A novel robust Virtual Reference Feedback Tuning approach for minimum and non-minimum phase systems.

Area of Science:

• Control Systems Engineering
• Robust Control Theory
• Discrete-Time Systems

Background:

• Achieving high performance and robustness in closed-loop systems is crucial for real-world applications.
• Existing control methods may not adequately address both performance and robustness simultaneously for diverse system types.

Purpose of the Study:

• To develop a novel robustness-based formulation for discrete-time minimum and non-minimum phase systems.
• To design Proportional Integral and Derivative (PID) controllers with enhanced robustness using the Virtual Reference Feedback Tuning (VRFT) framework.

Main Methods:

• Utilized the Virtual Reference Feedback Tuning (VRFT) framework for controller design.
• Employed a Maximum Sensitivity (Ms)-based closed-loop reference model.
• Minimized the VRFT objective function (JVR) to achieve robust controller design.
• Investigated controller fragility against parameter perturbations.

Main Results:

• The proposed VRFT approach demonstrated improved performance and robustness in simulations and experimental setups (Temperature and Level Control Processes).
• The method effectively enhances set-point tracking and disturbance rejection capabilities.
• Ensured closed-loop system stability and specific robustness properties.

Conclusions:

• The novel robustness-based VRFT formulation provides an effective strategy for designing robust PID controllers for discrete-time systems.
• The approach offers a practical solution for enhancing both performance and robustness in control system design.
• Validated efficacy on diverse systems, including experimental process control setups.