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This paper considers the prescribed-time leader-following consensus problem of input-constrained linear multi-agent systems under generally directed communication topology in two cases: the Laplacian matrix related to the entire communication topology between agents is either known or unknown. In particular, the consensus problem for the former case is solved by a novel bounded linear time-varying (LTV) protocol, where the feedback gain is formulated by the parametric Lyapunov equation and the knowledge of the Laplacian matrix. Moreover, by utilizing a distributed observer, a fully bounded LTV protocol is proposed for the latter case. It should be noted that, compared with the existing results, the system under consideration is more general, the designed protocols are linear, and the consensus problem is accomplished even in a fully distributed manner. Finally, the effectiveness of the proposed approach is verified by a numerical example.

This study investigates a fully distributed event-triggered consensus control problem for nonlinear multiagent systems (MASs). Initially, a polynomial fuzzy model is adopted to describe the nonlinear error dynamics of leader-following MASs. Subsequently, an edge-based event-triggered mechanism is proposed to asynchronously transmit the agent’s state to its neighbors. Based on this mechanism, a novel asynchronous event-triggered control protocol is proposed to accomplish the consensus task. Meanwhile, the control protocol is fully distributed and uses only information about the neighboring agents and itself. Furthermore, sufficient conditions based on the sum-of-squares are obtained to achieve asymptotic consensus for the studied systems with a strictly dissipative performance by constructing an ε-dependent Lyapunov function. Finally, a chaotic circuit example is provided to illustrate the validity of the proposed scheme by comparisons.

This paper presents a fully distributed adaptive dynamic event-triggered control (FDOAD-ETC) strategy for islanded AC microgrids (MGs). The proposed approach restores frequency and voltage to nominal values while achieving precise real power sharing. The fully distributed nature of the method eliminates the need for global information, such as the Laplacian matrix, relying only on local measurements from each distributed generator (DG). This enhances scalability and simplifies implementation, particularly for large-scale MGs. To demonstrate the core features of the approach, we introduce communication challenges such as delays and packet dropouts. These challenges highlight the strength of our adaptive dynamic event-triggered control (ADETC) system, which adjusts triggering thresholds in real time to ensure system stability and reduce communication overhead. Unlike static event-triggered methods, our dynamic approach is resilient to disruptions, prevents Zeno behavior, and adapts to varying network conditions. Simulations in MATLAB/SimPowerSystems validate the effectiveness of the FDOAD-ETC method, showing that it maintains stability and performance even under communication delays and data loss. The results confirm that our fully distributed and adaptive control framework provides a scalable, robust, and efficient solution for managing complex MGs.

This paper addresses the issue of robust prescribed time fully distributed synchronous tracking control of a multi-unmanned system with communication link faults. A novel prescribed time synchronous tracking control scheme is proposed by utilizing an adaptive control strategy under the formation leaderless case and uncertain formation topological weights. Firstly, a second-order multi-unmanned system cooperative control model based on unmanned aerial vehicles (UAVs) with aerodynamic damping and communication link faults is established. Secondly, as the system parameters of a leader are unknown to all followers, the leader’s dynamics are assumed to be linear with respect to its state variables to assist in the accomplishment of the fully distributed tracking control within the leaderless case. A parameter estimation method is proposed to estimate the unknown matrices of the leader for each follower. Then, to achieve formation synchronous tracking within a settling time, an adaptive robust distributed control strategy based on distributed state errors is designed for the formation prescribed time tracking under external disturbance and communication link faults. The control gains are designed using auxiliary parameters and a critical eigenvalue scaling technique that takes into account the constraints of the disturbance and communication. Finally, simulation results are shown to validate and demonstrate the effectiveness of the proposed approach.

The present study aims to assess a fully distributed optimal time-varying formation algorithm for a leader–follower system, which is characterized by linear second-order dynamics and operates under a dynamic communication topology with time-varying and uncertain communication weights. In this case, the communication topology’s weights may be negative, unlike most other conventional studies where the communication weights should have positive and constant values. Thus, the proposed algorithm resists changes in communication weights. The primary goal of the control strategy is to minimize control effort while ensuring fast convergence to the desired formation. Additionally, the algorithm allows agents to continuously adjust key formation parameters, such as orientation, centroid, and scale, providing flexibility and adaptability during formation. Information about the desired trajectory, rotational velocity, and scale of the formation is given to only one of the directly connected followers through a virtual leader to realize time-varying formation tracking. The designed controller, which is considered fully distributed, can be applied to modern commercial large-scale systems because it does not require information about the eigenvalues of the communication topology. Numerical simulations are implemented to validate the theoretical findings.

