Fixed-Time Fault Estimation and Prescribed Performance Fault-Tolerant Control for Interconnected Systems

Area of Science:

• Control Systems Engineering
• Fault Diagnosis and Fault-Tolerant Control
• Nonlinear Systems Analysis

Background:

• Interconnected systems are susceptible to actuator faults, which can be multiplicative or additive.
• Accurate fault estimation and robust control are crucial for system reliability and performance.
• Existing methods may lack fixed-time convergence or impose restrictions on initial conditions.

Purpose of the Study:

• To develop a fixed-time fault estimation observer for interconnected systems with actuator faults.
• To design an active fault-tolerant control (AFTC) strategy ensuring fixed-time tracking error convergence.
• To address both multiplicative and additive actuator faults while preserving system performance.

Main Methods:

• Utilizing bilimit homogeneous theory for exact fault estimation in a fixed time.
• Employing a prescribed performance function (PPF) for trajectory tracking error criteria.
• Incorporating a recursive fast terminal sliding-mode technique for active fault-tolerant control.

Main Results:

• The proposed fault estimation observer achieves exact system state and fault information in a fixed time, independent of initial errors.
• The AFTC strategy effectively eliminates fault influence, guaranteeing fixed-time convergence of tracking errors without initial condition restrictions.
• Comparative simulations demonstrate the feasibility and superiority of the proposed strategy.

Conclusions:

• The developed approach provides effective fixed-time fault estimation and fault-tolerant control for interconnected systems with actuator faults.
• The strategy ensures desirable transient and steady-state responses while maintaining robustness against system uncertainties.
• This research contributes to enhanced safety and reliability in complex control systems.