Specifically, a novel resilient distributed observer in the form of an upper triangular chain of first order low pass filters is designed to estimate the exosystem state based on a composite output observability condition. Then, a distributed adaptive controller is designed. It is shown that the resilient cooperative output regulation problem for the concerned class of uncertain nonlinear MASs can be solved by the proposed control scheme. A simulation example is finally provided to show the effectiveness of the proposed control scheme.

This article is concerned with the event-triggered output consensus problem for heterogeneous multiagent systems (MASs) with nonuniform communication delays. Unlike the existing event-triggered consensus results, more general heterogeneous linear MASs and nonuniform communication delays are considered. To reduce communication among subsystems, novel dynamic periodic event-triggered mechanisms are proposed. By using the event-triggered signals at the previous sampling instant, new distributed observers are designed to eliminate asynchronous behavior caused by nonuniform communication delays. Based on the developed observers, the observer error system is converted into a time-delay system with interval time-varying delays. Besides, a controller is designed by using the states of observers. It is shown that the consensus problem can be solved by the proposed method. Finally, an illustrative example is provided to verify the effectiveness of the developed method.