Prescribed-Time Control with Adaptive Performance Reset for Nonlinear Systems Under Abrupt Non-Affine Faults and Event-Triggering

This paper investigates a novel adaptive event-triggered control strategy for a class of nonlinear strict feedback systems with parameter uncertainties, external disturbances, and sudden non-affine actuator faults. This strategy aims to address the instability risks that the high gain of the PTC may introduce when encountering sudden faults, while balancing convergence speed and system robustness. First, to achieve fast convergence independent of initial conditions, a time-scale function is incorporated into the inversion design, ensuring that the system tracking error converges to a small neighborhood near the origin within a user-defined time Tp. Second, the non-affine fault term is decoupled into an affine form using the Mean Value Theorem (MVT), and a Nussbaum gain function is introduced to handle the unknown control direction caused by the fault. In order to optimize the trade-off between control performance and communication resource constraints, a dynamic event-triggered mechanism (DETM) incorporating a dynamic threshold variable is developed. This design aims to curb redundant data transmission while ensuring system stability. Through rigorous analysis founded on Lyapunov stability theory, it is demonstrated that all signals within the closed-loop system are Semi-Globally Uniformly Ultimately Bounded, and the occurrence of Zeno behavior is strictly excluded. Furthermore, numerical simulation results confirm the efficacy of the proposed method in terms of saving communication resources, coping with sudden non-affine faults, and ensuring convergence within the specified time.