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This article studies the event-based adaptive practical fixed-time decentralized control problem for a class of large-scale uncertain nonlinear systems subject to non-affine nonlinear faults. By fusing the techniques of fixed-time control and command filter, the problems such as singular-value and computational explosion in fixed-time control based on backstepping design framework are solved. Based on the fuzzy approximation theory and Butterworth low-pass filter (BLPF) technique, the non-affine nonlinear fault terms are processed and fault-tolerant controllers are designed to realize fault compensation. In order to relieve the communication the pressure between system components, a novel switching event-triggering mechanism (SETM) based on user-set threshold parameters is proposed. This switching threshold design the scheme combines the advantages of the traditional fixed threshold and relative threshold design strategies, providing greater flexibility in balancing system performance and network constraints. By combining the practical fixed-time stability criterion with the Lyapunov stability theory, it is demonstrated that both the tracking performance and the closed-loop stability can be ensured in a fixed-time. Finally, two simulation examples are given to verify the effectiveness of the proposed fixed-time switching event-triggered control (SETC) scheme. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the time-varying formation tracking control (TVFTC) problem for high-order uncertain nonlinear multi-agent systems (MASs) with a dynamic leader. Both unknown disturbances and uncertain nonlinear functions are considered. A novel fixed-time TVFTC strategy is proposed with two steps, which can avoid the communication loop problem. Firstly, a distributed fixed-time observer (DFTO) for the directed graph is introduced, such that the leader's information can be accurately obtained by each agent within a bounded time. Secondly, by using fixed-time technique, a Lyapunov-function-based design process has been schemed to avoid the singularity problem. The developed TVFTC protocols can ensure all the followers achieve the desired time-varying formation and track the leader simultaneously. Furthermore, according to practical requirements, the configuration of formation can be chosen as arbitrary shape and the corresponding convergence time is allowed to be pre-estimated or preset. Stability analysis and some simulation examples for the control strategy are given, which further verify the validity. [ABSTRACT FROM AUTHOR]