Robust MFC anti-windup scheme for LTI systems with norm-bounded uncertainty

Area of Science:

• Control Systems Engineering
• Robust Control Theory
• System Stability Analysis

Background:

• Practical systems exhibit bounded signals, leading to actuator saturation.
• Actuator saturation can degrade system performance and stability.
• Existing anti-windup strategies may not adequately address parametric uncertainty.

Purpose of the Study:

• To propose a novel 4-degree-of-freedom anti-windup scheme for saturated systems with parametric uncertainty.
• To develop a robust stability analysis framework for the proposed anti-windup structure.
• To provide separate control designs for disturbance response and set-point tracking.

Main Methods:

• Development of a 4-DoF anti-windup scheme.
• Application of Integral Quadratic Constraint (IQC) framework for robust stability analysis.
• Derivation of sufficient stability conditions based on transfer function definiteness.
• Separation of control design for disturbance and set-point responses.

Main Results:

• A straightforward tuning rule for robust stability analysis is introduced.
• Sufficient conditions for stability are derived and validated.
• The proposed scheme effectively handles parametric uncertainty in saturated systems.
• Numerical examples confirm significant performance improvements.

Conclusions:

• The proposed 4-DoF anti-windup scheme is effective for saturated systems with parametric uncertainty.
• The robust stability analysis provides a reliable method for controller design.
• The technique offers considerable performance enhancements in disturbance rejection and set-point tracking.