Related Experiment Video
Updated: Feb 2, 2026

Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface
Published on: May 8, 2021
Frequency frame approach on loop shaping of first order plus time delay systems using fractional order PI controller.
1Computer Engineering Department, Inonu University, Malatya, Turkey.
This study introduces a new analytical method for designing fractional order proportional integral (FOPI) controllers for first order plus time delay (FOPTD) systems. The method enhances system stability, performance, and robustness using a novel "frequency frame" concept.
Area of Science:
- Control Systems Engineering
- Automation and Process Control
- Fractional Order Systems
Background:
- First order plus time delay (FOPTD) systems are common in industrial processes.
- Designing effective controllers for FOPTD systems, especially with fractional order controllers, presents challenges in achieving stability and performance.
- Existing methods may not fully address the robustness requirements for these systems.
Purpose of the Study:
- To propose an analytical design method for fractional order proportional integral (FOPI) controllers specifically for FOPTD systems.
- To develop general computation equations for tuning FOPI controllers to meet desired frequency and phase properties.
- To introduce and utilize the concept of a
- frequency frame
- to enhance system robustness and stability.
Main Methods:
- Derivation of analytical design equations for FOPI controllers.
- Tuning controller parameters based on specified frequency and phase characteristics within the Bode plot.
- Application of the
- frequency frame
- concept to manipulate gain and phase crossover frequencies for improved robustness.
Main Results:
- The designed FOPI controllers ensure system stability for FOPTD systems.
- The proposed method positively impacts system performance and robustness.
- The
- frequency frame
- concept provides a quantifiable way to improve control system robustness by adjusting its boundaries.
Conclusions:
- The analytical design method offers a systematic approach to designing FOPI controllers for FOPTD systems.
- The
- frequency frame
- concept is a valuable tool for enhancing the robustness and stability of control systems.
- The method is validated through illustrative examples, demonstrating its practical applicability and advantages.
Related Concept Videos
Time and frequency -Domain Interpretation of PI Control
Acting as a low-pass filter, the PI controller slows the system's response and extends settling times. This requires...
Open and closed-loop control systems
An open-loop control system operates without feedback from the output. It consists of two primary elements: the controller and the controlled process. The controller receives an input signal...
PI Controller: Design
Time and frequency -Domain Interpretation of Phase-lead Control
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
Time and frequency -Domain Interpretation of Phase-lag Control
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
Control Systems
At the heart...

