PI/PID controller design based on IMC and percentage overshoot specification to controller setpoint change

Area of Science:

• Chemical Engineering
• Control Systems Engineering
• Process Control

Background:

• Process models with stable first and second-order plus time delay dynamics are common in industrial applications.
• Controller tuning often involves balancing performance metrics like overshoot and robustness.
• Internal Model Control (IMC) offers a systematic approach to controller design.

Purpose of the Study:

• To design a normalized Internal Model Control (IMC) filter time constant for specific maximum sensitivity values.
• To establish an empirical relationship between the normalized IMC filter time constant and percentage overshoot.
• To simplify PI/PID controller design by requiring only a user-defined overshoot.

Main Methods:

• Designing the normalized IMC filter time constant to meet a target maximum sensitivity.
• Developing an empirical correlation between the normalized IMC filter time constant and percentage overshoot.
• Utilizing simulation examples to validate the proposed controller design method.

Main Results:

• A method is presented to determine the normalized IMC filter time constant based on a desired maximum sensitivity.
• An empirical relationship is established linking the normalized IMC filter time constant to percentage overshoot.
• The proposed method allows for PI/PID controller design based solely on a user-specified overshoot.

Conclusions:

• The proposed method provides a straightforward approach for tuning PI/PID controllers for stable first and second-order plus time delay processes.
• Controller design is simplified by directly using a desired percentage overshoot as input.
• Simulation results demonstrate the effectiveness of the proposed tuning strategy.