Enhanced cascade control for a class of integrating processes with time delay.

Area of Science:

• Process Control
• Control Engineering
• Automation Systems

Background:

• Cascade control strategies are limited for integrating processes with time delays.
• Enhancing closed-loop performance in such systems is a significant challenge.

Purpose of the Study:

• To propose a novel series cascade control structure for integrating processes with time delay.
• To improve closed-loop performance and disturbance rejection capabilities.

Main Methods:

• The proposed structure utilizes two controllers and a setpoint filter.
• Inner loop controller designed using the Internal Model Control (IMC) approach.
• Primary load disturbance rejection controller designed using a PID controller in series with a lead/lag compensator, based on desired closed-loop complementary sensitivity function.
• Robustness analysis performed using Kharitonov's theorem.

Main Results:

• Simulation results demonstrate the efficacy of the proposed control structure.
• Satisfactory nominal performance achieved for integrating processes with time delay.
• Robust performance demonstrated under various conditions.

Conclusions:

• The novel series cascade control structure effectively enhances closed-loop performance for integrating processes with time delay.
• The proposed method offers a viable solution for challenging control problems in industrial processes.
• The controller design and robustness analysis provide a solid foundation for practical implementation.