Robust Consensus Of Multi-agent Systems Research Articles

Bridging the Gap Between Transmission Noise and Sampled Data for Robust Consensus of Multi-Agent Systems

It is well known that multi-agent systems (MASs) are ubiquitous in natural and artificial systems. This paper aims at bridging the gap between transmission noise and sampled data for robust consensus of MASs. In detail, we have developed a theoretical framework for analyzing the robust consensus of MASs with sampled-data controllers and transmission noises. Using the delay-input and discretization approaches, we obtain two sufficient conditions on the existence of sampling periods and controller parameters for robust consensus of MASs, respectively. In particular, we deduce the estimates of the convergence speeds of consensus errors for the above two methods. Finally, numerical simulations are also given to validate our theoretical results.

Distributed robust consensus of linear multi‐agent systems with switching topologies

This paper studies the consensus problem of multi-agent systems consisting of general linear node dynamics with external disturbances in transmission channels under fixed and switching communication topologies. A distributed observer-type robust consensus protocol based on relative output measurements is proposed. A model transformation approach is introduced to address the robust consensus of multi-agent systems. Some conditions for robust consensus are given in terms of linear matrix inequalities for fixed and jointly connected communication topologies. A multi-step robust consensus protocol design procedure is further presented. Finally, the effectiveness of the theoretical results is demonstrated through numerical simulations.

Low Conservative Criteria for Robust Consensus of Multiagent Systems with Delays, Disturbances, and Topologies Uncertainties

Considering the limited communications conditions such as delays, disturbances, and topologies uncertainties, the stability criteria for robust consensus of multiagent systems are proposed in this paper. Firstly, by using the idea of state decomposition and space transformation, the condition for guaranteeing consensus is converted into verifying the robust stability of the disagreement system. In order to deal with multiple time-varying delays and switching topologies, jointly quadratic common Lyapunov-Krasovskii (JQCLK) functional is built to analyze the robust stability. Then, the numerical criterion can be obtained through solving the corresponding feasible nonlinear matrix inequality (NLMI); at last, nonlinear minimization is used like solving cone complementarity problem. Therefore, the linear matrix inequality (LMI) criterion is obtained, which can be solved by mathematical toolbox conveniently. In order to relax the conservativeness, free-weighting matrices (FWM) method is employed. Further, the conclusion is extended to the case of strongly connected topologies. Numerical examples and simulation results are given to demonstrate the effectiveness and the benefit on reducing conservativeness of the proposed criteria.

Robust Consensus of Multi-Agent Systems with Nonuniform Time-Delays and Switching Topologies

This paper studies the robust consensus problem for multi-agent systems with nonuniform time-delays and switching topologies in the presence of external disturbances, where each agent has a self-delay and each delay is independent of each other. A neighbor-based rule is used for the agents with nonuniform time-delays and external disturbances. A sufficient condition is derived under which all agents achieve consensus while satisfying desired H_infinity performance. Finally, the effectiveness of the obtained theoretical results is demonstrated through numerical simulations.

Robust consensus of multi-agent systems with time-delays and exogenous disturbances

In this paper, the robust consensus of multi-agent dynamical systems with time-delays and exogenous disturbances is studied. A pinning control strategy is designed for a parts of agents of the multi-agent systems without disturbances, and this pinning control can bring multiple agents’ states to an expected consensus track. Under the effects of the disturbances, disturbance observers based control (DOBC) are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multi-agent systems with disturbances under the composite controller can be achieved for fixed and switching topologies. Finally, by applying an example of multi-agent systems with switching topologies and exogenous disturbances, the design of the parameters of DOBC are illuminated.

Robust consensus of second-order multi-agent systems with input and time-varying communication delays

In this paper, the robust consensus problem of second-order multi-agent systems with constant input delays and time-varying communication delays is investigated. By using the neighbour-based rule, a novel non-linear consensus protocol is introduced to realise local control strategies for the second-order continuous-time multi-agent systems. Firstly, based on a model transformation, the multi-agent systems with input delays are transformed into delay-free ones. Secondly, based on Lyapunov-Krasovskii function, consensus conditions are obtained to guarantee that the position and velocity of all agents can achieve consensus asymptotically. In addition, the robust consensus of multi-agent systems with weight perturbations on communication network is also studied. It is shown that the consensus conditions are independent of input delays. Finally, the proposed non-linear consensus protocol is extended to solve the formation problem of multiple non-holonomic mobile robots. Simulation results are presented to validate the analysis.

Robust Consensus of Multi-Agent Systems with Uncertain Exogenous Disturbances

The objective of this paper is to investigate the consensus of the multi-agent systems with nonlinear coupling function and external disturbances. The disturbance includes two parts, one part is supposed to be generated by an exogenous system, which is not required to be neutrally stable as in the output regulation theory, the other part is the modeling uncertainty in the exogenous disturbance system. A novel composite disturbance observer based control (DOBC) and H∞ control scheme is presented so that the disturbance with the exogenous system can be estimated and compensated and the consensus of the multi-agent systems with fixed and switching graph can be reached by using H∞ control law. Simulations demonstrate the advantages of the proposed DOBC and H∞ control scheme.

Robust consensus of multi-agent systems with time-varying delays in noisy environment

Over the last ten years, the consensus of multi-agent systems (MAS) has received increasing attention from mechanics, mathematics, physics, engineering sciences, social sciences, and so on. It is well known that the robustness of consensus of MAS is usually determined by several key factors, including noise, time-delays, and packet drop. In this paper, we introduce a general time-delayed MAS model with noise and also further investigate its robust consensus. In particular, we prove that the proposed algorithm is robust against the bounded time-varying delays and bounded noises. The effectiveness and robustness of the proposed consensus algorithm has been validated in the classical Vicsek model with time-varying delays. And two simulation examples are also given to justify the above theoretical results. These results may have some potential applications in various fields, including mechanics, biology, and engineering sciences.

Robust consensus of multi-agent systems with noise

The consensus problem of multi-agent systems has attracted wide attention from researchers in recent years, following the initial work of Jadbabaie et al. on the analysis of a simplified Vicsek model. While the original Vicsek model contains noise effects, almost all the existing theoretical results on consensus problem, however, do not take the noise effects into account. The purpose of this paper is to initiate a study of the consensus problems under noise disturbances. First, the class of multi-agent systems under study is transformed into a general time-varying system with noise. Then, for such a system, the equivalent relationships are established among (i) robust consensus, (ii) the positivity of the second smallest eigenvalue of a weighted Laplacian matrix, and (iii) the joint connectivity of the associated dynamical neighbor graphs. Finally, this basic equivalence result is shown to be applicable to several classes of concrete multi-agent models with noise.

Robust consensus of multi-agent systems with diverse input delays and asymmetric interconnection perturbations

The consensus problem of second-order multi-agent systems with diverse input delays is investigated. Based on the frequency-domain analysis, decentralized consensus conditions are obtained for the multi-agent system with symmetric coupling weights. Then, the robustness of the symmetric system with asymmetric perturbation is studied. A bound of the largest singular value of the perturbation matrix is obtained as the robust consensus condition. Simulation examples illustrate the design procedure of consensus protocols and validate the correctness of the results.