Composite Prescribed‐Time Filtered Performance Control for a Constrained Nonlinear System With Time‐Varying Actuator Fault

ABSTRACT This paper presents a composite prescribed‐time filtered performance control strategy for constrained nonlinear systems under actuator faults and preassigned performance. The main innovations are threefold. First, a more concise criterion for practically prescribed‐time stability (PPTS) is proposed, where the settling time is decoupled from initial states and system parameters. Second, an adaptive practically prescribed‐time filter (APPTF) is developed to circumvent the complexity explosion of backstepping method, accelerating convergence and achieving a prescribed convergence time for the filter error. Third, based on a high‐precision prescribed‐time preassigned performance function (HPPTPPF) and a transformation function, the tracking error is confined to a preset region within a user‐defined convergence time. The composite controller, synthesized via RBFNNs and adaptive laws, ensures both the PPTS of the system and state constraint satisfaction despite actuator faults. Moreover, the tracking error attains the preassigned performance requirements within the prescribed time. Comparative simulations substantiate the effectiveness of the proposed control approach.