In this article, a novel class of fully distributed practical predefined-time algorithms (FDPPTAs) is developed for three types of convex optimization problems of single-integrator systems with bounded disturbances. The task of this work is to reach an optimal state that minimizes the global cost function expressed by the sum of all convex local cost functions. Firstly, a two-stage robust FDPPTA, combined with two time-varying functions, zero-gradient-sum and integral sliding mode control, is constructed to solve the unconstrained optimization problem. Secondly, a two-stage robust FDPPTA is applied to the case with linear equality constraint by introducing auxiliary variables. On this basis, the exact penalty function is further introduced to deal with the difficulties caused by linear inequality constraint. Unlike the existing optimization algorithms, the developed FDPPTA, which does not rely on any global information, shows excellent performance from the three aspects of robustness, initialization-free and predefined-time. Finally, four cases are given to verify the effectiveness and superiority of proposed algorithms.

This study is focused on the scaled consensus problem of second-order multi-agent systems (SOMASs) with nonlinear dynamics under fully distributed adaptive aperiodic intermittent (DAAPI) communication. Motivated by the non-reduced order approach (NROA), a novel Lyapunov function is proposed to directly analyze the scaled consensus of pure second-order MASs. By contrast with the existing results, the approach in this study avoids the double dimension problem arising from the reduced order method, which greatly alleviates the complexity of the theoretical analysis. Moreover, two new fully DAAPI communication protocols are well designed to achieve scaled consensus for leaderless and leader-following, respectively. It is worth noting that two entirely different time-varying gains are devised in the protocols to regulate the position and velocity states of the agent, respectively, which can realize more flexible and precise control to fulfill the goal of reducing the control cost. Lastly, the effectiveness of the theoretical derivation is demonstrated by two numerical examples and comparative experiment.

This paper investigates prescribed‐time (Pre‐T) robust consensus tracking for general linear multi‐agent systems (LMASs) subject to uncertainties and disturbances. Such uncertainties and disturbances, which are common in practical systems, often hinder the achievement of Pre‐T convergence. To address this challenge, a class of time‐varying scaling functions is introduced as part of the observer and controller gains, ensuring robust consensus tracking of the closed‐loop system within the prescribed time while mitigating the adverse effects of disturbances on tracking performance. Building on these scaling functions, a novel distributed Pre‐T observer is developed to accurately estimate the leader's state for each follower at an arbitrarily chosen prescribed time T1 $T_1$ . The proposed Pre‐T observer relies solely on local interaction information among neighboring followers and does not require global knowledge of the entire LMAS. Using the estimated leader's state, a Pre‐T controller with some robustness terms is designed for each follower to counteract the negative impacts of system uncertainties and external disturbances. Furthermore, sufficient conditions for the existence of feasible control parameters are derived to guarantee that Pre‐T robust consensus tracking with a specified H∞ $H_\\infty$performance index is achieved at a prescribed settling time T2 $T_2$and maintained thereafter. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach. A Pre‐T robust consensus tracking method has been proposed for general LMASs with uncertainties and disturbances, such that the tracking errors systems are robustly Pre‐T stable with a given H∞ $H_\\infty$performance index. The proposed observer does not require global information of the general LMASs, resulting in higher flexibility and scalability. Then, a distributed Pre‐T controller has been designed to achieve the Pre‐T robust consensus tracking at a prescribed setting time.

In this paper, the cooperative output regulation (COR) problem of a class of unknown heterogeneous multi-agent systems (MASs) with directed graphs is studied via a model-free reinforcement learning (RL) based fully distributed event-triggered control (ETC) strategy. First, we consider the scenario that the exosystem is accessible globally to all agents, an internal model-based augmented algebraic Riccati equation (AARE) is constructed, and its solution is learned by the proposed model-free RL algorithm via online input-output data. Further, for the scenario that the exosystem is accessible only to its adjacent followers, the distributed observers are designed for each agent to get the state of the exosystem, and an internal modelbased fully distributed adaptive ETC protocol is then synthesized to construct the corresponding AARE, and the feedback gain matrix is learned in a model-free fashion. The model-free RL-based control protocol proposed in this paper can not only remove the prior knowledge of agents’ dynamics, but also release the dependence on global information by the adaptive event-triggered mechanism (ETM) and the new graph-based Lyapunov function. Finally, simulation results are illustrated to show the feasibility and effectiveness of the proposed control scheme.

A finite-time fully distributed consensus (FTFDC) control problem is studied for a second-order multi-agent system (MAS) with input saturation, limited communication resources and external bounded disturbances. Firstly, to deal with the input saturation characteristics, a second-order auxiliary system is designed to obtain the compensation signal. Secondly, because the leader information can only be obtained by a group of agents connected with the leader, a distributed estimator for each agent is designed to estimate the leader information. Then, to save communication resources, an event trigger condition is designed without continuous communication between agents. Based on the estimator and event trigger condition, a FTFDC controller is designed to realize the finite time fully distributed consensus control of MAS under limited communication resources and external bounded disturbances. Finally, the designed controller is verified by simulation on a multi-spacecraft attitude system model.