Distributed Consensus Control for General Linear Multi-agent Systems via a Dynamic Event-triggered Strategy

This article investigates the leader-following output consensus problem of heterogeneous linear multiagent systems, where the nonidentical followers are subject to norm bounded parameter uncertainties. Two novel distributed event-triggered consensus strategies based on state feedback and output feedback, respectively, are proposed to solve the leader-following output consensus problem. A dynamic event-triggering mechanism which involves internal state variables is proposed to determine the next triggering instant. It should be noted that the controllers can be designed without the knowledge of some global graph information, such as the eigenvalues of the Laplacian matrix associated with the corresponding communication graph and the number of agents. In addition, the interevent time can be prolonged and the Zeno behavior can be excluded with the proposed dynamic triggering mechanism. Finally, an example is presented to illustrate the effectiveness of the proposed controllers.

This paper investigates the issue of observer-based [Formula: see text] control for a class of continuous-time-switched systems with a dynamic event-triggered strategy (DETS). First, we design a DETS that introduces an internal dynamic variable (IDV) into the event-triggered condition, which can improve data transmission efficiency and decrease the cost of the system operation by expanding the interevent intervals. Second, we establish a state observer based on the DETS and further construct an observer-based state feedback controller. It is worth noting that asynchronous switching may occur between the subsystems and the controllers under the DETS. Third, by utilizing novel Lyapunov-like functions (LLFs) with IDV and the signal-combining approach, sufficient conditions to ensure the [Formula: see text] performance of the closed-loop system are presented. Moreover, we verify that Zeno phenomenon does not exist. Finally, the effectiveness of the proposed method is verified by two examples.

Considering heterogeneous general linear multiagent systems with an input-bounded leader, the focuses on the event-triggered output tracking problem is studied in this paper. The leader considered here has a nonzero and time-varying control input that is unavailable to any followers. In order to achieve output tracking, a hierarchical framework including a homogeneous internal model layer and a heterogeneous follower layer is adopted by using the internal model principle. Based on this treatment, a distributed control protocol based on dynamic triggering mechanism is further proposed to guarantee the asymptotic output tracking ability of followers to the leader with reducing communication overheads. An internal dynamic variable is involved in the proposed dynamic triggering law to construct a dynamic triggering threshold, which not only prolongs the inter-event intervals in theoretical analysis but also benefits the guarantee of the absence of Zeno behavior in applications. Additionally, the actions on triggering detections and controller updates are performed without the requirement on continuous state transmission, which not only captures the communication energy-saving feature of event-triggered control approaches but also offers more feasibilities.KeywordsHeterogeneous MASsOutput tracking controlDynamic event-triggering mechanism

The paper concerns the problem of reliable dissipative asynchronous controller design for a type of stochastic Markov jump systems (MJSs) with general conditional probabilities in the presence of the dynamic event-triggered rule. Since the mode information of the stochastic MJS is impossible to obtain, a reliable asynchronous controller is established such that the phenomena of nonsynchronous modes between the original stochastic MJS and the developed controller is formulated as a hidden Markov model. A novel dynamic event-triggered strategy is constructed to further decrease the data transmission frequency over the communication network. By taking the internal dynamic variable into account, the criteria of stochastically stable with the reliable dissipativity performance for the resulting closed-loop stochastic MJS are provided based on a collection of linear matrix inequalities. Further, the designs of reliable dissipative asynchronous controller and the dynamic event-triggered strategy are developed simultaneously. Lastly, a numerical instance is supplied to elucidate the superiority of proposed method.

