Global Fixed-Time PPF-Dependent Event-Triggered Adaptive Control for Thermoacoustic Systems With Multiple Unknown Time Delays via FAS Approach

Abstract

This article addresses the event-triggered adaptive control problem with a global fixed-time prescribed performance function (PPF) for the thermoacoustic system with multiple-acoustic-mode and multiple-time-delay nonlinear flame response coupling characteristics. First of all, the acoustic model coupled with the flame response subject to multiple unknown time delays is presented to describe the general thermoacoustic systems. Subsequently, an adaptive controller is proposed within the fully actuated system (FAS) framework, thereby ensuring the stability of the thermoacoustic system. Next, by constructing a global fixed-time PPF, the dynamic constraint on the system output pressure is achieved, ensuring that its transient and steady-state performance indicators meet the design requirements. What is more, an event-triggered scheme optimized in collaboration with the global fixed-time PPF is proposed, which significantly reduces the frequency of actuator actions and communication resource consumption while maintaining the system transient performance. Furthermore, the FAS architecture is employed to design the controller, which effectively avoids the nondifferentiability issue of the virtual control at event-triggered instants. Finally, simulation studies verify the superior performance and practical feasibility of the proposed controllers.