Fault-tolerant prescribed performance control for a class of uncertain nonlinear systems

Abstract

This paper addresses the enhancement of prescribed performance control (PPC) robustness under inelastic actuator faults. PPC is a control strategy that enforces user-defined bounds on output tracking errors to ensure desired transient and steady-state performance, assuming ideal actuator functioning. However, actuator faults compromise this guarantee, risking violation of performance bounds and potential system instability. To overcome this limitation, a robust modification of the conventional PPC is proposed, capable of effectively managing errors during performance bound violations while maintaining closed-loop stability. The approach ensures finite-time error recovery to the prescribed bounds once faults are mitigated, without relying on fault detection mechanisms, thereby simplifying the control scheme. Theoretical analysis confirms the stability and robustness of the proposed controller, and simulation studies validate its effectiveness.