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This paper addresses the finite-time and fixed-time bipartite average tracking (BAT) problems in multi-agent systems (MASs) subject to bounded disturbances. A novel non-smooth protocol is first constructed on the basis of utilizing the finite-time control method, which can realize the finite-time BAT with structurally balanced graph. Then, the fixed-time BAT problem is dealt with nonlinear fixed-time algorithm, the setting time of which is obtained without depending on initial states. By employing Lyapunov stability theory, some sufficient criteria are obtained to achieve the finite-time and fixed-time BAT for MASs with disturbances. Numerical examples are finally developed for illustration. [ABSTRACT FROM AUTHOR]

This paper proposes a novel distributed fault-tolerant consensus tracking control design for multi-agent systems with abrupt and incipient actuator faults under fixed and switching topologies. The fault and state information of each individual agent is estimated by merging unknown input observer in the decentralized fault estimation hierarchy. Then, two kinds of distributed fault-tolerant consensus tracking control schemes with average dwelling time technique are developed to guarantee the mean-square exponential consensus convergence of multi-agent systems, respectively, on the basis of the relative neighboring output information as well as the estimated information in fault estimation. Simulation results demonstrate the effectiveness of the proposed fault-tolerant consensus tracking control algorithm. [ABSTRACT FROM AUTHOR]

The current paper investigates energy-constraint formation design and analysis problems for multiagent systems with two types of switching interaction topologies; that is, leaderless ones and leader-following ones. Firstly, a new formation control protocol with switching interaction topologies is shown, where the whole energy supply is limited previously. Then, by constructing the relationship of the whole energy supply and the matrix variable, sufficient conditions for leaderless energy-constraint formation design and analysis are respectively presented by the linear matrix inequality tool. Furthermore, an approach is proposed to determine an explicit expression of the formation center function, which determines the macroscopic motion of a multiagent system as a whole and consists of two parts: the initial state term and the formation function term. Moreover, main conclusions of leaderless energy-constraint formation are extended into leader-following multiagent systems by a new two-step transformation approach, where the asymmetric structure feature of leader-following switching interaction topologies is well dealt with. Finally, two numerical examples are provided to demonstrate the effectiveness of main conclusions. [ABSTRACT FROM AUTHOR]

This paper is concerned with an observer-based distributed secure consensus control strategy for a class of linear multi-agent systems (MASs) with random attacks. Due to the fact that not all state information is available, observers are employed to estimate the internal states. The communication topology is randomly switching under the attacks, and a distributed secure consensus strategy is proposed using the output information. The feedback gains are calculated via solving the Riccati equation and Riccati inequality, and stability analysis is proven that the MAS achieves secure consensus tracking in the mean square sense. Finally, two examples are provided to verify the effectiveness of the observer-based control strategy. [ABSTRACT FROM AUTHOR]

This paper investigates the event-triggering containment control of multi-agent networks with fixed and switching topologies, where there exist interactions between the leaders. Two cases are studied, respectively: One is that the leaders are opinionated. Then each leader will converge to its initial goal and the followers converge to the convex hull formed by the leaders. The other is that the leaders are not opinionated. Then the leaders will not insist on their initial goals and converge to some compromising states due to the interactions among them, while the followers still converge to the convex hull formed by the leaders. By means of pull-based event-triggering control, the event-triggering containment control problems of multi-agent systems with fixed and switching topologies are investigated, respectively. Finally, simulations are given to illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

This paper aims at further investigating the finite-time distributed tracking control problems for multi-agent systems with a virtual leader under the conditions of fixed and switching topologies, respectively. Two continuous distributed tracking protocols are designed for tracking the virtual leader in finite time. Compared with the traditional distributed tracking protocols, the proposed distributed tracking protocols can reach consensus in finite time. In particular, to eliminate the chattering phenomenon occurred in non-Lipschitz dynamical systems, this paper introduces a saturation function to replace the original sign function in the proposed distributed tracking protocols. The improved protocols can guide all agents to track the virtual leader without chattering phenomenon in finite time for the same position. Numerical simulations are also given to validate the proposed distributed tracking protocols. [ABSTRACT FROM AUTHOR]