In this article, the sliding mode control (SMC) problem is addressed for a class of Markovian jump systems via the T–S fuzzy model. First, in order to reduce the frequency of state transmission for alleviating congestion phenomenon in the bandwidth-limited communication network, a dynamic event-triggered (DET) strategy is introduced into the sensor-to-controller channel, in which an additional internal dynamical variable is employed to adjust the event-triggered condition adaptively. A fundamental issue resulting from the event-triggered strategy is that the controller cannot obtain the information about system mode during the triggering interval. Aiming at the phenomenon, this work utilizes a mode detector to estimate the unavailable system mode. Then, this article proposes a detected-mode-dependent event-triggered sliding mode controller whose membership grades are determined only via the transmitted state at the triggering instant. By constructing a relation on the membership functions (MFs) between the fuzzy model and the controllers for MF-dependent analysis, the conditions on the reachability and stability conditions are relaxed. Furthermore, an optimization algorithm is provided for the minimum control power via a high-dimensional grid searching for the coefficients of the internal dynamic variables, which, together with the designed detected-mode-dependent sliding mode controller, constitutes the novel SMC scheme under the DET strategy. Finally, the simulation results via the single-link arm system are provided to illustrate the efficiency of the proposed method.

In this article, we investigate the event-triggered consensus problem for general linear multiagent systems with bounded communication network delay. To reduce the communication frequency, we propose some dynamic periodic event-triggering strategies, under which an auxiliary dynamic variable and a weighting parameter are introduced for each agent to build its event-triggering condition. Then, a distributed adaptive consensus protocol, which includes a time-varying coupling weight for each edge, is designed based on the proposed event-triggering strategies. With the well-designed updating laws of dynamic variables, coupling weights and weighting parameters, we can theoretically guarantee the consensus of the concerned multiagent systems. Our event-triggering strategies do not require agents to continuously verify the event-triggering conditions or read their neighbors’ real-time state information. Moreover, Zeno behavior is inherently excluded as the interevent intervals are bounded from below by one period in the periodic event-triggering framework. Two numerical examples are provided to verify the effectiveness of the proposed event-triggered consensus protocols.

This paper investigates the cooperative output regulation problem for heterogeneous linear multiagent systems under fixed communication graphs via event-triggered control. A fully distributed event-triggered dynamic output feedback control law is proposed based on the feedforward design approach. At the same time, a fully distributed dynamic event-triggering mechanism is designed so that each agent can determine when to broadcast its information to its neighbors. Compared with existing related results, both the control law and the event-triggering mechanism in this paper are independent of any global information. It is shown that with the proposed dynamic event-triggered control strategy, the cooperative output regulation problem can be solved in a fully distributed manner by intermittent communication. Moreover, Zeno behavior can be strictly ruled out for each agent. Finally, the effectiveness of the proposed dynamic event-triggered control strategy is validated by a numerical example.

This paper investigates the sampled-data consensus problem of general linear multi-agent systems via new event-based control. Both the leaderless and leader-following consensus problems are considered. Different from the existing results, the state information is assumed to be unknown for each following agent and only the relative output information between neighbouring agents can be measured. A new Kx-functional observer-based output feedback event-based protocol is designed, which may have lower dimension than the full-order and reduced-order observer. The improved event-based condition bounds each agent’s measurement error by a time-dependent threshold. Furthermore, the Zeno behavior is excluded by showing that the inter-event time between any two triggering events is lower bounded by a strictly positive value. Finally, a numerical simulation example is presented to demonstrate the effectiveness of the proposed control protocols.

This article presents the central finite-dimensional H ∞ controller for linear time-varying systems with unknown parameters, that is suboptimal for a given threshold γ with respect to a modified Bolza–Meyer quadratic criterion including the attenuation control term with the opposite sign. In contrast to the previously obtained results, this article reduces the original H ∞ controller problem to the corresponding H 2 controller problem, using the technique proposed in Doyle et al. [Doyle, J.C., Glover, K., Khargonekar, P.P., and Francis, B.A. (1989), ‘State-space Solutions to Standard H 2 and H Infinity Control Problems’, IEEE Transactions Automatic Control, 34, 831–847]. This article yields the central suboptimal H ∞ controller for linear systems with unknown parameters in a closed finite-dimensional form, based on the corresponding H 2 controller obtained in Basin and Calderon-Alvarez [Basin, M.V., and Calderon-Alvarez, D. (2008), ‘Optimal LQG Controller for Linear Systems with Unknown Parameters’, Journal of The Franklin Institute, 345, 293–302]. Numerical simulations are conducted to verify performance of the designed central suboptimal controller for uncertain linear systems with unknown parameters against the conventional central suboptimal H ∞ controller for linear systems with exactly known parameter values.

