Set point weighted modified Smith predictor for integrating and double integrating processes with time delay.

Area of Science:

• Process Control
• Control Engineering
• Automation Systems

Background:

• Integrating and double integrating processes with time delays present significant control challenges.
• Traditional controllers often struggle to achieve both effective set point tracking and robust load disturbance rejection simultaneously.
• Existing methods may not offer optimal performance for these complex process dynamics.

Purpose of the Study:

• To propose a simple and effective controller design method for a modified Smith predictor.
• To enhance set point tracking and load disturbance rejection capabilities for integrating processes with time delay.
• To provide guidelines for tuning controller parameters for improved performance.

Main Methods:

• A modified Smith predictor architecture with separate set point tracking and load disturbance rejection controllers.
• Classical direct synthesis method (without time delay) for the set point tracking controller.
• Proportional-Derivative (PD) controller design for disturbance rejection using optimal gain and phase margin.
• Inclusion of set point weighting to minimize overshoot and settling time.

Main Results:

• The proposed method demonstrates significant load disturbance rejection performance.
• Set point weighting effectively reduces undesirable overshoots and settling times.
• Illustrative examples confirm the superior performance compared to recently reported methods.
• Improved control performance is achieved for integrating and double integrating processes.

Conclusions:

• The developed controller design offers a simple yet powerful approach for modified Smith predictors.
• The dual-controller structure effectively decouples set point tracking and disturbance rejection tasks.
• The method provides a practical solution for enhancing control performance in challenging industrial processes.