Adaptive fuzzy fault-tolerant formation control for nonlinear multi-agent systems under cyber-physical threats

This article investigated the fuzzy adaptive fault-tolerant resilient formation control issue for uncertain nonlinear multi-agent systems (MASs) with immeasurable states and under denial-of-service (DoS) attacks. Fuzzy logic systems were utilized to model unknown agents, and a fuzzy state estimator was formulated to reconstruct the agents' unknown states. A distributed resilient formation estimator was proposed to obtain the unknown leader information estimation and its high-order derivatives under DoS attacks. Based on the designed fuzzy state and resilient formation estimators, a fault-tolerant fuzzy output-feedback adaptive resilient formation control scheme was developed via the backstepping control methodology. It was proven that the developed fault-tolerant fuzzy resilient formation control scheme can guarantee that the controlled nonlinear MASs were stable and formation tracking errors converged even under unknown states, actuator faults, and DoS attacks. Finally, the proposed fuzzy adaptive fault-tolerant resilient formation control method was applied to marine surface vehicles; the simulation results and comparisons showed the effectiveness of the presented control methodology.