Tuning PI controllers for stable processes with specifications on gain and phase margins

Area of Science:

• Control Engineering
• Process Systems Engineering
• Automation and Control Theory

Background:

• Industrial controller design relies on approximate process models, necessitating robust control systems resilient to variations.
• Gain and phase margins are critical metrics for assessing control system robustness.
• Physical systems exhibit variability due to operating conditions and time, impacting performance.

Purpose of the Study:

• To present a novel tuning algorithm for designing and tuning Proportional-Integral (PI) controllers.
• To ensure robust performance for stable processes with small dead times.
• To meet specified gain and phase margins for enhanced control system reliability.

Main Methods:

• Development of a specific tuning algorithm for PI controllers.
• Application of the algorithm to stable processes characterized by small dead times.
• Utilizing specified gain and phase margins as design constraints.

Main Results:

• The proposed algorithm successfully designs and tunes PI controllers meeting user-defined gain and phase margins.
• Simulation examples demonstrate superior closed-loop system performance compared to existing methods.
• The method is effective for stable processes with limited dead time.

Conclusions:

• The presented tuning algorithm offers an effective approach for designing robust PI controllers.
• The method provides improved closed-loop performance over existing techniques for specific process types.
• Achieving specified gain and phase margins is feasible with the proposed design strategy.