Revisiting Ziegler-Nichols. A fractional order approach

Area of Science:

• Control Systems Engineering
• Automation and Process Control

Background:

• Proportional-Integral-Derivative (PID) controllers are ubiquitous in industrial automation.
• Traditional auto-tuning methods like Ziegler-Nichols have limitations, prompting ongoing research for improvements.
• Fractional order PID (FOPID) controllers offer enhanced performance but require specialized tuning techniques.

Purpose of the Study:

• To introduce a novel auto-tuning method specifically designed for fractional order PID controllers.
• To leverage fractional order properties for improved controller tuning and performance.
• To demonstrate the superiority of the proposed method over existing techniques.

Main Methods:

• The proposed method shapes the direction of the loop frequency response at the critical Ziegler-Nichols point.
• Fractional order calculus is utilized to modify the frequency response characteristics.
• Numerical simulations and case studies are employed for validation.

Main Results:

• The new auto-tuning method achieves superior closed-loop performance compared to the standard Ziegler-Nichols method.
• Significant performance enhancements are observed across various case studies.
• The fractional order parameter effectively influences the frequency response for optimized tuning.

Conclusions:

• The proposed auto-tuning method is effective for fractional order PID controllers.
• This technique offers a valuable advancement in PID controller auto-tuning, particularly for fractional order systems.
• The method provides a practical approach to achieving better closed-loop performance in industrial applications.