This article investigates the optimal consensus problem for general linear multiagent systems (MASs) via a dynamic event-triggered approach. First, a modified interaction-related cost function is proposed. Second, a dynamic event-triggered approach is developed by constructing a new distributed dynamic triggering function and a new distributed event-triggered consensus protocol. Consequently, the modified interaction-related cost function can be minimized by applying the distributed control laws, which overcomes the difficulty in the optimal consensus problem that seeking the interaction-related cost function needs all agents' information. Then, some sufficient conditions are obtained to guarantee optimality. It is shown that the developed optimal consensus gain matrices are only related to the designed triggering parameters and the desirable modified interaction-related cost function, relaxing the constraint that the controller design requires the knowledge of system dynamics, initial states, and network scale. Meanwhile, the tradeoff between optimal consensus performance and event-triggered behavior is also considered. Finally, a simulation example is provided to verify the validity of the designed distributed event-triggered optimal controller.

In this paper, the issue of active power sharing between hybrid microgrids is investigated. A series of microgrids are linked through interlinking converters(ILCs). A dynamic event-triggered distributed approach is proposed, in which each ILC is counted as an agent that only needs update and broadcast at its triggered time instants. Different from traditional event-trigger, the proposed approach involves internal dynamic variable which ensures the system does not involve Zeno behavior. In this approach, the active power is indirectly regulated by a cooperative scheme, so as to achieve the proportional sharing of active power between hybrid microgrids. The simulation results prove the effectiveness of proposed control approach.

This brief studies the time-varying formation (TVF) control of linear multi-agent systems (MASs), where the communication topology switches from several different topologies and the switching signal is depicted by a right-continuous Markov process. The communication noises are taken into account simultaneously, which are described as independent white noises with noisy intensities. A class of stochastic-approximation type control protocols is given and certain sufficient conditions are derived for realizing the TVF stabilization in mean square sense. Moreover, the indicative function and infinitesimal generator are imported in Lyapunov functions to help proving that the MASs can be formed into stable TVF shapes with the proposed control protocols. In the end, an simulation example is performed to state the availability of the approach.

In this manuscript, the problem of event-triggered consensus for fractional general linear multi-agent systems is investigated, which include integer-order general linear multi-agent systems as the special case. A distributed event-triggered strategy is proposed to utilize in fractional multi-agent systems, under which the network can achieve consensus. Also, Zeno behavior can be precluded to ensure the feasibility of the devised event-triggered strategy. Furthermore, in order to avoid keeping track of the measurement errors continuously, a self-triggered strategy is designed, in which the next update time instant of each agent can be computed by using its local history state information. Finally, some numerical simulations are presented to indicate the validity of the devised control strategies.

This paper studies bipartite consensus problem for general linear multi-agent systems, where both collaboration and competition between agents coexist. We establish an equivalence between output feedback bipartite consensus problems and the conventional output feedback consensus problems, which enables a direct application of existing output feedback consensus algorithms to solve bipartite consensus problems. Moreover, we propose a systematic approach to design output feedback bipartite consensus controller.

This paper investigates the consensus disturbance rejection problem for general linear multi-agent systems in the presence of matched disturbances under the directed communication topology. Firstly, based on the local output information among agents, the disturbance observer is proposed to estimate the disturbances and compensate for their influences on the multi-agent systems. Secondly, the fully distributed output feedback consensus protocol is designed to guarantee that all agents can reach an agreement value. Finally, a simulation example is presented to illustrate the effectiveness of the results.