Anti-windup ADRC design for temperature control systems with output delay against asymmetric input constraint

Area of Science:

• Control Engineering
• Industrial Automation
• Chemical Engineering

Background:

• Industrial temperature control often faces asymmetric input constraints (e.g., 0-100% heating power).
• Output delays and input saturation are common challenges in practical control applications.
• Existing anti-windup strategies may not fully address these combined issues.

Purpose of the Study:

• To develop an effective anti-windup control strategy for industrial temperature systems with asymmetric input constraints and output delays.
• To enhance system stability, tracking accuracy, and robustness against disturbances.
• To provide a practical solution for precise temperature regulation in industrial processes.

Main Methods:

• An anti-windup extended state observer (AESO) was designed using artificial symmetric transformation and delay-free output prediction.
• The AESO estimates system states and external disturbances while providing anti-windup compensation.
• A feedback controller with repetitive-type poles and a set-point prefilter were designed for overshoot-free tracking.
• Linear matrix inequality (LMI) conditions were derived to guarantee asymptotic stability.

Main Results:

• The proposed anti-windup ADRC method demonstrated superior performance compared to existing anti-windup control designs in benchmark simulations.
• The control strategy effectively handled asymmetric input constraints and output delays.
• Real-world application to a jacketed crystallizer confirmed the method's effectiveness, outperforming a non-anti-windup approach.

Conclusions:

• The developed anti-windup ADRC with AESO provides a robust and effective solution for industrial temperature control under asymmetric input constraints and output delays.
• The method ensures system stability, precise tracking, and anti-windup compensation.
• This approach offers significant advantages for practical industrial applications, including chemical crystallization processes.