In this paper, distributed iterative algorithms for consensus problems are considered for multiagent networks. Each agent randomly contacts with other agents at each instant and receives corrupted information due to the noisy channel from its neighborhood. Neighbors of each agent are cooperative or competitive, i.e., the elements in the adjacent weight matrix may be positive or negative. In such a framework, asymptotic consensus and mean square consensus problems are investigated, based on random graph theory and stochastic stability theory. The control gains have been designed such that cooperation-competition random multiagent networks can reach almost sure consensus and mean square consensus. Simulation examples are finally given to illustrate the effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

In this paper, we study the problem of finite-time consensus of multiagent systems on a fixed directed interaction graph with a new protocol. Existing finite-time consensus protocols can be divided into two types: 1) continuous and 2) discontinuous, which were studied separately in the past. In this paper, we deal with both continuous and discontinuous protocols simultaneously, and design a centralized switching consensus protocol such that the finite-time consensus can be realized in a fast speed. The switching protocol depends on the range of the initial disagreement of the agents, for which we derive an exact bound to indicate at what time a continuous or a discontinuous protocol should be selected to use. Finally, we provide two numerical examples to illustrate the superiority of the proposed protocol and design method. [ABSTRACT FROM AUTHOR]

This paper studies the leader-following finite-time consensus problem for the second-order multi-agent networks with fixed and switched topologies. Based on the graph theory, matrix theory, homogeneity with dilation and LaSalle's invariance principle, finite-time consensus protocols are designed by the pinning control technique without assuming that the interaction graph is connected or the leader is globally reachable. Moreover, the control protocol of each agent using local information is presented, and some examples and simulation results are given to illustrate the effectiveness of the obtained theoretical results. [ABSTRACT FROM PUBLISHER]

In this paper, we provide a theoretical analysis for nonlinear discontinuous consensus protocols in networks of multiagents over weighted directed graphs. By integrating the analytic tools from nonsmooth stability analysis and graph theory, we investigate networks with both fixed topology and randomly switching topology. For networks with a fixed topology, we provide a sufficient and necessary condition for asymptotic consensus, and the consensus value can be explicitly calculated. As to networks with switching topologies, we provide a sufficient condition for the network to realize consensus almost surely. In particular, we consider the case that the switching sequence is independent and identically distributed. As applications of the theoretical results, we introduce a generalized blinking model and show that consensus can be realized almost surely under the proposed protocols. Numerical simulations are also provided to illustrate the theoretical results. [ABSTRACT FROM PUBLISHER]

To reduce actuation burden in dynamical network environment, the event-triggering strategy is applied to consensus protocol for a class of nonlinear multi-agent systems with a switching topology. The considered switching topology is assumed to be sequentially connected, which is directed disconnected. The combinational measurement approach is adopted in the event-triggering strategy such that each agent updates control rule only at its own event-triggering instants. First, by using the iterative method, we establish the recursive relationship of maximal distance sequence. Then, sufficient conditions of event-based bounded consensus can be obtained by the contractive property of maximal distance sequence. Meanwhile, it is proved that the designed event-triggering rule can avoid Zeno behavior. Furthermore, as an extension, we consider the case of jointly connected topology, and the corresponding consensus problem is also explored. Finally, a numerical simulation is provided to confirm the derived theoretical results. [ABSTRACT FROM AUTHOR]

Guaranteed-cost consensus problems for high-order singular multi-agent systems with switching topologies are investigated. Firstly, to achieve a trade-off design object between consensus regulation performances and control energy consumptions, a quadratic cost function is constructed by state errors among agents and control inputs of all agents and guaranteed-cost consensus problems are introduced. Then, based on linear matrix inequality techniques, sufficient conditions for guaranteed-cost consensus and consensualization are presented respectively, which can guarantee the scalability of singular multi-agent systems since the dimensions of all the variables in these conditions are independent of the number of agents. Moreover, an upper bound of the cost function is determined, explicit expressions of consensus functions are given on the basis of the Second Equivalent Form, and it is shown that consensus functions are dependent on the average of initial states of all agents but are independent of switching topologies. Finally, the applications of theoretical results in multi-agent supporting systems are shown. [ABSTRACT FROM AUTHOR]