Adaptive fuzzy connectivity-preserving consensus protocols for stochastic strict-feedback nonlinear MASs subject to unmeasured periodic disturbances

• Published in: Applied mathematics and computation Vol. 444; p. 127825
• Main Author: Yi, Jiale
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.05.2023
• Subjects: Connectivity preservation; Dynamic event-triggered mechanism; Fuzzy logic system; Nonlinear filter; Periodically disturbed nonlinearities; Nonlinear filter; Connectivity preservation; Periodically disturbed nonlinearities; Fuzzy logic system; Dynamic event-triggered mechanism
• ISSN: 0096-3003; 1873-5649
• DOI: 10.1016/j.amc.2022.127825

•Differently from the existing works on connectivity-preserving consensus where the deterministic dynamics are investigated, stochastic system model is considered in this paper.•The investigated stochastic system model is more general and has more extensive research significance since unmeasured periodic disturbances are involved.•From the perspective of function approximation, a novel Fourier series expansion-fuzzy logic system function approximator is employed, which plays a vital role in dealing with periodically disturbed functions.•Unlike the most existing connectivity-preserving consensus achievements where the potential function method is adopted, error transformation method is incorporated in this paper to preserve the connectivity of communication graph.•The proposed continuous controller is developed to the event-triggered one which significantly reduces the cost of the information transmission. Differently from the existing event-triggered mechanism with static threshold, the dynamic threshold strategy is designed. Two adaptive fuzzy connectivity-preserving consensus control schemes, in continuous and event-triggered manners, are proposed for stochastic strict-feedback nonlinear multi-agent systems subject to unmeasured periodic disturbances. Differently from the existing works on connectivity-preserving consensus where the deterministic dynamics are investigated, stochastic multi-agent systems are considered. An error transformation is incorporated to preserve the initial interaction pattern determined by initial positions and communication ranges of the agents. Moreover, the stochastic system model suffers from unmeasured periodic disturbances in a nonlinear manner. By associating Fourier series expansion with fuzzy logic system, a novel function approximator is constructed to describe the packaged disturbance-dependent nonlinear functions. Meanwhile, a nonlinear filter is designed to avert the ”explosion of complexity” problem in conventional backstepping recursive design procedure. In addition, the proposed continuous controller is developed to event-triggered one. Then, it is proved that the consensus is achieved and the initial connectivity of communication graph is preserved in the sense of probability. In simulations, two examples are provided to substantiate the effectiveness of the proposed consensus protocols.